glsl'ye başlarken
İlk OGL 4.0 GLSL gölgelendirici programı
Köşe konumu ve renk özniteliği ile basit bir OGL 4.0 GLSL gölgelendirici programı. Program bir phyton betiği ile yürütülür. Komut dosyasını çalıştırmak için PyOpenGL kurulu olmalıdır.
Bir gölgelendirici programı, en az bir köşe gölgelendiricisi ve bir parça gölgelendiricisinden oluşur (bilgisayar gölgelendiricileri hariç).
- gölgelendirici aşaması, tepe gölgelendiricisidir ve son gölgelendirici aşaması, parça gölgelendiricisidir (Arada, burada daha fazla açıklanmayan isteğe bağlı başka aşamalar da mümkündür).
Köşe gölgelendirici
ilk.vet
Köşe gölgelendiricisi, çizim komutu tarafından belirtilen köşeleri ve ilişkili nitelikleri işler. Köşe gölgelendiricisi, giriş akışındaki köşeleri işler ve onu herhangi bir şekilde işleyebilir. Bir tepe gölgelendiricisi, giriş akışından tek bir tepe noktası alır ve çıkış tepe noktası akışına tek bir tepe noktası oluşturur.
Örneğimizde tek bir üçgen çiziyoruz, bu nedenle köşe gölgelendiricisi üçgenin her köşe noktası için bir kez olmak üzere 3 kez yürütülüyor.
Bu durumda, köşe gölgelendiricisinin girdisi, ‘in vec3 inPos’ köşe konumu ve ‘in vec3 inCol’ renk özelliğidir. renk özellikleri
sonraki gölgelendirici aşamasına geçirilir (out vec3 vertCol).
#version 400
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec3 inCol;
out vec3 vertCol;
void main()
{
vertCol = inCol;
gl_Position = vec4( inPos, 1.0 );
}
Parça gölgelendirici
ilk.frag
Bu örnekte, parça gölgelendirici, köşe gölgelendiricisinden hemen sonra gelir. Köşe konumları ve nitelikleri, her parça için her yüz içinde enterpolasyon yapılır. Parça gölgelendiricisi, tüm üçgendeki her parça için bir kez yürütülür ve parça gölgelendiricisinden renk özniteliğini alır. Bir üçgen çizildiğinden, renk özniteliği, çizilen üçgene dayalı olarak parçanın barycentric koordinatlarına göre enterpole edilir.
#version 400
in vec3 vertCol;
out vec4 fragColor;
void main()
{
fragColor = vec4( vertCol, 1.0 );
}
Phyton komut dosyası
Python betiği sadece shader programını derlemek, bağlamak ve yürütmek ve geometri çizmek içindir. Önemsiz bir şekilde C veya başka bir şeyle yeniden yazılabilir. Bu belgelerin en büyük dikkatin verilmesi gereken kısmı bu değildir.
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
from sys import *
from array import array
# draw event
def OnDraw():
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glBindVertexArray( vaObj )
glDrawArrays( GL_TRIANGLES, 0, 3 )
glutSwapBuffers()
# read vertex shader program
with open( 'first.vert', 'r' ) as vertFile:
vertCode = vertFile.read()
print( '\nvertex shader code:' )
print( vertCode )
# read fragment shader program
with open( 'first.frag', 'r' ) as fragFile:
fragCode = fragFile.read()
print( '\nfragment shader code:' )
print( fragCode )
# initialize glut
glutInit()
# create window
wndW = 800
wndH = 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define triangle data
posData = [ -0.636, -0.45, 0.0, 0.636, -0.45, 0.0, 0.0, 0.9, 0.0 ]
colData = [ 1.0, 0.0, 0.0, 1.0, 1.0, 0.0, 0.0, 0.0, 1.0 ]
posAr = array( "f", posData )
colAr = array( "f", colData )
# create buffers
posBuffer = glGenBuffers(1)
glBindBuffer( GL_ARRAY_BUFFER, posBuffer )
glBufferData( GL_ARRAY_BUFFER, posAr.tostring(), GL_STATIC_DRAW )
colBuffer = glGenBuffers(1)
glBindBuffer( GL_ARRAY_BUFFER, colBuffer )
glBufferData( GL_ARRAY_BUFFER, colAr.tostring(), GL_STATIC_DRAW )
# create vertex array opject
vaObj = glGenVertexArrays( 1 )
glBindVertexArray( vaObj )
glEnableVertexAttribArray( 0 )
glEnableVertexAttribArray( 1 )
glBindBuffer( GL_ARRAY_BUFFER, posBuffer )
glVertexAttribPointer( 0, 3, GL_FLOAT, GL_FALSE, 0, None )
glBindBuffer( GL_ARRAY_BUFFER, colBuffer )
glVertexAttribPointer( 1, 3, GL_FLOAT, GL_FALSE, 0, None )
# compile vertex shader
vertShader = glCreateShader( GL_VERTEX_SHADER )
glShaderSource( vertShader, vertCode )
glCompileShader( vertShader )
result = glGetShaderiv( vertShader, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( vertShader ) )
sys.exit()
# compile fragment shader
fragShader = glCreateShader( GL_FRAGMENT_SHADER )
glShaderSource( fragShader, fragCode )
glCompileShader( fragShader )
result = glGetShaderiv( fragShader, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( fragShader ) )
sys.exit()
# link shader program
shaderProgram = glCreateProgram()
glAttachShader( shaderProgram, vertShader )
glAttachShader( shaderProgram, fragShader )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
# start main loop
glutMainLoop()
OGL 4.0 GLSL’de Model-, Görünüm- ve Projeksiyon matrisinin kullanılması
Bir model, görünüm ve projeksiyon matrisinin kullanımını gösteren basit bir OGL 4.0 GLSL gölgelendirici programı Program bir phyton betiği ile yürütülür. Komut dosyasını çalıştırmak için PyOpenGL ve NumPy kurulu olmalıdır.
-
Projeksiyon matrisi: Projeksiyon matrisi, bir iğne deliği kamerasının dünyadaki 3B noktalardan 2B noktalarına haritalanmasını tanımlar. görünüm penceresi. Bu örnekte, 90 derecelik görüş alanına sahip bir projeksiyon matrisi kullanıyoruz.
-
Matrisi görüntüle: Görünüm matrisi, sahnedeki göz konumunu ve görüş yönünü tanımlar. Bu örnekte, bir izleme yönünü sahnenin merkezine doğru tutarak sahnenin etrafında dairesel hareket ediyoruz.
-
Model matrisi: Model matrisi, sahnedeki bir nesnenin konumunu ve göreli boyutunu tanımlar. Bu örnekte model matrisleri nesneleri yukarı ve aşağı hareket ettirir.
Köşe gölgelendirici
mvp.know
#version 400
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec3 inCol;
out vec3 vertCol;
uniform mat4 projectionMat44;
uniform mat4 viewMat44;
uniform mat4 modelMat44;
void main()
{
vertCol = inCol;
vec4 modolPos = modelMat44 * vec4( inPos, 1.0 );
vec4 viewPos = viewMat44 * modolPos;
gl_Position = projectionMat44 * viewPos;
}
Parça gölgelendirici
mvp.frag
#version 400
in vec3 vertCol;
out vec4 fragColor;
void main()
{
fragColor = vec4( vertCol, 1.0 );
}
Phyton komut dosyası
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import numpy as np
from time import time
import math
import sys
# draw event
def OnDraw():
currentTime = time()
# set up projection matrix
prjMat = perspective( 90.0, wndW/wndH, 0.5, 100.0)
# set up view matrix
viewMat = Translate( np.matrix(np.identity(4), copy=False, dtype='float32'), np.array( [0.0, 0.0, -8.0] ) )
viewMat = RotateView( viewMat, [10.0, CalcAng( currentTime, 10.0 ), 0.0] )
# set up tetrahedron model matrix
tetModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
tetModelMat = RotateX( tetModelMat, -90.0 )
tetModelMat = Scale( tetModelMat, np.repeat( 2.0, 3 ) )
tetModelMat = Translate( tetModelMat, np.array( [-2.0, 0.0, CalcMove(currentTime, 6.0, [-1.0, 1.0])] ) )
# set up icosahedron model matrix
icoModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
icoModelMat = RotateX( icoModelMat, -90.0 )
icoModelMat = Scale( icoModelMat, np.repeat( 2.0, 3 ) )
icoModelMat = Translate( icoModelMat, np.array( [2.0, 0.0, CalcMove(currentTime, 6.0, [1.0, -1.0])] ) )
# set up attributes and shader program
glEnable( GL_DEPTH_TEST )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glUniformMatrix4fv( projectionMatLocation, 1, GL_FALSE, prjMat )
glUniformMatrix4fv( viewMatLocation, 1, GL_FALSE, viewMat )
# draw tetrahedron
glUniformMatrix4fv( modelMatLocation, 1, GL_FALSE, tetModelMat )
glBindVertexArray( tetVAObj )
glDrawElements(GL_TRIANGLES, len(tetIndices), GL_UNSIGNED_INT, tetIndices)
# draw tetrahedron
glUniformMatrix4fv( modelMatLocation, 1, GL_FALSE, icoModelMat )
glBindVertexArray( icoVAObj )
glDrawArrays( GL_TRIANGLES, 0, len(icoPosData) )
glutSwapBuffers()
def Fract(val): return val - math.trunc(val)
def CalcAng(currentTime, intervall): return Fract( (currentTime - startTime) / intervall ) * 360.0
def CalcMove(currentTime, intervall, range):
pos = Fract( (currentTime - startTime) / intervall ) * 2.0
pos = pos if pos < 1.0 else (2.0-pos)
return range[0] + (range[1] - range[0]) * pos
# read shader program and compile shader
def CompileShader( sourceFileName, shaderStage ):
with open( sourceFileName, 'r' ) as sourceFile:
sourceCode = sourceFile.read()
nameMap = { GL_VERTEX_SHADER: 'vertex', GL_FRAGMENT_SHADER: 'fragment' }
print( '\n%s shader code:' % nameMap.get(shaderStage, '') )
print( sourceCode )
shaderObj = glCreateShader( shaderStage )
glShaderSource( shaderObj, sourceCode )
glCompileShader( shaderObj )
result = glGetShaderiv( shaderObj, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( shaderObj ) )
sys.exit()
return shaderObj
# linke shader objects to shader program
def LinkProgram( shaderObjs ):
shaderProgram = glCreateProgram()
for shObj in shaderObjs:
glAttachShader( shaderProgram, shObj )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
return shaderProgram
# create vertex array opject
def CreateVAO( dataArrays ):
noOfBuffers = len(dataArrays)
buffers = glGenBuffers(noOfBuffers)
newVAObj = glGenVertexArrays( 1 )
glBindVertexArray( newVAObj )
for inx in range(0, noOfBuffers):
vertexSize, dataArr = dataArrays[inx]
arr = np.array( dataArr, dtype='float32' )
glBindBuffer( GL_ARRAY_BUFFER, buffers[inx] )
glBufferData( GL_ARRAY_BUFFER, arr, GL_STATIC_DRAW )
glEnableVertexAttribArray( inx )
glVertexAttribPointer( inx, vertexSize, GL_FLOAT, GL_FALSE, 0, None )
return newVAObj
def Translate(matA, trans):
matB = np.copy(matA)
for i in range(0, 4): matB[3,i] = matA[0,i] * trans[0] + matA[1,i] * trans[1] + matA[2,i] * trans[2] + matA[3,i]
return matB
def Scale(matA, s):
matB = np.copy(matA)
for i0 in range(0, 3):
for i1 in range(0, 4): matB[i0,i1] = matA[i0,i1] * s[i0]
return matB
def RotateHlp(matA, angDeg, a0, a1):
matB = np.copy(matA)
ang = math.radians(angDeg)
sinAng, cosAng = math.sin(ang), math.cos(ang)
for i in range(0, 4):
matB[a0,i] = matA[a0,i] * cosAng + matA[a1,i] * sinAng
matB[a1,i] = matA[a0,i] * -sinAng + matA[a1,i] * cosAng
return matB
def RotateX(matA, angDeg): return RotateHlp(matA, angDeg, 1, 2)
def RotateY(matA, angDeg): return RotateHlp(matA, angDeg, 2, 0)
def RotateZ(matA, angDeg): return RotateHlp(matA, angDeg, 0, 1)
def RotateView(matA, angDeg): return RotateZ(RotateY(RotateX(matA, angDeg[0]), angDeg[1]), angDeg[2])
def perspective(fov, aspectRatio, near, far):
fn, f_n = far + near, far - near
r, t = aspectRatio, 1.0 / math.tan( math.radians(fov) / 2.0 )
return np.matrix( [ [t/r,0,0,0], [0,t,0,0], [0,0,-fn/f_n,-2.0*far*near/f_n], [0,0,-1,0] ] )
# initialize glut
glutInit()
# create window
wndW, wndH = 800, 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define tetrahedron vertex array opject
sin120 = 0.8660254
tetPposData = [ 0.0, 0.0, 1.0, 0.0, -sin120, -0.5, sin120 * sin120, 0.5 * sin120, -0.5, -sin120 * sin120, 0.5 * sin120, -0.5 ]
tetColData = [ 1.0, 0.0, 0.0, 1.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, ]
tetIndices = [ 0, 1, 2, 0, 2, 3, 0, 3, 1, 1, 3, 2 ]
tetVAObj = CreateVAO( [ (3, tetPposData), (3, tetColData) ] )
tetInxArr = np.array( tetIndices, dtype='uint' )
# define icosahedron vertex array opject
icoPts = [
[ 0.000, 0.000, 1.000], [ 0.894, 0.000, 0.447], [ 0.276, 0.851, 0.447], [-0.724, 0.526, 0.447],
[-0.724, -0.526, 0.447], [ 0.276, -0.851, 0.447], [ 0.724, 0.526, -0.447], [-0.276, 0.851, -0.447],
[-0.894, 0.000, -0.447], [-0.276, -0.851, -0.447], [ 0.724, -0.526, -0.447], [ 0.000, 0.000, -1.000] ]
icoCol = [ [1.0, 0.0, 0.0], [0.0, 0.0, 1.0], [1.0, 1.0, 0.0], [0.0, 1.0, 0.0], [1.0, 0.5, 0.0], [1.0, 0.0, 1.0] ]
icoIndices = [
2, 0, 1, 3, 0, 2, 4, 0, 3, 5, 0, 4, 1, 0, 5, 11, 7, 6, 11, 8, 7, 11, 9, 8, 11, 10, 9, 11, 6, 10,
1, 6, 2, 2, 7, 3, 3, 8, 4, 4, 9, 5, 5, 10, 1, 2, 6, 7, 3, 7, 8, 4, 8, 9, 5, 9, 10, 1, 10, 6 ]
icoPosData = []
for inx in icoIndices:
for inx_s in range(0, 3):
icoPosData.append( icoPts[inx][inx_s] )
icoColData = []
for inx in range(0, len(icoPosData) // 9):
inx_col = inx % len(icoCol)
for inx_p in range(0, 3):
for inx_s in range(0, 3):
icoColData.append( icoCol[inx_col][inx_s] )
icoVAObj = CreateVAO( [ (3, icoPosData), (3, icoColData) ] )
# load, compile and link shader
shaderProgram = LinkProgram( [
CompileShader( 'mvp.vert', GL_VERTEX_SHADER ),
CompileShader( 'mvp.frag', GL_FRAGMENT_SHADER )
] )
projectionMatLocation = glGetUniformLocation(shaderProgram, "projectionMat44")
viewMatLocation = glGetUniformLocation(shaderProgram, "viewMat44")
modelMatLocation = glGetUniformLocation(shaderProgram, "modelMat44")
# start main loop
startTime = time()
glutMainLoop()
Modele bir doku koyun ve OGL 4.0 GLSL’de bir doku matrisi kullanın
Bir ağ üzerinde 2B bir dokunun nasıl haritalanacağını gösteren basit bir OGL 4.0 GLSL gölgelendirici programı. Program bir phyton betiği ile yürütülür. Komut dosyasını çalıştırmak için PyOpenGL ve NumPy kurulu olmalıdır.
Doku matrisi, dokunun ağ üzerinde nasıl eşlendiğini tanımlar. Doku matrisini manipüle ederek doku yer değiştirebilir, ölçeklenebilir ve döndürülebilir.
Köşe gölgelendirici
teks.vert
#sürüm 400
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec2 inTex;
out vec2 vertTex;
uniform mat4 u_projectionMat44;
uniform mat4 u_viewMat44;
uniform mat4 u_modelMat44;
uniform mat4 u_textureMat44;
void main()
{
vertTex = ( u_textureMat44 * vec4( inTex, 0.0, 1.0 ) ).st;
vec4 modolPos = u_modelMat44 * vec4( inPos, 1.0 );
vec4 viewPos = u_viewMat44 * modolPos;
gl_Position = u_projectionMat44 * viewPos;
}
Parça gölgelendirici
teks.frag
#version 400
in vec2 vertTex;
out vec4 fragColor;
uniform sampler2D u_texture;
void main()
{
vec4 texCol = texture( u_texture, vertTex.st );
fragColor = vec4( texCol.rgb, 1.0 );
}
Phyton komut dosyası
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import numpy as np
from time import time
import math
import sys
# draw event
def OnDraw():
currentTime = time()
# set up projection matrix
prjMat = perspective( 90.0, wndW/wndH, 0.5, 100.0)
# set up view matrix
viewMat = Translate( np.matrix(np.identity(4), copy=False, dtype='float32'), np.array( [0.0, 0.0, -15.0] ) )
viewMat = RotateView( viewMat, [30.0, CalcAng( currentTime, 60.0 ), 0.0] )
# set up tetrahedron model matrix
cubeModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
cubeModelMat = RotateX( cubeModelMat, -90.0 )
cubeModelMat = Scale( cubeModelMat, np.repeat( 5.0, 3 ) )
# set up texture matrix
texMat = np.matrix(np.identity(4), copy=False, dtype='float32')
deltaT = Fract( (currentTime - startTime) / 28.0 ) * 28.0
if deltaT < 7.0 or deltaT >= 21.0:
texMat = Scale( texMat, np.repeat( CalcMove(currentTime, 7.0, [1.0, 2.0]), 3 ) )
if deltaT >= 7.0 and deltaT < 14.0 or deltaT >= 21.0:
transAng = math.radians( CalcAng(currentTime, 7.0) )
texMat = Translate( texMat, np.array( [math.sin(transAng)*0.5, math.cos(transAng)*0.5-0.5, 0.0] ) )
if deltaT >= 14.0:
texMat = RotateZ( texMat, CalcAng(currentTime, 7.0) )
# set up attributes and shader program
glEnable( GL_DEPTH_TEST )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glUniformMatrix4fv( projectionMatLocation, 1, GL_FALSE, prjMat )
glUniformMatrix4fv( viewMatLocation, 1, GL_FALSE, viewMat )
glUniformMatrix4fv( textureMatLocation, 1, GL_FALSE, texMat )
glUniform1i( textureLocation, 0 )
# draw cube
glUniformMatrix4fv( modelMatLocation, 1, GL_FALSE, cubeModelMat )
glBindVertexArray( cubeVAObj )
glDrawElements(GL_TRIANGLES, len(cubeIndices), GL_UNSIGNED_INT, cubeIndices)
glutSwapBuffers()
def Fract(val): return val - math.trunc(val)
def CalcAng(currentTime, intervall): return Fract( (currentTime - startTime) / intervall ) * 360.0
def CalcMove(currentTime, intervall, range):
pos = Fract( (currentTime - startTime) / intervall ) * 2.0
pos = pos if pos < 1.0 else (2.0-pos)
return range[0] + (range[1] - range[0]) * pos
# read shader program and compile shader
def CompileShader( sourceFileName, shaderStage ):
with open( sourceFileName, 'r' ) as sourceFile:
sourceCode = sourceFile.read()
nameMap = { GL_VERTEX_SHADER: 'vertex', GL_FRAGMENT_SHADER: 'fragment' }
print( '\n%s shader code:' % nameMap.get(shaderStage, '') )
print( sourceCode )
shaderObj = glCreateShader( shaderStage )
glShaderSource( shaderObj, sourceCode )
glCompileShader( shaderObj )
result = glGetShaderiv( shaderObj, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( shaderObj ) )
sys.exit()
return shaderObj
# linke shader objects to shader program
def LinkProgram( shaderObjs ):
shaderProgram = glCreateProgram()
for shObj in shaderObjs:
glAttachShader( shaderProgram, shObj )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
return shaderProgram
# create vertex array object
def CreateVAO( dataArrays ):
noOfBuffers = len(dataArrays)
buffers = glGenBuffers(noOfBuffers)
newVAObj = glGenVertexArrays( 1 )
glBindVertexArray( newVAObj )
for inx in range(0, noOfBuffers):
vertexSize, dataArr = dataArrays[inx]
arr = np.array( dataArr, dtype='float32' )
glBindBuffer( GL_ARRAY_BUFFER, buffers[inx] )
glBufferData( GL_ARRAY_BUFFER, arr, GL_STATIC_DRAW )
glEnableVertexAttribArray( inx )
glVertexAttribPointer( inx, vertexSize, GL_FLOAT, GL_FALSE, 0, None )
return newVAObj
def Translate(matA, trans):
matB = np.copy(matA)
for i in range(0, 4): matB[3,i] = matA[0,i] * trans[0] + matA[1,i] * trans[1] + matA[2,i] * trans[2] + matA[3,i]
return matB
def Scale(matA, s):
matB = np.copy(matA)
for i0 in range(0, 3):
for i1 in range(0, 4): matB[i0,i1] = matA[i0,i1] * s[i0]
return matB
def RotateHlp(matA, angDeg, a0, a1):
matB = np.copy(matA)
ang = math.radians(angDeg)
sinAng, cosAng = math.sin(ang), math.cos(ang)
for i in range(0, 4):
matB[a0,i] = matA[a0,i] * cosAng + matA[a1,i] * sinAng
matB[a1,i] = matA[a0,i] * -sinAng + matA[a1,i] * cosAng
return matB
def RotateX(matA, angDeg): return RotateHlp(matA, angDeg, 1, 2)
def RotateY(matA, angDeg): return RotateHlp(matA, angDeg, 2, 0)
def RotateZ(matA, angDeg): return RotateHlp(matA, angDeg, 0, 1)
def RotateView(matA, angDeg): return RotateZ(RotateY(RotateX(matA, angDeg[0]), angDeg[1]), angDeg[2])
def perspective(fov, aspectRatio, near, far):
fn, f_n = far + near, far - near
r, t = aspectRatio, 1.0 / math.tan( math.radians(fov) / 2.0 )
return np.matrix( [ [t/r,0,0,0], [0,t,0,0], [0,0,-fn/f_n,-2.0*far*near/f_n], [0,0,-1,0] ] )
# initialize glut
glutInit()
# create window
wndW, wndH = 800, 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define cube vertex array opject
icoPts = [
[-1.0, -1.0, 1.0], [ 1.0, -1.0, 1.0], [ 1.0, 1.0, 1.0], [-1.0, 1.0, 1.0],
[-1.0, -1.0, -1.0], [ 1.0, -1.0, -1.0], [ 1.0, 1.0, -1.0], [-1.0, 1.0, -1.0] ]
cubePosData = []
for inx in [ 0, 1, 2, 3, 1, 5, 6, 2, 5, 4, 7, 6, 4, 0, 3, 7, 3, 2, 6, 7, 1, 0, 4, 5 ]:
for inx_s in range(0, 3): cubePosData.append( icoPts[inx][inx_s] )
cubeTexData = []
for inx in range(0, 6):
for texCoord in [-0.5, -0.5, 0.5, -0.5, 0.5, 0.5, -0.5, 0.5]: cubeTexData.append( texCoord )
icoCol = [ [1.0, 0.0, 0.0], [1.0, 0.5, 0.0], [1.0, 0.0, 1.0], [1.0, 1.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0] ]
cubeIndices = []
for inx in range(0, 6):
for inx_s in [0, 1, 2, 0, 2, 3]: cubeIndices.append( inx * 4 + inx_s )
cubeVAObj = CreateVAO( [ (3, cubePosData), (2, cubeTexData) ] )
cubeInxArr = np.array( cubeIndices, dtype='uint' )
# load, compile and link shader
shaderProgram = LinkProgram( [
CompileShader( 'python/ogl4tex/tex.vert', GL_VERTEX_SHADER ),
CompileShader( 'python/ogl4tex/tex.frag', GL_FRAGMENT_SHADER )
] )
projectionMatLocation = glGetUniformLocation(shaderProgram, "u_projectionMat44")
viewMatLocation = glGetUniformLocation(shaderProgram, "u_viewMat44")
modelMatLocation = glGetUniformLocation(shaderProgram, "u_modelMat44")
textureMatLocation = glGetUniformLocation(shaderProgram, "u_textureMat44")
textureLocation = glGetUniformLocation(shaderProgram, "u_texture")
# create texture
texCX, texCY = 128, 128
texPlan = np.zeros( texCX * texCY * 4, dtype=np.uint8 )
for inx_x in range(0, texCX):
for inx_y in range(0, texCY):
val_x = math.sin( math.pi * 6.0 * inx_x / texCX )
val_y = math.sin( math.pi * 6.0 * inx_y / texCY )
inx_tex = inx_y * texCX * 4 + inx_x * 4
texPlan[inx_tex + 0] = int( 128 + 127 * val_x )
texPlan[inx_tex + 1] = 63
texPlan[inx_tex + 2] = int( 128 + 127 * val_y )
texPlan[inx_tex + 3] = 255
glActiveTexture( GL_TEXTURE0 )
texObj = glGenTextures( 1 )
glBindTexture( GL_TEXTURE_2D, texObj )
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texCX, texCY, 0, GL_RGBA, GL_UNSIGNED_BYTE, texPlan)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
# start main loop
startTime = time()
glutMainLoop()
Arayüz Bloğu ve Tekdüzen Bloğu Kullanma : OGL 4.0 GLSL’de bir Cook-Torrance ışık modeli
Cook-Torrance mikro yüzey ışık modeli uygulamasında bir arayüz bloğu ve tek tip bir bloğun kullanımını gösteren basit bir OGL 4.0 GLSL gölgelendirici programı. Program bir phyton betiği ile yürütülür. Komut dosyasını çalıştırmak için PyOpenGL ve NumPy kurulu olmalıdır.
Bir Arayüz Bloğu, bir GLSL giriş, çıkış, tek biçimli veya depolama arabelleği değişkenleri grubudur. Uniform Blockis, depolama niteleyicisi olan bir Arayüz Bloğudur.
Köşe gölgelendirici
ibub.host
#version 400
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec3 inNV;
layout (location = 2) in vec3 inCol;
out TVertexData
{
vec3 pos;
vec3 nv;
vec3 col;
} outData;
uniform mat4 u_projectionMat44;
uniform mat4 u_modelViewMat44;
uniform mat3 u_normalMat33;
void main()
{
vec4 viewPos = u_modelViewMat44 * vec4( inPos, 1.0 );
outData.pos = viewPos.xyz / viewPos.w;
outData.nv = u_normalMat33 * normalize( inNV );
outData.col = inCol;
gl_Position = u_projectionMat44 * viewPos;
}
Parça gölgelendirici
ibub.ask
#version 400
in TVertexData
{
vec3 pos;
vec3 nv;
vec3 col;
} inData;
out vec4 fragColor;
uniform UB_material
{
float u_roughness;
float u_fresnel0;
vec4 u_specularTint;
};
struct TLightSource
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
vec4 dir;
};
uniform UB_lightSource
{
TLightSource u_lightSource;
};
vec3 CookTorrance( vec3 esPt, vec3 esPtNV, vec3 col, vec4 specularTint, float roughness, float fresnel0 )
{
vec3 esVLight = normalize( -u_lightSource.dir.xyz );
vec3 esVEye = normalize( -esPt );
vec3 halfVector = normalize( esVEye + esVLight );
vec3 reflVector = normalize( reflect( -esVLight, esPtNV ) );
float VdotR = dot( esVEye, reflVector );
float HdotL = dot( halfVector, esVLight );
float NdotL = dot( esPtNV, esVLight );
float NdotV = dot( esPtNV, esVEye );
float NdotH = dot( esPtNV, halfVector );
float NdotH2 = NdotH * NdotH;
float NdotL_clamped = max( NdotL, 0.0 );
float NdotV_clamped = max( NdotV, 0.0 );
float m2 = roughness * roughness;
// Lambertian diffuse
float k_diffuse = NdotL_clamped;
// Cook-Torrance fresnel
float theta = HdotL;
float n = (1.0 + sqrt(fresnel0)) / (1.0 - sqrt(fresnel0));
float g = sqrt( n*n + theta * theta + 1.0 );
float gc = g + theta;
float g_c = g - theta;
float q = (gc * theta - 1.0) / (g_c * theta + 1.0);
float fresnel = 0.5 * (g_c * g_c) / (gc * gc) * (1.0 + q * q);
// Gaussian distribution
float psi = acos( VdotR );
float distribution = max( 0.0, HdotL * exp( - psi * psi / m2 ) );
// Torrance-Sparrow geometric term
float geometric_att = min( 1.0, min( 2.0 * NdotH * NdotV_clamped / HdotL, 2.0 * NdotH * NdotL_clamped / HdotL ) );
// Microfacet bidirectional reflectance distribution function
float brdf_spec = fresnel * distribution * geometric_att / ( 4.0 * NdotL_clamped * NdotV_clamped );
float k_specular = brdf_spec;
vec3 lightColor = col.rgb * u_lightSource.ambient.rgb
+ max( 0.0, k_diffuse ) * col.rgb * u_lightSource.diffuse.rgb +
+ max( 0.0, k_specular ) * mix( col.rgb, specularTint.rgb, specularTint.a ) * u_lightSource.specular.rgb;
return lightColor;
}
void main()
{
vec3 lightCol = CookTorrance( inData.pos, inData.nv, inData.col, u_specularTint, u_roughness, u_fresnel0 );
fragColor = vec4( lightCol, 1.0 );
}
Phyton komut dosyası
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import numpy as np
from time import time
import math
import sys
sin120 = 0.8660254
rotateCamera = False
# draw event
def OnDraw():
dist = 3.0
currentTime = time()
comeraRotAng = CalcAng( currentTime, 10.0 )
# set up projection matrix
prjMat = Perspective(90.0, wndW/wndH, 0.5, 100.0)
# set up view matrix
viewMat = Translate( np.matrix(np.identity(4), copy=False, dtype='float32'), np.array( [0.0, 0.0, -12.0] ) )
viewMat = RotateView( viewMat, [30.0, comeraRotAng if rotateCamera else 0.0, 0.0] )
# set up light source
lightSourceBuffer.BindDataFloat(b'u_lightSource.dir', TransformVec4([-3.0, -2.0, -1.0, 0.0], viewMat) )
# set up tetrahedron model matrix
tetModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
if not rotateCamera: tetModelMat = RotateY( tetModelMat, comeraRotAng )
tetModelMat = RotateX( tetModelMat, -90.0 )
tetModelMat = Scale( tetModelMat, np.repeat( 2.4, 3 ) )
tetModelMat = Translate( tetModelMat, np.array( [0.0, dist, 0.0] ) )
tetModelMat = RotateY( tetModelMat, CalcAng( currentTime, 20.0 ) )
tetModelMat = RotateX( tetModelMat, CalcAng( currentTime, 9.0 ) )
# set up icosahedron model matrix
icoModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
if not rotateCamera: icoModelMat = RotateY( icoModelMat, comeraRotAng )
icoModelMat = RotateX( icoModelMat, -90.0 )
icoModelMat = Scale( icoModelMat, np.repeat( 2.0, 3 ) )
icoModelMat = Translate( icoModelMat, np.array( [dist * -sin120, dist * -0.5, 0.0] ) )
icoModelMat = RotateY( icoModelMat, CalcAng( currentTime, 20.0 ) )
icoModelMat = RotateX( icoModelMat, CalcAng( currentTime, 11.0 ) )
# set up cube model matrix
cubeModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
if not rotateCamera: cubeModelMat = RotateY( cubeModelMat, comeraRotAng )
cubeModelMat = RotateX( cubeModelMat, -90.0 )
cubeModelMat = Scale( cubeModelMat, np.repeat( 1.6, 3 ) )
cubeModelMat = Translate( cubeModelMat, np.array( [dist * sin120, dist * -0.5, 0.0] ) )
cubeModelMat = RotateY( cubeModelMat, CalcAng( currentTime, 20.0 ) )
cubeModelMat = RotateX( cubeModelMat, CalcAng( currentTime, 13.0 ) )
# set up attributes and shader program
glEnable( GL_DEPTH_TEST )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glUniformMatrix4fv( projectionMatLocation, 1, GL_FALSE, prjMat )
lightSourceBuffer.BindToTarget()
# draw tetrahedron
tetMaterialBuffer.BindToTarget()
modelViewMat = Multiply(viewMat, tetModelMat)
glUniformMatrix4fv( modelViewMatLocation, 1, GL_FALSE, modelViewMat )
glUniformMatrix3fv( normalMatLocation, 1, GL_FALSE, ToMat33(modelViewMat) )
glBindVertexArray( tetVAObj )
glDrawArrays( GL_TRIANGLES, 0, len(tetPosData) )
# draw icosahedron
icoMaterialBuffer.BindToTarget()
modelViewMat = Multiply(viewMat, icoModelMat)
glUniformMatrix4fv( modelViewMatLocation, 1, GL_FALSE, modelViewMat )
glUniformMatrix3fv( normalMatLocation, 1, GL_FALSE, ToMat33(modelViewMat) )
glBindVertexArray( icoVAObj )
glDrawArrays( GL_TRIANGLES, 0, len(icoPosData) )
# draw cube
cubeMaterialBuffer.BindToTarget()
modelViewMat = Multiply(viewMat, cubeModelMat)
glUniformMatrix4fv( modelViewMatLocation, 1, GL_FALSE, modelViewMat )
glUniformMatrix3fv( normalMatLocation, 1, GL_FALSE, ToMat33(modelViewMat) )
glBindVertexArray( cubeVAObj )
glDrawElements(GL_TRIANGLES, len(cubeIndices), GL_UNSIGNED_INT, cubeIndices)
glutSwapBuffers()
def Fract(val): return val - math.trunc(val)
def CalcAng(currentTime, intervall): return Fract( (currentTime - startTime) / intervall ) * 360.0
def CalcMove(currentTime, intervall, range):
pos = Fract( (currentTime - startTime) / intervall ) * 2.0
pos = pos if pos < 1.0 else (2.0-pos)
return range[0] + (range[1] - range[0]) * pos
# read shader program and compile shader
def CompileShader( sourceFileName, shaderStage ):
with open( sourceFileName, 'r' ) as sourceFile:
sourceCode = sourceFile.read()
nameMap = { GL_VERTEX_SHADER: 'vertex', GL_FRAGMENT_SHADER: 'fragment' }
print( '\n%s shader code:' % nameMap.get(shaderStage, '') )
print( sourceCode )
shaderObj = glCreateShader( shaderStage )
glShaderSource( shaderObj, sourceCode )
glCompileShader( shaderObj )
result = glGetShaderiv( shaderObj, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( shaderObj ) )
sys.exit()
return shaderObj
# linke shader objects to shader program
def LinkProgram( shaderObjs ):
shaderProgram = glCreateProgram()
for shObj in shaderObjs:
glAttachShader( shaderProgram, shObj )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
return shaderProgram
# create vertex array object
def CreateVAO( dataArrays ):
noOfBuffers = len(dataArrays)
buffers = glGenBuffers(noOfBuffers)
newVAObj = glGenVertexArrays( 1 )
glBindVertexArray( newVAObj )
for inx in range(0, noOfBuffers):
vertexSize, dataArr = dataArrays[inx]
arr = np.array( dataArr, dtype='float32' )
glBindBuffer( GL_ARRAY_BUFFER, buffers[inx] )
glBufferData( GL_ARRAY_BUFFER, arr, GL_STATIC_DRAW )
glEnableVertexAttribArray( inx )
glVertexAttribPointer( inx, vertexSize, GL_FLOAT, GL_FALSE, 0, None )
return newVAObj
# representation of a uniform block
class UniformBlock:
def __init__(self, shaderProg, name):
self.shaderProg = shaderProg
self.name = name
def Link(self, bindingPoint):
self.bindingPoint = bindingPoint
self.noOfUniforms = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORMS)
self.maxUniformNameLen = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORM_MAX_LENGTH)
self.index = glGetUniformBlockIndex(self.shaderProg, self.name)
intData = np.zeros(1, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS, intData)
self.count = intData[0]
self.indices = np.zeros(self.count, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES, self.indices)
self.offsets = np.zeros(self.count, dtype=int)
glGetActiveUniformsiv(self.shaderProg, self.count, self.indices, GL_UNIFORM_OFFSET, self.offsets)
self.size = 0
strLengthData = np.zeros(1, dtype=int)
arraysizeData = np.zeros(1, dtype=int)
typeData = np.zeros(1, dtype='uint32')
nameData = np.chararray(self.maxUniformNameLen+1)
self.namemap = {}
self.dataSize = 0
for inx in range(0, len(self.indices)):
glGetActiveUniform( self.shaderProg, self.indices[inx], self.maxUniformNameLen, strLengthData, arraysizeData, typeData, nameData.data )
name = nameData.tostring()[:strLengthData[0]]
self.namemap[name] = inx
self.dataSize = max(self.dataSize, self.offsets[inx] + arraysizeData * 16)
glUniformBlockBinding(self.shaderProg, self.index, self.bindingPoint)
print('\nuniform block %s size:%4d' % (self.name, self.dataSize))
for uName in self.namemap:
print( ' %-40s index:%2d offset:%4d' % (uName, self.indices[self.namemap[uName]], self.offsets [self.namemap[uName]]) )
# representation of a uniform block buffer
class UniformBlockBuffer:
def __init__(self, ub):
self.namemap = ub.namemap
self.offsets = ub.offsets
self.bindingPoint = ub.bindingPoint
self.object = glGenBuffers(1)
self.dataSize = ub.dataSize
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.zeros(self.dataSize//4, dtype='float32')
glBufferData(GL_UNIFORM_BUFFER, self.dataSize, dataArray, GL_DYNAMIC_DRAW)
def BindToTarget(self):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
glBindBufferBase(GL_UNIFORM_BUFFER, self.bindingPoint, self.object)
def BindDataFloat(self, name, dataArr):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.array(dataArr, dtype='float32')
glBufferSubData(GL_UNIFORM_BUFFER, self.offsets[self.namemap[name]], len(dataArr)*4, dataArray)
def Translate(matA, trans):
matB = np.copy(matA)
for i in range(0, 4): matB[3,i] = matA[0,i] * trans[0] + matA[1,i] * trans[1] + matA[2,i] * trans[2] + matA[3,i]
return matB
def Scale(matA, s):
matB = np.copy(matA)
for i0 in range(0, 3):
for i1 in range(0, 4): matB[i0,i1] = matA[i0,i1] * s[i0]
return matB
def RotateHlp(matA, angDeg, a0, a1):
matB = np.copy(matA)
ang = math.radians(angDeg)
sinAng, cosAng = math.sin(ang), math.cos(ang)
for i in range(0, 4):
matB[a0,i] = matA[a0,i] * cosAng + matA[a1,i] * sinAng
matB[a1,i] = matA[a0,i] * -sinAng + matA[a1,i] * cosAng
return matB
def RotateX(matA, angDeg): return RotateHlp(matA, angDeg, 1, 2)
def RotateY(matA, angDeg): return RotateHlp(matA, angDeg, 2, 0)
def RotateZ(matA, angDeg): return RotateHlp(matA, angDeg, 0, 1)
def RotateView(matA, angDeg): return RotateZ(RotateY(RotateX(matA, angDeg[0]), angDeg[1]), angDeg[2])
def Multiply(matA, matB):
matC = np.copy(matA)
for i0 in range(0, 4):
for i1 in range(0, 4):
matC[i0,i1] = matB[i0,0] * matA[0,i1] + matB[i0,1] * matA[1,i1] + matB[i0,2] * matA[2,i1] + matB[i0,3] * matA [3,i1]
return matC
def ToMat33(mat44):
mat33 = np.matrix(np.identity(3), copy=False, dtype='float32')
for i0 in range(0, 3):
for i1 in range(0, 3): mat33[i0, i1] = mat44[i0, i1]
return mat33
def TransformVec4(vecA,mat44):
vecB = np.zeros(4, dtype='float32')
for i0 in range(0, 4):
vecB[i0] = vecA[0] * mat44[0,i0] + vecA[1] * mat44[1,i0] + vecA[2] * mat44[2,i0] + vecA[3] * mat44[3,i0]
return vecB
def Perspective(fov, aspectRatio, near, far):
fn, f_n = far + near, far - near
r, t = aspectRatio, 1.0 / math.tan( math.radians(fov) / 2.0 )
return np.matrix( [ [t/r,0,0,0], [0,t,0,0], [0,0,-fn/f_n,-2.0*far*near/f_n], [0,0,-1,0] ] )
def AddToBuffer( buffer, data, count=1 ):
for inx_c in range(0, count):
for inx_s in range(0, len(data)): buffer.append( data[inx_s] )
# initialize glut
glutInit()
# create window
wndW, wndH = 800, 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define tetrahedron vertex array opject
tetPts = [ (0.0, 0.0, 1.0), (0.0, -sin120, -0.5), (sin120 * sin120, 0.5 * sin120, -0.5), (-sin120 * sin120, 0.5 * sin120, -0.5) ]
tetCol = [ [1.0, 0.0, 0.0], [1.0, 1.0, 0.0], [0.0, 0.0, 1.0], [0.0, 1.0, 0.0], ]
tetInxdices = [ 0, 1, 2, 0, 2, 3, 0, 3, 1, 1, 3, 2 ]
tetPosData = []
for inx in tetInxdices: AddToBuffer( tetPosData, tetPts[inx] )
tetNVData = []
for inx_nv in range(0, len(tetInxdices) // 3):
nv = [0.0, 0.0, 0.0]
for inx_p in range(0, 3):
for inx_s in range(0, 3): nv[inx_s] += tetPts[ tetInxdices[inx_nv*3 + inx_p] ][inx_s]
AddToBuffer( tetNVData, nv, 3 )
tetColData = []
for inx_col in range(0, len(tetInxdices) // 3): AddToBuffer( tetColData, tetCol[inx_col % len(tetCol)], 3 )
tetVAObj = CreateVAO( [ (3, tetPosData), (3, tetNVData), (3, tetColData) ] )
# define icosahedron vertex array opject
icoPts = [
( 0.000, 0.000, 1.000), ( 0.894, 0.000, 0.447), ( 0.276, 0.851, 0.447), (-0.724, 0.526, 0.447),
(-0.724, -0.526, 0.447), ( 0.276, -0.851, 0.447), ( 0.724, 0.526, -0.447), (-0.276, 0.851, -0.447),
(-0.894, 0.000, -0.447), (-0.276, -0.851, -0.447), ( 0.724, -0.526, -0.447), ( 0.000, 0.000, -1.000) ]
icoCol = [ [1.0, 0.0, 0.0], [0.0, 0.0, 1.0], [1.0, 1.0, 0.0], [0.0, 1.0, 0.0], [1.0, 0.5, 0.0], [1.0, 0.0, 1.0] ]
icoIndices = [
2, 0, 1, 3, 0, 2, 4, 0, 3, 5, 0, 4, 1, 0, 5, 11, 7, 6, 11, 8, 7, 11, 9, 8, 11, 10, 9, 11, 6, 10,
1, 6, 2, 2, 7, 3, 3, 8, 4, 4, 9, 5, 5, 10, 1, 2, 6, 7, 3, 7, 8, 4, 8, 9, 5, 9, 10, 1, 10, 6 ]
icoPosData = []
for inx in icoIndices: AddToBuffer( icoPosData, icoPts[inx] )
icoNVData = []
for inx in icoIndices: AddToBuffer( icoNVData, icoPts[inx] )
#for inx_nv in range(0, len(icoIndices) // 3):
# nv = [0.0, 0.0, 0.0]
# for inx_p in range(0, 3):
# for inx_s in range(0, 3): nv[inx_s] += icoPts[ icoIndices[inx_nv*3 + inx_p] ][inx_s]
# AddToBuffer( icoNVData, nv, 3 )
icoColData = []
for inx_col in range(0, len(icoIndices) // 3): AddToBuffer( icoColData, icoCol[inx_col % len(icoCol)], 3 )
icoVAObj = CreateVAO( [ (3, icoPosData), (3, icoNVData), (3, icoColData) ] )
# define cube vertex array opject
cubePts = [
(-1.0, -1.0, 1.0), ( 1.0, -1.0, 1.0), ( 1.0, 1.0, 1.0), (-1.0, 1.0, 1.0),
(-1.0, -1.0, -1.0), ( 1.0, -1.0, -1.0), ( 1.0, 1.0, -1.0), (-1.0, 1.0, -1.0) ]
cubeCol = [ [1.0, 0.0, 0.0], [1.0, 0.5, 0.0], [1.0, 0.0, 1.0], [1.0, 1.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0] ]
cubeHlpInx = [ 0, 1, 2, 3, 1, 5, 6, 2, 5, 4, 7, 6, 4, 0, 3, 7, 3, 2, 6, 7, 1, 0, 4, 5 ]
cubePosData = []
for inx in cubeHlpInx: AddToBuffer( cubePosData, cubePts[inx] )
cubeNVData = []
for inx_nv in range(0, len(cubeHlpInx) // 4):
nv = [0.0, 0.0, 0.0]
for inx_p in range(0, 4):
for inx_s in range(0, 3): nv[inx_s] += cubePts[ cubeHlpInx[inx_nv*4 + inx_p] ][inx_s]
AddToBuffer( cubeNVData, nv, 4 )
cubeColData = []
for inx_col in range(0, 6):
AddToBuffer( cubeColData, cubeCol[inx_col % len(cubeCol)], 4 )
cubeIndices = []
for inx in range(0, 6):
for inx_s in [0, 1, 2, 0, 2, 3]: cubeIndices.append( inx * 4 + inx_s )
cubeVAObj = CreateVAO( [ (3, cubePosData), (3, cubeNVData), (3, cubeColData) ] )
# load, compile and link shader
shaderProgram = LinkProgram( [
CompileShader( 'ibub.vert', GL_VERTEX_SHADER ),
CompileShader( 'ibub.frag', GL_FRAGMENT_SHADER )
] )
# get unifor locations
projectionMatLocation = glGetUniformLocation(shaderProgram, "u_projectionMat44")
modelViewMatLocation = glGetUniformLocation(shaderProgram, "u_modelViewMat44")
normalMatLocation = glGetUniformLocation(shaderProgram, "u_normalMat33")
# linke uniform blocks
ubMaterial = UniformBlock(shaderProgram, "UB_material")
ubLightSource = UniformBlock(shaderProgram, "UB_lightSource")
ubMaterial.Link(1)
ubLightSource.Link(2)
# create uniform block buffers
lightSourceBuffer = UniformBlockBuffer(ubLightSource)
lightSourceBuffer.BindDataFloat(b'u_lightSource.ambient', [0.1, 0.1, 0.1, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.diffuse', [0.4, 0.4, 0.4, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.specular', [1.0, 1.0, 1.0, 1.0])
tetMaterialBuffer = UniformBlockBuffer(ubMaterial)
tetMaterialBuffer.BindDataFloat(b'u_roughness', [0.3])
tetMaterialBuffer.BindDataFloat(b'u_fresnel0', [0.5])
tetMaterialBuffer.BindDataFloat(b'u_specularTint',[1.0, 1.0, 1.0, 0.7])
icoMaterialBuffer = UniformBlockBuffer(ubMaterial)
icoMaterialBuffer.BindDataFloat(b'u_roughness', [0.1])
icoMaterialBuffer.BindDataFloat(b'u_fresnel0', [0.2])
icoMaterialBuffer.BindDataFloat(b'u_specularTint',[1.0, 1.0, 1.0, 0.7])
cubeMaterialBuffer = UniformBlockBuffer(ubMaterial)
cubeMaterialBuffer.BindDataFloat(b'u_roughness', [0.5])
cubeMaterialBuffer.BindDataFloat(b'u_fresnel0', [0.3])
cubeMaterialBuffer.BindDataFloat(b'u_specularTint',[1.0, 1.0, 1.0, 0.7])
# start main loop
startTime = time()
glutMainLoop()
OGL 4.0 GLSL’de bir geometri gölgelendirici kullanarak geometri oluşturma
Geometri gölgelendiricilerin kullanımını gösteren basit bir OGL 4.0 GLSL gölgelendirici programı. Program bir phyton betiği ile yürütülür. Komut dosyasını çalıştırmak için PyOpenGL ve NumPy kurulu olmalıdır.
Bu örnekte, geometri gölgelendiricide tüm geometri (bir silindir) oluşturulur.
Köşe gölgelendirici
geo.vert
#version 400
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec3 inNormal;
layout (location = 2) in vec3 inTangent;
out TVertexData
{
mat3 orientationMat;
} outData;
void main()
{
vec3 normal = normalize( inNormal );
vec3 tangent = normalize( inTangent );
vec3 binormal = cross( tangent, normal );
outData.orientationMat = mat3( normal, cross( binormal, normal ), binormal );
gl_Position = vec4( inPos, 1.0 );
}
Geometri gölgelendirici
geo.geo
#version 400
layout( invocations = 3 ) in;
layout( points ) in;
layout( triangle_strip, max_vertices = 160 ) out;
in TVertexData
{
mat3 orientationMat;
} inData[];
out TGeometryData
{
vec3 pos;
vec3 nv;
vec3 col;
} outData;
uniform mat4 u_projectionMat44;
uniform mat4 u_viewMat44;
uniform mat4 u_modelMat44;
void NewVertex( in vec3 pt, in mat4 transMat )
{
vec4 viewPos = transMat * vec4( pt, 1.0 );
outData.pos = viewPos.xyz / viewPos.w;
gl_Position = u_projectionMat44 * viewPos;
EmitVertex();
}
const int circumferenceTile = 36;
void main()
{
vec4 origin = gl_in[0].gl_Position;
origin /= origin.w;
mat4 orintationMat = mat4( vec4( inData[0].orientationMat[0], 0.0 ),
vec4( inData[0].orientationMat[1], 0.0 ),
vec4( inData[0].orientationMat[2], 0.0 ),
origin );
mat4 modelViewMat = u_viewMat44 * u_modelMat44 * orintationMat;
mat3 normalMat = mat3( modelViewMat );
outData.col = vec3( 0.5, 0.7, 0.6 );
if ( gl_InvocationID == 0 ) // top of the cylinder
{
outData.nv = normalMat * vec3(0.0, 0.0, 1.0);
vec2 prevPt = vec2( 0.0, 1.0 );
for ( int inx = 1; inx <= circumferenceTile; inx += 2 )
{
float ang1 = 2.0 * 3.14159 * float(inx) / float(circumferenceTile);
float ang2 = 2.0 * 3.14159 * float(inx+1) / float(circumferenceTile);
vec2 actPt1 = vec2( sin(ang1), cos(ang1) );
vec2 actPt2 = vec2( sin(ang2), cos(ang2) );
NewVertex( vec3(prevPt.xy, 1.0), modelViewMat );
NewVertex( vec3(actPt1.xy, 1.0), modelViewMat );
NewVertex( vec3(0.0, 0.0, 1.0), modelViewMat );
NewVertex( vec3(actPt2.xy, 1.0), modelViewMat );
EndPrimitive();
prevPt = actPt2;
}
}
if ( gl_InvocationID == 1 ) // bottom of the cylinder
{
outData.nv = normalMat * vec3(0.0, 0.0, -1.0);
vec2 prevPt = vec2( 0.0, 1.0 );
for ( int inx = circumferenceTile-1; inx >= 0; inx -= 2 )
{
float ang1 = 2.0 * 3.14159 * float(inx) / float(circumferenceTile);
float ang2 = 2.0 * 3.14159 * float(inx-1) / float(circumferenceTile);
vec2 actPt1 = vec2( sin(ang1), cos(ang1) );
vec2 actPt2 = vec2( sin(ang2), cos(ang2) );
NewVertex( vec3(prevPt.xy, -1.0), modelViewMat );
NewVertex( vec3(actPt1.xy, -1.0), modelViewMat );
NewVertex( vec3(0.0, 0.0, -1.0), modelViewMat );
NewVertex( vec3(actPt2.xy, -1.0), modelViewMat );
EndPrimitive();
prevPt = actPt2;
}
}
if ( gl_InvocationID == 2 ) // hull of the cylinder
{
vec2 prevPt = vec2( 0.0, 1.0 );
for ( int inx = 1; inx <= circumferenceTile; ++ inx )
{
float ang = 2.0 * 3.14159 * float(inx) / float(circumferenceTile);
vec2 actPt = vec2( sin(ang), cos(ang) );
outData.nv = normalMat * vec3(prevPt, 0.0);
NewVertex( vec3(prevPt.xy, -1.0), modelViewMat );
outData.nv = normalMat * vec3(actPt, 0.0);
NewVertex( vec3(actPt.xy, -1.0), modelViewMat );
outData.nv = normalMat * vec3(prevPt, 0.0);
NewVertex( vec3(prevPt.xy, 1.0), modelViewMat );
outData.nv = normalMat * vec3(actPt, 0.0);
NewVertex( vec3(actPt.xy, 1.0), modelViewMat );
prevPt = actPt;
}
EndPrimitive();
}
}
Parça gölgelendirici
geo.frag
#version 400
in TGeometryData
{
vec3 pos;
vec3 nv;
vec3 col;
} inData;
out vec4 fragColor;
uniform UB_material
{
float u_roughness;
float u_fresnel0;
vec4 u_specularTint;
};
struct TLightSource
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
vec4 dir;
};
uniform UB_lightSource
{
TLightSource u_lightSource;
};
float Fresnel_Schlick( float theta )
{
float m = clamp( 1.0 - theta, 0.0, 1.0 );
float m2 = m * m;
return m2 * m2 * m; // pow( m, 5.0 )
}
vec3 LightModel( vec3 esPt, vec3 esPtNV, vec3 col, vec4 specularTint, float roughness, float fresnel0 )
{
vec3 esVLight = normalize( -u_lightSource.dir.xyz );
vec3 esVEye = normalize( -esPt );
vec3 halfVector = normalize( esVEye + esVLight );
float HdotL = dot( halfVector, esVLight );
float NdotL = dot( esPtNV, esVLight );
float NdotV = dot( esPtNV, esVEye );
float NdotH = dot( esPtNV, halfVector );
float NdotH2 = NdotH * NdotH;
float NdotL_clamped = max( NdotL, 0.0 );
float NdotV_clamped = max( NdotV, 0.0 );
float m2 = roughness * roughness;
// Lambertian diffuse
float k_diffuse = NdotL_clamped;
// Schlick approximation
float fresnel = fresnel0 + ( 1.0 - fresnel0 ) * Fresnel_Schlick( HdotL );
// Beckmann distribution
float distribution = max( 0.0, exp( ( NdotH2 - 1.0 ) / ( m2 * NdotH2 ) ) / ( 3.14159265 * m2 * NdotH2 * NdotH2 ) );
// Torrance-Sparrow geometric term
float geometric_att = min( 1.0, min( 2.0 * NdotH * NdotV_clamped / HdotL, 2.0 * NdotH * NdotL_clamped / HdotL ) );
// Microfacet bidirectional reflectance distribution function
float k_specular = fresnel * distribution * geometric_att / ( 4.0 * NdotL_clamped * NdotV_clamped );
vec3 lightColor = col.rgb * u_lightSource.ambient.rgb +
max( 0.0, k_diffuse ) * col.rgb * u_lightSource.diffuse.rgb +
max( 0.0, k_specular ) * mix( col.rgb, specularTint.rgb, specularTint.a ) * u_lightSource.specular.rgb;
return lightColor;
}
void main()
{
vec3 lightCol = LightModel( inData.pos, inData.nv, inData.col, u_specularTint, u_roughness, u_fresnel0 );
fragColor = vec4( clamp( lightCol, 0.0, 1.0 ), 1.0 );
}
Phyton komut dosyası
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import numpy as np
from time import time
import math
import sys
sin120 = 0.8660254
rotateCamera = False
# draw event
def OnDraw():
dist = 3.0
currentTime = time()
comeraRotAng = CalcAng( currentTime, 10.0 )
# set up projection matrix
prjMat = Perspective(90.0, wndW/wndH, 0.5, 100.0)
# set up view matrix
viewMat = np.matrix(np.identity(4), copy=False, dtype='float32')
viewMat = Translate( viewMat, np.array( [0.0, 0.0, -12.0] ) )
viewMat = RotateView( viewMat, [30.0, comeraRotAng if rotateCamera else 0.0, 0.0] )
# set up light source
lightSourceBuffer.BindDataFloat(b'u_lightSource.dir', TransformVec4([-0.1, 1.0, -5.0, 0.0], viewMat) )
# set up the model matrix
modelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
if not rotateCamera: modelMat = RotateY( modelMat, comeraRotAng )
modelMat = Scale( modelMat, np.repeat( 4, 3 ) )
#modelMat = Translate( modelMat, np.array( [0.0, 0.0, 1.0] ) )
#modelMat = RotateY( modelMat, CalcAng( currentTime, 20.0 ) )
modelMat = RotateX( modelMat, CalcAng( currentTime, 9.0 ) )
# set up attributes and shader program
glEnable( GL_DEPTH_TEST )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glUniformMatrix4fv( projectionMatLocation, 1, GL_FALSE, prjMat )
glUniformMatrix4fv( viewMatLocation, 1, GL_FALSE, viewMat )
lightSourceBuffer.BindToTarget()
# draw point
materialBuffer.BindToTarget()
glUniformMatrix4fv( modelMatLocation, 1, GL_FALSE, modelMat )
glBindVertexArray( pointVAObj )
glDrawArrays( GL_POINTS, 0, 1 )
glutSwapBuffers()
def Fract(val): return val - math.trunc(val)
def CalcAng(currentTime, intervall): return Fract( (currentTime - startTime) / intervall ) * 360.0
def CalcMove(currentTime, intervall, range):
pos = Fract( (currentTime - startTime) / intervall ) * 2.0
pos = pos if pos < 1.0 else (2.0-pos)
return range[0] + (range[1] - range[0]) * pos
# read shader program and compile shader
def CompileShader( sourceFileName, shaderStage ):
with open( sourceFileName, 'r' ) as sourceFile:
sourceCode = sourceFile.read()
nameMap = { GL_VERTEX_SHADER: 'vertex', GL_GEOMETRY_SHADER: 'geometry', GL_FRAGMENT_SHADER: 'fragment' }
print( '\n%s shader code:' % nameMap.get(shaderStage, '') )
print( sourceCode )
shaderObj = glCreateShader( shaderStage )
glShaderSource( shaderObj, sourceCode )
glCompileShader( shaderObj )
result = glGetShaderiv( shaderObj, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( shaderObj ) )
sys.exit()
return shaderObj
# linke shader objects to shader program
def LinkProgram( shaderObjs ):
shaderProgram = glCreateProgram()
for shObj in shaderObjs:
glAttachShader( shaderProgram, shObj )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
return shaderProgram
# create vertex array object
def CreateVAO( dataArrays ):
noOfBuffers = len(dataArrays)
buffers = glGenBuffers(noOfBuffers)
newVAObj = glGenVertexArrays( 1 )
glBindVertexArray( newVAObj )
for inx in range(0, noOfBuffers):
vertexSize, dataArr = dataArrays[inx]
arr = np.array( dataArr, dtype='float32' )
glBindBuffer( GL_ARRAY_BUFFER, buffers[inx] )
glBufferData( GL_ARRAY_BUFFER, arr, GL_STATIC_DRAW )
glEnableVertexAttribArray( inx )
glVertexAttribPointer( inx, vertexSize, GL_FLOAT, GL_FALSE, 0, None )
return newVAObj
# representation of a uniform block
class UniformBlock:
def __init__(self, shaderProg, name):
self.shaderProg = shaderProg
self.name = name
def Link(self, bindingPoint):
self.bindingPoint = bindingPoint
self.noOfUniforms = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORMS)
self.maxUniformNameLen = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORM_MAX_LENGTH)
self.index = glGetUniformBlockIndex(self.shaderProg, self.name)
intData = np.zeros(1, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS, intData)
self.count = intData[0]
self.indices = np.zeros(self.count, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES, self.indices)
self.offsets = np.zeros(self.count, dtype=int)
glGetActiveUniformsiv(self.shaderProg, self.count, self.indices, GL_UNIFORM_OFFSET, self.offsets)
strLengthData = np.zeros(1, dtype=int)
arraysizeData = np.zeros(1, dtype=int)
typeData = np.zeros(1, dtype='uint32')
nameData = np.chararray(self.maxUniformNameLen+1)
self.namemap = {}
self.dataSize = 0
for inx in range(0, len(self.indices)):
glGetActiveUniform( self.shaderProg, self.indices[inx], self.maxUniformNameLen, strLengthData, arraysizeData, typeData, nameData.data )
name = nameData.tostring()[:strLengthData[0]]
self.namemap[name] = inx
self.dataSize = max(self.dataSize, self.offsets[inx] + arraysizeData * 16)
glUniformBlockBinding(self.shaderProg, self.index, self.bindingPoint)
print('\nuniform block %s size:%4d' % (self.name, self.dataSize))
for uName in self.namemap:
print( ' %-40s index:%2d offset:%4d' % (uName, self.indices[self.namemap[uName]], self.offsets [self.namemap[uName]]) )
# representation of a uniform block buffer
class UniformBlockBuffer:
def __init__(self, ub):
self.namemap = ub.namemap
self.offsets = ub.offsets
self.bindingPoint = ub.bindingPoint
self.object = glGenBuffers(1)
self.dataSize = ub.dataSize
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.zeros(self.dataSize//4, dtype='float32')
glBufferData(GL_UNIFORM_BUFFER, self.dataSize, dataArray, GL_DYNAMIC_DRAW)
def BindToTarget(self):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
glBindBufferBase(GL_UNIFORM_BUFFER, self.bindingPoint, self.object)
def BindDataFloat(self, name, dataArr):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.array(dataArr, dtype='float32')
glBufferSubData(GL_UNIFORM_BUFFER, self.offsets[self.namemap[name]], len(dataArr)*4, dataArray)
def Translate(matA, trans):
matB = np.copy(matA)
for i in range(0, 4): matB[3,i] = matA[0,i] * trans[0] + matA[1,i] * trans[1] + matA[2,i] * trans[2] + matA[3,i]
return matB
def Scale(matA, s):
matB = np.copy(matA)
for i0 in range(0, 3):
for i1 in range(0, 4): matB[i0,i1] = matA[i0,i1] * s[i0]
return matB
def RotateHlp(matA, angDeg, a0, a1):
matB = np.copy(matA)
ang = math.radians(angDeg)
sinAng, cosAng = math.sin(ang), math.cos(ang)
for i in range(0, 4):
matB[a0,i] = matA[a0,i] * cosAng + matA[a1,i] * sinAng
matB[a1,i] = matA[a0,i] * -sinAng + matA[a1,i] * cosAng
return matB
def RotateX(matA, angDeg): return RotateHlp(matA, angDeg, 1, 2)
def RotateY(matA, angDeg): return RotateHlp(matA, angDeg, 2, 0)
def RotateZ(matA, angDeg): return RotateHlp(matA, angDeg, 0, 1)
def RotateView(matA, angDeg): return RotateZ(RotateY(RotateX(matA, angDeg[0]), angDeg[1]), angDeg[2])
def Multiply(matA, matB):
matC = np.copy(matA)
for i0 in range(0, 4):
for i1 in range(0, 4):
matC[i0,i1] = matB[i0,0] * matA[0,i1] + matB[i0,1] * matA[1,i1] + matB[i0,2] * matA[2,i1] + matB[i0,3] * matA [3,i1]
return matC
def ToMat33(mat44):
mat33 = np.matrix(np.identity(3), copy=False, dtype='float32')
for i0 in range(0, 3):
for i1 in range(0, 3): mat33[i0, i1] = mat44[i0, i1]
return mat33
def TransformVec4(vecA,mat44):
vecB = np.zeros(4, dtype='float32')
for i0 in range(0, 4):
vecB[i0] = vecA[0] * mat44[0,i0] + vecA[1] * mat44[1,i0] + vecA[2] * mat44[2,i0] + vecA[3] * mat44[3,i0]
return vecB
def Perspective(fov, aspectRatio, near, far):
fn, f_n = far + near, far - near
r, t = aspectRatio, 1.0 / math.tan( math.radians(fov) / 2.0 )
return np.matrix( [ [t/r,0,0,0], [0,t,0,0], [0,0,-fn/f_n,-2.0*far*near/f_n], [0,0,-1,0] ] )
def AddToBuffer( buffer, data, count=1 ):
for inx_c in range(0, count):
for inx_s in range(0, len(data)): buffer.append( data[inx_s] )
# initialize glut
glutInit()
# create window
wndW, wndH = 800, 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define location vertex array opject
pointVAObj = CreateVAO( [ (3, [0.0, 0.0, 0.0] ), (3, [0.0, 0.0, -1.0]), (3, [1.0, 0.0, 0.0]) ] )
# load, compile and link shader
shaderProgram = LinkProgram( [
CompileShader( 'geo.vert', GL_VERTEX_SHADER ),
CompileShader( 'geo.geo', GL_GEOMETRY_SHADER ),
CompileShader( 'geo.frag', GL_FRAGMENT_SHADER )
] )
# get unifor locations
projectionMatLocation = glGetUniformLocation(shaderProgram, "u_projectionMat44")
viewMatLocation = glGetUniformLocation(shaderProgram, "u_viewMat44")
modelMatLocation = glGetUniformLocation(shaderProgram, "u_modelMat44")
# linke uniform blocks
ubMaterial = UniformBlock(shaderProgram, "UB_material")
ubLightSource = UniformBlock(shaderProgram, "UB_lightSource")
ubMaterial.Link(1)
ubLightSource.Link(2)
# create uniform block buffers
lightSourceBuffer = UniformBlockBuffer(ubLightSource)
lightSourceBuffer.BindDataFloat(b'u_lightSource.ambient', [0.2, 0.2, 0.2, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.diffuse', [0.2, 0.2, 0.2, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.specular', [1.0, 1.0, 1.0, 1.0])
materialBuffer = UniformBlockBuffer(ubMaterial)
materialBuffer.BindDataFloat(b'u_roughness', [0.5])
materialBuffer.BindDataFloat(b'u_fresnel0', [0.2])
materialBuffer.BindDataFloat(b'u_specularTint',[1.0, 0.5, 0.5, 0.8])
# start main loop
startTime = time()
glutMainLoop()
OGL 4.0 GLSL’de alt rutinleri kullanarak geometriyi ve yüzey temsilini değiştirme
Kullanım gölgelendirici alt programlarını gösteren basit bir OGL 4.0 GLSL gölgelendirici programı. Program bir phyton betiği ile yürütülür. Komut dosyasını çalıştırmak için PyOpenGL ve NumPy kurulu olmalıdır.
Alt programlar, geometri gölgelendiricisinde oluşturulan farklı geometriler arasında geçiş yapar ve yüzey temsilini değiştirir.
Köşe gölgelendirici
alt.vert
#version 400
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec3 inNormal;
layout (location = 2) in vec3 inTangent;
out TVertexData
{
mat3 orientationMat;
} outData;
void main()
{
vec3 normal = normalize( inNormal );
vec3 tangent = normalize( inTangent );
vec3 binormal = cross( tangent, normal );
outData.orientationMat = mat3( normal, cross( binormal, normal ), binormal );
gl_Position = vec4( inPos, 1.0 );
}
Geometri gölgelendirici
alt.geo
#version 400
layout( points ) in;
layout( triangle_strip, max_vertices = 512 ) out;
in TVertexData
{
mat3 orientationMat;
} inData[];
out TGeometryData
{
vec3 pos;
vec3 nv;
vec2 tex;
} outData;
uniform mat4 u_projectionMat44;
uniform mat4 u_viewMat44;
uniform mat4 u_modelMat44;
uniform mat4 u_textureMat44;
void SetTextureCoord( in vec2 tecCoord )
{
vec4 tex = u_textureMat44 * vec4( tecCoord, 0.0, 1.0 );
outData.tex = tex.xy;
}
void NewVertex( in vec3 pt, in mat4 transMat )
{
vec4 viewPos = transMat * vec4( pt, 1.0 );
outData.pos = viewPos.xyz / viewPos.w;
gl_Position = u_projectionMat44 * viewPos;
EmitVertex();
}
void NewVertexAndTex( in vec3 pt, in mat4 transMat )
{
SetTextureCoord( pt.xy * 0.5 + 0.5 );
NewVertex( pt, transMat );
}
void NewVertexNvTex( in vec3 pt, in mat4 transMat, in vec3 nv, in vec2 tex )
{
outData.nv = nv;
SetTextureCoord( tex );
vec4 viewPos = transMat * vec4( pt, 1.0 );
outData.pos = viewPos.xyz / viewPos.w;
gl_Position = u_projectionMat44 * viewPos;
EmitVertex();
}
subroutine void TShape( in mat4 );
subroutine uniform TShape su_shape;
void main()
{
vec4 origin = gl_in[0].gl_Position;
origin /= origin.w;
mat4 orintationMat = mat4( vec4( inData[0].orientationMat[0], 0.0 ),
vec4( inData[0].orientationMat[1], 0.0 ),
vec4( inData[0].orientationMat[2], 0.0 ),
origin );
mat4 modelMat = u_modelMat44 * orintationMat;
su_shape( modelMat );
}
subroutine(TShape) void DrawSphere( in mat4 modelMat )
{
const int circumferenceTile = 18;
const int layersTile = 11;
mat4 modelViewMat = u_viewMat44 * modelMat;
mat3 normalMat = mat3( modelViewMat );
float preStepLay = 0.0;
vec2 prePtLay = vec2( 0.0, -1.0 );
for ( int inxLay = 1; inxLay <= layersTile; ++ inxLay )
{
float stepLay = float(inxLay) / float(layersTile);
float angLay = 3.14159 * stepLay;
vec2 ptLay = vec2( sin(angLay), -cos(angLay) );
float preStepCir = 0.0;
vec2 prePtCir = vec2( 0.0, 1.0 );
for ( int inxCir = 0; inxCir <= circumferenceTile; ++ inxCir )
{
float stepCir = float(inxCir) / float(circumferenceTile);
float angCir = 2.0 * 3.14159 * stepCir;
vec2 ptCir = vec2( sin(angCir), cos(angCir) );
if ( inxLay == 1 )
{
if ( inxCir >= 0 )
{
vec3 pt1 = vec3( ptLay.x * prePtCir.x, ptLay.x * prePtCir.y, ptLay.y );
vec3 pt2 = vec3( 0.0, 0.0, -1.0 );
vec3 pt3 = vec3( ptLay.x * ptCir.x, ptLay.x * ptCir.y, ptLay.y );
NewVertexNvTex( pt1, modelViewMat, normalMat * pt1, vec2( preStepCir * 2.0, stepLay ) );
NewVertexNvTex( pt2, modelViewMat, normalMat * pt2, vec2( preStepCir + stepCir, preStepLay ) );
NewVertexNvTex( pt3, modelViewMat, normalMat * pt3, vec2( stepCir * 2.0, stepLay ) );
EndPrimitive();
}
}
else if ( inxLay == layersTile )
{
if ( inxCir > 0 )
{
vec3 pt1 = vec3( prePtLay.x * prePtCir.x, prePtLay.x * prePtCir.y, prePtLay.y );
vec3 pt2 = vec3( prePtLay.x * ptCir.x, prePtLay.x * ptCir.y, prePtLay.y );
vec3 pt3 = vec3( 0.0, 0.0, 1.0 );
NewVertexNvTex( pt1, modelViewMat, normalMat * pt1, vec2( preStepCir * 2.0, preStepLay ) );
NewVertexNvTex( pt2, modelViewMat, normalMat * pt2, vec2( stepCir * 2.0, preStepLay ) );
NewVertexNvTex( pt3, modelViewMat, normalMat * pt3, vec2( preStepCir + stepCir, stepLay ) );
EndPrimitive();
}
}
else
{
vec3 pt1 = vec3( prePtLay.x * ptCir.x, prePtLay.x * ptCir.y, prePtLay.y );
vec3 pt2 = vec3( ptLay.x * ptCir.x, ptLay.x * ptCir.y, ptLay.y );
NewVertexNvTex( pt1, modelViewMat, normalMat * pt1, vec2( stepCir * 2.0, preStepLay ) );
NewVertexNvTex( pt2, modelViewMat, normalMat * pt2, vec2( stepCir * 2.0, stepLay ) );
}
preStepCir = stepCir;
prePtCir = ptCir;
}
if ( inxLay > 1 && inxLay < layersTile )
EndPrimitive();
preStepLay = stepLay;
prePtLay = ptLay;
}
}
subroutine(TShape) void DrawTorus( in mat4 modelMat )
{
const int circumferenceTile = 12;
const int layersTile = 18;
const float torusRad = 0.8;
const float ringRad = 0.4;
mat4 modelViewMat = u_viewMat44 * modelMat;
mat3 normalMat = mat3( modelViewMat );
float preStepLay = 0.0;
mat4 prePosMat;
for ( int inxLay = 0; inxLay <= layersTile; ++ inxLay )
{
float stepLay = float(inxLay) / float(layersTile);
float angLay = 2.0 * 3.14159 * stepLay;
mat4 posMat = mat4(
vec4( cos(angLay), sin(angLay), 0.0, 0.0 ),
vec4( sin(angLay), cos(angLay), 0.0, 0.0 ),
vec4( 0.0, 0.0, 1.0, 0.0 ),
vec4( cos(angLay) * torusRad, sin(angLay) * torusRad, 0.0, 1.0 ) );
for ( int inxCir = 0; inxLay > 0 && inxCir <= circumferenceTile; ++ inxCir )
{
float stepCir = float(inxCir) / float(circumferenceTile);
float angCir = 2.0 * 3.14159 * stepCir;
vec2 ptCir = vec2( sin(angCir), cos(angCir) );
vec4 tempPt = vec4( ptCir.x * ringRad, 0.0, ptCir.y * ringRad, 1.0 );
vec4 pt1 = prePosMat * tempPt;
vec4 pt2 = posMat * tempPt;
NewVertexNvTex( pt1.xyz, modelViewMat, normalMat * normalize(pt1.xyz - prePosMat[3].xyz), vec2(stepCir, preStepLay*2.0) );
NewVertexNvTex( pt2.xyz, modelViewMat, normalMat * normalize(pt2.xyz - posMat[3].xyz), vec2(stepCir, stepLay*2.0) );
}
EndPrimitive();
preStepLay = stepLay;
prePosMat = posMat;
}
}
Parça gölgelendirici
alt.frag
#version 400
in TGeometryData
{
vec3 pos;
vec3 nv;
vec2 tex;
} inData;
out vec4 fragColor;
uniform sampler2D u_texture;
uniform UB_material
{
float u_roughness;
float u_fresnel0;
vec4 u_color;
vec4 u_specularTint;
};
struct TLightSource
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
vec4 dir;
};
uniform UB_lightSource
{
TLightSource u_lightSource;
};
subroutine vec4 TSurface( void );
subroutine uniform TSurface su_surface;
float Fresnel_Schlick( in float theta );
vec3 LightModel( in vec3 esPt, in vec3 esPtNV, in vec3 col, in vec4 specularTint, in float roughness, in float fresnel0 );
void main()
{
vec4 fragCol = su_surface();
vec3 lightCol = LightModel( inData.pos, inData.nv, fragCol.rgb, u_specularTint, u_roughness, u_fresnel0 );
fragColor = vec4( clamp( lightCol, 0.0, 1.0 ), fragCol.a );
}
subroutine(TSurface) vec4 SurfaceColor( void )
{
return u_color;
}
subroutine(TSurface) vec4 SurfaceTexture( void )
{
return texture( u_texture, inData.tex.st );
}
float Fresnel_Schlick( in float theta )
{
float m = clamp( 1.0 - theta, 0.0, 1.0 );
float m2 = m * m;
return m2 * m2 * m; // pow( m, 5.0 )
}
vec3 LightModel( in vec3 esPt, in vec3 esPtNV, in vec3 col, in vec4 specularTint, in float roughness, in float fresnel0 )
{
vec3 esVLight = normalize( -u_lightSource.dir.xyz );
vec3 esVEye = normalize( -esPt );
vec3 halfVector = normalize( esVEye + esVLight );
float HdotL = dot( halfVector, esVLight );
float NdotL = dot( esPtNV, esVLight );
float NdotV = dot( esPtNV, esVEye );
float NdotH = dot( esPtNV, halfVector );
float NdotH2 = NdotH * NdotH;
float NdotL_clamped = max( NdotL, 0.0 );
float NdotV_clamped = max( NdotV, 0.0 );
float m2 = roughness * roughness;
// Lambertian diffuse
float k_diffuse = NdotL_clamped;
// Schlick approximation
float fresnel = fresnel0 + ( 1.0 - fresnel0 ) * Fresnel_Schlick( HdotL );
// Beckmann distribution
float distribution = max( 0.0, exp( ( NdotH2 - 1.0 ) / ( m2 * NdotH2 ) ) / ( 3.14159265 * m2 * NdotH2 * NdotH2 ) );
// Torrance-Sparrow geometric term
float geometric_att = min( 1.0, min( 2.0 * NdotH * NdotV_clamped / HdotL, 2.0 * NdotH * NdotL_clamped / HdotL ) );
// Microfacet bidirectional reflectance distribution function
float k_specular = fresnel * distribution * geometric_att / ( 4.0 * NdotL_clamped * NdotV_clamped );
vec3 lightColor = col.rgb * u_lightSource.ambient.rgb +
max( 0.0, k_diffuse ) * col.rgb * u_lightSource.diffuse.rgb +
max( 0.0, k_specular ) * mix( col.rgb, specularTint.rgb, specularTint.a ) * u_lightSource.specular.rgb;
return lightColor;
}
Phyton komut dosyası
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import numpy as np
from time import time
import math
import sys
sin120 = 0.8660254
rotateCamera = False
# draw event
def OnDraw():
dist = 3.0
currentTime = time()
comeraRotAng = CalcAng( currentTime, 10.0 )
# set up projection matrix
prjMat = Perspective(90.0, wndW/wndH, 0.5, 100.0)
# set up view matrix
viewMat = np.matrix(np.identity(4), copy=False, dtype='float32')
viewMat = Translate( viewMat, np.array( [0.0, 0.0, -14.0] ) )
viewMat = RotateView( viewMat, [30.0, comeraRotAng if rotateCamera else 0.0, 0.0] )
# set up light source
lightSourceBuffer.BindDataFloat(b'u_lightSource.dir', TransformVec4([-1.0, -1.0, -5.0, 0.0], viewMat) )
# set up model matrices
modelMat = []
for inx in range(0, 2):
modelMat.append( np.matrix(np.identity(4), copy=False, dtype='float32') )
if not rotateCamera: modelMat[inx] = RotateY( modelMat[inx], comeraRotAng )
modelMat[0] = Scale( modelMat[0], np.repeat( 3, 3 ) )
modelMat[0] = Translate( modelMat[0], np.array( [0.0, 0.0, -2.0] ) )
modelMat[0] = RotateY( modelMat[0], CalcAng( currentTime, 23.0 ) )
modelMat[0] = RotateX( modelMat[0], CalcAng( currentTime, 13.0 ) )
modelMat[1] = Scale( modelMat[1], np.repeat( 3, 3 ) )
modelMat[1] = Translate( modelMat[1], np.array( [0.0, 0.0, 2.0] ) )
modelMat[1] = RotateY( modelMat[1], CalcAng( currentTime, 17.0 ) )
modelMat[1] = RotateX( modelMat[1], CalcAng( currentTime, 9.0 ) )
# set up texture matrix
texMat = np.matrix(np.identity(4), copy=False, dtype='float32')
# set up attributes and shader program
glEnable( GL_DEPTH_TEST )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glUniformMatrix4fv( projectionMatLocation, 1, GL_FALSE, prjMat )
glUniformMatrix4fv( viewMatLocation, 1, GL_FALSE, viewMat )
glUniformMatrix4fv( textureMatLocation, 1, GL_FALSE, texMat )
glUniform1i( textureLocation, 0 )
lightSourceBuffer.BindToTarget()
# draw points
glBindVertexArray( pointVAObj )
for inx in range(0, 2):
# set up geometry shader subroutine
shape = 1 if inx==0 else 0 # 0: sphere, 1: torus
glUniformSubroutinesuiv(GL_GEOMETRY_SHADER, 1, np.array( [shape], dtype='uint' ))
# set up fragment shader subroutine
surfaceKind = inx # 0: color, 1: texture
glUniformSubroutinesuiv(GL_FRAGMENT_SHADER, 1, np.array( [surfaceKind], dtype='uint' ))
materialBuffer[inx].BindToTarget()
glUniformMatrix4fv( modelMatLocation, 1, GL_FALSE, modelMat[inx] )
glDrawArrays( GL_POINTS, 0, 1 )
glutSwapBuffers()
def Fract(val): return val - math.trunc(val)
def CalcAng(currentTime, intervall): return Fract( (currentTime - startTime) / intervall ) * 360.0
def CalcMove(currentTime, intervall, range):
pos = Fract( (currentTime - startTime) / intervall ) * 2.0
pos = pos if pos < 1.0 else (2.0-pos)
return range[0] + (range[1] - range[0]) * pos
# read shader program and compile shader
def CompileShader( sourceFileName, shaderStage ):
with open( sourceFileName, 'r' ) as sourceFile:
sourceCode = sourceFile.read()
nameMap = { GL_VERTEX_SHADER: 'vertex', GL_GEOMETRY_SHADER: 'geometry', GL_FRAGMENT_SHADER: 'fragment' }
print( '\n%s shader code:' % nameMap.get(shaderStage, '') )
print( sourceCode )
shaderObj = glCreateShader( shaderStage )
glShaderSource( shaderObj, sourceCode )
glCompileShader( shaderObj )
result = glGetShaderiv( shaderObj, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( shaderObj ) )
sys.exit()
return shaderObj
# linke shader objects to shader program
def LinkProgram( shaderObjs ):
shaderProgram = glCreateProgram()
for shObj in shaderObjs:
glAttachShader( shaderProgram, shObj )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
return shaderProgram
# create vertex array object
def CreateVAO( dataArrays ):
noOfBuffers = len(dataArrays)
buffers = glGenBuffers(noOfBuffers)
newVAObj = glGenVertexArrays( 1 )
glBindVertexArray( newVAObj )
for inx in range(0, noOfBuffers):
vertexSize, dataArr = dataArrays[inx]
arr = np.array( dataArr, dtype='float32' )
glBindBuffer( GL_ARRAY_BUFFER, buffers[inx] )
glBufferData( GL_ARRAY_BUFFER, arr, GL_STATIC_DRAW )
glEnableVertexAttribArray( inx )
glVertexAttribPointer( inx, vertexSize, GL_FLOAT, GL_FALSE, 0, None )
return newVAObj
# representation of a uniform block
class UniformBlock:
def __init__(self, shaderProg, name):
self.shaderProg = shaderProg
self.name = name
def Link(self, bindingPoint):
self.bindingPoint = bindingPoint
self.noOfUniforms = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORMS)
self.maxUniformNameLen = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORM_MAX_LENGTH)
self.index = glGetUniformBlockIndex(self.shaderProg, self.name)
intData = np.zeros(1, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS, intData)
self.count = intData[0]
self.indices = np.zeros(self.count, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES, self.indices)
self.offsets = np.zeros(self.count, dtype=int)
glGetActiveUniformsiv(self.shaderProg, self.count, self.indices, GL_UNIFORM_OFFSET, self.offsets)
strLengthData = np.zeros(1, dtype=int)
arraysizeData = np.zeros(1, dtype=int)
typeData = np.zeros(1, dtype='uint32')
nameData = np.chararray(self.maxUniformNameLen+1)
self.namemap = {}
self.dataSize = 0
for inx in range(0, len(self.indices)):
glGetActiveUniform( self.shaderProg, self.indices[inx], self.maxUniformNameLen, strLengthData, arraysizeData, typeData, nameData.data )
name = nameData.tostring()[:strLengthData[0]]
self.namemap[name] = inx
self.dataSize = max(self.dataSize, self.offsets[inx] + arraysizeData * 16)
glUniformBlockBinding(self.shaderProg, self.index, self.bindingPoint)
print('\nuniform block %s size:%4d' % (self.name, self.dataSize))
for uName in self.namemap:
print( ' %-40s index:%2d offset:%4d' % (uName, self.indices[self.namemap[uName]], self.offsets[self.namemap [uName]]) )
# representation of a uniform block buffer
class UniformBlockBuffer:
def __init__(self, ub):
self.namemap = ub.namemap
self.offsets = ub.offsets
self.bindingPoint = ub.bindingPoint
self.object = glGenBuffers(1)
self.dataSize = ub.dataSize
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.zeros(self.dataSize//4, dtype='float32')
glBufferData(GL_UNIFORM_BUFFER, self.dataSize, dataArray, GL_DYNAMIC_DRAW)
def BindToTarget(self):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
glBindBufferBase(GL_UNIFORM_BUFFER, self.bindingPoint, self.object)
def BindDataFloat(self, name, dataArr):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.array(dataArr, dtype='float32')
glBufferSubData(GL_UNIFORM_BUFFER, self.offsets[self.namemap[name]], len(dataArr)*4, dataArray)
def Translate(matA, trans):
matB = np.copy(matA)
for i in range(0, 4): matB[3,i] = matA[0,i] * trans[0] + matA[1,i] * trans[1] + matA[2,i] * trans[2] + matA[3,i]
return matB
def Scale(matA, s):
matB = np.copy(matA)
for i0 in range(0, 3):
for i1 in range(0, 4): matB[i0,i1] = matA[i0,i1] * s[i0]
return matB
def RotateHlp(matA, angDeg, a0, a1):
matB = np.copy(matA)
ang = math.radians(angDeg)
sinAng, cosAng = math.sin(ang), math.cos(ang)
for i in range(0, 4):
matB[a0,i] = matA[a0,i] * cosAng + matA[a1,i] * sinAng
matB[a1,i] = matA[a0,i] * -sinAng + matA[a1,i] * cosAng
return matB
def RotateX(matA, angDeg): return RotateHlp(matA, angDeg, 1, 2)
def RotateY(matA, angDeg): return RotateHlp(matA, angDeg, 2, 0)
def RotateZ(matA, angDeg): return RotateHlp(matA, angDeg, 0, 1)
def RotateView(matA, angDeg): return RotateZ(RotateY(RotateX(matA, angDeg[0]), angDeg[1]), angDeg[2])
def Multiply(matA, matB):
matC = np.copy(matA)
for i0 in range(0, 4):
for i1 in range(0, 4):
matC[i0,i1] = matB[i0,0] * matA[0,i1] + matB[i0,1] * matA[1,i1] + matB[i0,2] * matA[2,i1] + matB[i0,3] * matA[3,i1]
return matC
def ToMat33(mat44):
mat33 = np.matrix(np.identity(3), copy=False, dtype='float32')
for i0 in range(0, 3):
for i1 in range(0, 3): mat33[i0, i1] = mat44[i0, i1]
return mat33
def TransformVec4(vecA,mat44):
vecB = np.zeros(4, dtype='float32')
for i0 in range(0, 4):
vecB[i0] = vecA[0] * mat44[0,i0] + vecA[1] * mat44[1,i0] + vecA[2] * mat44[2,i0] + vecA[3] * mat44[3,i0]
return vecB
def Perspective(fov, aspectRatio, near, far):
fn, f_n = far + near, far - near
r, t = aspectRatio, 1.0 / math.tan( math.radians(fov) / 2.0 )
return np.matrix( [ [t/r,0,0,0], [0,t,0,0], [0,0,-fn/f_n,-2.0*far*near/f_n], [0,0,-1,0] ] )
def AddToBuffer( buffer, data, count=1 ):
for inx_c in range(0, count):
for inx_s in range(0, len(data)): buffer.append( data[inx_s] )
# initialize glut
glutInit()
# create window
wndW, wndH = 800, 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define location vertex array opject
pointVAObj = CreateVAO( [ (3, [0.0, 0.0, 0.0] ), (3, [0.0, 0.0, 1.0]), (3, [1.0, 0.0, 0.0]) ] )
# create texture
texCX, texCY = 128, 128
texPlan = np.zeros( texCX * texCY * 4, dtype=np.uint8 )
for inx_x in range(0, texCX):
for inx_y in range(0, texCY):
val_x = math.sin( math.pi * 6.0 * inx_x / texCX )
val_y = math.sin( math.pi * 6.0 * inx_y / texCY )
inx_tex = inx_y * texCX * 4 + inx_x * 4
texPlan[inx_tex + 0] = int( 128 + 127 * val_x )
texPlan[inx_tex + 1] = 63
texPlan[inx_tex + 2] = int( 128 + 127 * val_y )
texPlan[inx_tex + 3] = 255
glActiveTexture( GL_TEXTURE0 )
texObj = glGenTextures( 1 )
glBindTexture( GL_TEXTURE_2D, texObj )
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texCX, texCY, 0, GL_RGBA, GL_UNSIGNED_BYTE, texPlan)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
# load, compile and link shader
shaderProgram = LinkProgram( [
CompileShader( 'python/ogl4subr/subr.vert', GL_VERTEX_SHADER ),
CompileShader( 'python/ogl4subr/subr.geo', GL_GEOMETRY_SHADER ),
CompileShader( 'python/ogl4subr/subr.frag', GL_FRAGMENT_SHADER )
] )
# get unifor locations
projectionMatLocation = glGetUniformLocation(shaderProgram, "u_projectionMat44")
viewMatLocation = glGetUniformLocation(shaderProgram, "u_viewMat44")
modelMatLocation = glGetUniformLocation(shaderProgram, "u_modelMat44")
textureMatLocation = glGetUniformLocation(shaderProgram, "u_textureMat44")
textureLocation = glGetUniformLocation(shaderProgram, "u_texture")
# linke uniform blocks
ubMaterial = UniformBlock(shaderProgram, "UB_material")
ubLightSource = UniformBlock(shaderProgram, "UB_lightSource")
ubMaterial.Link(1)
ubLightSource.Link(2)
# create uniform block buffers
lightSourceBuffer = UniformBlockBuffer(ubLightSource)
lightSourceBuffer.BindDataFloat(b'u_lightSource.ambient', [0.2, 0.2, 0.2, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.diffuse', [0.2, 0.2, 0.2, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.specular', [1.0, 1.0, 1.0, 1.0])
materialBuffer = [ UniformBlockBuffer(ubMaterial), UniformBlockBuffer(ubMaterial) ]
materialBuffer[0].BindDataFloat(b'u_roughness', [0.45])
materialBuffer[0].BindDataFloat(b'u_fresnel0', [0.45])
materialBuffer[0].BindDataFloat(b'u_color', [0.5, 0.7, 0.6, 1.0])
materialBuffer[0].BindDataFloat(b'u_specularTint',[1.0, 0.5, 0.5, 0.8])
materialBuffer[1].BindDataFloat(b'u_roughness', [0.4])
materialBuffer[1].BindDataFloat(b'u_fresnel0', [0.4])
materialBuffer[1].BindDataFloat(b'u_color', [0.7, 0.5, 0.6, 1.0])
materialBuffer[1].BindDataFloat(b'u_specularTint',[0.5, 1.0, 0.5, 0.8])
# start main loop
startTime = time()
glutMainLoop()
OGL 4.0 GLSL’de mozaik gölgelendiricilerle geometriyi değiştirme
Geometriye mozaik gölgelendirici ile ayrıntıların nasıl ekleneceğini gösteren basit bir OGL 4.0 GLSL gölgelendirici programı. Program bir python betiği ile yürütülür. Komut dosyasını çalıştırmak için PyOpenGL ve NumPy kurulu olmalıdır.
Bu örnekteki temel ağ, 20 üçgenden oluşan bir ikosahedrondur. Mozaikleme kontrol gölgelendiricisi, her bir üçgenin bir dizi küçük parçaya nasıl bölüneceğini tanımlar. Bir üçgeni mozaiklerken, oluşturulan veriler orijinal üçgene dayalı barycentric koordinatlardır. Mozaikleme değerlendirme gölgelendiricisi, bu şekilde elde edilen verilerden yeni geometri üretir. Bu örnekte, her üçgen ortada, icosader’ın merkezinden dışarı doğru yükselen bir tepe noktası alır. Bu şekilde orijinal ikosahedrondan çok daha karmaşık bir geometri oluşturulur.
Köşe gölgelendirici
tess.vert
layout (location = 0) in vec3 inPos;
layout (location = 1) in vec3 inNV;
out TVertexData
{
vec3 pos;
vec3 nv;
} outData;
uniform mat4 u_projectionMat44;
uniform mat4 u_modelViewMat44;
uniform mat3 u_normalMat33;
void main()
{
vec4 viewPos = u_modelViewMat44 * vec4( inPos, 1.0 );
outData.pos = viewPos.xyz / viewPos.w;
outData.nv = u_normalMat33 * normalize( inNV );
gl_Position = u_projectionMat44 * viewPos;
}
Mozaik kontrol gölgelendiricisi
tess.tctrl
#version 400
layout( vertices=3 ) out;
in TVertexData
{
vec3 pos;
vec3 nv;
} inData[];
out TVertexData
{
vec3 pos;
vec3 nv;
} outData[];
void main()
{
outData[gl_InvocationID].pos = inData[gl_InvocationID].pos;
outData[gl_InvocationID].nv = inData[gl_InvocationID].nv;
if ( gl_InvocationID == 0 )
{
gl_TessLevelOuter[0] = 10.0;
gl_TessLevelOuter[1] = 10.0;
gl_TessLevelOuter[2] = 10.0;
gl_TessLevelInner[0] = 10.0;
}
}
Mozaik değerlendirme gölgelendiricisi
tess.teval
#version 400
layout(triangles, equal_spacing, ccw) in;
in TVertexData
{
vec3 pos;
vec3 nv;
} inData[];
out TTessData
{
vec3 pos;
vec3 nv;
float height;
} outData;
uniform mat4 u_projectionMat44;
void main()
{
float sideLen[3] = float[3]
(
length( inData[1].pos - inData[0].pos ),
length( inData[2].pos - inData[1].pos ),
length( inData[0].pos - inData[2].pos )
);
float s = ( sideLen[0] + sideLen[1] + sideLen[2] ) / 2.0;
float rad = sqrt( (s - sideLen[0]) * (s - sideLen[1]) * (s - sideLen[2]) / s );
vec3 cpt = ( inData[0].pos + inData[1].pos + inData[2].pos ) / 3.0;
vec3 pos = inData[0].pos * gl_TessCoord.x + inData[1].pos * gl_TessCoord.y + inData[2].pos * gl_TessCoord.z;
vec3 nv = normalize( inData[0].nv * gl_TessCoord.x + inData[1].nv * gl_TessCoord.y + inData[2].nv * gl_TessCoord.z );
float cptDist = length( cpt - pos );
float sizeRelation = 1.0 - min( rad, cptDist ) / rad;
float height = pow( sizeRelation, 2.0 );
outData.pos = pos + nv * height * rad;
outData.nv = mix( nv, normalize( pos - cpt ), height );
outData.height = height;
gl_Position = u_projectionMat44 * vec4( outData.pos, 1.0 );
}
Parça gölgelendirici
tess.frag
#version 400
in TTessData
{
vec3 pos;
vec3 nv;
float height;
} inData;
out vec4 fragColor;
uniform sampler2D u_texture;
uniform UB_material
{
float u_roughness;
float u_fresnel0;
vec4 u_color;
vec4 u_specularTint;
};
struct TLightSource
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
vec4 dir;
};
uniform UB_lightSource
{
TLightSource u_lightSource;
};
float Fresnel_Schlick( in float theta );
vec3 LightModel( in vec3 esPt, in vec3 esPtNV, in vec3 col, in vec4 specularTint, in float roughness, in float fresnel0 );
void main()
{
vec3 col = mix( u_color.rgb, vec3( 1.0, 1.0, 1.0 ), inData.height );
vec3 lightCol = LightModel( inData.pos, inData.nv, col, u_specularTint, u_roughness, u_fresnel0 );
fragColor = vec4( clamp( lightCol, 0.0, 1.0 ), 1.0 );
}
float Fresnel_Schlick( in float theta )
{
float m = clamp( 1.0 - theta, 0.0, 1.0 );
float m2 = m * m;
return m2 * m2 * m; // pow( m, 5.0 )
}
vec3 LightModel( in vec3 esPt, in vec3 esPtNV, in vec3 col, in vec4 specularTint, in float roughness, in float fresnel0 )
{
vec3 esVLight = normalize( -u_lightSource.dir.xyz );
vec3 esVEye = normalize( -esPt );
vec3 halfVector = normalize( esVEye + esVLight );
float HdotL = dot( halfVector, esVLight );
float NdotL = dot( esPtNV, esVLight );
float NdotV = dot( esPtNV, esVEye );
float NdotH = dot( esPtNV, halfVector );
float NdotH2 = NdotH * NdotH;
float NdotL_clamped = max( NdotL, 0.0 );
float NdotV_clamped = max( NdotV, 0.0 );
float m2 = roughness * roughness;
// Lambertian diffuse
float k_diffuse = NdotL_clamped;
// Schlick approximation
float fresnel = fresnel0 + ( 1.0 - fresnel0 ) * Fresnel_Schlick( HdotL );
// Beckmann distribution
float distribution = max( 0.0, exp( ( NdotH2 - 1.0 ) / ( m2 * NdotH2 ) ) / ( 3.14159265 * m2 * NdotH2 * NdotH2 ) );
// Torrance-Sparrow geometric term
float geometric_att = min( 1.0, min( 2.0 * NdotH * NdotV_clamped / HdotL, 2.0 * NdotH * NdotL_clamped / HdotL ) );
// Microfacet bidirectional reflectance distribution function
float k_specular = fresnel * distribution * geometric_att / ( 4.0 * NdotL_clamped * NdotV_clamped );
vec3 lightColor = col.rgb * u_lightSource.ambient.rgb +
max( 0.0, k_diffuse ) * col.rgb * u_lightSource.diffuse.rgb +
max( 0.0, k_specular ) * mix( col.rgb, specularTint.rgb, specularTint.a ) * u_lightSource.specular.rgb;
return lightColor;
}
Python komut dosyası
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import numpy as np
from time import time
import math
import sys
sin120 = 0.8660254
rotateCamera = False
# draw event
def OnDraw():
dist = 3.0
currentTime = time()
comeraRotAng = CalcAng( currentTime, 10.0 )
# set up projection matrix
prjMat = Perspective(90.0, wndW/wndH, 0.5, 100.0)
# set up view matrix
viewMat = np.matrix(np.identity(4), copy=False, dtype='float32')
viewMat = Translate( viewMat, np.array( [0.0, 0.0, -12.0] ) )
viewMat = RotateView( viewMat, [30.0, comeraRotAng if rotateCamera else 0.0, 0.0] )
# set up light source
lightSourceBuffer.BindDataFloat(b'u_lightSource.dir', TransformVec4([-1.0, -1.0, -5.0, 0.0], viewMat) )
# set up icosahedron model matrix
icoModelMat = np.matrix(np.identity(4), copy=False, dtype='float32')
if not rotateCamera: icoModelMat = RotateY( icoModelMat, comeraRotAng )
icoModelMat = Scale( icoModelMat, np.repeat( 5, 3 ) )
icoModelMat = RotateY( icoModelMat, CalcAng( currentTime, 17.0 ) )
icoModelMat = RotateX( icoModelMat, CalcAng( currentTime, 13.0 ) )
# set up attributes and shader program
glEnable( GL_DEPTH_TEST )
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
glUseProgram( shaderProgram )
glUniformMatrix4fv( projectionMatLocation, 1, GL_FALSE, prjMat )
lightSourceBuffer.BindToTarget()
# draw icosahedron
icoMaterialBuffer.BindToTarget()
modelViewMat = Multiply(viewMat, icoModelMat)
glUniformMatrix4fv( modelViewMatLocation, 1, GL_FALSE, modelViewMat )
glUniformMatrix3fv( normalMatLocation, 1, GL_FALSE, ToMat33(modelViewMat) )
glBindVertexArray( icoVAObj )
glPatchParameteri( GL_PATCH_VERTICES, 3 )
glDrawArrays( GL_PATCHES, 0, len(icoPosData) )
glutSwapBuffers()
def Fract(val): return val - math.trunc(val)
def CalcAng(currentTime, intervall): return Fract( (currentTime - startTime) / intervall ) * 360.0
def CalcMove(currentTime, intervall, range):
pos = Fract( (currentTime - startTime) / intervall ) * 2.0
pos = pos if pos < 1.0 else (2.0-pos)
return range[0] + (range[1] - range[0]) * pos
# read shader program and compile shader
def CompileShader( sourceFileName, shaderStage ):
with open( sourceFileName, 'r' ) as sourceFile:
sourceCode = sourceFile.read()
nameMap = { GL_VERTEX_SHADER: 'vertex', GL_GEOMETRY_SHADER: 'geometry', GL_FRAGMENT_SHADER: 'fragment' }
print( '\n%s shader code:' % nameMap.get(shaderStage, '') )
print( sourceCode )
shaderObj = glCreateShader( shaderStage )
glShaderSource( shaderObj, sourceCode )
glCompileShader( shaderObj )
result = glGetShaderiv( shaderObj, GL_COMPILE_STATUS )
if not (result):
print( glGetShaderInfoLog( shaderObj ) )
sys.exit()
return shaderObj
# link shader objects to shader program
def LinkProgram( shaderObjs ):
shaderProgram = glCreateProgram()
for shObj in shaderObjs:
glAttachShader( shaderProgram, shObj )
glLinkProgram( shaderProgram )
result = glGetProgramiv( shaderProgram, GL_LINK_STATUS )
if not (result):
print( 'link error:' )
print( glGetProgramInfoLog( shaderProgram ) )
sys.exit()
return shaderProgram
# create vertex array object
def CreateVAO( dataArrays ):
noOfBuffers = len(dataArrays)
buffers = glGenBuffers(noOfBuffers)
newVAObj = glGenVertexArrays( 1 )
glBindVertexArray( newVAObj )
for inx in range(0, noOfBuffers):
vertexSize, dataArr = dataArrays[inx]
arr = np.array( dataArr, dtype='float32' )
glBindBuffer( GL_ARRAY_BUFFER, buffers[inx] )
glBufferData( GL_ARRAY_BUFFER, arr, GL_STATIC_DRAW )
glEnableVertexAttribArray( inx )
glVertexAttribPointer( inx, vertexSize, GL_FLOAT, GL_FALSE, 0, None )
return newVAObj
# representation of a uniform block
class UniformBlock:
def __init__(self, shaderProg, name):
self.shaderProg = shaderProg
self.name = name
def Link(self, bindingPoint):
self.bindingPoint = bindingPoint
self.noOfUniforms = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORMS)
self.maxUniformNameLen = glGetProgramiv(self.shaderProg, GL_ACTIVE_UNIFORM_MAX_LENGTH)
self.index = glGetUniformBlockIndex(self.shaderProg, self.name)
intData = np.zeros(1, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS, intData)
self.count = intData[0]
self.indices = np.zeros(self.count, dtype=int)
glGetActiveUniformBlockiv(self.shaderProg, self.index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES, self.indices)
self.offsets = np.zeros(self.count, dtype=int)
glGetActiveUniformsiv(self.shaderProg, self.count, self.indices, GL_UNIFORM_OFFSET, self.offsets)
strLengthData = np.zeros(1, dtype=int)
arraysizeData = np.zeros(1, dtype=int)
typeData = np.zeros(1, dtype='uint32')
nameData = np.chararray(self.maxUniformNameLen+1)
self.namemap = {}
self.dataSize = 0
for inx in range(0, len(self.indices)):
glGetActiveUniform( self.shaderProg, self.indices[inx], self.maxUniformNameLen, strLengthData, arraysizeData, typeData, nameData.data )
name = nameData.tostring()[:strLengthData[0]]
self.namemap[name] = inx
self.dataSize = max(self.dataSize, self.offsets[inx] + arraysizeData * 16)
glUniformBlockBinding(self.shaderProg, self.index, self.bindingPoint)
print('\nuniform block %s size:%4d' % (self.name, self.dataSize))
for uName in self.namemap:
print( ' %-40s index:%2d offset:%4d' % (uName, self.indices[self.namemap[uName]], self.offsets[self.namemap [uName]]) )
# representation of a uniform block buffer
class UniformBlockBuffer:
def __init__(self, ub):
self.namemap = ub.namemap
self.offsets = ub.offsets
self.bindingPoint = ub.bindingPoint
self.object = glGenBuffers(1)
self.dataSize = ub.dataSize
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.zeros(self.dataSize//4, dtype='float32')
glBufferData(GL_UNIFORM_BUFFER, self.dataSize, dataArray, GL_DYNAMIC_DRAW)
def BindToTarget(self):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
glBindBufferBase(GL_UNIFORM_BUFFER, self.bindingPoint, self.object)
def BindDataFloat(self, name, dataArr):
glBindBuffer(GL_UNIFORM_BUFFER, self.object)
dataArray = np.array(dataArr, dtype='float32')
glBufferSubData(GL_UNIFORM_BUFFER, self.offsets[self.namemap[name]], len(dataArr)*4, dataArray)
def Translate(matA, trans):
matB = np.copy(matA)
for i in range(0, 4): matB[3,i] = matA[0,i] * trans[0] + matA[1,i] * trans[1] + matA[2,i] * trans[2] + matA[3,i]
return matB
def Scale(matA, s):
matB = np.copy(matA)
for i0 in range(0, 3):
for i1 in range(0, 4): matB[i0,i1] = matA[i0,i1] * s[i0]
return matB
def RotateHlp(matA, angDeg, a0, a1):
matB = np.copy(matA)
ang = math.radians(angDeg)
sinAng, cosAng = math.sin(ang), math.cos(ang)
for i in range(0, 4):
matB[a0,i] = matA[a0,i] * cosAng + matA[a1,i] * sinAng
matB[a1,i] = matA[a0,i] * -sinAng + matA[a1,i] * cosAng
return matB
def RotateX(matA, angDeg): return RotateHlp(matA, angDeg, 1, 2)
def RotateY(matA, angDeg): return RotateHlp(matA, angDeg, 2, 0)
def RotateZ(matA, angDeg): return RotateHlp(matA, angDeg, 0, 1)
def RotateView(matA, angDeg): return RotateZ(RotateY(RotateX(matA, angDeg[0]), angDeg[1]), angDeg[2])
def Multiply(matA, matB):
matC = np.copy(matA)
for i0 in range(0, 4):
for i1 in range(0, 4):
matC[i0,i1] = matB[i0,0] * matA[0,i1] + matB[i0,1] * matA[1,i1] + matB[i0,2] * matA[2,i1] + matB[i0,3] * matA[3,i1]
return matC
def ToMat33(mat44):
mat33 = np.matrix(np.identity(3), copy=False, dtype='float32')
for i0 in range(0, 3):
for i1 in range(0, 3): mat33[i0, i1] = mat44[i0, i1]
return mat33
def TransformVec4(vecA,mat44):
vecB = np.zeros(4, dtype='float32')
for i0 in range(0, 4):
vecB[i0] = vecA[0] * mat44[0,i0] + vecA[1] * mat44[1,i0] + vecA[2] * mat44[2,i0] + vecA[3] * mat44[3,i0]
return vecB
def Perspective(fov, aspectRatio, near, far):
fn, f_n = far + near, far - near
r, t = aspectRatio, 1.0 / math.tan( math.radians(fov) / 2.0 )
return np.matrix( [ [t/r,0,0,0], [0,t,0,0], [0,0,-fn/f_n,-2.0*far*near/f_n], [0,0,-1,0] ] )
def AddToBuffer( buffer, data, count=1 ):
for inx_c in range(0, count):
for inx_s in range(0, len(data)): buffer.append( data[inx_s] )
# initialize glut
glutInit()
# create window
wndW, wndH = 800, 600
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
glutInitWindowSize(wndW, wndH)
wndID = glutCreateWindow(b'OGL window')
glutDisplayFunc(OnDraw)
glutIdleFunc(OnDraw)
# define icosahedron vertex array opject
icoPts = [
( 0.000, 0.000, 1.000), ( 0.894, 0.000, 0.447), ( 0.276, 0.851, 0.447), (-0.724, 0.526, 0.447),
(-0.724, -0.526, 0.447), ( 0.276, -0.851, 0.447), ( 0.724, 0.526, -0.447), (-0.276, 0.851, -0.447),
(-0.894, 0.000, -0.447), (-0.276, -0.851, -0.447), ( 0.724, -0.526, -0.447), ( 0.000, 0.000, -1.000) ]
icoCol = [ [1.0, 0.0, 0.0], [0.0, 0.0, 1.0], [1.0, 1.0, 0.0], [0.0, 1.0, 0.0], [1.0, 0.5, 0.0], [1.0, 0.0, 1.0] ]
icoIndices = [
2, 0, 1, 3, 0, 2, 4, 0, 3, 5, 0, 4, 1, 0, 5, 11, 7, 6, 11, 8, 7, 11, 9, 8, 11, 10, 9, 11, 6, 10,
1, 6, 2, 2, 7, 3, 3, 8, 4, 4, 9, 5, 5, 10, 1, 2, 6, 7, 3, 7, 8, 4, 8, 9, 5, 9, 10, 1, 10, 6 ]
icoPosData = []
for inx in icoIndices: AddToBuffer( icoPosData, icoPts[inx] )
icoNVData = []
for inx_nv in range(0, len(icoIndices) // 3):
nv = [0.0, 0.0, 0.0]
for inx_p in range(0, 3):
for inx_s in range(0, 3): nv[inx_s] += icoPts[ icoIndices[inx_nv*3 + inx_p] ][inx_s]
AddToBuffer( icoNVData, nv, 3 )
icoVAObj = CreateVAO( [ (3, icoPosData), (3, icoNVData) ] )
# load, compile and link shader
shaderProgram = LinkProgram( [
CompileShader( 'tess.vert', GL_VERTEX_SHADER ),
CompileShader( 'tess.tctrl', GL_TESS_CONTROL_SHADER ),
CompileShader( 'tess.teval', GL_TESS_EVALUATION_SHADER ),
CompileShader( 'tess.frag', GL_FRAGMENT_SHADER )
] )
# get unifor locations
projectionMatLocation = glGetUniformLocation(shaderProgram, "u_projectionMat44")
modelViewMatLocation = glGetUniformLocation(shaderProgram, "u_modelViewMat44")
normalMatLocation = glGetUniformLocation(shaderProgram, "u_normalMat33")
# linke uniform blocks
ubMaterial = UniformBlock(shaderProgram, "UB_material")
ubLightSource = UniformBlock(shaderProgram, "UB_lightSource")
ubMaterial.Link(1)
ubLightSource.Link(2)
# create uniform block buffers
lightSourceBuffer = UniformBlockBuffer(ubLightSource)
lightSourceBuffer.BindDataFloat(b'u_lightSource.ambient', [0.2, 0.2, 0.2, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.diffuse', [0.2, 0.2, 0.2, 1.0])
lightSourceBuffer.BindDataFloat(b'u_lightSource.specular', [1.0, 1.0, 1.0, 1.0])
icoMaterialBuffer = UniformBlockBuffer(ubMaterial)
icoMaterialBuffer.BindDataFloat(b'u_roughness', [0.45])
icoMaterialBuffer.BindDataFloat(b'u_fresnel0', [0.4])
icoMaterialBuffer.BindDataFloat(b'u_color', [0.6, 0.5, 0.8, 1.0])
icoMaterialBuffer.BindDataFloat(b'u_specularTint',[1.0, 0.5, 0.5, 0.8])
# start main loop
startTime = time()
glutMainLoop()
Kurulum veya Kurulum
glsl kurulumu veya kurulumu hakkında ayrıntılı talimatlar.