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我一直在通過這個excellent tutorial在現代OpenGL編程上工作，我正在慢慢地適應它在PyOpenGL和pygame上工作。然而，我最難得到應該是一個「微不足道」的例子來處理透視幾何。代碼如下發現：PyOpenGL，Pygame和着色器似乎沒有合作
import pygame
import numpy as np
from OpenGL.GL import *
##########################################
# Define the simple pass-through shaders
##########################################
import cStringIO
vshade = cStringIO.StringIO("""
#version 110
uniform mat4 p_matrix;
uniform mat4 mv_matrix;
attribute vec4 position;
void main()
{
vec4 eye_position = mv_matrix * position;
gl_Position = p_matrix * eye_position;
}
""")
fshade = cStringIO.StringIO("""
#version 110
void main()
{
gl_FragColor = vec4(1.0,0.0,0.0,1.0);
}
""")
###################################################
# Set up a simple square composed of two triangles
###################################################
verts = np.array([[0,0,0,1],[1,0,0,1],[1,1,0,1],[0,1,0,1]]).astype(np.float32)
polys = np.array([[0,1,3],[1,2,3]]).astype(np.ushort)
mv_matrix = np.eye(4)
mv_matrix[:3,-1] = [0,0,2]
projection = np.array([ [ 1.071429, 0. , 0. , 0. ],
[ 0. , 1.428571, 0. , 0. ],
[ 0. , 0. , 1.000489, -0.125031],
[ 0. , 0. , 1. , 0. ]])
def _make_shader(stype, src):
shader = glCreateShader(stype)
glShaderSource(shader, src)
glCompileShader(shader)
if not glGetShaderiv(shader, GL_COMPILE_STATUS):
err = glGetShaderInfoLog(shader)
glDeleteShader(shader)
raise Exception(err)
return shader
##################################
# Initialize pygame and opengl
##################################
flags = pygame.DOUBLEBUF | pygame.HWSURFACE | pygame.OPENGL
pygame.display.set_mode((800,600), flags)
glEnable(GL_BLEND)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
glClearColor(0.5,0.5,0.5,1)
glClearDepth(1.0)
glDepthFunc(GL_LESS)
glEnable(GL_DEPTH_TEST)
glEnable(GL_TEXTURE_2D)
######################################
# Make the shaders and programs
######################################
vshade = _make_shader(GL_VERTEX_SHADER, vshade.read())
fshade = _make_shader(GL_FRAGMENT_SHADER, fshade.read())
program = glCreateProgram()
glAttachShader(program, vshade)
glAttachShader(program, fshade)
glLinkProgram(program)
#######################################
# Fetch positions, push poly to card
#######################################
posidx = glGetAttribLocation(program, "position")
pidx = glGetUniformLocation(program, "p_matrix")
mvidx = glGetUniformLocation(program, "mv_matrix")
vbuf = glGenBuffers(1)
ebuf = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, vbuf)
glBufferData(GL_ARRAY_BUFFER,
verts.astype(np.float32).ravel(), GL_STATIC_DRAW)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebuf)
glBufferData(GL_ELEMENT_ARRAY_BUFFER,
polys.astype(np.uint16).ravel(), GL_STATIC_DRAW)
#####################################
# Enter main drawing loop!
#####################################
glViewport(0,0,800,600)
while True:
# Clear the screen
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glUseProgram(program)
# Push the transforms to the card
glUniformMatrix4fv(pidx, 1, GL_TRUE, projection.astype(np.float32))
glUniformMatrix4fv(mvidx, 1, GL_TRUE, mv_matrix.astype(np.float32))
# Enable the position attribute
glEnableVertexAttribArray(posidx)
glBindBuffer(GL_ARRAY_BUFFER, vbuf)
glVertexAttribPointer(posidx, 4, GL_FLOAT, GL_FALSE, 4*4, 0)
# Draw the two triangles
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebuf);
glDrawElements(
GL_TRIANGLES, # mode
len(polys)*3, # count
GL_UNSIGNED_SHORT, # type
0 # element array buffer offset
)
glDisableVertexAttribArray(posidx)
#inspect the values -- does it make sense?
glBindBuffer(GL_ARRAY_BUFFER, vbuf)
l, l2 = (GLfloat*16)() , (GLushort*6)()
glGetBufferSubData(GL_ARRAY_BUFFER, 0, 4*4*4, l)
print list(l)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebuf)
glGetBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, 2*6, l2)
print list(l2)
glGetUniformfv(program, pidx, l)
print list(l)
glGetUniformfv(program, mvidx, l)
print list(l)
pygame.display.flip()
根據我的理解，我應該得到一個紅色正方形，以覆蓋屏幕的右上象限，但沒有我這樣做似乎影響完全灰色屏幕。任何洞察什麼是錯誤的將非常感謝！
請添加您的代碼，否則我們不能幫助 – 2012-02-22 13:04:21
有一個pastebin鏈接在那裏與完整的代碼。我甚至嘗試過在着色器中沒有投影的直接傳遞版本，但它仍然不起作用。 – jamesshuang 2012-02-22 18:26:04