glBufferSubData ，还没有为列表实现类型推断 - 实例化渲染
glBufferSubData , Haven't implemented type-inference for lists yet - instanced rendering
从 Superbible OpenGL 第 7 版移植实例渲染的第 7 章示例。和 运行 变成函数 glBufferSubData
的问题
无论我对它做什么，它都不会接受数据。把它变成一个指针，一个字节串，列表本身。请帮助任何帮助将不胜感激。谢谢。
更新：使用 Rabbid76 的优秀答案，函数 glBufferSubData 现在正在接受数据，numpy 版本非常好，ctypes 版本是一个有见地的答案很高兴知道。另外，关于第二个参数，它确实需要是 int 或 long，而不是 python.
中的 GLuint(0)
更新并成功：Rabbid76 的另一个非常好的答案使渲染工作。
函数 glVertexAttribPointer 需要一个指向初始数据列表长度的指针，以便它可以偏移。非常感谢。
源代码到：instancedattribs.py
#!/usr/bin/python3
import sys
import time
import ctypes
fullscreen = True
try:
from OpenGL.GLUT import *
from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.raw.GL.ARB.vertex_array_object import glGenVertexArrays, glBindVertexArray
except:
print ('''
ERROR: PyOpenGL not installed properly.
''')
sys.exit()
import numpy as np
square_buffer = GLuint(0)
square_vao = GLuint(0)
square_program = GLuint(0)
square_vs_source = '''
#version 410 core
layout (location = 0) in vec4 position;
layout (location = 1) in vec4 instance_color;
layout (location = 2) in vec4 instance_position;
out Fragment
{
vec4 color;
} fragment;
void main(void)
{
gl_Position = (position + instance_position) * vec4(0.25, 0.25, 1.0, 1.0);
fragment.color = instance_color;
}
'''
square_fs_source = '''
#version 410 core
precision highp float;
in Fragment
{
vec4 color;
} fragment;
out vec4 color;
void main(void)
{
color = fragment.color;
}
'''
class Scene:
def __init__(self, width, height):
global square_buffer
global square_vao
global square_program
self.width = width
self.height = height
square_vertices = np.array([
-1.0, -1.0, 0.0, 1.0,
1.0, -1.0, 0.0, 1.0,
1.0, 1.0, 0.0, 1.0,
-1.0, 1.0, 0.0, 1.0], dtype='float32')
instance_colors = np.array([
1.0, 0.0, 0.0, 1.0,
0.0, 1.0, 0.0, 1.0,
0.0, 0.0, 1.0, 1.0,
1.0, 1.0, 0.0, 1.0], dtype='float32')
instance_positions = np.array([
-2.0, -2.0, 0.0, 0.0,
2.0, -2.0, 0.0, 0.0,
2.0, 2.0, 0.0, 0.0,
-2.0, 2.0, 0.0, 0.0], dtype='float32')
glGenVertexArrays(1, square_vao)
glGenBuffers(1, square_buffer)
glBindVertexArray(square_vao)
glBindBuffer(GL_ARRAY_BUFFER, square_buffer)
offset = 0 # not GLuint(0)
bufferSize = (len(square_vertices) + len(instance_colors) + len(instance_positions))*4
glBufferData(GL_ARRAY_BUFFER, bufferSize, None, GL_STATIC_DRAW)
glBufferSubData(GL_ARRAY_BUFFER, offset, len(square_vertices)*4, square_vertices)
offset += len(square_vertices)*4
glBufferSubData(GL_ARRAY_BUFFER, offset, len(instance_colors)*4, instance_colors)
offset += len(instance_colors)*4
glBufferSubData(GL_ARRAY_BUFFER, offset, len(instance_positions)*4, instance_positions)
offset += len(instance_positions)*4
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, None)
offsetInstanceColor = len(square_vertices)*4
glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(offsetInstanceColor))
offsetInstancPosition = (len(instance_colors) + len(instance_positions))*4
glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(offsetInstancPosition))
glEnableVertexAttribArray(0)
glEnableVertexAttribArray(1)
glEnableVertexAttribArray(2)
glVertexAttribDivisor(1, 1)
glVertexAttribDivisor(2, 1)
square_program = glCreateProgram()
square_vs = GLuint(0)
square_vs = glCreateShader(GL_VERTEX_SHADER)
glShaderSource(square_vs, square_vs_source)
glCompileShader(square_vs)
glAttachShader(square_program, square_vs)
square_fs = GLuint(0)
square_fs = glCreateShader(GL_FRAGMENT_SHADER)
glShaderSource(square_fs, square_fs_source)
glCompileShader(square_fs)
glAttachShader(square_program, square_fs)
glLinkProgram(square_program)
glDeleteShader(square_vs)
glDeleteShader(square_fs)
def display(self):
black = [ 0.0, 0.0, 0.0, 0.0 ]
glClearBufferfv(GL_COLOR, 0, black)
glUseProgram(square_program)
glBindVertexArray(square_vao)
glDrawArraysInstanced(GL_TRIANGLE_FAN, 0, 4, 4)
glutSwapBuffers()
def reshape(self, width, height):
self.width = width
self.height = height
def keyboard(self, key, x, y ):
global fullscreen
print ('key:' , key)
if key == b'\x1b': # ESC
sys.exit()
elif key == b'f' or key == b'F': #fullscreen toggle
if (fullscreen == True):
glutReshapeWindow(512, 512)
glutPositionWindow(int((1360/2)-(512/2)), int((768/2)-(512/2)))
fullscreen = False
else:
glutFullScreen()
fullscreen = True
print('done')
def init(self):
pass
def timer(self, blah):
glutPostRedisplay()
glutTimerFunc( int(1/60), self.timer, 0)
time.sleep(1/60.0)
if __name__ == '__main__':
start = time.time()
glutInit()
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH)
glutInitWindowSize(512, 512)
w1 = glutCreateWindow('OpenGL SuperBible - Instanced Attributes')
glutInitWindowPosition(int((1360/2)-(512/2)), int((768/2)-(512/2)))
fullscreen = False
many_cubes = False
#glutFullScreen()
scene = Scene(512,512)
glutReshapeFunc(scene.reshape)
glutDisplayFunc(scene.display)
glutKeyboardFunc(scene.keyboard)
glutIdleFunc(scene.display)
#glutTimerFunc( int(1/60), scene.timer, 0)
scene.init()
glutMainLoop()
预期渲染输出：
与glBufferData, PyOpenGl's glBufferSubData相比，size参数不能省略。
您必须传递缓冲区的大小（以字节为单位）和指向缓冲区的指针。但是请注意，第二个和第三个参数必须是 python int 或 long，即使 PyOpneGL 的 GLuint 也会导致错误。
你有一些可能性，要么创建数组 PyOpenGL 的 GLfloat
offset = 0
dataArray = (GLfloat*len(square_vertices))(*square_vertices)
glBufferSubData(GL_ARRAY_BUFFER, offset, len(dataArray)*4, dataArray)
或使用 pythons built-in ctypes 库：
import ctypes
offset = 0
dataArray = (ctypes.c_float*len(square_vertices))(*square_vertices)
glBufferSubData(GL_ARRAY_BUFFER, offset, len(dataArray)*4, dataArray)
或创建一个NumPy数组：
import numpy as np
offset = 0
dataArray = np.array(square_vertices, dtype='float32')
glBufferSubData(GL_ARRAY_BUFFER, offset, len(dataArray)*4, dataArray)
请注意，对于第二个和第三个参数，您可以使用强制转换为 int（例如 int(offset)）或 long（例如 long(offset)）。
进一步注意，glBufferData、glBufferSubData 和 glVertexAttribPointer 的偏移量和大小参数是字节大小的值，而不是数组元素的数量。
以字节为单位的大小由元素数乘以 1 个元素的大小计算得出。
1 个元素的大小为 4，因为 float（GLfloat、ctypes.c_float、'float32'）的字节大小为 4。
如果绑定了命名缓冲区对象，那么 glVertexAttribPointer 的最后一个参数将被视为缓冲区对象数据存储中的字节偏移量，但参数的类型仍然是指针。
所以你必须使用 ctypes.c_void_p(offset)。如果偏移量为 0，则可以传递 None.
bufferSize = (len(square_vertices) + len(instance_colors) + len(instance_positions))*4
glBufferData(GL_ARRAY_BUFFER, bufferSize, None, GL_STATIC_DRAW)
glBufferSubData(GL_ARRAY_BUFFER, offset, len(square_vertices)*4, square_vertices)
offset += len(square_vertices)*4
glBufferSubData(GL_ARRAY_BUFFER, offset, len(instance_colors)*4, instance_colors)
offset += len(instance_colors)*4
glBufferSubData(GL_ARRAY_BUFFER, offset, len(instance_positions)*4, instance_positions)
offset += len(instance_positions)*4
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, None)
offsetInstanceColor = len(square_vertices)*4
glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(offsetInstanceColor))
offsetInstancPosition = (len(instance_colors) + len(instance_positions))*4
glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(offsetInstancPosition))
从 Superbible OpenGL 第 7 版移植实例渲染的第 7 章示例。和 运行 变成函数 glBufferSubData
无论我对它做什么，它都不会接受数据。把它变成一个指针，一个字节串，列表本身。请帮助任何帮助将不胜感激。谢谢。
更新：使用 Rabbid76 的优秀答案，函数 glBufferSubData 现在正在接受数据，numpy 版本非常好，ctypes 版本是一个有见地的答案很高兴知道。另外，关于第二个参数，它确实需要是 int 或 long，而不是 python.
GLuint(0)
更新并成功：Rabbid76 的另一个非常好的答案使渲染工作。
函数 glVertexAttribPointer 需要一个指向初始数据列表长度的指针，以便它可以偏移。非常感谢。
源代码到：instancedattribs.py
#!/usr/bin/python3
import sys
import time
import ctypes
fullscreen = True
try:
from OpenGL.GLUT import *
from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.raw.GL.ARB.vertex_array_object import glGenVertexArrays, glBindVertexArray
except:
print ('''
ERROR: PyOpenGL not installed properly.
''')
sys.exit()
import numpy as np
square_buffer = GLuint(0)
square_vao = GLuint(0)
square_program = GLuint(0)
square_vs_source = '''
#version 410 core
layout (location = 0) in vec4 position;
layout (location = 1) in vec4 instance_color;
layout (location = 2) in vec4 instance_position;
out Fragment
{
vec4 color;
} fragment;
void main(void)
{
gl_Position = (position + instance_position) * vec4(0.25, 0.25, 1.0, 1.0);
fragment.color = instance_color;
}
'''
square_fs_source = '''
#version 410 core
precision highp float;
in Fragment
{
vec4 color;
} fragment;
out vec4 color;
void main(void)
{
color = fragment.color;
}
'''
class Scene:
def __init__(self, width, height):
global square_buffer
global square_vao
global square_program
self.width = width
self.height = height
square_vertices = np.array([
-1.0, -1.0, 0.0, 1.0,
1.0, -1.0, 0.0, 1.0,
1.0, 1.0, 0.0, 1.0,
-1.0, 1.0, 0.0, 1.0], dtype='float32')
instance_colors = np.array([
1.0, 0.0, 0.0, 1.0,
0.0, 1.0, 0.0, 1.0,
0.0, 0.0, 1.0, 1.0,
1.0, 1.0, 0.0, 1.0], dtype='float32')
instance_positions = np.array([
-2.0, -2.0, 0.0, 0.0,
2.0, -2.0, 0.0, 0.0,
2.0, 2.0, 0.0, 0.0,
-2.0, 2.0, 0.0, 0.0], dtype='float32')
glGenVertexArrays(1, square_vao)
glGenBuffers(1, square_buffer)
glBindVertexArray(square_vao)
glBindBuffer(GL_ARRAY_BUFFER, square_buffer)
offset = 0 # not GLuint(0)
bufferSize = (len(square_vertices) + len(instance_colors) + len(instance_positions))*4
glBufferData(GL_ARRAY_BUFFER, bufferSize, None, GL_STATIC_DRAW)
glBufferSubData(GL_ARRAY_BUFFER, offset, len(square_vertices)*4, square_vertices)
offset += len(square_vertices)*4
glBufferSubData(GL_ARRAY_BUFFER, offset, len(instance_colors)*4, instance_colors)
offset += len(instance_colors)*4
glBufferSubData(GL_ARRAY_BUFFER, offset, len(instance_positions)*4, instance_positions)
offset += len(instance_positions)*4
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, None)
offsetInstanceColor = len(square_vertices)*4
glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(offsetInstanceColor))
offsetInstancPosition = (len(instance_colors) + len(instance_positions))*4
glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(offsetInstancPosition))
glEnableVertexAttribArray(0)
glEnableVertexAttribArray(1)
glEnableVertexAttribArray(2)
glVertexAttribDivisor(1, 1)
glVertexAttribDivisor(2, 1)
square_program = glCreateProgram()
square_vs = GLuint(0)
square_vs = glCreateShader(GL_VERTEX_SHADER)
glShaderSource(square_vs, square_vs_source)
glCompileShader(square_vs)
glAttachShader(square_program, square_vs)
square_fs = GLuint(0)
square_fs = glCreateShader(GL_FRAGMENT_SHADER)
glShaderSource(square_fs, square_fs_source)
glCompileShader(square_fs)
glAttachShader(square_program, square_fs)
glLinkProgram(square_program)
glDeleteShader(square_vs)
glDeleteShader(square_fs)
def display(self):
black = [ 0.0, 0.0, 0.0, 0.0 ]
glClearBufferfv(GL_COLOR, 0, black)
glUseProgram(square_program)
glBindVertexArray(square_vao)
glDrawArraysInstanced(GL_TRIANGLE_FAN, 0, 4, 4)
glutSwapBuffers()
def reshape(self, width, height):
self.width = width
self.height = height
def keyboard(self, key, x, y ):
global fullscreen
print ('key:' , key)
if key == b'\x1b': # ESC
sys.exit()
elif key == b'f' or key == b'F': #fullscreen toggle
if (fullscreen == True):
glutReshapeWindow(512, 512)
glutPositionWindow(int((1360/2)-(512/2)), int((768/2)-(512/2)))
fullscreen = False
else:
glutFullScreen()
fullscreen = True
print('done')
def init(self):
pass
def timer(self, blah):
glutPostRedisplay()
glutTimerFunc( int(1/60), self.timer, 0)
time.sleep(1/60.0)
if __name__ == '__main__':
start = time.time()
glutInit()
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH)
glutInitWindowSize(512, 512)
w1 = glutCreateWindow('OpenGL SuperBible - Instanced Attributes')
glutInitWindowPosition(int((1360/2)-(512/2)), int((768/2)-(512/2)))
fullscreen = False
many_cubes = False
#glutFullScreen()
scene = Scene(512,512)
glutReshapeFunc(scene.reshape)
glutDisplayFunc(scene.display)
glutKeyboardFunc(scene.keyboard)
glutIdleFunc(scene.display)
#glutTimerFunc( int(1/60), scene.timer, 0)
scene.init()
glutMainLoop()
预期渲染输出：
与glBufferData, PyOpenGl's glBufferSubData相比，size参数不能省略。
您必须传递缓冲区的大小（以字节为单位）和指向缓冲区的指针。但是请注意，第二个和第三个参数必须是 python int 或 long，即使 PyOpneGL 的 GLuint 也会导致错误。
你有一些可能性，要么创建数组 PyOpenGL 的 GLfloat
offset = 0
dataArray = (GLfloat*len(square_vertices))(*square_vertices)
glBufferSubData(GL_ARRAY_BUFFER, offset, len(dataArray)*4, dataArray)
或使用 pythons built-in ctypes 库：
import ctypes
offset = 0
dataArray = (ctypes.c_float*len(square_vertices))(*square_vertices)
glBufferSubData(GL_ARRAY_BUFFER, offset, len(dataArray)*4, dataArray)
或创建一个NumPy数组：
import numpy as np
offset = 0
dataArray = np.array(square_vertices, dtype='float32')
glBufferSubData(GL_ARRAY_BUFFER, offset, len(dataArray)*4, dataArray)
请注意，对于第二个和第三个参数，您可以使用强制转换为 int（例如 int(offset)）或 long（例如 long(offset)）。
进一步注意，glBufferData、glBufferSubData 和 glVertexAttribPointer 的偏移量和大小参数是字节大小的值，而不是数组元素的数量。
以字节为单位的大小由元素数乘以 1 个元素的大小计算得出。
1 个元素的大小为 4，因为 float（GLfloat、ctypes.c_float、'float32'）的字节大小为 4。
如果绑定了命名缓冲区对象，那么 glVertexAttribPointer 的最后一个参数将被视为缓冲区对象数据存储中的字节偏移量，但参数的类型仍然是指针。
所以你必须使用 ctypes.c_void_p(offset)。如果偏移量为 0，则可以传递 None.
bufferSize = (len(square_vertices) + len(instance_colors) + len(instance_positions))*4
glBufferData(GL_ARRAY_BUFFER, bufferSize, None, GL_STATIC_DRAW)
glBufferSubData(GL_ARRAY_BUFFER, offset, len(square_vertices)*4, square_vertices)
offset += len(square_vertices)*4
glBufferSubData(GL_ARRAY_BUFFER, offset, len(instance_colors)*4, instance_colors)
offset += len(instance_colors)*4
glBufferSubData(GL_ARRAY_BUFFER, offset, len(instance_positions)*4, instance_positions)
offset += len(instance_positions)*4
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, None)
offsetInstanceColor = len(square_vertices)*4
glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(offsetInstanceColor))
offsetInstancPosition = (len(instance_colors) + len(instance_positions))*4
glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(offsetInstancPosition))