glVertexAttribPointer() 上的 pyopengl 错误

Question

我在 glVertexAttribPointer 上遇到了一个错误，可能是因为值或任何东西（？）有谁知道如何解决这个问题？

import glfw
from OpenGL.GL import *
import OpenGL.GL.shaders
import numpy as np
from PIL import Image


def main():
    if not glfw.init():
        return

    window = glfw.create_window(720, 720, "08_A_xxx: PyOpengl dan tekstur", None, None)

    if not window:
        glfw.terminate()
        return

    glfw.make_context_current(window)


                   #posisi          warna               koordinat tekstur
    rectangle = [-0.5, -0.5, 0.0,   1.0, 0.0, 0.0,          0.0, 0.0,
            0.5, -0.5, 0.0,         0.0, 1.0, 0.0,          1.0, 0.0,
            0.5, 0.5, 0.0,          0.0, 0.0, 1.0,          1.0, 1.0,
            -0.5, 0.5, 0.0,         1.0, 1.0, 1.0,           0.0, 1.0]


    # ubah ke 32 bit (float)

    rectangle = np.array(rectangle, dtype=np.float32)


    indices = [0,1,2,
              2,3,0]

    indices = np.array(indices, dtype = np.uint32)

    VERTEX_SHADER = """

           #version 330

           in vec3 position;
           in vec3 color;
           in vec2 InTexCoords;

           out vec3 newColor;
           out vec2 OutTexCoords;

           void main() {

            gl_Position = vec4(position, 1.0);
            newColor = color;
            OutTexCoords = InTexCoords;

             }


       """

    FRAGMENT_SHADER = """
        #version 330

         in vec3 newColor;
         in vec2 OutTexCoords;

         out vec4 outColor;
         uniform sampler2D samplerTex;

        void main() {

           outColor = texture(samplerTex, OutTexCoords);

        }

    """

    # Kompilasi program dan shaders

    shader = OpenGL.GL.shaders.compileProgram(OpenGL.GL.shaders.compileShader(VERTEX_SHADER, GL_VERTEX_SHADER),
                                              OpenGL.GL.shaders.compileShader(FRAGMENT_SHADER, GL_FRAGMENT_SHADER))

    # Buat objek buffer dalam gpu
    VBO = glGenBuffers(1)
    # Bind the buffer
    glBindBuffer(GL_ARRAY_BUFFER, VBO)
    glBufferData(GL_ARRAY_BUFFER, 128, rectangle, GL_STATIC_DRAW)


    # Buat EBO
    EBO = glGenBuffers(1)
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO)
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices, GL_STATIC_DRAW)



    # mendapatkan posisi dari shader
    position = glGetAttribLocation(shader, 'position')
    glVertexAttribPointer(position, 3, GL_FLOAT, GL_FALSE, 32, ctypes.c_void_p(0))
    glEnableVertexAttribArray(position)

    # mendapatkan warna dari  shader
    color = glGetAttribLocation(shader, 'color')
    glVertexAttribPointer(color, 3, GL_FLOAT, GL_FALSE, 32, ctypes.c_void_p(12))
    glEnableVertexAttribArray(color)

    texCoords = glGetAttribLocation(shader, "InTexCoords")
    glVertexAttribPointer(texCoords,2, GL_FLOAT, GL_FALSE, 32, ctypes.c_void_p(24))
    glEnableVertexAttribArray(texCoords)

    # Buat Tekstur
    texture = glGenTextures(1)
    glBindTexture(GL_TEXTURE_2D, texture)
    # texture wrapping params
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
    # texture filtering params
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)

    image = Image.open("hello.jpg")
    img_data = np.array(list(image.getdata()), np.uint8)
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 512, 512, 0, GL_RGB, GL_UNSIGNED_BYTE, img_data)


    glUseProgram(shader)

    glClearColor(0.0, 0.0, 0.0, 1.0)

    while not glfw.window_should_close(window):
        glfw.poll_events()

        glClear(GL_COLOR_BUFFER_BIT)

        # Gambar segiempat

        glDrawElements(GL_TRIANGLES,6, GL_UNSIGNED_INT,  None)

        glfw.swap_buffers(window)

    glfw.terminate()


if __name__ == "__main__":
    main()

Answer 1

属性color不是活动的程序资源，因为属性在着色器程序中不是"used"。该属性从顶点传递到片段着色器，但片段着色器忽略输入变量newColor。优化算法整理出属性color.
因此 glGetAttribLocation returns -1 最后 glVertexAttribPointer 失败。

不需要为属性color指定顶点属性数据的数组，因为根本不需要。判断glGetAttribLocation returns 是否大于等于0，解决问题：

color = glGetAttribLocation(shader, 'color')
if color >= 0:
    glVertexAttribPointer(color, 3, GL_FLOAT, GL_FALSE, 32, ctypes.c_void_p(12))
    glEnableVertexAttribArray(color)

glVertexAttribPointer() 上的 pyopengl 错误

pyopengl Error on glVertexAttribPointer()

python

opengl

glsl

shader

pyopengl