pyopengl如何创建着色器绘制多个点

要在 PyOpenGL 中创建着色器并绘制多个点，可以按照以下步骤进行：

1. 导入必要的库

from OpenGL.GL import *
from OpenGL.GL.shaders import compileProgram, compileShader
import numpy as np

2. 编写顶点着色器和片元着色器

vertex_shader = """
#version 330
in vec4 position;
void main()
{
    gl_Position = position;
}
"""

fragment_shader = """
#version 330
void main()
{
    gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0);
}
"""

3. 编译着色器程序

shader = compileProgram(compileShader(vertex_shader, GL_VERTEX_SHADER), compileShader(fragment_shader, GL_FRAGMENT_SHADER))

4. 创建顶点数据并绑定到缓冲区对象

vertices = np.array([0.0, 0.5, 0.0, 1.0,
                     -0.5, -0.5, 0.0, 1.0,
                     0.5, -0.5, 0.0, 1.0], dtype=np.float32)

vbo = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, vbo)
glBufferData(GL_ARRAY_BUFFER, vertices.nbytes, vertices, GL_STATIC_DRAW)

5. 启用顶点属性并指定其数据格式

position = glGetAttribLocation(shader, "position")
glEnableVertexAttribArray(position)
glVertexAttribPointer(position, 4, GL_FLOAT, GL_FALSE, 0, None)

6. 使用着色器程序并绘制多个点

glUseProgram(shader)
glDrawArrays(GL_POINTS, 0, 3)

完整代码如下：

from OpenGL.GL import *
from OpenGL.GL.shaders import compileProgram, compileShader
import numpy as np
import glfw

vertex_shader = """
#version 330
in vec4 position;
void main()
{
    gl_Position = position;
}
"""

fragment_shader = """
#version 330
void main()
{
    gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0);
}
"""

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

    window = glfw.create_window(640, 480, "PyOpenGL Demo", None, None)

    if not window:
        glfw.terminate()
        return

    glfw.make_context_current(window)

    shader = compileProgram(compileShader(vertex_shader, GL_VERTEX_SHADER), compileShader(fragment_shader, GL_FRAGMENT_SHADER))

    vertices = np.array([0.0, 0.5, 0.0, 1.0,
                         -0.5, -0.5, 0.0, 1.0,
                         0.5, -0.5, 0.0, 1.0], dtype=np.float32)

    vbo = glGenBuffers(1)
    glBindBuffer(GL_ARRAY_BUFFER, vbo)
    glBufferData(GL_ARRAY_BUFFER, vertices.nbytes, vertices, GL_STATIC_DRAW)

    position = glGetAttribLocation(shader, "position")
    glEnableVertexAttribArray(position)
    glVertexAttribPointer(position, 4, GL_FLOAT, GL_FALSE, 0, None)

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

        glClear(GL_COLOR_BUFFER_BIT)

        glUseProgram(shader)
        glDrawArrays(GL_POINTS, 0, 3)

        glfw.swap_buffers(window)

    glfw.terminate()

if __name__ == '__main__':
    main()

这个程序将创建一个包含三个点的三角形，并以白色绘制它们。你可以使用 `glDrawArrays` 函数中的第二个参数来指定要绘制的点的数量。