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MorganBorman/main.py

Created December 9, 2012 04:33
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Revisions

  1. @philipbjorge philipbjorge renamed this gist Jan 19, 2013. 1 changed file with 0 additions and 0 deletions.
    0 VAOs in PyOpenGL → main.py
    View file
    File renamed without changes.
  2. MorganBorman created this gist Dec 9, 2012.
    99 changes: 99 additions & 0 deletions VAOs in PyOpenGL
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,99 @@
    import OpenGL.GL as GL
    import OpenGL.GL.shaders
    import ctypes
    import pygame
    import numpy

    vertex_shader = """
    #version 330

    in vec4 position;
    void main()
    {
    gl_Position = position;
    }
    """

    fragment_shader = """
    #version 330

    void main()
    {
    gl_FragColor = vec4(1.0f, 1.0f, 1.0f, 1.0f);
    }
    """

    vertices = [ 0.6, 0.6, 0.0, 1.0,
    -0.6, 0.6, 0.0, 1.0,
    0.0, -0.6, 0.0, 1.0]

    vertices = numpy.array(vertices, dtype=numpy.float32)

    def create_object(shader):
    # Create a new VAO (Vertex Array Object) and bind it
    vertex_array_object = GL.glGenVertexArrays(1)
    GL.glBindVertexArray( vertex_array_object )

    # Generate buffers to hold our vertices
    vertex_buffer = GL.glGenBuffers(1)
    GL.glBindBuffer(GL.GL_ARRAY_BUFFER, vertex_buffer)

    # Get the position of the 'position' in parameter of our shader and bind it.
    position = GL.glGetAttribLocation(shader, 'position')
    GL.glEnableVertexAttribArray(position)

    # Describe the position data layout in the buffer
    GL.glVertexAttribPointer(position, 4, GL.GL_FLOAT, False, 0, ctypes.c_void_p(0))

    # Send the data over to the buffer
    GL.glBufferData(GL.GL_ARRAY_BUFFER, 48, vertices, GL.GL_STATIC_DRAW)

    # Unbind the VAO first (Important)
    GL.glBindVertexArray( 0 )

    # Unbind other stuff
    GL.glDisableVertexAttribArray(position)
    GL.glBindBuffer(GL.GL_ARRAY_BUFFER, 0)

    return vertex_array_object

    def display(shader, vertex_array_object):
    GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT)
    GL.glUseProgram(shader)

    GL.glBindVertexArray( vertex_array_object )
    GL.glDrawArrays(GL.GL_TRIANGLES, 0, 3)
    GL.glBindVertexArray( 0 )

    GL.glUseProgram(0)

    def main():
    pygame.init()
    screen = pygame.display.set_mode((512, 512), pygame.OPENGL|pygame.DOUBLEBUF)
    GL.glClearColor(0.5, 0.5, 0.5, 1.0)
    GL.glEnable(GL.GL_DEPTH_TEST)

    shader = OpenGL.GL.shaders.compileProgram(
    OpenGL.GL.shaders.compileShader(vertex_shader, GL.GL_VERTEX_SHADER),
    OpenGL.GL.shaders.compileShader(fragment_shader, GL.GL_FRAGMENT_SHADER)
    )

    vertex_array_object = create_object(shader)

    clock = pygame.time.Clock()

    while True:
    for event in pygame.event.get():
    if event.type == pygame.QUIT:
    return
    if event.type == pygame.KEYUP and event.key == pygame.K_ESCAPE:
    return

    display(shader, vertex_array_object)
    pygame.display.flip()

    if __name__ == '__main__':
    try:
    main()
    finally:
    pygame.quit()