glue

Python OpenGL Utilities and Extensions.

Basic Usage

The library aims to aid rapid prototyping with OpenGL. It is under development and subject to change. Currently, it can be used as follows:

In plain_texture.vs:

#version 440 core

layout(location = 0) in vec3 position;
layout(location = 1) in vec2 texCoord;
layout(location = 2) in vec4 color;
layout(location = 3) in vec3 normal;

uniform mat4 projection;
uniform mat4 model_view;

out VertexData {
    vec2 texCoord;
    vec4 color;
    vec3 normal;
} vs;

void main() {
    gl_Position = projection * model_view * vec4(position, 1.0);
    
    vs.texCoord = texCoord;
    vs.color = color;
    vs.normal = normal;
}

In plain_texture.fs:

#version 440 core

uniform sampler2D texture;

in VertexData {
    vec2 texCoord;
    vec4 color;
    vec3 normal;
} vs;

out vec4 fragColor;

void main() {
    fragColor = texture2D(texture, vs.texCoord);
}

In main.py:

program = None
texture = None
vao = None
vbo = None

def rect(w=1.0, h=1.0):
    data = np.zeros(4, dtype = [
        ("position", np.float32, 3),
        ("texCoord", np.float32, 2),
        ("color", np.float32, 4),
        ("normal", np.float32, 3),
    ])
    
    w_half, h_half = w/2.0, h/2.0
    
    data['position'] = [(-w_half, -h_half, 0), (-w_half, +h_half, 0), (+w_half, -h_half, 0), (+w_half, +h_half, 0)]
    data['texCoord'] = [(0, 0), (0, +1), (+1, 0), (+1, +1)]
    data['color'] = [(1, 0, 0, 1), (0, 1, 0, 1), (0, 0, 1, 1), (1, 1, 0, 1)]
    data['normal'] = [(+1, 0, 0), (+1, 0, 0), (+1, 0, 0), (+1, 0, 0)]
    
    return data

def init(window):
    global program, texture, vao, vbo
    
    program = gl.utilities.load_program([
        'data/shader/plain_texture.vs',
        'data/shader/plain_texture.fs',
    ])
    
    texture = gl.utilities.load_texture('data/image/smile.png')
    
    vao = gl.VertexArrayObject()
    gl.VertexArrayObject.bind(vao)
    
    vbo = gl.VertexBufferObject()
    gl.VertexBufferObject.bind(vbo)
    vbo.set_data(rect())

def render(window):
    global program, texture, vao, vbo
    
    gl.clear_color([1.0,1.0,1.0])
    gl.clear()
    
    size = np.asarray(window.size)
    aspect = size / np.min(size)
    
    projection = projections.ortho(-aspect[0], +aspect[0], -aspect[1], +aspect[1], -1.0, +1.0)
    model_view = transforms.translate(0.0, np.sin(2*np.pi*(np.fmod(time.time(), 5.0)/5.0)), 0.0)
    
    gl.Program.bind(program)
    
    program.uniforms['projection'] = projection
    program.uniforms['model_view'] = model_view
    program.uniforms['texture'] = texture
    
    program.inputs['position'] = vbo
    program.inputs['texCoord'] = vbo
    program.inputs['color'] = vbo
    program.inputs['normal'] = vbo
    
    GL.glDrawArrays(GL.GL_TRIANGLE_STRIP, 0, 4)

def main():
    window = glfw.Window((800, 600), "Hello GLUE!")
    glfw.Context.set_current(window.context)
    
    info()
    
    init(window)
    
    gl.cleanup()
    
    while not window.should_close():
        glfw.poll_events()
        
        render(window)
        
        gl.cleanup()
        
        window.swap_buffers()
    
    window.dispose()

if __name__ == "__main__":
    with glfw.initialized():
        main()

See main.py for complete code listing.