gltest.py

'''
    Renders a blue triangle
'''

import moderngl
import numpy as np

from example_window import Example, run_example


class HelloWorld(Example):
    def __init__(self):
        self.ctx = moderngl.create_context()

        self.prog = self.ctx.program(
            vertex_shader='''
                #version 330

                in vec2 in_vert;

                void main() {
                    gl_Position = vec4(in_vert, 0.0, 1.0);
                }
            ''',
            fragment_shader='''
                #version 330

                out vec4 f_color;

                void main() {
                    f_color = vec4(0.3, 0.5, 1.0, 1.0);
                }
            ''',
        )

        vertices = np.array([
            -1.0, 1.0,
            -1.0, -1.0,
            1.0, -1.0,
        ])

        self.vbo = self.ctx.buffer(vertices.astype('f4').tobytes())
        self.vao = self.ctx.simple_vertex_array(self.prog, self.vbo, 'in_vert')

    def render(self):
        self.ctx.viewport = self.wnd.viewport
        self.ctx.clear(1.0, 1.0, 1.0)
        self.vao.render()


run_example(HelloWorld)