Modern GL and frame buffer work

gistfile1.txt

import numpy as np
import moderngl
from moderngl_window import geometry
from ported._example import Example
from pathlib import Path
import os

class SimpleColorTriangle(Example):
    gl_version = (3, 3)
    aspect_ratio = 16 / 9
    title = "Simple Color Triangle"
    resource_dir = os.path.dirname(os.path.abspath(__file__))

    def __init__(self, **kwargs):
        super().__init__(**kwargs)

        self.prog = self.ctx.program(
            vertex_shader='''
                #version 330
                in vec2 in_vert;
                in vec3 in_color;
                out vec3 v_color;    // Goes to the fragment shader
                void main() {
                    gl_Position = vec4(in_vert, 0.0, 1.0);
                    v_color = in_color;
                }
            ''',
            fragment_shader='''
                #version 330
                in vec3 v_color;
                out vec4 f_color;
                void main() {
                    // We're not interested in changing the alpha value
                    f_color = vec4(v_color, 1.0);
                }
            ''',
        )

        # Point coordinates are put followed by the vec3 color values
        vertices = np.array([
            # x, y, red, green, blue
            0.0, 0.8, 1.0, 0.0, 0.0,
            -0.6, -0.8, 0.0, 1.0, 0.0,
            0.6, -0.8, 0.0, 0.0, 1.0,
        ], dtype='f4')

        self.vbo = self.ctx.buffer(vertices)

        # We control the 'in_vert' and `in_color' variables
        self.vao = self.ctx.vertex_array(
            self.prog,
            [
                # Map in_vert to the first 2 floats
                # Map in_color to the next 3 floats
                (self.vbo, '2f 3f', 'in_vert', 'in_color')
            ],
        )

        self.offscreen_color = self.ctx.texture(self.wnd.buffer_size, 4)
        self.offscreen = self.ctx.framebuffer(color_attachments=[self.offscreen_color])
        self.texture_prog = self.load_program('texture.glsl')
        self.quad_fs = geometry.quad_fs()


    def render(self, time: float, frame_time: float):
        self.offscreen.use()
        self.offscreen.clear(1.0, 1.0, 1.0)
        self.vao.render()
        self.wnd.use()

        self.offscreen_color.use(location=0)
        self.quad_fs.render(self.texture_prog)

if __name__ == '__main__':
    SimpleColorTriangle.run()