Inside the companion

The browser shader lab

The two GLSL stages behind your editable WebGL postcard.

Project files 2

Cover the postcard canvas

The WebGL vertex stage that supplies the fragment shader with a drawing surface.

#version 300 es
layout(location = 0) in vec2 a_position;

void main() {
    gl_Position = vec4(a_position, 0.0, 1.0);
}

This is the file included with the course. Copy and download give you its complete source.