#version 150 core

uniform vec3 iResolution;

in vec2 position;
out vec2 fragCoord;

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

    // Convert from OpenGL coordinate system (with origin in center
    // of screen) to Shadertoy/texture coordinate system (with origin
    // in lower left corner)
    fragCoord = (gl_Position.xy + vec2(1.0)) / vec2(2.0) * iResolution.xy;
}