geometra/assets/shaders/sprite.vert

#version 150 core

uniform ivec2 Viewport;
uniform mat3  Transform;
uniform sampler2D Texture;

in vec2 Vert;
in vec4 Rect;
in vec4 Clip;

out vec2 TextureCoord;

void main() {
  vec2 vert = mix(Rect.xy, Rect.zw, Vert);
  vec3 pos = Transform * vec3(vert, 1.0);

  TextureCoord = mix(Clip.st, Clip.pq, Vert) / textureSize(Texture, 0);

  gl_Position.xy = pos.xy * vec2(2.0, -2.0) / Viewport + vec2(-1.0, 1.0);
  gl_Position.z = 0.0;
  gl_Position.w = 1.0;
}