#version 150 core

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

/* TODO: instanced */
uniform vec2 Offset;
uniform vec4 Atlas;
uniform vec4 Plane;

in vec2 Vert;

out vec2 TextureCoord;

void main() {
  vec2 planeVert = mix(Plane.sq, Plane.pt, Vert);
  vec3 pos = Transform * vec3(planeVert + Offset, 1.0);

  vec2 atlasVert = mix(Atlas.sq, Atlas.pt, Vert);
  TextureCoord = atlasVert / 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;
}