#version 450
#extension GL_EXT_buffer_reference : require

struct Rect {
  vec3 pos;
  vec2 size;
  vec4 color;
};

layout(std430, buffer_reference) readonly buffer RectList {
  Rect r[];
};

layout(std430, buffer_reference) readonly buffer ScreenInfo {
  mat4 bounds;
};

layout(std430, push_constant) uniform PushConstant {
  ScreenInfo screen;
  RectList rects;
} pc;

layout(location = 0) out vec4 fragColor;

const vec2 square[6] = {
  vec2(0.0, 0.0),
  vec2(1.0, 0.0),
  vec2(0.0, 1.0),
  vec2(1.0, 0.0),
  vec2(1.0, 1.0),
  vec2(0.0, 1.0),
};

void main() {
  Rect rect = pc.rects.r[gl_InstanceIndex];
  gl_Position = pc.screen.bounds * vec4(vec3(square[gl_VertexIndex] * rect.size, 0.0) + rect.pos.xyz, 1.0);
  fragColor = rect.color;
}