#version 450
#extension GL_EXT_buffer_reference : require

#include "ui_common.glsl"

layout(std430, push_constant) uniform PushConstant {
  Context context;
  Layer   layer;
} pc;

layout(local_size_x = 1) in;

void main() {
  uint gID = gl_GlobalInvocationID.x;
  String string = pc.layer.strings.s[gID];
  Font font = pc.context.fonts.f[pc.layer.font_index];

  uint buffer_pos = atomicAdd(pc.layer.draw.instance_count, string.len);
  float x = 0;
  for(uint i = 0; i < string.len; i++) {
    uint code = pc.layer.codes.c[string.offset + i];
    Symbol symbol = font.symbols.s[code];
    pc.layer.drawables.d[buffer_pos + i].pos = string.pos + vec2(x, 0);
    x += string.size*symbol.advance/font.width;
    pc.layer.drawables.d[buffer_pos + i].size = vec2(string.size, string.size);
    pc.layer.drawables.d[buffer_pos + i].color = string.color;
    pc.layer.drawables.d[buffer_pos + i].code = pc.layer.codes.c[string.offset + i];
    pc.layer.drawables.d[buffer_pos + i].type = 1;
  }
}