#version 450
#extension GL_EXT_buffer_reference : require

#include "ui_common.glsl"

layout(local_size_x = 1) in;

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

  uint buffer_pos = atomicAdd(pc.layer.draw.instance_count, string.len);
  vec2 pen = vec2(0.0, 0.0);

  for(uint i = 0; i < string.len; i++) {
    uint code = (pc.layer.codes.c[(string.offset + i)/4] >> ((string.offset + i) % 4)*8) & 0xFF;
    Symbol symbol = font.symbols.s[code];
    pc.layer.drawables.d[buffer_pos + i].pos = string.pos + pen;
    pen += string.size*symbol.advance;
    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].var1 = code;
    pc.layer.drawables.d[buffer_pos + i].var2 = string.font;
    pc.layer.drawables.d[buffer_pos + i].type = 1;
  }
}