struct Hex {
  float heights[6];
  uint  colors[7];
};

layout(std430, buffer_reference) readonly buffer Region {
  int q;
  int r;
  int y;
  uint map;
  Hex hexes[];
};

layout(std430, buffer_reference) readonly buffer HexContext {
  mat4 proj;
  mat4 view;
  vec4 click_start;
  vec4 click_end;
  vec4 hover_start;
  vec4 hover_end;
  uint current_map;
  uint clicked_region;
  int  clicked_hex;
  uint hovered_region;
  int  hovered_hex;
  Region regions[];
};

layout(std430, push_constant) uniform PushConstant {
  HexContext context;
  float time;
} pc;

#define PI 3.1415926535897932384626433832795
const float w = 0.5;
const float x = 0.75;
const float z = sqrt(3.0)/2.0;

const int region_size = 10;
const float region_diameter = 2*region_size-1;
const float region_width = x*region_diameter;
const float region_height = z*region_diameter;
const int region_hex_count = 3*region_size*(region_size-1)+1;

const vec4 vertices[] = {
  vec4(0,             0, 0,             1),
  vec4(w*cos(0*PI/3), 0, w*sin(0*PI/3), 1),
  vec4(w*cos(1*PI/3), 0, w*sin(1*PI/3), 1),
  vec4(w*cos(2*PI/3), 0, w*sin(2*PI/3), 1),
  vec4(w*cos(3*PI/3), 0, w*sin(3*PI/3), 1),
  vec4(w*cos(4*PI/3), 0, w*sin(4*PI/3), 1),
  vec4(w*cos(5*PI/3), 0, w*sin(5*PI/3), 1),
};

const uint indices[] = {
  0, 2, 1,
  0, 3, 2,
  0, 4, 3,
  0, 5, 4,
  0, 6, 5,
  0, 1, 6,
};

const vec4 starts[] = {
  vec4( 0, 0,    z, 0), //  0, -1
  vec4(-x, 0,  z/2, 0), // -1,  0
  vec4(-x, 0, -z/2, 0), // -1, +1
  vec4( 0, 0,   -z, 0), //  0, +1
  vec4( x, 0, -z/2, 0), // +1,  0
  vec4( x, 0,  z/2, 0), // +1, -1
};

const vec2 start_coords[] = {
  vec2(0, -1),
  vec2(-1, 0),
  vec2(-1, 1),
  vec2(0, 1),
  vec2(1, 0),
  vec2(1, -1),
};

const vec4 direction[] = {
  vec4(-x, 0, -z/2, 0),
  vec4( 0, 0,   -z, 0),
  vec4( x, 0, -z/2, 0),
  vec4( x, 0,  z/2, 0),
  vec4( 0, 0,    z, 0),
  vec4(-x, 0,  z/2, 0),
};

const vec2 direction_coords[] = {
  vec2(-1, 1),
  vec2(0, 1),
  vec2(1, 0),
  vec2(1, -1),
  vec2(0, -1),
  vec2(-1, 0),
};