#version 400
uniform mat4 camera;
uniform mat4 modelViewMatrix;
uniform mat4 projectionMatrix;

uniform mat4 normalMatrix;
uniform mat4 modelMatrix;
uniform mat4 worldMatrix;

layout(location = 0) in vec3 position;
layout(location = 1) in vec2 inCoord;

layout (location = 2) in float zPos;
layout (location = 3) in vec3 inNormal;

out vec2 fragTexCoord;
out vec2 tilePos;
out vec3 fragVert;
smooth out vec3 vWorldPos;
uniform mat4 MVP;
smooth out vec3 vNormal;
out float z_pos;

void main()
{
  gl_Position = MVP * vec4(position.x, position.y, zPos, 1.0);

  // World position: anchored to terrain ground
  vec4 wPos = worldMatrix * vec4(position.x, position.y, zPos, 1.0);
  vWorldPos = wPos.xyz;

  // Texture coordinates based on world coordinates (stays fixed when camera moves)
  fragTexCoord = vec2(wPos.x * 0.5, wPos.y * 0.5);

  // Tile-local position for the hexagon border outline
  vec4 tpos = modelMatrix * vec4(position.x, position.y, 0.0, 1.0);
  tilePos = vec2(tpos.x, tpos.y);

  vNormal = inNormal.xyz;
  fragVert = position;
  z_pos = zPos;
}