out vec4 FragColor;

uniform vec3 uCamera;

in vec4 aColour;
in vec2 aUv;
in vec3 aNorm;
in vec3 aCo;
in vec3 aWorldCo;

#include "common_world.glsl"

// Water blending
// ==============

float water_depth( vec3 pos, vec3 halfview )
{
   vec3 pnorm = g_water_plane.xyz;
   float pdist = g_water_plane.w;

   float d = dot( pnorm, halfview );
   float t = dot((pnorm*pdist - pos), pnorm) / d;
   return t * g_water_fog;
}

void main()
{
   vec3 halfview = normalize( uCamera - aCo );
   vec3 world_pos = vec3( aCo.y, aCo.x, aCo.z );
   FragColor = vec4( world_pos, water_depth( aCo, halfview ) );
}