#ifdef GL_ES
#extension GL_OES_texture_3D : enable
precision mediump int;
precision mediump float;
precision mediump sampler3D;
#endif

#define USE_OGRE_FROM_FUTURE
#include <OgreUnifiedShader.h>

SAMPLER2D(Input, 0);
SAMPLER3D(NoiseMap, 1);
SAMPLER2D(HeatLookup, 2);

OGRE_UNIFORMS(
uniform vec4 heatBiasScale;
uniform vec4 depth_modulator;
uniform float time;
)

MAIN_PARAMETERS
IN(vec2 oUv0, TEXCOORD0)
MAIN_DECLARATION
{
  float depth, heat, interference;

  //  Output constant color:
  depth = texture2D(Input, oUv0).x;
  depth *= (depth * depth_modulator).x;

  heat = (depth * heatBiasScale.y);

  // if (depth > 0)
  {
      interference = -0.5 + 0.2 * (texture3D(NoiseMap, vec3(oUv0 * vec2_splat(5.0), time))).x;
      interference *= interference;
      interference *= 1.0 - heat;
      heat += interference + heatBiasScale.x;
  }

  // Clamp UVs
  heat = max(0.005, min(0.995, heat));
  gl_FragColor = texture2D(HeatLookup, vec2(heat, 0.0));
}