#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(RT, 0);
SAMPLER3D(Chars, 1);

OGRE_UNIFORMS(
uniform vec2 numTiles;
uniform vec2 iNumTiles;
uniform vec2 iNumTiles2;
uniform vec4 lum;
uniform float charBias;
)

MAIN_PARAMETERS
IN(vec2 oUv0, TEXCOORD0)
MAIN_DECLARATION
{  
  //sample RT
	vec2 off = mod(oUv0, iNumTiles);
	vec2 middle = oUv0 - off + iNumTiles2;  
	vec4 outc = texture2D(RT, middle);
  
  //multiply luminance by charbias, because not all slices of the ascii
	//volume texture are used
  
  vec3 local = vec3(off.x * numTiles.x, off.y * numTiles.y, dot(outc, lum) * charBias);
  
  //fix to brighten the dark pixels with small characters
	//outc *= lerp(2.0, 1.0, local.z);
  
  outc *= texture3D(Chars, local);
  
	gl_FragColor = outc;
}