//-------------------------------
//BrightBloom_ps20.glsl
// High-pass filter for obtaining lumminance
// We use an aproximation formula that is pretty fast:
//   f(x) = ( -3 * ( x - 1 )^2 + 1 ) * 2
//   Color += Grayscale( f(Color) ) + 0.6
//
// Special thanks to ATI for their great HLSL2GLSL utility
//     http://sourceforge.net/projects/hlsl2glsl
//-------------------------------

#ifdef GL_ES
precision mediump int;
precision mediump float;
#endif

#define USE_OGRE_FROM_FUTURE
#include <OgreUnifiedShader.h>

SAMPLER2D(RT, 0);

MAIN_PARAMETERS
IN(vec2 oUv0, TEXCOORD0)
MAIN_DECLARATION
{
  vec4 tex = texture2D(RT, oUv0);
  tex -= vec4_splat(1.00000);
  vec4 bright4 = vec4_splat(-6.00000) * tex * tex + vec4_splat(2.00000);
  float bright = dot(bright4, vec4(0.333333, 0.333333, 0.333333, 0.000000));
  tex += vec4_splat(bright + 0.600000);

  gl_FragColor = tex;
}