//-----------------------------------------------------------------------------
// Copyright (c) 2012 GarageGames, LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//-----------------------------------------------------------------------------

#include "core/rendering/shaders/gl/hlslCompat.glsl"
#include "core/rendering/shaders/postFX/gl/postFx.glsl"

uniform sampler2D inputTex;
uniform vec2 oneOverTargetSize;

out vec4 OUT_col;

const vec2 gTapOffsets[16] = vec2[]
(
   vec2( -1.5, -1.5 ), vec2( -0.5, -1.5 ), vec2( 0.5, -1.5 ), vec2( 1.5, -1.5 ),
   vec2( -1.5, -0.5 ), vec2( -0.5, -0.5 ), vec2( 0.5, -0.5 ), vec2( 1.5, -0.5 ),
   vec2( -1.5, 0.5 ),  vec2( -0.5, 0.5 ),  vec2( 0.5, 0.5 ),  vec2( 1.5, 0.5 ),
   vec2( -1.5, 1.5 ),  vec2( -0.5, 1.5 ),  vec2( 0.5, 1.5 ),  vec2( 1.5, 1.5 )
);

void main()
{
   vec2 pixelSize = oneOverTargetSize;

   float average = 0.0;

   for ( int i = 0; i < 16; i++ )
   {
      float lum = texture( inputTex, IN_uv0 + ( gTapOffsets[i] * pixelSize ) ).r;
      average += lum;
   }

   OUT_col = vec4( average / 16.0, 0.0, 0.0, 1.0 );
}
