//-----------------------------------------------------------------------------
// 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 "shadergen:/autogenConditioners.h"
#include "../postFx.hlsl"

uniform sampler2D frameSampler : register( s0 );
uniform sampler2D backBuffer : register( s1 );

uniform float3 camForward;
uniform float3 lightDirection;
uniform float2 screenSunPos;
uniform float2 oneOverTargetSize;
uniform int numSamples;
uniform float density;
uniform float weight;
uniform float decay;
uniform float exposure;

float4 main( PFXVertToPix IN ) : COLOR0
{
float4 texCoord = float4( IN.uv0.xy, 0, 0 );

// Store initial sample.
half3 color = (half3)tex2D( frameSampler, texCoord.xy ).rgb;

// Store original bb color.
float4 bbCol = tex2D( backBuffer, IN.uv1 );

// Set up illumination decay factor.
half illuminationDecay = 1.0;

float amount = saturate( dot( -lightDirection, camForward ) );

int samples = numSamples * amount;

if ( samples <= 0 )
return bbCol;

// Calculate vector from pixel to light source in screen space.
half2 deltaTexCoord = (half2)( texCoord.xy - screenSunPos );

// Divide by number of samples and scale by control factor.
deltaTexCoord *= (half)(1.0 / samples * density);

// Evaluate summation from Equation 3 NUM_SAMPLES iterations.
for ( int i = 0; i < samples; i++ )
{
// Step sample location along ray.
texCoord.xy -= deltaTexCoord;

// Retrieve sample at new location.
half3 sample = (half3)tex2Dlod( frameSampler, texCoord );

// Apply sample attenuation scale/decay factors.
sample *= half(illuminationDecay * weight);

// Accumulate combined color.
color += sample;

// Update exponential decay factor.
illuminationDecay *= half(decay);
}

//return saturate( amount ) * color * Exposure;
//return bbCol * decay;

// Output final color with a further scale control factor.
//return saturate( amount ) * float4( color * exposure, 1 ) + bbCol;
//return saturate( amount ) * float4( color * exposure, 1 ) + bbCol;

float b = 0;

//float4 base = tex2D(backBuffer, ( texCoord.xy - screenSunPos ));
float4 base = tex2D(backBuffer, IN.uv0);
float2 uv = IN.uv0;

[loop] for (int i = 1; i <= samples; i++)
{
uv -= b;
uv *= amount;
b = (1-(1*pow(abs(amount), i))) / 2;
uv += b;
base += tex2Dlod(backBuffer, float4(uv.x, uv.y, 0, 0));
}

//return base / (samples + 1);

uv = IN.uv0;
float BlurStart = 1.0;
float BlurWidth = 0.2;
half4 c = 0;
texCoord.xy = float4( IN.uv0.xy, 0, 0 );
float2 Center = ( texCoord.xy - screenSunPos );

for (int i = 1; i <= samples; i++)
{
texCoord.xy -= Center;
Center = ( texCoord.xy - screenSunPos ); //comment this to see the wide ef
float scale = BlurStart + BlurWidth*(i/(float) (samples-1.0));
texCoord.xy += float2(1.0-scale,1.0-scale);
//c += tex2Dlod(backBuffer, float4(( uv.x*scale + Center.x),(uv.y*scale + Center.y),0,0 ));
c += tex2Dlod(frameSampler, float4(( uv.x*scale + Center.x),(uv.y*scale + Center.y),0,0 ));
}

c /=samples;
return c;


}