/*
    Braid Rewind
    Authors: hunterk, cgwg
 
    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the Free
    Software Foundation; either version 2 of the License, or (at your option)
    any later version.
*/

struct previous
{
   uniform sampler2D texture;
   float2 tex_coord;
};

struct input
{
    float2 video_size;
    float2 texture_size;
    float2 output_size;
    float frame_count;
    float frame_direction;
    float frame_rotation;
};

void main_vertex
(
   float4 position : POSITION,
   out float4 oPosition : POSITION,
   uniform float4x4 modelViewProj,

   float4 color : COLOR,
   out float4 oColor : COLOR,

   float2 texCoord : TEXCOORD,
   out float2 oTexCoord : TEXCOORD,

   uniform input IN
)
{
   oPosition = mul(modelViewProj, position);
   oColor = color;
   oTexCoord = texCoord;
}

struct output 
{
  float4 col    : COLOR;
};

output main_fragment(in sampler2D s0 : TEXUNIT0, in float2 texCoord : TEXCOORD0,
uniform input IN,
      previous PREV,
      previous PREV1,
      previous PREV2,
      previous PREV3,
      previous PREV4,
      previous PREV5,
      previous PREV6
)
{
   float4 current = tex2D(s0, texCoord);

   float4 color = tex2D(PREV6.texture, texCoord);
   color = color + tex2D(PREV5.texture, texCoord);
   color = color + tex2D(PREV4.texture, texCoord);
   color = color + tex2D(PREV3.texture, texCoord);
   color = color + tex2D(PREV2.texture, texCoord);
   color = color + tex2D(PREV1.texture, texCoord);
   color = color + tex2D(PREV.texture, texCoord);
   color = color + current;

   float4 sepia = float4(1.0,0.8,0.6,1.0); 

   if (IN.frame_direction < 0.0)
   {
      current = ((current + (color / 7.0)) / 2.0) * sepia;
   }
   else
   {
      current = current;
   }

   output OUT;
   OUT.col = current;
   return OUT;
}