unblend.cg

/* COMPATIBILITY
   - HLSL compilers
   - Cg   compilers
*/

/*
   Hyllian's Unblend Shader

   Copyright (C) 2011-2014 Hyllian/Jararaca - sergiogdb@gmail.com

   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.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/


float c_df(float3 c1, float3 c2)
{
      float3 df = abs(c1 - c2);
      return df.r + df.g + df.b;
//      return 2*df.r + 3*df.g + df.b;
}


float3 bestfit(float3 ca, float3 cb, float3 cref)
{
//      return lerp(ca, cb, step(c_df(cref, cb), c_df(cref, ca)));
      return lerp(min(ca, cb), max(ca, cb), step((ca+cb)*0.5, cref));
}



struct orig
{
	float2 tex_coord;
	uniform float2 texture_size;
	uniform sampler2D texture;
};


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

struct out_vertex {
	float4 position : POSITION;
	float4 color    : COLOR;
	float2 texCoord : TEXCOORD0;
	float2 orig_tex;
};

/*    VERTEX_SHADER    */
void main_vertex
(
	float4 position	: POSITION,
	float4 color	: COLOR,
	float2 texCoord : TEXCOORD0,

   	uniform float4x4 modelViewProj,
	orig ORIG,
	out out_vertex co
)
{
	co.position = mul(modelViewProj, position);
	co.color = color;

	co.texCoord = texCoord;
	co.orig_tex = ORIG.tex_coord;
}


/*    FRAGMENT SHADER    */
float4 main_fragment(in out_vertex co, uniform sampler2D decal : TEXUNIT0, orig ORIG, uniform input IN) : COLOR
{
      float2 dx = float2(1.0, 0.0)/IN.texture_size;
      float2 dy = float2(0.0, 1.0)/IN.texture_size;

      float2 tc = (floor(co.texCoord*IN.texture_size-float2(0.5,0.5))+float2(0.5,0.5))/IN.texture_size;

      float3 A = tex2D(ORIG.texture, tc       ).xyz;
      float3 B = tex2D(ORIG.texture, tc +dx   ).xyz;
      float3 C = tex2D(ORIG.texture, tc    +dy).xyz;
      float3 D = tex2D(ORIG.texture, tc +dx+dy).xyz;

      float3 color = tex2D(decal,  co.texCoord).xyz;

      color = bestfit(bestfit(A, B, color), bestfit(C, D, color), color);

      return float4(color, 1.0);
}