source: data/trunk/programs/glow.cg @ 12181

//A.
float4 GlowX_fp
        (
                float2 uv: TEXCOORD0,

                uniform sampler2D scene: register(s0),
                uniform float4 invTexSize
        ) : COLOR
#define RENDER_SCENE 1
#define BLUR_RADIUS 1
{
        float4 colour = float4(0);
        float blurSize = BLUR_RADIUS * invTexSize.x;

        //X-blur.
        int x = uv.x/blurSize;
        colour += tex2D(scene, float2((x - 4.0) * blurSize, uv.y)) * 1.0/25.0;
        colour += tex2D(scene, float2((x - 3.0) * blurSize, uv.y)) * 2.0/25.0;
        colour += tex2D(scene, float2((x - 2.0) * blurSize, uv.y)) * 3.0/25.0;
        colour += tex2D(scene, float2((x - 1.0) * blurSize, uv.y)) * 4.0/25.0;
        colour += tex2D(scene, float2((x + 0.0) * blurSize, uv.y)) * 5.0/25.0;
        colour += tex2D(scene, float2((x + 1.0) * blurSize, uv.y)) * 4.0/25.0;
        colour += tex2D(scene, float2((x + 2.0) * blurSize, uv.y)) * 3.0/25.0;
        colour += tex2D(scene, float2((x + 3.0) * blurSize, uv.y)) * 2.0/25.0;
        colour += tex2D(scene, float2((x + 4.0) * blurSize, uv.y)) * 1.0/25.0;

        return colour;
}

//B.
float4 GlowY_fp
        (
                float2 uv: TEXCOORD0,
 
                uniform sampler2D blurX: register(s0),
                uniform float4 invTexSize
        ) : COLOR
{
        float4 colour = float4(0);
        float blurSize = BLUR_RADIUS * invTexSize.y;

        //Y-blur.
        int y = uv.y/blurSize;
        colour += tex2D(blurX, float2(uv.x, (y - 4.0) * blurSize)) * 1.0/25.0;
        colour += tex2D(blurX, float2(uv.x, (y - 3.0) * blurSize)) * 2.0/25.0;
        colour += tex2D(blurX, float2(uv.x, (y - 2.0) * blurSize)) * 3.0/25.0;
        colour += tex2D(blurX, float2(uv.x, (y - 1.0) * blurSize)) * 4.0/25.0;
        colour += tex2D(blurX, float2(uv.x, (y + 0.0) * blurSize)) * 5.0/25.0;
        colour += tex2D(blurX, float2(uv.x, (y + 1.0) * blurSize)) * 4.0/25.0;
        colour += tex2D(blurX, float2(uv.x, (y + 2.0) * blurSize)) * 3.0/25.0;
        colour += tex2D(blurX, float2(uv.x, (y + 3.0) * blurSize)) * 2.0/25.0;
        colour += tex2D(blurX, float2(uv.x, (y + 4.0) * blurSize)) * 1.0/25.0;

        return colour;
}

//C.
float4 GlowBlend_fp
        (
                float2 uv: TEXCOORD0,

                uniform sampler2D scene: register(s0),
                uniform sampler2D blurXY: register(s1)
        ) : COLOR
{
        //Add this to original, return.
        return
#if RENDER_SCENE
                tex2D(scene, uv) +
#endif
                tex2D(blurXY, uv) * 1;
}