
// glow 효과
#define MAX_SAMPLES		15
float2 g_avSampleOffsets[MAX_SAMPLES];
float4 g_avSampleWeights[MAX_SAMPLES];
// Glow 효과에 사용하는 텍스처 리스트
sampler g_s0 : register(s0) = sampler_state
{
   MinFilter = LINEAR;
   MagFilter = LINEAR;
   MipFilter = NONE;
   AddressU  = Clamp;
   AddressV  = Clamp;
};
sampler g_s1 : register(s1);
sampler g_s2 : register(s2);
sampler g_s3 : register(s3);
sampler g_s4 : register(s4);
sampler g_s5 : register(s5);
sampler g_s6 : register(s6);
sampler g_s7 : register(s7);

float4 color_average = { 0.3333, 0.3333, 0.3333, 0 };
//============================================================================= 
//Glow 효과 pixel shader
float4 Glow_PS( in float2 vScreenPosition : TEXCOORD0 ) : COLOR
{
    float4 vSample = 0.0f;
    float4 vColor = 0.0f;

    float2 vSamplePosition = vScreenPosition;

    // Perform a one-directional gaussian blur
    for(int iSample = 0; iSample < MAX_SAMPLES; iSample++)
    {
        vSamplePosition += g_avSampleOffsets[iSample];
        vColor = tex2D(g_s0, vSamplePosition);
        vColor = dot(vColor, color_average);
        vSample += g_avSampleWeights[iSample]*vColor;
    }

    return vSample;
}

technique GlowScreenTech
{
    pass P0
    {
		VertexShader = NULL;
        PixelShader = compile ps_2_0 Glow_PS();
    }
}