source: 2016/23/ohjaajat/Punasininen/Punasininen/PunasininenContent/Shockwave.fx @ 7204

static const int MAX_WAVES = 3;
float4 Waves[MAX_WAVES];
float2 Resolution;

float4x4 MatrixTransform;
sampler TextureSampler: register(s0);


float2 Shock(float2 uv, float2 center, float time, float coefficient)
{
        float3 shockParams = float3(10.0, 0.9, 0.1);

        float dist = distance(uv, center);
        if ((dist <= time + shockParams.z) && (dist >= time - shockParams.z))
        {
                float diff = dist - time;
                float powDiff = 1.0 - pow(abs(diff * shockParams.x), shockParams.y);
                float diffTime = diff * powDiff;
                float2 diffUV = normalize(uv - center);
                uv += diffUV * diffTime * coefficient;
        }
        return uv;
}

float4 PixShader(float2 texCoord: TEXCOORD0) : COLOR0
{
        float2 uv = texCoord;
        [unroll] for(int i=0; i<MAX_WAVES; i++)
        {
                float4 wave = Waves[i];
                uv = Shock(uv, float2(wave.x, wave.y), wave.z, wave.w);
        }
        float3 color = tex2D(TextureSampler, uv).rgb;
        
        /*
        float radius = 1.5;
        float3 glow = float3(0, 0, 0);
        for (int x = -5; x<5; x++) {
                for (int y = -5; y<5; y++) {
                        float w = 0.0;
                        if (!(x == 0 && y == 0))
                                w = 0.1 * 1.0 / sqrt(float(x*x + y*y));
                        glow += w * tex2D(TextureSampler, uv + float2(radius * x / Resolution.x, radius * y / Resolution.y)).rgb;
                }
        }
        glow *= 1.0 / 10.0 * 10.0;
        color += 0.2 * glow;
        */

        return float4(color, 1);
}


void SpriteVertexShader(inout float4 color    : COLOR0,
                        inout float2 texCoord : TEXCOORD0,
                        inout float4 position : SV_Position)
{
    position = mul(position, MatrixTransform);
}

technique Technique1
{
    pass Pass1
    {
        VertexShader = compile vs_3_0 SpriteVertexShader();
        PixelShader = compile ps_3_0 PixShader();
    }
}