--track@str:strength,0,100,5,1
--[[computeshader@cserosion:
RWTexture2D<half4> buffer : register(u0);
Texture2D texture0 : register(t0);

[numthreads(1, 1, 1)]
void cserosion(uint2 pos : SV_DispatchThreadID) {
    float minA = 1.0;
    float4 tex = texture0[pos];
    for (int y = -1; y <= 1; y++) { // 3x3の周囲をチェックする
        for (int x = -1; x <= 1; x++) {
            int2 offset = int2(pos) + int2(x, y);
            float4 col = texture0[offset];
            if (col.a < minA) {
                minA = col.a;
            }
        }
    }

    float4 result = float4(tex.rgb*minA, minA); //rgbにαかけるの忘れるな
    buffer[pos] = result;
}
]]
--[[pixelshader@pserosion:
Texture2D InputTexture : register(t0);
float4 pserosion(float4 pos : SV_Position) : SV_Target { 
    float4 tex = InputTexture[uint2(pos.xy)];
    float minA = 1.0;
    for (int y = -1; y <= 1; y++) {
        for (int x = -1; x <= 1; x++) {
            int2 offset = int2(pos.xy) + int2(x, y);
            float4 col = InputTexture[offset];
            if (col.a < minA) {
                minA = col.a;
            }
        }
    }
    return float4(tex.rgb*minA,minA);;
}
]]

for i = 1 , str do
    --obj.computeshader("cserosion","object","object",{},obj.w,obj.h) --computeshaderでやる意味なかった
    obj.pixelshader("pserosion","object","object",{})
end