Function Resize

BeefTools/ImgCreate/ImgCreate.cpp:9–60

USING_NS_BF;

void Resize(ImageData* srcImage, int srcX, int srcY, int srcScale, ImageData* destImage, int destX, int destY, int scale)
{
	if (srcScale > scale)
	{
		struct Color
		{
			uint8 mElems[4];
		};

		struct ColorT
		{
			float mElems[4];
		};

		ColorT colorT = { 0 };

		int sampleScale = srcScale / scale;
		float totalDiv = 0;
		for (int srcYOfs = 0; srcYOfs < sampleScale; srcYOfs++)
		{
			for (int srcXOfs = 0; srcXOfs < sampleScale; srcXOfs++)
			{
				auto color = *(Color*)&srcImage->mBits[(srcX - srcImage->mX + srcXOfs) + (srcY - srcImage->mY + srcYOfs)*srcImage->mWidth];

				totalDiv += 1.0f;

				float alpha = color.mElems[3];
				colorT.mElems[0] += color.mElems[0] * alpha;
				colorT.mElems[1] += color.mElems[1] * alpha;
				colorT.mElems[2] += color.mElems[2] * alpha;
				colorT.mElems[3] += alpha;
			}
		}

		Color outColor;
		float alpha = colorT.mElems[3] / totalDiv;
		float valScale = 0;
		if (alpha > 0)
			valScale = 1 / alpha / totalDiv;
		outColor.mElems[0] = (int)round(colorT.mElems[0] * valScale);
		outColor.mElems[1] = (int)round(colorT.mElems[1] * valScale);
		outColor.mElems[2] = (int)round(colorT.mElems[2] * valScale);
		outColor.mElems[3] = (int)round(alpha);

		destImage->mBits[destX + destY * destImage->mWidth] = *(uint32*)&outColor;
	}
	else
	{
		uint32 color = srcImage->mBits[(srcX - srcImage->mX) + (srcY - srcImage->mY)*srcImage->mWidth];
		destImage->mBits[destX + destY * destImage->mWidth] = color;
	}
}

void ConvImage(const StringImpl& baseName, int wantSize)
{