public static void ComposePixels <TSrcPixel, TDstPixel>(SpanBitmap <TSrcPixel> src, SpanBitmap <TDstPixel> dst, TRANSFORM srcXform, bool useBilinear, float opacity)
where TSrcPixel : unmanaged, Pixel.IConvertTo
where TDstPixel : unmanaged, Pixel.IConvertTo
{
int opacityQ = (int)(opacity * 256);
void _rowProcessorNearest(Span <TDstPixel> dst, SpanQuantized8Sampler <TSrcPixel, Pixel.BGRP32> src, _RowTransformIterator srcIterator)
{
Pixel.BGRP32 srcPixel = default;
Pixel.BGRP32 composer = default;
for (int i = 0; i < dst.Length; ++i)
{
srcIterator.MoveNext(out int sx, out int sy);
src.GetSourcePixelOrDefault(sx, sy).CopyTo(ref srcPixel);
if (srcPixel.A == 0)
{
continue;
}
ref var dstI = ref dst[i];
dstI.CopyTo(ref composer);
composer.SetSourceOver(srcPixel, opacityQ);
composer.CopyTo(ref dstI);
}
}
void _rowProcessorBilinear(Span <TDstPixel> dst, SpanQuantized8Sampler <TSrcPixel, Pixel.BGRP32> src, _RowTransformIterator srcIterator)
{
Pixel.BGRP32 srcPixel = default;
Pixel.BGRP32 composer = default;
for (int i = 0; i < dst.Length; ++i)
{
srcIterator.MoveNext(out int sx, out int sy, out int rx, out int ry);
srcPixel = src.GetSampleOrDefault(sx, sy, rx, ry);
if (srcPixel.A == 0)
{
continue;
}
ref var dstI = ref dst[i];
dstI.CopyTo(ref composer);
composer.SetSourceOver(srcPixel, opacityQ);
composer.CopyTo(ref dstI);
}
