[PATCH 0/1] MR8294: gdiplus: Changed comparison from floating-point (ptf) to integer (pti) coordinates for accuracy
Fixed potential image resampling conditions by using exact pixel coordinates -- https://gitlab.winehq.org/wine/wine/-/merge_requests/8294
From: Wei Xie <xiewei(a)uniontech.com> Fixed potential image resampling conditions by using exact pixel coordinates --- dlls/gdiplus/graphics.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/dlls/gdiplus/graphics.c b/dlls/gdiplus/graphics.c index 8fa0d689cbe..6dd5a83092f 100644 --- a/dlls/gdiplus/graphics.c +++ b/dlls/gdiplus/graphics.c @@ -3260,8 +3260,8 @@ GpStatus WINGDIPAPI GdipDrawImagePointsRect(GpGraphics *graphics, GpImage *image graphics->scale, image->xres, image->yres, bitmap->format, imageAttributes ? imageAttributes->outside_color : 0); - if (ptf[1].Y != ptf[0].Y || ptf[2].X != ptf[0].X || - ptf[1].X - ptf[0].X != srcwidth || ptf[2].Y - ptf[0].Y != srcheight || + if (pti[1].y != pti[0].y || pti[2].x != pti[0].x|| + pti[1].x - pti[0].x != gdip_round(srcwidth) || pti[2].y - pti[0].y != gdip_round(srcheight) || srcx < 0 || srcy < 0 || srcx + srcwidth > bitmap->width || srcy + srcheight > bitmap->height) do_resampling = TRUE; -- GitLab https://gitlab.winehq.org/wine/wine/-/merge_requests/8294
I'm not sure about this. We may still want to rescale the image even if the coordinates are within 1 pixel. Maybe we could use a smaller delta? -- https://gitlab.winehq.org/wine/wine/-/merge_requests/8294#note_106365
[test_draw_image_resampling.cpp](/uploads/283a7f5a477eb2ea2496c371639e32a1/test_draw_image_resampling.cpp) Using this program to compare the execution results of wine and Windows, it can be seen that the difference below Windows is 0.1 should not be resampled. {width=408 height=104} {width=413 height=92} -- https://gitlab.winehq.org/wine/wine/-/merge_requests/8294#note_106479
@madewokherd Please see if this demo can prove it -- https://gitlab.winehq.org/wine/wine/-/merge_requests/8294#note_106801
I'd want to see a test case for behavior, not execution time, and ideally in Wine's test suite. -- https://gitlab.winehq.org/wine/wine/-/merge_requests/8294#note_106809
I don't know how to add test cases to wine to prove this behavior -- https://gitlab.winehq.org/wine/wine/-/merge_requests/8294#note_107019
Draw a 2-color bitmap to a GC on another bitmap (with something like a bilinear filter) and see if you get colors that aren't in the source? -- https://gitlab.winehq.org/wine/wine/-/merge_requests/8294#note_107164
participants (3)
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Esme Povirk (＠madewokherd) -
Wei Xie
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Wei Xie (＠wayne)