[PATCH 0/2] MR10094: gdi32/tests: Add tests for GdiTransparentBlt() with 32-bit DIB bitmaps.

[Zhiyi Zhang (＠zhiyi)]

Test that the alpha channels in 32-bit DIB bitmaps are ignored in GdiTransparentBlt(). Also add
tests to show that the alpha channels are not ignored when converting 32-bit DIB bitmaps to mono
bitmaps. This suggests that the alpha channels are ignored in GdiTransparentBlt(), not when
generating the mono mask bitmap.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10094

[PATCH 1/2] gdi32/tests: Add tests for GdiTransparentBlt() with 32-bit DIB bitmaps.

[Zhiyi Zhang]

From: Zhiyi Zhang <[e-mail]>

Test that the alpha channels in 32-bit DIB bitmaps are ignored in GdiTransparentBlt(). Also add
tests to show that the alpha channels are not ignored when converting 32-bit DIB bitmaps to mono
bitmaps. This suggests that the alpha channels are ignored in GdiTransparentBlt(), not when
generating the mono mask bitmap.
---
 dlls/gdi32/tests/bitmap.c | 73 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/dlls/gdi32/tests/bitmap.c b/dlls/gdi32/tests/bitmap.c
index 773e0fad5ee..0d381541443 100644
--- a/dlls/gdi32/tests/bitmap.c
+++ b/dlls/gdi32/tests/bitmap.c
@@ -3125,6 +3125,7 @@ static void test_StretchBlt(void)
     BITMAPINFO biDst, biSrc;
     UINT32 expected[256];
     RGBQUAD colors[2];
+    COLORREF color;
 
     memset(&biDst, 0, sizeof(BITMAPINFO));
     biDst.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
@@ -3434,6 +3435,34 @@ static void test_StretchBlt(void)
     DeleteObject(bmpDst);
     DeleteDC(hdcDst);
 
+    /* Test blitting from 32-bit bitmap to a mono bitmap when the 32-bit bitmap has 0xffffff as the
+     * background color and the pixel data is 0xffffffff. This shows that the raw pixel value is
+     * compared with the background color when calculating the destination mono bitmap pixel value */
+    hdcDst = CreateCompatibleDC( hdcScreen );
+    bmpDst = CreateBitmap( 1, 1, 1, 1, 0 );
+    oldDst = SelectObject( hdcDst, bmpDst );
+    hdcSrc = CreateCompatibleDC( hdcDst );
+    biSrc.bmiHeader.biWidth = 1;
+    biSrc.bmiHeader.biHeight = 1;
+    biSrc.bmiHeader.biBitCount = 32;
+    bmpSrc = CreateDIBSection( hdcSrc, &biSrc, DIB_RGB_COLORS, (void **)&srcBuffer, NULL, 0 );
+    oldSrc = SelectObject( hdcSrc, bmpSrc );
+
+    srcBuffer[0] = 0xfffffff;
+    SetBkColor( hdcSrc, RGB(0xff, 0xff, 0xff) );
+    StretchBlt( hdcDst, 0, 0, 1, 1, hdcSrc, 0, 0, 1, 1, SRCCOPY );
+    SetBkColor( hdcSrc, RGB(0xff, 0x0, 0x0) );
+    StretchBlt( hdcSrc, 0, 0, 1, 1, hdcDst, 0, 0, 1, 1, SRCCOPY );
+    color = GetPixel( hdcSrc, 0, 0 );
+    ok( color == 0, "Got unexpected color %#lx\n", color );
+
+    SelectObject( hdcSrc, oldSrc );
+    SelectObject( hdcDst, oldDst );
+    DeleteObject( bmpSrc );
+    DeleteObject( bmpDst );
+    DeleteDC( hdcDst );
+    DeleteDC( hdcSrc );
+
     DeleteDC(hdcScreen);
 }
 
@@ -6314,6 +6343,49 @@ todo_wine_if (y == 25 || x == 40)
     DeleteDC( dc );
 }
 
+static void test_GdiTransparentBlt(void)
+{
+    HBITMAP bmp_dst, bmp_src, old_dst, old_src;
+    HDC hdc_screen, hdc_dst, hdc_src;
+    UINT32 *dst_buffer, *src_buffer;
+    BITMAPINFO bmi;
+    BOOL ret;
+
+    hdc_screen = CreateCompatibleDC( 0 );
+    hdc_dst = CreateCompatibleDC( hdc_screen );
+    hdc_src = CreateCompatibleDC( hdc_dst );
+
+    memset( &bmi, 0, sizeof(BITMAPINFO) );
+    bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
+    bmi.bmiHeader.biWidth = 1;
+    bmi.bmiHeader.biHeight = 1;
+    bmi.bmiHeader.biPlanes = 1;
+    bmi.bmiHeader.biBitCount = 32;
+    bmi.bmiHeader.biCompression = BI_RGB;
+
+    /* Test when the source pixel is 0xffffffff and the transparent color is 0xffffff. The alpha
+     * channel of the source pixel should be ignored for DIB bitmaps */
+    bmp_dst = CreateDIBSection( hdc_screen, &bmi, DIB_RGB_COLORS, (void **)&dst_buffer, NULL, 0 );
+    old_dst = SelectObject( hdc_dst, bmp_dst );
+    bmp_src = CreateDIBSection( hdc_screen, &bmi, DIB_RGB_COLORS, (void **)&src_buffer, NULL, 0 );
+    old_src = SelectObject( hdc_src, bmp_src );
+
+    dst_buffer[0] = 0x00123456;
+    src_buffer[0] = 0xffffffff;
+    ret = GdiTransparentBlt( hdc_dst, 0, 0, 1, 1, hdc_src, 0, 0, 1, 1, RGB(0xff, 0xff, 0xff) );
+    ok( ret, "GdiTransparentBlt failed, error %lu.\n", GetLastError() );
+    todo_wine
+    ok( dst_buffer[0] == 0x123456, "Got unexpected color %#x.\n", dst_buffer[0] );
+
+    SelectObject( hdc_src, old_src );
+    SelectObject( hdc_dst, old_dst );
+    DeleteObject( bmp_src );
+    DeleteObject( bmp_dst );
+    DeleteDC( hdc_src );
+    DeleteDC( hdc_dst );
+    DeleteDC( hdc_screen );
+}
+
 START_TEST(bitmap)
 {
     HMODULE hdll;
@@ -6342,6 +6414,7 @@ START_TEST(bitmap)
     test_CreateBitmap();
     test_BitBlt();
     test_StretchBlt();
+    test_GdiTransparentBlt();
     test_StretchDIBits();
     test_GdiAlphaBlend();
     test_GdiGradientFill();
-- 
GitLab


https://gitlab.winehq.org/wine/wine/-/merge_requests/10094

[PATCH 2/2] win32: Ignore alpha channels for 32-bit DIB bitmaps.

[Zhiyi Zhang]

From: Zhiyi Zhang <[e-mail]>

---
 dlls/gdi32/tests/bitmap.c | 1 -
 dlls/win32u/bitblt.c      | 8 ++------
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/dlls/gdi32/tests/bitmap.c b/dlls/gdi32/tests/bitmap.c
index 0d381541443..d4d04b26927 100644
--- a/dlls/gdi32/tests/bitmap.c
+++ b/dlls/gdi32/tests/bitmap.c
@@ -6374,7 +6374,6 @@ static void test_GdiTransparentBlt(void)
     src_buffer[0] = 0xffffffff;
     ret = GdiTransparentBlt( hdc_dst, 0, 0, 1, 1, hdc_src, 0, 0, 1, 1, RGB(0xff, 0xff, 0xff) );
     ok( ret, "GdiTransparentBlt failed, error %lu.\n", GetLastError() );
-    todo_wine
     ok( dst_buffer[0] == 0x123456, "Got unexpected color %#x.\n", dst_buffer[0] );
 
     SelectObject( hdc_src, old_src );
diff --git a/dlls/win32u/bitblt.c b/dlls/win32u/bitblt.c
index 7721d3b4b73..c6021dde98f 100644
--- a/dlls/win32u/bitblt.c
+++ b/dlls/win32u/bitblt.c
@@ -855,7 +855,6 @@ BOOL WINAPI NtGdiTransparentBlt( HDC hdcDest, int xDest, int yDest, int widthDes
     COLORREF oldBackground;
     COLORREF oldForeground;
     int oldStretchMode;
-    DIBSECTION dib;
     DC *dc_src;
     DC *dc_work;
 
@@ -874,12 +873,9 @@ BOOL WINAPI NtGdiTransparentBlt( HDC hdcDest, int xDest, int yDest, int widthDes
     if (oldStretchMode == BLACKONWHITE || oldStretchMode == WHITEONBLACK)
         dc_src->attr->stretch_blt_mode = COLORONCOLOR;
     hdcWork = NtGdiCreateCompatibleDC( hdcDest );
-    if ((get_gdi_object_type( hdcDest ) != NTGDI_OBJ_MEMDC ||
-         NtGdiExtGetObjectW( NtGdiGetDCObject( hdcDest, NTGDI_OBJ_SURF ),
-                             sizeof(dib), &dib ) == sizeof(BITMAP)) &&
-        NtGdiGetDeviceCaps( hdcDest, BITSPIXEL ) == 32)
+    if (NtGdiGetDeviceCaps( hdcDest, BITSPIXEL ) == 32)
     {
-        /* screen DCs or DDBs are not supposed to have an alpha channel, so use a 24-bpp bitmap as copy */
+        /* the alpha channel should be ignored. use a 24-bpp bitmap as copy */
         BITMAPINFO info;
         info.bmiHeader.biSize = sizeof(info.bmiHeader);
         info.bmiHeader.biWidth = widthDest;
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10094