ReceiveTempSMS
/
Sweden-Number
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

winex11: Ignore the alpha if all pixels are 0.

This commit is contained in:
Stefan Dösinger 2007-12-13 12:12:23 +01:00 committed by Alexandre Julliard
parent e8f69b5a42
commit 7f97af2e2e
1 changed files with 33 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
dlls/winex11.drv/mouse.c
View File

@ -409,6 +409,7 @@ static XcursorImage *create_cursor_image( CURSORICONINFO *ptr )
int and_width_bytes, xor_width_bytes;
XcursorPixel *pixel_ptr;
XcursorImage *image;
BOOL alpha_zero = TRUE;
ymax = (ptr->nHeight > 32) ? 32 : ptr->nHeight;
xmax = (ptr->nWidth > 32) ? 32 : ptr->nWidth;
@ -425,6 +426,37 @@ static XcursorImage *create_cursor_image( CURSORICONINFO *ptr )
image = pXcursorImageCreate( xmax, ymax );
pixel_ptr = image->pixels;
/* Generally 32 bit bitmaps have an alpha channel which is used in favor
* of the AND mask. However, if all pixels have alpha = 0x00, the bitmap
* is treated like one without alpha and the masks are used. As soon as
* one pixel has alpha != 0x00, and the mask ignored as described in the
* docs.
*
* This is most likely for applications which create the bitmaps with
* CreateDIBitmap, which creates a device dependent bitmap, so the format
* that arrives when loading depends on the screen's bpp. Apps that were
* written at 8 / 16 bpp times do not know about the 32 bit alpha, so
* they would get a completely transparent cursor on 32 bit displays.
*
* Non-32 bit bitmaps always use the AND mask
*/
if(ptr->bBitsPerPixel == 32)
{
for (y = 0; alpha_zero && y < ymax; ++y)
{
xor_ptr = xor_bits + (y * xor_width_bytes);
for (x = 0; x < xmax; ++x)
{
if (xor_ptr[3] != 0x00)
{
alpha_zero = FALSE;
break;
}
xor_ptr+=4;
}
}
}
/* On windows, to calculate the color for a pixel, first an AND is done
* with the background and the "and" bitmap, then an XOR with the "xor"
* bitmap. This means that when the data in the "and" bitmap is 0, the
@ -484,7 +516,7 @@ static XcursorImage *create_cursor_image( CURSORICONINFO *ptr )
return 0;
}
if (ptr->bBitsPerPixel != 32)
if (alpha_zero)
{
/* Alpha channel */
if (~*and_ptr & (1 << (7 - (x & 7)))) *pixel_ptr |= 0xff << 24;