comctl32/imagelist: Generate the mask from the alpha channel if present.

This commit is contained in:
Alexandre Julliard 2010-05-16 12:48:08 +02:00
parent f2b993d414
commit 45fd49bab6
1 changed files with 27 additions and 10 deletions

View File

@ -145,15 +145,18 @@ static BOOL add_with_alpha( HIMAGELIST himl, HDC hdc, int pos, int count,
BOOL ret = FALSE;
HDC hdcMask = 0;
BITMAP bm;
BITMAPINFO *info;
BITMAPINFO *info, *mask_info = NULL;
DWORD *bits = NULL;
BYTE *mask_bits = NULL;
int i, j, n;
POINT pt;
DWORD mask_width;
if (himl->uBitsPixel != 32) return FALSE;
if (!GetObjectW( hbmImage, sizeof(bm), &bm )) return FALSE;
/* if neither the imagelist nor the source bitmap can have an alpha channel, bail out now */
if (himl->uBitsPixel != 32 && bm.bmBitsPixel != 32) return FALSE;
SelectObject( hdc, hbmImage );
mask_width = (bm.bmWidth + 31) / 32 * 4;
@ -174,13 +177,13 @@ static BOOL add_with_alpha( HIMAGELIST himl, HDC hdc, int pos, int count,
if (hbmMask)
{
info->bmiHeader.biBitCount = 1;
info->bmiHeader.biSizeImage = mask_width * height;
if (!(mask_info = HeapAlloc( GetProcessHeap(), 0, FIELD_OFFSET( BITMAPINFO, bmiColors[2] ))))
goto done;
mask_info->bmiHeader = info->bmiHeader;
mask_info->bmiHeader.biBitCount = 1;
mask_info->bmiHeader.biSizeImage = mask_width * height;
if (!(mask_bits = HeapAlloc( GetProcessHeap(), 0, info->bmiHeader.biSizeImage ))) goto done;
if (!GetDIBits( hdc, hbmMask, 0, height, mask_bits, info, DIB_RGB_COLORS )) goto done;
/* restore values for color info */
info->bmiHeader.biBitCount = 32;
info->bmiHeader.biSizeImage = bm.bmWidth * height * 4;
if (!GetDIBits( hdc, hbmMask, 0, height, mask_bits, mask_info, DIB_RGB_COLORS )) goto done;
hdcMask = CreateCompatibleDC( 0 );
SelectObject( hdcMask, hbmMask );
}
@ -202,6 +205,8 @@ static BOOL add_with_alpha( HIMAGELIST himl, HDC hdc, int pos, int count,
for (j = n * width; j < (n + 1) * width; j++)
if (!mask_bits || !((mask_bits[i * mask_width + j / 8] << (j % 8)) & 0x80))
bits[i * bm.bmWidth + j] |= 0xff000000;
if (hdcMask) StretchBlt( himl->hdcMask, pt.x, pt.y, himl->cx, himl->cy,
hdcMask, n * width, 0, width, height, SRCCOPY );
}
else
{
@ -209,6 +214,7 @@ static BOOL add_with_alpha( HIMAGELIST himl, HDC hdc, int pos, int count,
/* pre-multiply by the alpha channel */
for (i = 0; i < height; i++)
{
for (j = n * width; j < (n + 1) * width; j++)
{
DWORD argb = bits[i * bm.bmWidth + j];
@ -219,11 +225,22 @@ static BOOL add_with_alpha( HIMAGELIST himl, HDC hdc, int pos, int count,
(((argb & 0x000000ff) * alpha / 255)));
}
}
if (mask_info && himl->hbmMask) /* generate the mask from the alpha channel */
{
for (i = 0; i < height; i++)
for (j = n * width; j < (n + 1) * width; j++)
if ((bits[i * bm.bmWidth + j] >> 24) > 25) /* more than 10% alpha */
mask_bits[i * mask_width + j / 8] &= ~(0x80 >> (j % 8));
else
mask_bits[i * mask_width + j / 8] |= 0x80 >> (j % 8);
StretchDIBits( himl->hdcMask, pt.x, pt.y, himl->cx, himl->cy,
n * width, 0, width, height, mask_bits, mask_info, DIB_RGB_COLORS, SRCCOPY );
}
}
StretchDIBits( himl->hdcImage, pt.x, pt.y, himl->cx, himl->cy,
n * width, 0, width, height, bits, info, DIB_RGB_COLORS, SRCCOPY );
if (hdcMask) StretchBlt( himl->hdcMask, pt.x, pt.y, himl->cx, himl->cy,
hdcMask, n * width, 0, width, height, SRCCOPY );
}
ret = TRUE;