void EraseRectAndAlpha(GWorldPtr gWorld, Rect *pRect)
{
PixMapHandle pixMap = GetGWorldPixMap(gWorld);
long rows;
Ptr rowBaseAddr;
LockPixels(pixMap);
rows = pRect->bottom - pRect->top;
rowBaseAddr = GetPixBaseAddr(pixMap) + (GetPixRowBytes(pixMap) & 0x3fff) * pRect->top + pRect->left * GetPixDepth(pixMap) / 8;
do
{
long cols;
UInt32 *baseAddr;
cols = pRect->right - pRect->left;
baseAddr = (UInt32*)rowBaseAddr;
rowBaseAddr += (**pixMap).rowBytes & 0x3fff;
do
{
*baseAddr++ = 0;
} while (--cols);
} while (--rows);
UnlockPixels(pixMap);
} // EraseRectAndAlpha
//------------------------------------------------------------------------
int pixel_map::row_bytes() const
{
if(m_pmap == nil) return 0;
PixMapHandle pm = GetGWorldPixMap (m_pmap);
return calc_row_len(width(), GetPixDepth(pm));
}
