wine/dlls/gdi32/bitblt.c

630 lines
20 KiB
C

/*
* GDI bit-blit operations
*
* Copyright 1993, 1994 Alexandre Julliard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include "config.h"
#include <stdarg.h>
#include <math.h>
#ifdef HAVE_FLOAT_H
#include <float.h>
#endif
#include "windef.h"
#include "winbase.h"
#include "wingdi.h"
#include "gdi_private.h"
#include "wine/debug.h"
WINE_DEFAULT_DEBUG_CHANNEL(bitblt);
/***********************************************************************
* PatBlt (GDI32.@)
*/
BOOL WINAPI PatBlt( HDC hdc, INT left, INT top,
INT width, INT height, DWORD rop)
{
DC * dc = get_dc_ptr( hdc );
BOOL bRet = FALSE;
if (!dc) return FALSE;
TRACE("%p %d,%d %dx%d %06x\n", hdc, left, top, width, height, rop );
if (dc->funcs->pPatBlt)
{
update_dc( dc );
bRet = dc->funcs->pPatBlt( dc->physDev, left, top, width, height, rop );
}
else if (dc->funcs->pStretchBlt)
{
update_dc( dc );
bRet = dc->funcs->pStretchBlt( dc->physDev, left, top, width, height, NULL, 0, 0, 0, 0, rop );
}
release_dc_ptr( dc );
return bRet;
}
/***********************************************************************
* BitBlt (GDI32.@)
*/
BOOL WINAPI BitBlt( HDC hdcDst, INT xDst, INT yDst, INT width,
INT height, HDC hdcSrc, INT xSrc, INT ySrc, DWORD rop )
{
BOOL ret = FALSE;
DC *dcDst, *dcSrc;
TRACE("hdcSrc=%p %d,%d -> hdcDest=%p %d,%d %dx%d rop=%06x\n",
hdcSrc, xSrc, ySrc, hdcDst, xDst, yDst, width, height, rop);
if (!(dcDst = get_dc_ptr( hdcDst ))) return FALSE;
if (dcDst->funcs->pBitBlt || dcDst->funcs->pStretchBlt)
{
update_dc( dcDst );
dcSrc = get_dc_ptr( hdcSrc );
if (dcSrc) update_dc( dcSrc );
if (dcDst->funcs->pBitBlt)
ret = dcDst->funcs->pBitBlt( dcDst->physDev, xDst, yDst, width, height,
dcSrc ? dcSrc->physDev : NULL, xSrc, ySrc, rop );
else
ret = dcDst->funcs->pStretchBlt( dcDst->physDev, xDst, yDst, width, height,
dcSrc ? dcSrc->physDev : NULL, xSrc, ySrc,
width, height, rop );
release_dc_ptr( dcDst );
if (dcSrc) release_dc_ptr( dcSrc );
}
else if (dcDst->funcs->pStretchDIBits)
{
BITMAP bm;
BITMAPINFOHEADER info_hdr;
HBITMAP hbm;
LPVOID bits;
INT lines;
release_dc_ptr( dcDst );
if(GetObjectType( hdcSrc ) != OBJ_MEMDC)
{
FIXME("hdcSrc isn't a memory dc. Don't yet cope with this\n");
return FALSE;
}
GetObjectW(GetCurrentObject(hdcSrc, OBJ_BITMAP), sizeof(bm), &bm);
info_hdr.biSize = sizeof(info_hdr);
info_hdr.biWidth = bm.bmWidth;
info_hdr.biHeight = bm.bmHeight;
info_hdr.biPlanes = 1;
info_hdr.biBitCount = 32;
info_hdr.biCompression = BI_RGB;
info_hdr.biSizeImage = 0;
info_hdr.biXPelsPerMeter = 0;
info_hdr.biYPelsPerMeter = 0;
info_hdr.biClrUsed = 0;
info_hdr.biClrImportant = 0;
if(!(bits = HeapAlloc(GetProcessHeap(), 0, bm.bmHeight * bm.bmWidth * 4)))
return FALSE;
/* Select out the src bitmap before calling GetDIBits */
hbm = SelectObject(hdcSrc, GetStockObject(DEFAULT_BITMAP));
GetDIBits(hdcSrc, hbm, 0, bm.bmHeight, bits, (BITMAPINFO*)&info_hdr, DIB_RGB_COLORS);
SelectObject(hdcSrc, hbm);
lines = StretchDIBits(hdcDst, xDst, yDst, width, height, xSrc, bm.bmHeight - height - ySrc,
width, height, bits, (BITMAPINFO*)&info_hdr, DIB_RGB_COLORS, rop);
HeapFree(GetProcessHeap(), 0, bits);
return (lines == height);
}
else release_dc_ptr( dcDst );
return ret;
}
/***********************************************************************
* StretchBlt (GDI32.@)
*/
BOOL WINAPI StretchBlt( HDC hdcDst, INT xDst, INT yDst,
INT widthDst, INT heightDst,
HDC hdcSrc, INT xSrc, INT ySrc,
INT widthSrc, INT heightSrc,
DWORD rop )
{
BOOL ret = FALSE;
DC *dcDst, *dcSrc;
TRACE("%p %d,%d %dx%d -> %p %d,%d %dx%d rop=%06x\n",
hdcSrc, xSrc, ySrc, widthSrc, heightSrc,
hdcDst, xDst, yDst, widthDst, heightDst, rop );
if (!(dcDst = get_dc_ptr( hdcDst ))) return FALSE;
if (dcDst->funcs->pStretchBlt)
{
if ((dcSrc = get_dc_ptr( hdcSrc )))
{
update_dc( dcDst );
update_dc( dcSrc );
ret = dcDst->funcs->pStretchBlt( dcDst->physDev, xDst, yDst, widthDst, heightDst,
dcSrc->physDev, xSrc, ySrc, widthSrc, heightSrc,
rop );
release_dc_ptr( dcDst );
release_dc_ptr( dcSrc );
}
}
else if (dcDst->funcs->pStretchDIBits)
{
BITMAP bm;
BITMAPINFOHEADER info_hdr;
HBITMAP hbm;
LPVOID bits;
INT lines;
POINT pts[2];
pts[0].x = xSrc;
pts[0].y = ySrc;
pts[1].x = xSrc + widthSrc;
pts[1].y = ySrc + heightSrc;
LPtoDP(hdcSrc, pts, 2);
xSrc = pts[0].x;
ySrc = pts[0].y;
widthSrc = pts[1].x - pts[0].x;
heightSrc = pts[1].y - pts[0].y;
release_dc_ptr( dcDst );
if(GetObjectType( hdcSrc ) != OBJ_MEMDC) return FALSE;
GetObjectW(GetCurrentObject(hdcSrc, OBJ_BITMAP), sizeof(bm), &bm);
info_hdr.biSize = sizeof(info_hdr);
info_hdr.biWidth = bm.bmWidth;
info_hdr.biHeight = bm.bmHeight;
info_hdr.biPlanes = 1;
info_hdr.biBitCount = 32;
info_hdr.biCompression = BI_RGB;
info_hdr.biSizeImage = 0;
info_hdr.biXPelsPerMeter = 0;
info_hdr.biYPelsPerMeter = 0;
info_hdr.biClrUsed = 0;
info_hdr.biClrImportant = 0;
if(!(bits = HeapAlloc(GetProcessHeap(), 0, bm.bmHeight * bm.bmWidth * 4)))
return FALSE;
/* Select out the src bitmap before calling GetDIBits */
hbm = SelectObject(hdcSrc, GetStockObject(DEFAULT_BITMAP));
GetDIBits(hdcSrc, hbm, 0, bm.bmHeight, bits, (BITMAPINFO*)&info_hdr, DIB_RGB_COLORS);
SelectObject(hdcSrc, hbm);
lines = StretchDIBits(hdcDst, xDst, yDst, widthDst, heightDst, xSrc, bm.bmHeight - heightSrc - ySrc,
widthSrc, heightSrc, bits, (BITMAPINFO*)&info_hdr, DIB_RGB_COLORS, rop);
HeapFree(GetProcessHeap(), 0, bits);
return (lines == heightSrc);
}
else release_dc_ptr( dcDst );
return ret;
}
#define FRGND_ROP3(ROP4) ((ROP4) & 0x00FFFFFF)
#define BKGND_ROP3(ROP4) (ROP3Table[((ROP4)>>24) & 0xFF])
/***********************************************************************
* MaskBlt [GDI32.@]
*/
BOOL WINAPI MaskBlt(HDC hdcDest, INT nXDest, INT nYDest,
INT nWidth, INT nHeight, HDC hdcSrc,
INT nXSrc, INT nYSrc, HBITMAP hbmMask,
INT xMask, INT yMask, DWORD dwRop)
{
HBITMAP hBitmap1, hOldBitmap1, hBitmap2, hOldBitmap2;
HDC hDC1, hDC2;
HBRUSH hbrMask, hbrDst, hbrTmp;
static const DWORD ROP3Table[256] =
{
0x00000042, 0x00010289,
0x00020C89, 0x000300AA,
0x00040C88, 0x000500A9,
0x00060865, 0x000702C5,
0x00080F08, 0x00090245,
0x000A0329, 0x000B0B2A,
0x000C0324, 0x000D0B25,
0x000E08A5, 0x000F0001,
0x00100C85, 0x001100A6,
0x00120868, 0x001302C8,
0x00140869, 0x001502C9,
0x00165CCA, 0x00171D54,
0x00180D59, 0x00191CC8,
0x001A06C5, 0x001B0768,
0x001C06CA, 0x001D0766,
0x001E01A5, 0x001F0385,
0x00200F09, 0x00210248,
0x00220326, 0x00230B24,
0x00240D55, 0x00251CC5,
0x002606C8, 0x00271868,
0x00280369, 0x002916CA,
0x002A0CC9, 0x002B1D58,
0x002C0784, 0x002D060A,
0x002E064A, 0x002F0E2A,
0x0030032A, 0x00310B28,
0x00320688, 0x00330008,
0x003406C4, 0x00351864,
0x003601A8, 0x00370388,
0x0038078A, 0x00390604,
0x003A0644, 0x003B0E24,
0x003C004A, 0x003D18A4,
0x003E1B24, 0x003F00EA,
0x00400F0A, 0x00410249,
0x00420D5D, 0x00431CC4,
0x00440328, 0x00450B29,
0x004606C6, 0x0047076A,
0x00480368, 0x004916C5,
0x004A0789, 0x004B0605,
0x004C0CC8, 0x004D1954,
0x004E0645, 0x004F0E25,
0x00500325, 0x00510B26,
0x005206C9, 0x00530764,
0x005408A9, 0x00550009,
0x005601A9, 0x00570389,
0x00580785, 0x00590609,
0x005A0049, 0x005B18A9,
0x005C0649, 0x005D0E29,
0x005E1B29, 0x005F00E9,
0x00600365, 0x006116C6,
0x00620786, 0x00630608,
0x00640788, 0x00650606,
0x00660046, 0x006718A8,
0x006858A6, 0x00690145,
0x006A01E9, 0x006B178A,
0x006C01E8, 0x006D1785,
0x006E1E28, 0x006F0C65,
0x00700CC5, 0x00711D5C,
0x00720648, 0x00730E28,
0x00740646, 0x00750E26,
0x00761B28, 0x007700E6,
0x007801E5, 0x00791786,
0x007A1E29, 0x007B0C68,
0x007C1E24, 0x007D0C69,
0x007E0955, 0x007F03C9,
0x008003E9, 0x00810975,
0x00820C49, 0x00831E04,
0x00840C48, 0x00851E05,
0x008617A6, 0x008701C5,
0x008800C6, 0x00891B08,
0x008A0E06, 0x008B0666,
0x008C0E08, 0x008D0668,
0x008E1D7C, 0x008F0CE5,
0x00900C45, 0x00911E08,
0x009217A9, 0x009301C4,
0x009417AA, 0x009501C9,
0x00960169, 0x0097588A,
0x00981888, 0x00990066,
0x009A0709, 0x009B07A8,
0x009C0704, 0x009D07A6,
0x009E16E6, 0x009F0345,
0x00A000C9, 0x00A11B05,
0x00A20E09, 0x00A30669,
0x00A41885, 0x00A50065,
0x00A60706, 0x00A707A5,
0x00A803A9, 0x00A90189,
0x00AA0029, 0x00AB0889,
0x00AC0744, 0x00AD06E9,
0x00AE0B06, 0x00AF0229,
0x00B00E05, 0x00B10665,
0x00B21974, 0x00B30CE8,
0x00B4070A, 0x00B507A9,
0x00B616E9, 0x00B70348,
0x00B8074A, 0x00B906E6,
0x00BA0B09, 0x00BB0226,
0x00BC1CE4, 0x00BD0D7D,
0x00BE0269, 0x00BF08C9,
0x00C000CA, 0x00C11B04,
0x00C21884, 0x00C3006A,
0x00C40E04, 0x00C50664,
0x00C60708, 0x00C707AA,
0x00C803A8, 0x00C90184,
0x00CA0749, 0x00CB06E4,
0x00CC0020, 0x00CD0888,
0x00CE0B08, 0x00CF0224,
0x00D00E0A, 0x00D1066A,
0x00D20705, 0x00D307A4,
0x00D41D78, 0x00D50CE9,
0x00D616EA, 0x00D70349,
0x00D80745, 0x00D906E8,
0x00DA1CE9, 0x00DB0D75,
0x00DC0B04, 0x00DD0228,
0x00DE0268, 0x00DF08C8,
0x00E003A5, 0x00E10185,
0x00E20746, 0x00E306EA,
0x00E40748, 0x00E506E5,
0x00E61CE8, 0x00E70D79,
0x00E81D74, 0x00E95CE6,
0x00EA02E9, 0x00EB0849,
0x00EC02E8, 0x00ED0848,
0x00EE0086, 0x00EF0A08,
0x00F00021, 0x00F10885,
0x00F20B05, 0x00F3022A,
0x00F40B0A, 0x00F50225,
0x00F60265, 0x00F708C5,
0x00F802E5, 0x00F90845,
0x00FA0089, 0x00FB0A09,
0x00FC008A, 0x00FD0A0A,
0x00FE02A9, 0x00FF0062,
};
if (!hbmMask)
return BitBlt(hdcDest, nXDest, nYDest, nWidth, nHeight, hdcSrc, nXSrc, nYSrc, FRGND_ROP3(dwRop));
hbrMask = CreatePatternBrush(hbmMask);
hbrDst = SelectObject(hdcDest, GetStockObject(NULL_BRUSH));
/* make bitmap */
hDC1 = CreateCompatibleDC(hdcDest);
hBitmap1 = CreateCompatibleBitmap(hdcDest, nWidth, nHeight);
hOldBitmap1 = SelectObject(hDC1, hBitmap1);
/* draw using bkgnd rop */
BitBlt(hDC1, 0, 0, nWidth, nHeight, hdcDest, nXDest, nYDest, SRCCOPY);
hbrTmp = SelectObject(hDC1, hbrDst);
BitBlt(hDC1, 0, 0, nWidth, nHeight, hdcSrc, nXSrc, nYSrc, BKGND_ROP3(dwRop));
SelectObject(hDC1, hbrTmp);
/* make bitmap */
hDC2 = CreateCompatibleDC(hdcDest);
hBitmap2 = CreateCompatibleBitmap(hdcDest, nWidth, nHeight);
hOldBitmap2 = SelectObject(hDC2, hBitmap2);
/* draw using foregnd rop */
BitBlt(hDC2, 0, 0, nWidth, nHeight, hdcDest, nXDest, nYDest, SRCCOPY);
hbrTmp = SelectObject(hDC2, hbrDst);
BitBlt(hDC2, 0, 0, nWidth, nHeight, hdcSrc, nXSrc, nYSrc, FRGND_ROP3(dwRop));
/* combine both using the mask as a pattern brush */
SelectObject(hDC2, hbrMask);
BitBlt(hDC2, 0, 0, nWidth, nHeight, hDC1, 0, 0, 0xac0744 ); /* (D & P) | (S & ~P) */
SelectObject(hDC2, hbrTmp);
/* blit to dst */
BitBlt(hdcDest, nXDest, nYDest, nWidth, nHeight, hDC2, 0, 0, SRCCOPY);
/* restore all objects */
SelectObject(hdcDest, hbrDst);
SelectObject(hDC1, hOldBitmap1);
SelectObject(hDC2, hOldBitmap2);
/* delete all temp objects */
DeleteObject(hBitmap1);
DeleteObject(hBitmap2);
DeleteObject(hbrMask);
DeleteDC(hDC1);
DeleteDC(hDC2);
return TRUE;
}
/******************************************************************************
* GdiTransparentBlt [GDI32.@]
*/
BOOL WINAPI GdiTransparentBlt( HDC hdcDest, int xDest, int yDest, int widthDest, int heightDest,
HDC hdcSrc, int xSrc, int ySrc, int widthSrc, int heightSrc,
UINT crTransparent )
{
BOOL ret = FALSE;
HDC hdcWork;
HBITMAP bmpWork;
HGDIOBJ oldWork;
HDC hdcMask = NULL;
HBITMAP bmpMask = NULL;
HBITMAP oldMask = NULL;
COLORREF oldBackground;
COLORREF oldForeground;
int oldStretchMode;
if(widthDest < 0 || heightDest < 0 || widthSrc < 0 || heightSrc < 0) {
TRACE("Cannot mirror\n");
return FALSE;
}
oldBackground = SetBkColor(hdcDest, RGB(255,255,255));
oldForeground = SetTextColor(hdcDest, RGB(0,0,0));
/* Stretch bitmap */
oldStretchMode = GetStretchBltMode(hdcSrc);
if(oldStretchMode == BLACKONWHITE || oldStretchMode == WHITEONBLACK)
SetStretchBltMode(hdcSrc, COLORONCOLOR);
hdcWork = CreateCompatibleDC(hdcDest);
bmpWork = CreateCompatibleBitmap(hdcDest, widthDest, heightDest);
oldWork = SelectObject(hdcWork, bmpWork);
if(!StretchBlt(hdcWork, 0, 0, widthDest, heightDest, hdcSrc, xSrc, ySrc, widthSrc, heightSrc, SRCCOPY)) {
TRACE("Failed to stretch\n");
goto error;
}
SetBkColor(hdcWork, crTransparent);
/* Create mask */
hdcMask = CreateCompatibleDC(hdcDest);
bmpMask = CreateCompatibleBitmap(hdcMask, widthDest, heightDest);
oldMask = SelectObject(hdcMask, bmpMask);
if(!BitBlt(hdcMask, 0, 0, widthDest, heightDest, hdcWork, 0, 0, SRCCOPY)) {
TRACE("Failed to create mask\n");
goto error;
}
/* Replace transparent color with black */
SetBkColor(hdcWork, RGB(0,0,0));
SetTextColor(hdcWork, RGB(255,255,255));
if(!BitBlt(hdcWork, 0, 0, widthDest, heightDest, hdcMask, 0, 0, SRCAND)) {
TRACE("Failed to mask out background\n");
goto error;
}
/* Replace non-transparent area on destination with black */
if(!BitBlt(hdcDest, xDest, yDest, widthDest, heightDest, hdcMask, 0, 0, SRCAND)) {
TRACE("Failed to clear destination area\n");
goto error;
}
/* Draw the image */
if(!BitBlt(hdcDest, xDest, yDest, widthDest, heightDest, hdcWork, 0, 0, SRCPAINT)) {
TRACE("Failed to paint image\n");
goto error;
}
ret = TRUE;
error:
SetStretchBltMode(hdcSrc, oldStretchMode);
SetBkColor(hdcDest, oldBackground);
SetTextColor(hdcDest, oldForeground);
if(hdcWork) {
SelectObject(hdcWork, oldWork);
DeleteDC(hdcWork);
}
if(bmpWork) DeleteObject(bmpWork);
if(hdcMask) {
SelectObject(hdcMask, oldMask);
DeleteDC(hdcMask);
}
if(bmpMask) DeleteObject(bmpMask);
return ret;
}
/******************************************************************************
* GdiAlphaBlend [GDI32.@]
*/
BOOL WINAPI GdiAlphaBlend(HDC hdcDst, int xDst, int yDst, int widthDst, int heightDst,
HDC hdcSrc, int xSrc, int ySrc, int widthSrc, int heightSrc,
BLENDFUNCTION blendFunction)
{
BOOL ret = FALSE;
DC *dcDst, *dcSrc;
dcSrc = get_dc_ptr( hdcSrc );
if (!dcSrc) return FALSE;
if ((dcDst = get_dc_ptr( hdcDst )))
{
update_dc( dcSrc );
update_dc( dcDst );
TRACE("%p %d,%d %dx%d -> %p %d,%d %dx%d op=%02x flags=%02x srcconstalpha=%02x alphafmt=%02x\n",
hdcSrc, xSrc, ySrc, widthSrc, heightSrc,
hdcDst, xDst, yDst, widthDst, heightDst,
blendFunction.BlendOp, blendFunction.BlendFlags,
blendFunction.SourceConstantAlpha, blendFunction.AlphaFormat);
if (dcDst->funcs->pAlphaBlend)
ret = dcDst->funcs->pAlphaBlend( dcDst->physDev, xDst, yDst, widthDst, heightDst,
dcSrc->physDev, xSrc, ySrc, widthSrc, heightSrc,
blendFunction );
release_dc_ptr( dcDst );
}
release_dc_ptr( dcSrc );
return ret;
}
/*********************************************************************
* PlgBlt [GDI32.@]
*
*/
BOOL WINAPI PlgBlt( HDC hdcDest, const POINT *lpPoint,
HDC hdcSrc, INT nXSrc, INT nYSrc, INT nWidth,
INT nHeight, HBITMAP hbmMask, INT xMask, INT yMask)
{
int oldgMode;
/* parallelogram coords */
POINT plg[3];
/* rect coords */
POINT rect[3];
XFORM xf;
XFORM SrcXf;
XFORM oldDestXf;
double det;
/* save actual mode, set GM_ADVANCED */
oldgMode = SetGraphicsMode(hdcDest,GM_ADVANCED);
if (oldgMode == 0)
return FALSE;
memcpy(plg,lpPoint,sizeof(POINT)*3);
rect[0].x = nXSrc;
rect[0].y = nYSrc;
rect[1].x = nXSrc + nWidth;
rect[1].y = nYSrc;
rect[2].x = nXSrc;
rect[2].y = nYSrc + nHeight;
/* calc XFORM matrix to transform hdcDest -> hdcSrc (parallelogram to rectangle) */
/* determinant */
det = rect[1].x*(rect[2].y - rect[0].y) - rect[2].x*(rect[1].y - rect[0].y) - rect[0].x*(rect[2].y - rect[1].y);
if (fabs(det) < 1e-5)
{
SetGraphicsMode(hdcDest,oldgMode);
return FALSE;
}
TRACE("hdcSrc=%p %d,%d,%dx%d -> hdcDest=%p %d,%d,%d,%d,%d,%d\n",
hdcSrc, nXSrc, nYSrc, nWidth, nHeight, hdcDest, plg[0].x, plg[0].y, plg[1].x, plg[1].y, plg[2].x, plg[2].y);
/* X components */
xf.eM11 = (plg[1].x*(rect[2].y - rect[0].y) - plg[2].x*(rect[1].y - rect[0].y) - plg[0].x*(rect[2].y - rect[1].y)) / det;
xf.eM21 = (rect[1].x*(plg[2].x - plg[0].x) - rect[2].x*(plg[1].x - plg[0].x) - rect[0].x*(plg[2].x - plg[1].x)) / det;
xf.eDx = (rect[0].x*(rect[1].y*plg[2].x - rect[2].y*plg[1].x) -
rect[1].x*(rect[0].y*plg[2].x - rect[2].y*plg[0].x) +
rect[2].x*(rect[0].y*plg[1].x - rect[1].y*plg[0].x)
) / det;
/* Y components */
xf.eM12 = (plg[1].y*(rect[2].y - rect[0].y) - plg[2].y*(rect[1].y - rect[0].y) - plg[0].y*(rect[2].y - rect[1].y)) / det;
xf.eM22 = (plg[1].x*(rect[2].y - rect[0].y) - plg[2].x*(rect[1].y - rect[0].y) - plg[0].x*(rect[2].y - rect[1].y)) / det;
xf.eDy = (rect[0].x*(rect[1].y*plg[2].y - rect[2].y*plg[1].y) -
rect[1].x*(rect[0].y*plg[2].y - rect[2].y*plg[0].y) +
rect[2].x*(rect[0].y*plg[1].y - rect[1].y*plg[0].y)
) / det;
GetWorldTransform(hdcSrc,&SrcXf);
CombineTransform(&xf,&xf,&SrcXf);
/* save actual dest transform */
GetWorldTransform(hdcDest,&oldDestXf);
SetWorldTransform(hdcDest,&xf);
/* now destination and source DCs use same coords */
MaskBlt(hdcDest,nXSrc,nYSrc,nWidth,nHeight,
hdcSrc, nXSrc,nYSrc,
hbmMask,xMask,yMask,
SRCCOPY);
/* restore dest DC */
SetWorldTransform(hdcDest,&oldDestXf);
SetGraphicsMode(hdcDest,oldgMode);
return TRUE;
}