Posted for posterity and for archival searches.
I was looking for a working solution to get a bitmap Ptr of the screen (both
pre/post 3.5 routines). After much silence and a few wrong answers (or not
complete/legal/buildable examples), I had placed this on the back burner for
now. I had completed that part of my application using only 3.5 or better
routines.
The Signature ++ example does NOT build in the current SDK and that's the
reason most folks are scrathing thier heads.
I found buildable source (and source that made sense to me) in the Beamer
sample application. It is posted here for completeness.
/***********************************************************************
*
* FUNCTION: PrvGetBitmap
*
* DESCRIPTION: This routine creates a bitmap copy of the bits in the window
passed
* This is for compatability with pre version 3.5 roms as
well as 3.5 roms
*
* PARAMETERS: winH window handle to create bitmap from
* (output bitmap will have same dimensions as
this window)
* sizeP pointer to the size of the created bitmap
* errorP pointer to any error encountered by this
function
*
* RETURNED: Handle to the new bitmap
*
*
***********************************************************************/
static BitmapPtr PrvGetBitmap (WinHandle winH, UInt32 *sizeP, Err *errorP)
{
UInt16 width, height;
UInt16 rowBytes;
BitmapPtr bitmapP;
UInt8 depth;
WindowType *winP;
*errorP = 0;
*sizeP = 0;
// can we use the new window functions?
if (newAPI)
{
BitmapPtr winBmpP = WinGetBitmap(WinGetDrawWindow());
ColorTableType *clrTableP = BmpGetColortable(winBmpP);
UInt8 depth = winBmpP->pixelSize;
WinHandle winH;
// we create a bitmap and then make a window to it so that we can
// create a bitmap whose depth does not match that of the screen
bitmapP = BmpCreate(drawArea.extent.x, drawArea.extent.y, depth,
clrTableP, errorP);
if (!*errorP)
{
winH = WinCreateBitmapWindow(bitmapP,errorP);
}
if (!*errorP)
{
// copy draw area into the bitmap
WinCopyRectangle (WinGetDrawWindow(), winH, &drawArea, 0, 0,
winPaint);
WinDeleteWindow(winH,false);
// compress the bitmap
*errorP = BmpCompress(bitmapP,BitmapCompressionTypeScanLine);
// get the size of the bitmap
*sizeP = BmpSize(bitmapP);
}
}
else
{
winP = WinGetWindowHandle(winH);
width = winP->windowBounds.extent.x;
height = winP->windowBounds.extent.y;
depth = 1; // assume one pixel depth
if ((width == 0) || (height == 0))
{ *errorP = memErrNotEnoughSpace;
return NULL;
}
// Create a display buffer for the window. Round the line width
// up to an even word boundary.
rowBytes = ((((width*depth)+15) >> 4) << 1);
*sizeP = (rowBytes * height) + sizeof(BitmapType);
// note that we do NOT output a color map here...
bitmapP = (BitmapPtr) MemPtrNew(*sizeP);
if (! bitmapP)
{ *errorP = memErrNotEnoughSpace;
return NULL;
}
MemSet(bitmapP,*sizeP,0); // erase it ...
bitmapP->width = width;
bitmapP->height = height;
bitmapP->rowBytes = rowBytes;
bitmapP->pixelSize = depth;
bitmapP->version = 1;
// copy the bitmap contents from the offscreen window
// The only way to do this on older ROMS is to acesss the obsolete
v20 field.
MemMove(bitmapP+1,winP->displayAddrV20, rowBytes * height);
}
return (bitmapP);
}
--
Matt Disher
[EMAIL PROTECTED]
--
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