Using CopyRects in C#

[Devoid]

Has anybody out there used the CopyRects in C# successfully?

Basically I have a bitmap that I have loaded onto a surface that contains about a dozen tiles, all 32 x 32 pixels. I then try to render the scene by looping through my map array (20 tiles by 15 tiles )which contains the numbers 1 through 12 to represent the tile at the location.

What I want to do, find the tile number (lets say 3) which will start (3 * 32 ) pixels into the tile bitmap for a length and height of 32 pixels. I want to copy that rectangle to the appropriate place on back buffer.

The C++ code that I am trying to convert looks like this:

RECT SrcTileRect;
POINT DstPoint;
SrcTileRect.left = TileNumber2SourceX(TileNumber, numTileCols, tileSize);
SrcTileRect.right = SrcTileRect.left + tileSize;
SrcTileRect.top = TileNumber2SourceY(TileNumber,
numTileCols, tileSize);
SrcTileRect.bottom = SrcTileRect.top + tileSize;
DstPoint.x = Column2X(DstCol, tileSize, numMapCols) + xOffset;
DstPoint.y = Row2Y(DstRow, tileSize) + yOffset;
HRESULT hResult = m_Direct3D.GetDevice()->
CopyRects(pTileSurface, &SrcTileRect,
1, pBackBuffer, &DstPoint);
return hResult;

My converted C# codes is as follows:

DxVBLibA.RECT srcTileRect = new DxVBLibA.RECT();
DxVBLibA.POINT dstPoint = new DxVBLibA.POINT();

srcTileRect.left = this.TileNumber2SourceX( tileNumber, numTileCols, tileSize );
srcTileRect.right = srcTileRect.left + tileSize;
srcTileRect.top = this.TileNumber2SourceY( tileNumber, numTileCols, tileSize );
srcTileRect.bottom = srcTileRect.top + tileSize;

dstPoint.x = this.Column2X( dstCol, tileSize, numMapCols ) + xOffset;
dstPoint.y = this.Row2Y( dstRow, tileSize ) + yOffset;

this.OurDirect3D.DeviceD3D.CopyRects( tileSurface, &srcTileRect,	1, backBuf, &dstPoint );

I have everything converted fine up until the copyrects line and am having problems with the &SrcTileRect and &DstPoint parameters. Error is cannot convert from DxVBLibA.RECT* to System.IntPtr.

Anybody have an example of something similiar? I have used the copyrects before when I wanted to copy the entire source to the desintation (the source tile rectangle and point are both passed as null).

Cheers,
Devoid

 

[Divil]

You could try the StructureToPtr method of the Marshal class, if you have no control over the declare of the CopyRects method.

 

[Nerseus]

You can try the following. If you want to use StructureToPtr, youll have to allocate the memory for the IntPtr first.

GCHandle hSrc = GCHandle.Alloc(srcTileRect, GCHandleType.Pinned);

GCHandle hDest = GCHandle.Alloc(dstPoint, GCHandleType.Pinned);

this.OurDirect3D.DeviceD3D.CopyRects(tileSurface, hSrc.AddrOfPinnedObject(), 1, backBuf, hDest.AddrOfPinnedObject());

hSrc.Free();

hDest.Free();

-ner