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BitBltPlaneMaskedBM
Copy a block of system memory to a location in video memory with Bus Mastering using an associated bit plane mask
Declaration
void NAPI GA_2DRenderFuncs::BitBltPlaneMaskedBM(
void *srcAddr,
N_int32 srcPhysAddr,
N_int32 srcPitch,
N_int32 srcLeft,
N_int32 srcTop,
N_int32 width,
N_int32 height,
N_int32 dstLeft,
N_int32 dstTop,
N_uint32 planeMask)
Prototype In
snap/graphics.h
Parameters
srcAddr |
Address of source bitmap in system memory |
srcPhysAddr |
Physical address of source bitmap in system memory |
srcPitch |
Pitch of source bitmap in bytes |
srcLeft |
Left coordinate within source bitmap to copy |
srcTop |
Top coordinate within source bitmap to copy |
width |
Width of the rectangle in pixels |
height |
Height of the rectangle in scanlines |
dstLeft |
Left coordinate of destination |
dstTop |
Top coordinate of destination |
planeMask |
Plane mask to use during the copy |
Description
This routine will copy a bitmap from system memory with a physical starting address of srcPhysAddr to the destination rectangle (dstLeft, dstTop, dstLeft+width-1, dstTop+height-1) with the specified plane mask. The plane mask is used to determine which bits in the destination pixels will be affected by the copy. Each bit in the plane mask is used to mask out a bit in the destination pixel values, and where a bit is a 1 the destination bit comes from the source pixel while where a bit is 0 the destination bit is left unchanged.
This version is different to the BitBltSys function in that the bitmap data is copied using Bus Mastering by the graphics accelerator, which allows this function to return before the copy has completed and the accelerator will complete the copy in the background with a DMA Bus Master operation. If this hardware supports Bus Mastering and this function is available, it will usually be the fastest method to copy a block of system memory to video memory.
Note that the srcLeft and srcTop coordinates define an offset within the source bitmap to be copied, so it will copy only a portion of the memory bitmap.
See Also
BitBlt, BitBltPlaneMasked, BitBltPlaneMaskedLin, BitBltPlaneMaskedSys
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