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BitBltSys
Copy a block of system memory to a location in video memory.
Declaration
void NAPI GA_2DRenderFuncs::BitBltSys(
void *srcAddr,
N_int32 srcPitch,
N_int32 srcLeft,
N_int32 srcTop,
N_int32 width,
N_int32 height,
N_int32 dstLeft,
N_int32 dstTop,
N_int32 mix,
N_int32 flipY)
Prototype In
snap/graphics.h
Parameters
srcAddr |
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 |
mix |
Mix code for the copy (GA_mixCodesType) |
flipY |
True if the image should be flipped vertically |
Description
This routine will copy a bitmap from system memory with a starting address of srcAddr to the destination rectangle (dstLeft, dstTop, dstLeft+width-1, dstTop+height-1) with the specified mix. The mix code will be used to combine the source bitmap data with the pixels in the destination bitmap.
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.
Note: This routine is provided for completeness, and for the simple case of performing a system memory to video memory copy with a mix of GA_REPLACE_MIX, it is usually always as fast or faster to copy the bitmap data directly using a CPU memory copy directly over the system bus to the linear framebuffer. However if either hardware clipping is in use, or the mix mode is something other than GA_REPLACE_MIX, this function can be more efficient than doing a software only bitmap copy.
See Also
BitBlt, BitBltSys, BitBltBM, SrcTransBlt, DstTransBlt, BitBltFx
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