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BitBltPlaneMaskedSys

Copy a block of system memory to a location in video memory with an associated bit plane mask

Declaration

void NAPI GA_2DRenderFuncs::BitBltPlaneMaskedSys(
    void *srcAddr,
    N_int32 srcPitch,
    N_int32 srcLeft,
    N_int32 srcTop,
    N_int32 width,
    N_int32 height,
    N_int32 dstLeft,
    N_int32 dstTop,
    N_uint32 planeMask,
    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

planeMask

Plane mask to use during the copy

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 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.

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, BitBltPlaneMasked, BitBltPlaneMaskedLin, BitBltPlaneMaskedBM

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