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(svn r10206) -Codechange: more moving things to blitter-layer: ScrollBuffer

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truelight
2007-06-18 20:08:21 +00:00
parent 49220cc6f1
commit 26e9b5ca5f
7 changed files with 120 additions and 47 deletions
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52
src/blitter/8bpp_base.cpp
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@@ -126,6 +126,58 @@ void Blitter_8bppBase::MoveBuffer(void *video_dst, const void *video_src, int wi
}
}
void Blitter_8bppBase::ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y)
{
const uint8 *src;
uint8 *dst;
if (scroll_y > 0) {
/*Calculate pointers */
dst = (uint8 *)video + left + (top + height - 1) * _screen.pitch;
src = dst - scroll_y * _screen.pitch;
/* Decrease height and increase top */
top += scroll_y;
height -= scroll_y;
assert(height > 0);
/* Adjust left & width */
if (scroll_x >= 0) {
dst += scroll_x;
left += scroll_x;
width -= scroll_x;
} else {
src -= scroll_x;
width += scroll_x;
}
/* Negative height as we want to copy from bottom to top */
this->CopyFromBuffer(dst, src, width, -height, _screen.pitch);
} else {
/* Calculate pointers */
dst = (uint8 *)video + left + top * _screen.pitch;
src = dst - scroll_y * _screen.pitch;
/* Decrese height. (scroll_y is <=0). */
height += scroll_y;
assert(height > 0);
/* Adjust left & width */
if (scroll_x >= 0) {
dst += scroll_x;
left += scroll_x;
width -= scroll_x;
} else {
src -= scroll_x;
width += scroll_x;
}
/* the y-displacement may be 0 therefore we have to use memmove,
* because source and destination may overlap */
this->MoveBuffer(dst, src, width, height);
}
}
int Blitter_8bppBase::BufferSize(int width, int height)
{
return width * height;