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

6 files changed, 119 insertions, 0 deletions

diff --git a/src/blitter/32bpp_base.cpp b/src/blitter/32bpp_base.cpp
index adfc0fbef..f788b56a7 100644
--- a/src/blitter/32bpp_base.cpp
+++ b/src/blitter/32bpp_base.cpp
@@ -121,6 +121,58 @@ void Blitter_32bppBase::MoveBuffer(void *video_dst, const void *video_src, int w
 	}
 }
 
+void Blitter_32bppBase::ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y)
+{
+	const uint32 *src;
+	uint32 *dst;
+
+	if (scroll_y > 0) {
+		/*Calculate pointers */
+		dst = (uint32 *)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 = (uint32 *)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_32bppBase::BufferSize(int width, int height)
 {
 	return width * height * sizeof(uint32);
diff --git a/src/blitter/32bpp_base.hpp b/src/blitter/32bpp_base.hpp
index df593247c..0149330d8 100644
--- a/src/blitter/32bpp_base.hpp
+++ b/src/blitter/32bpp_base.hpp
@@ -21,6 +21,7 @@ public:
 	/* virtual */ void CopyFromBuffer(void *video, const void *src, int width, int height, int src_pitch);
 	/* virtual */ void CopyToBuffer(const void *video, void *dst, int width, int height, int dst_pitch);
 	/* virtual */ void MoveBuffer(void *video_dst, const void *video_src, int width, int height);
+	/* virtual */ void ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y);
 	/* virtual */ int BufferSize(int width, int height);
 
 	static inline uint32 LookupColourInPalette(uint8 index) {
diff --git a/src/blitter/8bpp_base.cpp b/src/blitter/8bpp_base.cpp
index 65de3b195..0a2ca6b52 100644
--- a/src/blitter/8bpp_base.cpp
+++ b/src/blitter/8bpp_base.cpp
@@ -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;
diff --git a/src/blitter/8bpp_base.hpp b/src/blitter/8bpp_base.hpp
index 3e93885c7..3b313bb30 100644
--- a/src/blitter/8bpp_base.hpp
+++ b/src/blitter/8bpp_base.hpp
@@ -21,6 +21,7 @@ public:
 	/* virtual */ void CopyFromBuffer(void *video, const void *src, int width, int height, int src_pitch);
 	/* virtual */ void CopyToBuffer(const void *video, void *dst, int width, int height, int dst_pitch);
 	/* virtual */ void MoveBuffer(void *video_dst, const void *video_src, int width, int height);
+	/* virtual */ void ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y);
 	/* virtual */ int BufferSize(int width, int height);
 };
 
diff --git a/src/blitter/base.hpp b/src/blitter/base.hpp
index 6e59f4e2e..90e1dde03 100644
--- a/src/blitter/base.hpp
+++ b/src/blitter/base.hpp
@@ -139,6 +139,18 @@ public:
 	virtual void MoveBuffer(void *video_dst, const void *video_src, int width, int height) = 0;
 
 	/**
+	 * Scroll the videobuffer some 'x' and 'y' value.
+	 * @param video The buffer to scroll into.
+	 * @param left The left value of the screen to scroll.
+	 * @param top The top value of the screen to scroll.
+	 * @param width The width of the screen to scroll.
+	 * @param height The height of the screen to scroll.
+	 * @param scroll_x How much to scroll in X.
+	 * @param scroll_y How much to scroll in Y.
+	 */
+	virtual void ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y) = 0;
+
+	/**
 	 * Calculate how much memory there is needed for an image of this size in the video-buffer.
 	 * @param width The width of the buffer-to-be.
 	 * @param height The height of the buffer-to-be.
diff --git a/src/blitter/null.hpp b/src/blitter/null.hpp
index 61c4f222d..6c519b023 100644
--- a/src/blitter/null.hpp
+++ b/src/blitter/null.hpp
@@ -22,6 +22,7 @@ public:
 	/* virtual */ void CopyFromBuffer(void *video, const void *src, int width, int height, int src_pitch) {};
 	/* virtual */ void CopyToBuffer(const void *video, void *dst, int width, int height, int dst_pitch) {};
 	/* virtual */ void MoveBuffer(void *video_dst, const void *video_src, int width, int height) {};
+	/* virtual */ void ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y) {};
 	/* virtual */ int BufferSize(int width, int height) { return 0; };
 };