cpp/openttd-patchpack/source Changeset - r375:03e218deba16

Changeset - r375:03e218deba16

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tron - 20 years ago 2004-11-13 16:10:25
tron@openttd.org

(svn r564) Simplify scroll logic and correct one erroneous use of memcpy()

1 file changed with 15 insertions and 26 deletions:

gfx.c

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gfx.c

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@@ @@ -44,9 +44,9 @@ void GfxScroll(int left, int top, int wi @@
 	p = _screen.pitch;
-	if (yo > 0 || (yo == 0 && xo > 0)) {
 	if (yo > 0) {
 		// Calculate pointers
-		dst = _screen.dst_ptr + (top+height-1) * p + (left+width-1);
+		dst = _screen.dst_ptr + (top + height - 1) * p + left;
 		src = dst - yo * p;
 		// Decrease height and increase top
@@ @@ -56,31 +56,21 @@ void GfxScroll(int left, int top, int wi @@
 		// Adjust left & width
 		if (xo >= 0) {
 			dst += xo;
 			left += xo;
 			src -= xo;
 			width -= xo;
 		} else {
-			dst += xo;
+			src -= xo;
 			width += xo;
+		}
 		// Offset pointers to fit into the memmove call
 		dst += -width + 1;
 		src += -width + 1;
 		ht = height;
 		do {
 			memmove(dst, src, width);
 		for (ht = height; ht > 0; --ht) {
 			memcpy(dst, src, width);
 			src -= p;
 			dst -= p;
 		} while (--ht);
 		// This part of the screen is now dirty.
 		_video_driver->make_dirty(left, top, width, height);
+		}
 	} else {
-		// Calculate pointers to mem.
 		// Calculate pointers
 		dst = _screen.dst_ptr + top * p + left;
 		src = dst - yo * p;
@@ @@ -98,17 +88,16 @@ void GfxScroll(int left, int top, int wi @@
 			width += xo;
+		}
 		ht = height;
 		do {
 			memcpy(dst, src, width);
 		// the y-displacement may be 0 therefore we have to use memmove,
 		// because source and destination may overlap
 		for (ht = height; ht > 0; --ht) {
 			memmove(dst, src, width);
 			src += p;
 			dst += p;
 		} while (--ht);
 		// This part of the screen is now dirty.
 		_video_driver->make_dirty(left, top, width, height);
+		}
+	}
 	// This part of the screen is now dirty.
 	_video_driver->make_dirty(left, top, width, height);
+}

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