GRAPHICS: ATARI: Align surface on a 16-byte boundary

scummvm · Mar 12, 2023 · 4b95038 · 4b95038
1 parent 6f87f19
commit 4b95038
Show file tree

Hide file tree

Showing 2 changed files with 34 additions and 12 deletions.
diff --git a/backends/graphics/atari/atari-graphics.cpp b/backends/graphics/atari/atari-graphics.cpp
@@ -1001,7 +1001,7 @@ void AtariGraphicsManager::Cursor::setSurface(const void *buf, int w, int h, int
 	if (surface.w != w || surface.h != h || surface.format != format)
 		surface.create(w, h, format);
 
-	surface.copyRectToSurface(buf, surface.pitch, 0, 0, w, h);
+	surface.copyRectToSurface(buf, w * format.bytesPerPixel, 0, 0, w, h);
 
 	hotspotX = _hotspotX;
 	hotspotY = _hotspotY;

diff --git a/graphics/blit-atari.cpp b/graphics/blit-atari.cpp
@@ -22,12 +22,13 @@
 #include "graphics/blit.h"
 #include "graphics/surface.h"
 
-#include <cstdlib>	// calloc
-#include <cstring>	// memcpy
+#include <cstdlib>	// malloc
+#include <cstring>	// memcpy, memset
 #include <mint/cookie.h>
 #include <mint/falcon.h>
 
 #include "backends/graphics/atari/atari-graphics-superblitter.h"
+#include "common/textconsole.h"	// error
 
 namespace Graphics {
 
@@ -37,27 +38,46 @@ void Surface::create(int16 width, int16 height, const PixelFormat &f) {
 	assert(width >= 0 && height >= 0);
 	free();
 
+	constexpr size_t ALIGN = 16;	// 16 bytes
+
 	w = width;
 	h = height;
 	format = f;
-	pitch = w * format.bytesPerPixel;
+	// align pitch to a 16-byte boundary for a possible C2P optimization
+	pitch = (w * format.bytesPerPixel + ALIGN - 1) & (-ALIGN);
 
 	if (width && height) {
-		if (VgetMonitor() == MON_VGA && Getcookie(C_SupV, NULL) == C_FOUND)
-			pixels = (void*)ct60_vmalloc(width * height * format.bytesPerPixel);
-		else
-			pixels = calloc(width * height, format.bytesPerPixel);
-		assert(pixels);
+		if (VgetMonitor() == MON_VGA && Getcookie(C_SupV, NULL) == C_FOUND) {
+			pixels = (void *)ct60_vmalloc(height * pitch);
+
+			if (!pixels)
+				error("Not enough SVRAM to allocate a surface");
+
+			assert((uintptr)pixels >= 0xA0000000);
+		} else {
+			// align buffer to a 16-byte boundary for move16
+			void *pixelsUnaligned = ::malloc(sizeof(uintptr) + (height * pitch) + ALIGN - 1);
+
+			if (!pixelsUnaligned)
+				error("Not enough memory to allocate a surface");
+
+			pixels = (void *)(((uintptr)pixelsUnaligned + sizeof(uintptr) + ALIGN - 1) & (-ALIGN));
+
+			// store the unaligned pointer for later free()
+			*((uintptr *)pixels - 1) = (uintptr)pixelsUnaligned;
+		}
+
+		memset(pixels, 0, height * pitch);
 	}
 }
 
 void Surface::free() {
 	if (((uintptr)pixels & 0xFF000000) >= 0xA0000000)
 		ct60_vmfree(pixels);
-	else
-		::free(pixels);
+	else if (pixels)
+		::free((void *)*((uintptr *)pixels - 1));
 
-	pixels = 0;
+	pixels = nullptr;
 	w = h = pitch = 0;
 	format = PixelFormat();
 }
@@ -87,9 +107,11 @@ void copyBlit(byte *dst, const byte *src,
 		// wait until we finish otherwise we may overwrite pixels written manually afterwards
 		while (*SV_BLITTER_CONTROL & 1);
 	} else if (dstPitch == srcPitch && ((w * bytesPerPixel) == dstPitch)) {
+		// TODO: replace with move16
 		memcpy(dst, src, dstPitch * h);
 	} else {
 		for (uint i = 0; i < h; ++i) {
+			// TODO: replace with move16
 			memcpy(dst, src, w * bytesPerPixel);
 			dst += dstPitch;
 			src += srcPitch;