(svn r2924) Introduce the ALIGN() macro which aligns values to multiples of a power of 2, for exact semantics see the commment in macros.h

5 files changed, 12 insertions, 6 deletions

diff --git a/gfx.c b/gfx.c
index d22d864c7..38c6cd009 100644
--- a/gfx.c
+++ b/gfx.c
@@ -1755,8 +1755,8 @@ void RedrawScreenRect(int left, int top, int right, int bottom)
 void DrawDirtyBlocks(void)
 {
 	byte *b = _dirty_blocks;
-	const int w = (_screen.width + 63) & ~63;
-	const int h = (_screen.height + 7) & ~7;
+	const int w = ALIGN(_screen.width, 64);
+	const int h = ALIGN(_screen.height, 8);
 	int x;
 	int y;
 
diff --git a/macros.h b/macros.h
index 1232005cd..26c4d9985 100644
--- a/macros.h
+++ b/macros.h
@@ -158,6 +158,12 @@ static inline void swap_tile(TileIndex *a, TileIndex *b) { TileIndex t = *a; *a
 #define ROL(x, n) ((x) << (n) | (x) >> (sizeof(x) * 8 - (n)))
 #define ROR(x, n) ((x) >> (n) | (x) << (sizeof(x) * 8 - (n)))
 
+/**
+ * Return the smallest multiple of n equal or greater than x
+ * @note n must be a power of 2
+ */
+#define ALIGN(x, n) (((x) + (n) - 1) & ~((n) - 1))
+
 /* IS_INT_INSIDE = filter for ascii-function codes like BELL and so on [we need an special filter here later] */
 static inline bool IsValidAsciiChar(byte key)
 {
diff --git a/screenshot.c b/screenshot.c
index ee5153d3b..ac9a4433f 100644
--- a/screenshot.c
+++ b/screenshot.c
@@ -78,7 +78,7 @@ static bool MakeBmpImage(const char *name, ScreenshotCallback *callb, void *user
 	if (f == NULL) return false;
 
 	// each scanline must be aligned on a 32bit boundary
-	padw = (w + 3) & ~3;
+	padw = ALIGN(w, 4);
 
 	// setup the file header
 	bfh.type = TO_LE16('MB');
diff --git a/settings.c b/settings.c
index 65eef0544..9e3580299 100644
--- a/settings.c
+++ b/settings.c
@@ -50,7 +50,7 @@ static void *pool_alloc(SettingsMemoryPool **pool, uint size)
 	uint pos;
 	SettingsMemoryPool *p = *pool;
 
-	size = (size + 3) & ~3; // align everything to a 32 bit boundary
+	size = ALIGN(size, 4); // align everything to a 32 bit boundary
 
 	// first check if there's memory in the next pool
 	if (p->next && p->next->pos + size <= p->next->size) {
diff --git a/video/win32_v.c b/video/win32_v.c
index 3656e66ad..90997804a 100644
--- a/video/win32_v.c
+++ b/video/win32_v.c
@@ -536,7 +536,7 @@ static bool AllocateDibSection(int w, int h)
 		return false;
 
 	_screen.width = w;
-	_screen.pitch = (w + 3) & ~0x3;
+	_screen.pitch = ALIGN(w, 4);
 	_screen.height = h;
 
 	if (_wnd.alloced_bits) {
@@ -549,7 +549,7 @@ static bool AllocateDibSection(int w, int h)
 	bi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
 
 	if (_wnd.double_size) {
-		w = (w + 3) & ~0x3;
+		w = ALIGN(w, 4);
 		_wnd.alloced_bits = _wnd.buffer_bits = malloc(w * h);
 		w *= 2;
 		h *= 2;