Get rid of doubling memory allocation and a lot of copying.

The Sprite class points to the original buffer (which is cached in the memory
thanks to BArchive machinery) instead of allocating its own buffer and
copying the source there.

svn-id: r45594

engines/draci/sprite.cpp

@@ -58,8 +58,8 @@ static void transformToRows(byte *img, uint16 width, uint16 height) {
 /**
  *  Constructor for loading sprites from a raw data buffer, one byte per pixel.
  */
-Sprite::Sprite(const byte *raw_data, uint16 width, uint16 height, int x, int y,
-    bool columnwise) : _data(NULL) {
+Sprite::Sprite(uint16 width, uint16 height, byte *raw_data, int x, int y, bool columnwise)
+    : _ownsData(true), _data(raw_data), _mirror(false) {
 
 	 _width = width;
 	 _height = height;
@@ -72,17 +72,9 @@ Sprite::Sprite(const byte *raw_data, uint16 width, uint16 height, int x, int y,
 
 	_delay = 0;
 
-	_mirror = false;
-
-	byte *data = new byte[width * height];
-
-	memcpy(data, raw_data, width * height);
-
-	// If the sprite is stored column-wise, transform it to row-wise
 	if (columnwise) {
-		transformToRows(data, width, height);
+		transformToRows(raw_data, _width, _height);
 	}
-	_data = data;
 }
 
 /**
@@ -90,36 +82,36 @@ Sprite::Sprite(const byte *raw_data, uint16 width, uint16 height, int x, int y,
  *  pixel.
  */
 Sprite::Sprite(const byte *sprite_data, uint16 length, int x, int y, bool columnwise)
-    : _data(NULL) {
-
-	 _x = x;
-	 _y = y;
-
-	_delay = 0;
-
-	_mirror = false;
+    : _ownsData(false), _data(NULL), _mirror(false) {
 
 	Common::MemoryReadStream reader(sprite_data, length);
-
 	_width = reader.readSint16LE();
 	_height = reader.readSint16LE();
 
 	_scaledWidth = _width;
 	_scaledHeight = _height;
 
-	byte *data = new byte[_width * _height];
+	 _x = x;
+	 _y = y;
 
-	reader.read(data, _width * _height);
+	_delay = 0;
 
-	// If the sprite is stored column-wise, transform it to row-wise
-	if (columnwise) {
+	if (!columnwise) {
+		_ownsData = false;
+		_data = sprite_data + 4;
+	} else {
+		_ownsData = true;
+		byte *data = new byte[_width * _height];
+		memcpy(data, sprite_data + 4, _width * _height);
 		transformToRows(data, _width, _height);
+		_data = data;
 	}
-	_data = data;
 }
 
 Sprite::~Sprite() {
-	delete[] _data;
+	if (_ownsData) {
+		delete[] _data;
+	}
 }
 
 // Macro to simulate lround() for non-C99 compilers

engines/draci/sprite.h

@@ -101,7 +101,14 @@ protected:
 
 class Sprite : public Drawable {
 public:
-	Sprite(const byte *raw_data, uint16 width, uint16 height, int x, int y, bool columnwise);
+	// Takes ownership of raw_data.
+	Sprite(uint16 width, uint16 height, byte *raw_data, int x, int y, bool columnwise);
+
+	// It doesn't take ownership of sprite_data.  If columnwise is false,
+	// it internally points to the original buffer (which has lifetime at
+	// least as long as this sprite, assumming that it comes from a cached
+	// BArchive file), otherwise it allocates its own buffer with the
+	// transposed image.
 	Sprite(const byte *sprite_data, uint16 length, int x, int y, bool columnwise);
 
 	~Sprite();
@@ -120,6 +127,7 @@ public:
 	DrawableType getType() const { return kDrawableSprite; }
 
 private:
+	bool _ownsData;
 	const byte *_data;  ///< Pointer to a buffer containing raw sprite data (row-wise)
 	bool _mirror;
 };

engines/draci/walking.cpp

@@ -71,8 +71,8 @@ Sprite *WalkingMap::constructDrawableOverlay() const {
 		}
 	}
 
-	Sprite *ov = new Sprite(wlk, kScreenWidth, kScreenHeight, 0, 0, false);
-        delete[] wlk;
+	Sprite *ov = new Sprite(kScreenWidth, kScreenHeight, wlk, 0, 0, false);
+	// ov has taken the ownership of wlk.
 
 	return ov;
 }