From f91c89560f9e50f6cecfe93795d4c00513f45206 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20=C5=A0palek?= <spalek@google.com>
Date: Sun, 1 Nov 2009 10:03:37 +0000
Subject: [PATCH] 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  | 44 ++++++++++++++++-----------------------
 engines/draci/sprite.h    | 10 ++++++++-
 engines/draci/walking.cpp |  4 ++--
 3 files changed, 29 insertions(+), 29 deletions(-)

diff --git a/engines/draci/sprite.cpp b/engines/draci/sprite.cpp
index 1fdd5339f47..32c4044e4ec 100644
--- a/engines/draci/sprite.cpp
+++ b/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
diff --git a/engines/draci/sprite.h b/engines/draci/sprite.h
index 0d805e03855..7756d55d6a5 100644
--- a/engines/draci/sprite.h
+++ b/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;
 };
diff --git a/engines/draci/walking.cpp b/engines/draci/walking.cpp
index b9d74343490..f7c85d9bcd4 100644
--- a/engines/draci/walking.cpp
+++ b/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;
 }