From 02657f5a91bba15c7d494f71d0c975ece7178861 Mon Sep 17 00:00:00 2001
From: Paul Gilbert <dreammaster@scummvm.org>
Date: Mon, 16 Mar 2015 00:02:45 -0400
Subject: [PATCH] SHERLOCK: Fix loading of sprite for startup animation

---
 engines/sherlock/animation.cpp |  2 +-
 engines/sherlock/sprite.cpp    | 47 +++++++++++++++++++---------------
 engines/sherlock/sprite.h      |  6 +++--
 3 files changed, 31 insertions(+), 24 deletions(-)

diff --git a/engines/sherlock/animation.cpp b/engines/sherlock/animation.cpp
index 3da0201a6170..4111f6f88f7c 100644
--- a/engines/sherlock/animation.cpp
+++ b/engines/sherlock/animation.cpp
@@ -91,7 +91,7 @@ void Animation::playPrologue(const Common::String &filename, int minDelay, int f
 	// Load initial image
 	Common::String vdaName = baseName + ".vda";
 	Common::SeekableReadStream *vdaStream = _vm->_res->load(vdaName);
-	Sprite sprite(*vdaStream);
+	Sprite sprite(*vdaStream, true);
 	
 	// TODO
 
diff --git a/engines/sherlock/sprite.cpp b/engines/sherlock/sprite.cpp
index f686f0b27e03..ee7c8e501963 100644
--- a/engines/sherlock/sprite.cpp
+++ b/engines/sherlock/sprite.cpp
@@ -25,8 +25,8 @@
 
 namespace Sherlock {
 
-Sprite::Sprite(Common::SeekableReadStream &stream) {
-	load(stream);
+Sprite::Sprite(Common::SeekableReadStream &stream, bool skipPal) {
+	load(stream, skipPal);
 }
 
 Sprite::~Sprite() {
@@ -37,22 +37,26 @@ Sprite::~Sprite() {
 /**
  * Load the data of the sprite
  */
-void Sprite::load(Common::SeekableReadStream &stream) {
-    while (!stream.eos()) {
+void Sprite::load(Common::SeekableReadStream &stream, bool skipPal) {
+    while (stream.pos() < stream.size()) {
 		SpriteFrame frame;
-
 		frame._width = stream.readUint16LE() + 1;
 		frame._height = stream.readUint16LE() + 1;
 		frame._flags = stream.readUint16LE();
         stream.readUint16LE();
         
+		if (skipPal)
+			frame._flags = 0;
+
 		if (frame._flags & 0xFF) {
+			// Nibble packed frame data
 			frame._size = (frame._width * frame._height) / 2;
-		} else if (frame._flags & 0x0100) {
+		} else if (frame._flags & RLE_ENCODED) {
             // this size includes the header size, which we subtract
 			frame._size = stream.readUint16LE() - 11;
 			frame._rleMarker = stream.readByte();
         } else {
+			// Uncompressed data
 			frame._size = frame._width * frame._height;
         }
 
@@ -74,24 +78,25 @@ void Sprite::decompressFrame(SpriteFrame &frame, const byte *src) {
 
 	if (frame._flags & 0xFF) {
 	    debug("TODO: Sprite::decompressFrame() 4-bits/pixel\n");
-	} else if (frame._flags & 0x0100) {
+	} else if (frame._flags & RLE_ENCODED) {
+		// RLE encoded
 	    byte *dst = (byte *)frame._frame.getPixels();
-		for (uint16 h = 0; h < frame._height; ++h) {
-			int16 w = frame._width;
-			while (w > 0) {
-			    if (*src == frame._rleMarker) {
-			        byte rleColor = src[1];
-			        byte rleCount = src[2];
-			        src += 3;
-			        w -= rleCount;
-			        while (rleCount--)
-			            *dst++ = rleColor;
-				} else {
-				    *dst++ = *src++;
-				    w--;
-				}
+
+		int size = frame._width * frame._height;
+		while (size > 0) {
+			if (*src == frame._rleMarker) {
+			    byte rleColor = src[1];
+			    byte rleCount = src[2];
+			    src += 3;
+			    size -= rleCount;
+			    while (rleCount--)
+			        *dst++ = rleColor;
+			} else {
+				*dst++ = *src++;
+				--size;
 			}
 		}
+		assert(size == 0);
 	} else {
 		// Uncompressed frame
 		Common::copy(src, src + frame._width * frame._height,
diff --git a/engines/sherlock/sprite.h b/engines/sherlock/sprite.h
index 1f81cf807170..17566c81bdb7 100644
--- a/engines/sherlock/sprite.h
+++ b/engines/sherlock/sprite.h
@@ -30,6 +30,8 @@
 
 namespace Sherlock {
 
+enum { RLE_ENCODED = 0x0100 };
+
 struct SpriteFrame {
 	uint32 _size;
 	uint16 _width, _height;
@@ -41,10 +43,10 @@ struct SpriteFrame {
 
 class Sprite: public Common::Array<SpriteFrame> {
 private:
-	void load(Common::SeekableReadStream &stream);
+	void load(Common::SeekableReadStream &stream, bool skipPal);
 	void decompressFrame(SpriteFrame  &frame, const byte *src);
 public:
-    Sprite(Common::SeekableReadStream &stream);
+    Sprite(Common::SeekableReadStream &stream, bool skipPal = false);
     ~Sprite();
 };