ZVISION: Make rlf animation logic equivalent to video decoder methods.

3 files changed, 24 insertions, 20 deletions

diff --git a/engines/zvision/animation_control.cpp b/engines/zvision/animation_control.cpp
index 3f9a2e9cc7..5b35a4a468 100644
--- a/engines/zvision/animation_control.cpp
+++ b/engines/zvision/animation_control.cpp
@@ -94,7 +94,7 @@ bool AnimationControl::process(uint32 deltaTimeInMillis) {
 					return false;
 				}
 
-				const Graphics::Surface *frame = _animation.rlf->getNextFrame();
+				const Graphics::Surface *frame = _animation.rlf->decodeNextFrame();
 
 				// Animation frames for PANORAMAs are transposed, so un-transpose them
 				RenderTable::RenderState state = renderManager->getRenderTable()->getRenderState();
diff --git a/engines/zvision/rlf_animation.cpp b/engines/zvision/rlf_animation.cpp
index 795167e572..dab32aed17 100644
--- a/engines/zvision/rlf_animation.cpp
+++ b/engines/zvision/rlf_animation.cpp
@@ -43,7 +43,7 @@ RlfAnimation::RlfAnimation(const Common::String &fileName, bool stream)
 	  _height(0),
 	  _frameTime(0),
 	  _frames(0),
-	  _currentFrame(-1),
+	  _currentFrame(0),
 	  _frameBufferByteSize(0) {
 	if (!_file.open(fileName)) {
 		warning("RLF animation file %s could not be opened", fileName.c_str());
@@ -157,8 +157,11 @@ void RlfAnimation::seekToFrame(int frameNumber) {
 	assert(!_stream);
 	assert(frameNumber < (int)_frameCount || frameNumber >= -1);
 
-	if (frameNumber == -1) {
-		_currentFrame = -1;
+	if (_currentFrame == frameNumber)
+		return;
+
+	if (frameNumber < 0) {
+		_currentFrame = 0;
 		return;
 	}
 
@@ -166,13 +169,15 @@ void RlfAnimation::seekToFrame(int frameNumber) {
 	int distance = (int)frameNumber - _currentFrame;
 	for (uint i = 0; i < _completeFrames.size(); ++i) {
 		int newDistance = (int)frameNumber - (int)(_completeFrames[i]);
-		if (newDistance > 0 && (closestFrame == -1 || newDistance < distance)) {
+		if (newDistance < 0)
+			break;
+		if (newDistance > 0 && newDistance < distance) {
 			closestFrame = _completeFrames[i];
 			distance = newDistance;
 		}
 	}
 
-	for (int i = closestFrame; i <= frameNumber; ++i) {
+	for (int i = closestFrame; i < frameNumber; ++i) {
 		applyFrameToCurrent(i);
 	}
 
@@ -184,24 +189,24 @@ const Graphics::Surface *RlfAnimation::getFrameData(uint frameNumber) {
 	assert(frameNumber < _frameCount);
 
 	// Since this method is so expensive, first check to see if we can use
-	// getNextFrame() it's cheap.
-	if ((int)frameNumber == _currentFrame) {
+	// decodeNextFrame() it's cheap.
+	if ((int)frameNumber == _currentFrame - 1) {
 		return &_currentFrameBuffer;
-	} else if (_currentFrame + 1 == (int)frameNumber) {
-		return getNextFrame();
+	} else if (_currentFrame == (int)frameNumber) {
+		return decodeNextFrame();
 	}
 
 	seekToFrame(frameNumber);
-	return &_currentFrameBuffer;
+	return decodeNextFrame();
 }
 
-const Graphics::Surface *RlfAnimation::getNextFrame() {
-	assert(_currentFrame + 1 < (int)_frameCount);
+const Graphics::Surface *RlfAnimation::decodeNextFrame() {
+	assert(_currentFrame < (int)_frameCount);
 
 	if (_stream) {
 		applyFrameToCurrent(readNextFrame());
 	} else {
-		applyFrameToCurrent(_currentFrame + 1);
+		applyFrameToCurrent(_currentFrame);
 	}
 
 	_currentFrame++;
diff --git a/engines/zvision/rlf_animation.h b/engines/zvision/rlf_animation.h
index b0f7ee204e..35916de6cb 100644
--- a/engines/zvision/rlf_animation.h
+++ b/engines/zvision/rlf_animation.h
@@ -92,7 +92,7 @@ public:
 
 	/**
 	 * Returns the pixel data of the frame specified. It will try to use
-	 * getNextFrame() if possible. If not, it uses seekToFrame() to
+	 * decodeNextFrame() if possible. If not, it uses seekToFrame() to
 	 * update the internal Surface and then returns a pointer to it.
 	 * This function requires _stream = false
 	 *
@@ -101,19 +101,18 @@ public:
 	 */
 	const Graphics::Surface *getFrameData(uint frameNumber);
 	/**
-	 * Returns the pixel data of the next frame. It is up to the user to
-	 * check if the next frame is valid before calling this.
+	 * Returns the pixel data of current frame and go to next. It is up to the user to
+	 * check if the current frame is valid before calling this.
 	 * IE. Use endOfAnimation()
 	 *
 	 * @return    A pointer to the pixel data. Do NOT delete this.
 	 */
-	const Graphics::Surface *getNextFrame();
-
+	const Graphics::Surface *decodeNextFrame();
 	/**
 	 * @return Is the currentFrame is the last frame in the animation?
 	 */
 	bool endOfAnimation() {
-		return _currentFrame == (int)_frameCount - 1;
+		return _currentFrame == (int)_frameCount;
 	}
 
 private: