Animation: Fix times_played for single-frame back_forth animations

This commit also replaces the `additional_data` variable with one called
`reverse_playback`, which is more descriptive for how it is used.

RELEASE_NOTES.txt

@@ -54,6 +54,7 @@ Engine fixes:
 * Fixed potential crash if a hazard was created before the map loaded.
 * Fixed infinite loop caused by trying to move an entity before the map loaded.
 * Fix case where sounds may be unloaded prematurely if they were playing during certain sitations.
+* Fix single-frame "back_forth" animations taking an extra frame to complete.
 * Android: Fix 'Flare' directory not being automatically created.
 * Android: Added a dialog to direct the player to the wiki page for installing if no game data is found.
 

src/Animation.cpp

@@ -47,7 +47,7 @@ Animation::Animation(const std::string &_name, const std::string &_type, Animati
 	, cur_frame_duration(0)
 	, cur_frame_index_f(0)
 	, max_kinds(0)
-	, additional_data(0)
+	, reverse_playback(false)
 	, times_played(0)
 	, gfx()
 	, render_offset()
@@ -127,21 +127,15 @@ void Animation::setup(unsigned short _frames, unsigned short _duration, unsigned
 
 	if (!frames.empty()) number_frames = static_cast<unsigned short>(frames.back()+1);
 
-	if (type == ANIMTYPE_PLAY_ONCE) {
-		additional_data = 0;
-	}
-	else if (type == ANIMTYPE_LOOPED) {
-		additional_data = 0;
-	}
-	else if (type == ANIMTYPE_BACK_FORTH) {
+	if (type == ANIMTYPE_BACK_FORTH) {
 		number_frames = static_cast<unsigned short>(2 * number_frames);
-		additional_data = 1;
 	}
 	cur_frame = 0;
 	cur_frame_index = 0;
 	cur_frame_index_f = 0;
 	max_kinds = _maxkinds;
 	times_played = 0;
+	reverse_playback = false;
 
 	active_frames.push_back(static_cast<unsigned short>(number_frames-1)/2);
 
@@ -197,21 +191,24 @@ void Animation::advanceFrame() {
 
 		case ANIMTYPE_BACK_FORTH:
 
-			if (additional_data == 1) {
+			if (!reverse_playback) {
 				if (cur_frame_index < last_base_index) {
 					cur_frame_index_f += speed;
 					cur_frame_index = static_cast<unsigned short>(cur_frame_index_f);
 				}
-				else
-					additional_data = -1;
+				else {
+					reverse_playback = true;
+					if (frame_count == 1)
+						times_played++;
+				}
 			}
-			else if (additional_data == -1) {
+			else if (reverse_playback) {
 				if (cur_frame_index > 0) {
 					cur_frame_index_f -= speed;
 					cur_frame_index = static_cast<unsigned short>(cur_frame_index_f);
 				}
 				else {
-					additional_data = 1;
+					reverse_playback = false;
 					times_played++;
 				}
 			}
@@ -250,7 +247,7 @@ void Animation::reset() {
 	cur_frame_index = 0;
 	cur_frame_index_f = 0;
 	times_played = 0;
-	additional_data = 1;
+	reverse_playback = false;
 	elapsed_frames = 0;
 	active_frame_triggered = false;
 }
@@ -260,7 +257,7 @@ bool Animation::syncTo(const Animation *other) {
 	cur_frame_index = other->cur_frame_index;
 	cur_frame_index_f = other->cur_frame_index_f;
 	times_played = other->times_played;
-	additional_data = other->additional_data;
+	reverse_playback = other->reverse_playback;
 	elapsed_frames = other->elapsed_frames;
 
 	if (cur_frame_index >= frames.size()) {
@@ -356,7 +353,7 @@ bool Animation::isCompleted() {
 unsigned short Animation::getLastFrameIndex(const short &frame) {
 	if (frames.empty() || frame < 0) return 0;
 
-	if (type == ANIMTYPE_BACK_FORTH && additional_data == -1) {
+	if (type == ANIMTYPE_BACK_FORTH && reverse_playback) {
 		// since the animation is advancing backwards here, the first frame index is actually the last
 		for (unsigned short i=0; i<frames.size(); i++) {
 			if (frames[i] == frame) return i;

src/Animation.h

@@ -55,10 +55,7 @@ class Animation {
 
 	unsigned short max_kinds;
 
-	short additional_data;  // additional state depending on type:
-	// if type == BACK_FORTH then it is 1 for advancing, and -1 for going back, 0 at the end
-	// if type == LOOPED, then it is the number of loops to be played.
-	// if type == PLAY_ONCE or NONE, this has no meaning.
+	bool reverse_playback;  // only for type == BACK_FORTH
 
 	short times_played; // how often this animation was played (loop counter for type LOOPED)
 

src/Version.cpp

@@ -30,7 +30,7 @@ FLARE.  If not, see http://www.gnu.org/licenses/
 
 #include <SDL.h>
 
-Version VersionInfo::ENGINE(1, 14, 63);
+Version VersionInfo::ENGINE(1, 14, 64);
 Version VersionInfo::MIN(0, 0, 0);
 Version VersionInfo::MAX(USHRT_MAX, USHRT_MAX, USHRT_MAX);