spritesheets: support for predecessors and reversed animations

src/character.c

@@ -28,6 +28,11 @@
 
 SYMBOL_EXPORT void SelectSpritesheet(struct Game* game, struct Character* character, char* name) {
 	struct Spritesheet* tmp = character->spritesheets;
+	bool reversed = false;
+	if (name[0] == '-') {
+		reversed = true;
+		name++;
+	}
 	PrintConsole(game, "Selecting spritesheet for %s: %s", character->name, name);
 	if (!tmp) {
 		PrintConsole(game, "ERROR: No spritesheets registered for %s!", character->name);
@@ -44,9 +49,18 @@ SYMBOL_EXPORT void SelectSpritesheet(struct Game* game, struct Character* charac
 			} else {
 				character->successor = NULL;
 			}
+			if (character->predecessor) {
+				free(character->predecessor);
+			}
+			if (tmp->predecessor) {
+				character->predecessor = strdup(tmp->predecessor);
+			} else {
+				character->predecessor = NULL;
+			}
 			character->repeats = tmp->repeats;
-			character->reversing = tmp->reversed;
+			character->pos = reversed ? (tmp->frameCount - 1) : 0;
-			character->pos = 0;
+			character->reversed = reversed;
+			character->reversing = tmp->reversed ^ reversed;
 			character->frame = &tmp->frames[character->pos];
 			//character->bitmap = tmp->frames[character->pos].bitmap;
 			PrintConsole(game, "SUCCESS: Spritesheet for %s activated: %s (%dx%d)", character->name, character->spritesheet->name, character->spritesheet->width, character->spritesheet->height);
@@ -178,6 +192,14 @@ SYMBOL_EXPORT void RegisterSpritesheet(struct Game* game, struct Character* char
 		strncpy(s->successor, successor, len);
 	}
 
+	s->predecessor = NULL;
+	const char* predecessor = al_get_config_value(config, "animation", "predecessor");
+	if (predecessor) {
+		int len = strlen(predecessor) + 1;
+		s->predecessor = malloc(len * sizeof(char));
+		strncpy(s->predecessor, predecessor, len);
+	}
+
 	{
 		s->file = NULL;
 		const char* file = al_get_config_value(config, "animation", "file");
@@ -242,6 +264,7 @@ SYMBOL_EXPORT struct Character* CreateCharacter(struct Game* game, char* name) {
 	character->pos = 0;
 	character->delta = 0.0;
 	character->successor = NULL;
+	character->predecessor = NULL;
 	character->x = -1;
 	character->y = -1;
 	character->tint = al_map_rgb(255, 255, 255);
@@ -276,6 +299,9 @@ SYMBOL_EXPORT void DestroyCharacter(struct Game* game, struct Character* charact
 			if (tmp->successor) {
 				free(tmp->successor);
 			}
+			if (tmp->predecessor) {
+				free(tmp->predecessor);
+			}
 			if (tmp->file) {
 				free(tmp->file);
 			}
@@ -322,15 +348,25 @@ SYMBOL_EXPORT void AnimateCharacter(struct Game* game, struct Character* charact
 			if (character->spritesheet->bidir) {
 				character->pos -= 2;
 				character->reversing = true;
+				if (character->reversed) {
+					reachedEnd = true;
+				}
 			} else {
 				character->pos = 0;
 				reachedEnd = true;
 			}
 		}
 		if (character->pos < 0) {
-			character->pos += 2;
+			if (character->spritesheet->bidir) {
-			character->reversing = false;
+				character->pos += 2;
-			reachedEnd = true;
+				character->reversing = false;
+				if (!character->reversed) {
+					reachedEnd = true;
+				}
+			} else {
+				character->pos = character->spritesheet->frameCount - 1;
+				reachedEnd = true;
+			}
 		}
 
 		if (character->spritesheet->frameCount == 1) {
@@ -343,11 +379,20 @@ SYMBOL_EXPORT void AnimateCharacter(struct Game* game, struct Character* charact
 				if (character->callback) {
 					character->callback(game, character, NULL, character->spritesheet->name, character->callbackData);
 				}
-			} else if (character->successor) {
+			} else {
-				char* old = character->spritesheet->name;
+				if ((!character->reversed) && (character->successor)) {
-				SelectSpritesheet(game, character, character->successor);
+					char* old = character->spritesheet->name;
-				if (character->callback) {
+					SelectSpritesheet(game, character, character->successor);
-					character->callback(game, character, character->spritesheet->name, old, character->callbackData);
+					if (character->callback) {
+						character->callback(game, character, character->spritesheet->name, old, character->callbackData);
+					}
+				}
+				if ((character->reversed) && (character->predecessor)) {
+					char* old = character->spritesheet->name;
+					SelectSpritesheet(game, character, character->predecessor);
+					if (character->callback) {
+						character->callback(game, character, character->spritesheet->name, old, character->callbackData);
+					}
 				}
 			}
 		}

src/character.h

@@ -48,6 +48,7 @@ struct Spritesheet {
 	char* file;
 	int repeats; /*!< Number of repeats to make before the spritesheet is changed to its successor. */
 	char* successor; /*!< Name of animation successor. If it's not blank, then animation will be played only once. */
+	char* predecessor;
 	bool bidir;
 	bool reversed;
 	double pivotX;
@@ -75,6 +76,7 @@ struct Character {
 	int pos; /*!< Current spritesheet position. */
 	double delta; /*!< A counter used internally to slow down spritesheet animation. */ // TODO: change to delta
 	char* successor; /*!< Name of the next spritesheet to be played when the current one finishes. */
+	char* predecessor; /*!< Name of the next spritesheet to be played when the current one finishes when in reverse mode. */
 	float x; /*!< Horizontal position of character. */
 	float y; /*!< Vertical position of character. */
 	ALLEGRO_COLOR tint; /*!< Color with which the character's pixels will be multiplied (tinted). White for no effect. */
@@ -88,7 +90,8 @@ struct Character {
 	bool flipX; /*!< Flips the character's sprite vertically. */
 	bool flipY; /*!< Flips the character's sprite horizontally. */
 	int repeats; /*!< Number of repeats left before the spritesheet is changed to its successor. */
-	bool reversing;
+	bool reversing; /*!< Whether the animation is currently played backwards. */
+	bool reversed; /*!< Whether the current animation has been requested as reversed. */
 	bool hidden;
 	void* data; /*!< Additional, custom character data (HP etc.). */
 	void (*callback)(struct Game*, struct Character*, char* newAnim, char* oldAnim, void*);