implemented animation and sprite flipping

src/sprite.c

@@ -15,6 +15,8 @@ struct Sprite {
 
     // The local transformation of this sprite.
     Vector origin;
+
+    SDL_RendererFlip flip_state;
 };
 
 Sprite* sprite_from_spritesheet(Spritesheet* sheet, size_t initial_frame) {
@@ -25,6 +27,7 @@ Sprite* sprite_from_spritesheet(Spritesheet* sheet, size_t initial_frame) {
     self->spritesheet = sheet;
     self->origin = (Vector){0.5f, 0.5f};
     self->tile_index = initial_frame;
+    self->flip_state = SDL_FLIP_NONE;
 
     return self;
 }
@@ -34,22 +37,28 @@ void sprite_destroy(Sprite* self) {
 }
 
 void sprite_draw(Sprite* self, Transform transform) {
-    // #warning "sprite drawing disabled"
-    // return;
     SDL_Texture* texture = spritesheet_get_texture(self->spritesheet);
     SDL_Rect source = spritesheet_get_tile_rect(self->spritesheet, self->tile_index);
 
-    Vector left_top = transform_point(&transform, vinvf(self->origin));
+    Vector origin = self->origin;
+    if(self->flip_state && SDL_FLIP_HORIZONTAL) {
+        origin.x = 1.0-origin.x;
+    }
+    if((self->flip_state & SDL_FLIP_VERTICAL) != 0) {
+        origin.y = 1.0-origin.y;
+    }
 
+    Vector left_top = transform_point(&transform, vinvf(origin));
     SDL_FRect destination = (SDL_FRect) {
         left_top.x, left_top.y,
         transform.scale.x, transform.scale.y
     };
     destination = camera_world_to_pixel_rect(&g_camera, &destination);
-    Vector origin = vmulf(self->origin, transform.scale);
+
+    origin = vmulf(origin, transform.scale);
 
     SDL_RenderCopyExF(g_renderer, texture, &source, &destination,
-                      transform.rotation * 57.2958, &origin, SDL_FLIP_NONE);
+                      transform.rotation * 57.2958, &origin, self->flip_state);
     SDL_SetRenderDrawColor(g_renderer, 255, 255, 255, 255);
 }
 
@@ -66,6 +75,7 @@ size_t sprite_get_tile(const Sprite* self) {
 }
 
 void sprite_set_tile(Sprite* self, size_t frame) {
+    frame = frame % spritesheet_get_tile_count(self->spritesheet);
     self->tile_index = frame;
 }
 
@@ -76,3 +86,19 @@ Spritesheet* sprite_get_spritesheet(const Sprite* self) {
 void sprite_set_spritesheet(Sprite* self, Spritesheet* spritesheet) {
     self->spritesheet = spritesheet;
 }
+
+void sprite_flip_horizontal(Sprite* self, int horizontal) {
+    if(horizontal) {
+        self->flip_state |= SDL_FLIP_HORIZONTAL;
+    } else {
+        self->flip_state &= ~SDL_FLIP_HORIZONTAL;
+    }
+}
+
+void sprite_flip_vertical(Sprite* self, int vertical) {
+    if(vertical) {
+        self->flip_state |= SDL_FLIP_VERTICAL;
+    } else {
+        self->flip_state &= ~SDL_FLIP_VERTICAL;
+    }
+}

src/sprite.h

@@ -24,4 +24,7 @@ extern void sprite_set_tile(Sprite* self, size_t tile);
 extern Spritesheet* sprite_get_spritesheet(const Sprite* self);
 extern void sprite_set_spritesheet(Sprite* self, Spritesheet* spritesheet);
 
+extern void sprite_flip_horizontal(Sprite* self, int horizontal);
+extern void sprite_flip_vertical(Sprite* self, int vertical);
+
 #endif // !_fencer_sprite_h

src/spritesheet.c

@@ -71,6 +71,10 @@ IVector spritesheet_get_resolution(const Spritesheet* self) {
     return self->resolution;
 }
 
+size_t spritesheet_get_tile_count(const Spritesheet* self) {
+    return self->tile_count;
+}
+
 asset_id spritesheet_get_asset_id(Spritesheet* self) {
     return self->asset_id;
 }

src/spritesheet.h

@@ -14,6 +14,7 @@ extern void spritesheet_destroy(Spritesheet* self);
 extern SDL_Texture* spritesheet_get_texture(const Spritesheet* self);
 extern SDL_Rect spritesheet_get_tile_rect(const Spritesheet* self, size_t index);
 extern IVector spritesheet_get_resolution(const Spritesheet* self);
+extern size_t spritesheet_get_tile_count(const Spritesheet* self);
 
 extern asset_id spritesheet_get_asset_id(Spritesheet* self);
 extern void spritesheet_set_asset_id(Spritesheet* self, asset_id id);