add sprite texture index increment function

src/Sprite.hpp

@@ -192,6 +192,17 @@ namespace sb
             return _texture_index;
         }
 
+        /*!
+         * Increment the texture index the given number of times. Defaults to 1. It will wrap around at the end. Negative increment can be used.
+         *
+         * @param increment  amount to increment the texture index
+         */
+        void texture_increment(int increment = 1)
+        {
+            /* Add and wrap (even though model wraps as well) */
+            _texture_index = glm::mod(_texture_index + increment, static_cast<int>(plane.textures().size()));
+        }
+
         /*!
          * If the GL context is active, this can be called to load image paths previously associated with textures attached to the
          * sprite's plane object.