selected tile tracks cursor, loads tile gfx

src/app/gfx/bitmap.cc

@@ -39,6 +39,7 @@ Bitmap::Bitmap(int width, int height, int depth, uchar *data, int data_size) {
 
 // Pass raw pixel data directly to the surface
 void Bitmap::Create(int width, int height, int depth, uchar *data) {
+  active_ = true;
   width_ = width;
   height_ = height;
   depth_ = depth;
@@ -53,6 +54,7 @@ void Bitmap::Create(int width, int height, int depth, uchar *data) {
 
 // Reserves data to later draw to surface via pointer
 void Bitmap::Create(int width, int height, int depth, int size) {
+  active_ = true;
   width_ = width;
   height_ = height;
   depth_ = depth;
@@ -69,6 +71,7 @@ void Bitmap::Create(int width, int height, int depth, int size) {
 
 // Pass raw pixel data directly to the surface
 void Bitmap::Create(int width, int height, int depth, uchar *data, int size) {
+  active_ = true;
   width_ = width;
   height_ = height;
   depth_ = depth;
@@ -83,6 +86,7 @@ void Bitmap::Create(int width, int height, int depth, uchar *data, int size) {
 }
 
 void Bitmap::Create(int width, int height, int depth, Bytes data) {
+  active_ = true;
   width_ = width;
   height_ = height;
   depth_ = depth;

src/app/gfx/bitmap.h

@@ -45,6 +45,7 @@ class Bitmap {
   auto GetByte(int i) const { return pixel_data_[i]; }
   auto GetTexture() const { return texture_.get(); }
   auto GetSurface() const { return surface_.get(); }
+  auto IsActive() const { return active_; }
 
  private:
   struct SDL_Texture_Deleter {
@@ -71,6 +72,7 @@ class Bitmap {
   int depth_ = 0;
   int data_size_ = 0;
   bool freed_ = false;
+  bool active_ = false;
   uchar *pixel_data_;
   Bytes data_;
   gfx::SNESPalette palette_;