Add texture alpha blending

sdlpp/sdlpp_renderobject.cpp

@@ -186,4 +186,13 @@ void RenderObject::copyTo( std::shared_ptr< RenderObject > other ) {
     }
     other->colidedWith.clear();
 }
+void RenderObject::setTextureAlpha( uint8_t alpha ) {
+    texture->setAlpha( alpha );
+}
+void RenderObject::setTextureSourceRect( SDL_Rect source_rect ) {
+    src_rect = source_rect;
+}
+void RenderObject::setTextureSourceRect( int x, int y, int w, int h ) {
+    setTextureSourceRect( { x, y, w, h } );
+}
 } // namespace SDLPP

sdlpp/sdlpp_renderobject.hpp

@@ -86,6 +86,9 @@ public:
     bool isStatic();
     void setStatic( bool stat = true );
     std::shared_ptr< Renderer > getRenderer() const;
+    void setTextureAlpha( uint8_t alpha );
+    void setTextureSourceRect( SDL_Rect source_rect );
+    void setTextureSourceRect( int x, int y, int w, int h );
 
 protected:
     virtual void copyTo( std::shared_ptr< RenderObject > other );

sdlpp/sdlpp_texture.cpp

@@ -73,4 +73,9 @@ void Texture::setTextureFromSurface( std::shared_ptr< Renderer > &renderer,
     }
     SDL_FreeSurface( surface );
 }
+
+void Texture::setAlpha( uint8_t alpha ) {
+    SDL_SetTextureBlendMode( texture, SDL_BLENDMODE_BLEND );
+    SDL_SetTextureAlphaMod( texture, alpha );
+}
 } // namespace SDLPP

sdlpp/sdlpp_texture.hpp

@@ -22,6 +22,7 @@ public:
              const int outline_size = -1 );
     virtual ~Texture();
     SDL_Texture *getTexturePtr();
+    void setAlpha( uint8_t alpha );
 
 private:
     void setTextureFromSurface( std::shared_ptr< Renderer > &renderer,