add texture index to Sprite class, add more error checks to texture surface creation

src/Log.cpp

@@ -72,9 +72,10 @@ bool sb::Log::gl_errors(const std::string& heading)
     return error_logged;
 }
 
-void sb::Log::sdl_error(const std::string& message)
+std::ostringstream sb::Log::sdl_error(const std::string& message)
 {
     std::ostringstream full_message;
     full_message << message << " " << SDL_GetError();
     log(full_message, Level::ERROR);
+    return full_message;
 }

src/Log.hpp

@@ -81,11 +81,12 @@ namespace sb
 
         /*!
          * Log a message, adding the results of `SDL_GetError` to the end of the message. Should be used to add more information to
-         * an error statement when the error happened in SDL. The priority level will always be `Level::ERROR`
+         * an error statement when the error happened in SDL. The priority level will always be `Level::ERROR`.
          *
          * @param message   text to log before the SDL error is appended
+         * @return          a string stream containing the full message
          */
-        static void sdl_error(const std::string& message);
+        static std::ostringstream sdl_error(const std::string& message = "");
 
     };
 

src/Pad.hpp

@@ -209,7 +209,7 @@ namespace sb
                 {
                     glUniform1i(texture_flag_uniform.value(), true);
                 }
-                plane.bind_textures();
+                plane.texture().bind();
             }
             else if (texture_flag_uniform.has_value())
             {

src/Sprite.hpp

@@ -36,6 +36,9 @@ namespace sb
          * without having to set all the transformations every time one is changed. */
         glm::mat4 _scale {1.0f}, _translation {1.0f}, _rotation {1.0f};
 
+        /* A sprite by definition has only one texture per draw, so keep an index to the currently active texture. */
+        int _texture_index = 0;
+
     public:
 
         /*!
@@ -145,14 +148,31 @@ namespace sb
         }
 
         /*!
-         * Get a constant reference to the texture attached to the sprite's plane object at the given index . If no index is given,
-         * get the texture at index 0. If there are no textures, an exception will be thrown.
+         * Get a constant reference to the texture attached to the sprite's plane object at the object's current texture index.
          *
          * @param index   index of texture to get
          */
-        const sb::Texture& texture(int index = 0) const
+        const sb::Texture& texture() const
         {
-            return plane.texture(index);
+            return plane.texture(_texture_index);
+        }
+
+        /*!
+         * @param index    set the object's texture index
+         * @return         constant reference to the texture at the given index
+         */
+        const sb::Texture& texture_index(int index)
+        {
+            _texture_index = index;
+            return texture();
+        }
+
+        /*!
+         * @return   the object's current texture index value
+         */
+        int texture_index() const
+        {
+            return _texture_index;
         }
 
         /*!
@@ -178,12 +198,13 @@ namespace sb
         }
 
         /*!
-         * Bind all of this sprite's attributes and textures by calling each of their bind methods. Textures and attributes all must already
+         * Bind all of this sprite's attributes and its active texture by calling each of their bind methods. Textures and attributes all must already
          * have GL indices set, for example by calling Texture::generate() and Attributes::index(GLint) on each.
          */
         void bind()
         {
-            plane.bind();
+            plane.bind_attributes();
+            texture().bind();
         }
 
         /*!
@@ -296,7 +317,7 @@ namespace sb
                 {
                     glUniform1i(texture_flag_uniform.value(), true);
                 }
-                plane.bind_textures();
+                texture().bind();
             }
             else if (texture_flag_uniform.has_value())
             {

src/Text.hpp

@@ -7,6 +7,7 @@
 
 #include "Model.hpp"
 #include "Color.hpp"
+#include "Log.hpp"
 
 namespace sb
 {

src/Texture.cpp

@@ -75,10 +75,26 @@ void Texture::load(fs::path path)
         /* Load file path as a surface object to access pixel data and flip into OpenGL orientation. Attach a destructor so it will free
          * itself when it goes out of scope at the end of this function. */
         std::unique_ptr<SDL_Surface, decltype(&SDL_FreeSurface)> surface(IMG_Load(path.c_str()), SDL_FreeSurface);
-        std::unique_ptr<SDL_Surface, decltype(&SDL_FreeSurface)> flipped_surface(rotozoomSurfaceXY(surface.get(), 0, 1, -1, 0), SDL_FreeSurface);
-        load(flipped_surface.get());
-        message << "Loading image at " << path;
-        message_level = sb::Log::INFO;
+        if (surface.get() != nullptr)
+        {
+            std::unique_ptr<SDL_Surface, decltype(&SDL_FreeSurface)> flipped_surface(rotozoomSurfaceXY(surface.get(), 0, 1, -1, 0), SDL_FreeSurface);
+            if (flipped_surface.get() != nullptr)
+            {
+                load(flipped_surface.get());
+                message << "Loading image at " << path;
+                message_level = sb::Log::INFO;
+            }
+            else
+            {
+                message << "Error flipping image surface at " << path;
+                throw std::runtime_error(sb::Log::sdl_error(message.str()).str());
+            }
+        }
+        else
+        {
+            message << "Error opening image " << path;
+            throw std::runtime_error(sb::Log::sdl_error(message.str()).str());
+        }
     }
     else
     {