7 files changed, 107 insertions, 14 deletions

diff --git a/src/resources/imagehelper.h b/src/resources/imagehelper.h
index 6752f3eae..b7080ee4b 100644
--- a/src/resources/imagehelper.h
+++ b/src/resources/imagehelper.h
@@ -75,15 +75,22 @@ class ImageHelper notfinal
         { return nullptr; }
 #endif
 
+        virtual SDL_Surface *create32BitSurface(int width,
+                                                int height)
+                                                const A_WARN_UNUSED;
+
+        virtual void copySurfaceToImage(Image *const image A_UNUSED,
+                                        const int x A_UNUSED,
+                                        const int y A_UNUSED,
+                                        SDL_Surface *const surface A_UNUSED)
+                                        const
+        { }
+
         static SDL_Surface *convertTo32Bit(SDL_Surface *const tmpImage)
                                            A_WARN_UNUSED;
 
         static void dumpSurfaceFormat(const SDL_Surface *const image);
 
-        virtual SDL_Surface *create32BitSurface(int width,
-                                                int height)
-                                                const A_WARN_UNUSED;
-
         static void setEnableAlpha(const bool n)
         { mEnableAlpha = n; }
 
diff --git a/src/resources/openglimagehelper.cpp b/src/resources/openglimagehelper.cpp
index d083b22b5..5f1ec643c 100644
--- a/src/resources/openglimagehelper.cpp
+++ b/src/resources/openglimagehelper.cpp
@@ -133,19 +133,12 @@ int OpenGLImageHelper::powerOfTwo(const int input)
     return value >= mTextureSize ? mTextureSize : value;
 }
 
-Image *OpenGLImageHelper::glLoad(SDL_Surface *tmpImage,
-                                 int width, int height)
+SDL_Surface *OpenGLImageHelper::convertSurface(SDL_Surface *tmpImage,
+                                               int width, int height)
 {
     if (!tmpImage)
         return nullptr;
 
-    // Flush current error flag.
-    graphicsManager.getLastError();
-
-    if (!width)
-        width = tmpImage->w;
-    if (!height)
-        height = tmpImage->h;
     int realWidth = powerOfTwo(width);
     int realHeight = powerOfTwo(height);
 
@@ -197,6 +190,28 @@ Image *OpenGLImageHelper::glLoad(SDL_Surface *tmpImage,
         }
         SDL_BlitSurface(oldImage, nullptr, tmpImage, nullptr);
     }
+    return tmpImage;
+}
+
+Image *OpenGLImageHelper::glLoad(SDL_Surface *tmpImage,
+                                 int width, int height)
+{
+    if (!tmpImage)
+        return nullptr;
+
+    // Flush current error flag.
+    graphicsManager.getLastError();
+
+    if (!width)
+        width = tmpImage->w;
+    if (!height)
+        height = tmpImage->h;
+
+    SDL_Surface *oldImage = tmpImage;
+    tmpImage = convertSurface(tmpImage, width, height);
+
+    const int realWidth = tmpImage->w;
+    const int realHeight = tmpImage->h;
 
     const GLuint texture = getNewTexture();
     switch (mUseOpenGL)
@@ -281,7 +296,7 @@ Image *OpenGLImageHelper::glLoad(SDL_Surface *tmpImage,
     if (SDL_MUSTLOCK(tmpImage))
         SDL_UnlockSurface(tmpImage);
 
-    if (oldImage)
+    if (oldImage != tmpImage)
         MSDL_FreeSurface(tmpImage);
 
     GLenum error = graphicsManager.getLastError();
@@ -358,4 +373,23 @@ void OpenGLImageHelper::invalidate(const GLuint textureId)
     }
 }
 
+void OpenGLImageHelper::copySurfaceToImage(Image *const image,
+                                           const int x, const int y,
+                                           SDL_Surface *surface) const
+{
+    if (!surface)
+        return;
+
+    SDL_Surface *const oldSurface = surface;
+    surface = convertSurface(surface, surface->w, surface->h);
+
+    glTexSubImage2D(mTextureType, 0,
+        x, y,
+        surface->w, surface->h,
+        GL_RGBA, GL_UNSIGNED_BYTE, surface->pixels);
+
+    if (surface != oldSurface)
+        MSDL_FreeSurface(surface);
+}
+
 #endif
diff --git a/src/resources/openglimagehelper.h b/src/resources/openglimagehelper.h
index 2a91689d9..b413e21ae 100644
--- a/src/resources/openglimagehelper.h
+++ b/src/resources/openglimagehelper.h
@@ -123,12 +123,19 @@ class OpenGLImageHelper final : public ImageHelper
 
         void postInit() override final;
 
+        void copySurfaceToImage(Image *const image,
+                                const int x, const int y,
+                                SDL_Surface *surface) const;
+
     protected:
         /**
          * Returns the first power of two equal or bigger than the input.
          */
         static int powerOfTwo(const int input) A_WARN_UNUSED;
 
+        static SDL_Surface *convertSurface(SDL_Surface *tmpImage,
+                                           int width, int height);
+
         Image *glLoad(SDL_Surface *tmpImage,
                       int width = 0, int height = 0) A_WARN_UNUSED;
 
diff --git a/src/resources/sdl2imagehelper.cpp b/src/resources/sdl2imagehelper.cpp
index c671a60c1..12e975ae6 100644
--- a/src/resources/sdl2imagehelper.cpp
+++ b/src/resources/sdl2imagehelper.cpp
@@ -94,4 +94,22 @@ int SDLImageHelper::combineSurface(SDL_Surface *restrict const src,
     return 1;
 }
 
+void SDLImageHelper::copySurfaceToImage(Image *const image,
+                                        const int x, const int y,
+                                        SDL_Surface *const surface) const
+{
+    if (!image || !surface)
+        return;
+
+    SDL_SetSurfaceAlphaMod(surface, SDL_ALPHA_OPAQUE);
+    SDL_SetSurfaceBlendMode(surface, SDL_BLENDMODE_NONE);
+
+    SDL_Rect rect =
+    {
+        x, y,
+        surface->w, surface->h
+    };
+
+    SDL_BlitSurface(surface, nullptr, image->mSDLSurface, &rect);
+}
 #endif  // USE_SDL2
diff --git a/src/resources/sdl2imagehelper.h b/src/resources/sdl2imagehelper.h
index e7ddc2987..f59a6bee1 100644
--- a/src/resources/sdl2imagehelper.h
+++ b/src/resources/sdl2imagehelper.h
@@ -62,6 +62,11 @@ class SDLImageHelper final : public ImageHelper
                                  const float alpha)
                                  override final A_WARN_UNUSED;
 
+        void copySurfaceToImage(Image *const image,
+                                const int x, const int y,
+                                SDL_Surface *const surface)
+                                const override final;
+
         static void SDLSetEnableAlphaCache(const bool n)
         { mEnableAlphaCache = n; }
 
diff --git a/src/resources/sdlimagehelper.cpp b/src/resources/sdlimagehelper.cpp
index 7d4090deb..baf1125fa 100644
--- a/src/resources/sdlimagehelper.cpp
+++ b/src/resources/sdlimagehelper.cpp
@@ -284,4 +284,21 @@ int SDLImageHelper::combineSurface(SDL_Surface *restrict const src,
     return SDL_gfxBlitRGBA(src, srcrect, dst, dstrect);
 }
 
+void SDLImageHelper::copySurfaceToImage(Image *const image,
+                                        const int x, const int y,
+                                        SDL_Surface *const surface) const
+{
+    if (!image || !surface)
+        return;
+
+    SDL_SetAlpha(surface, 0, SDL_ALPHA_OPAQUE);
+    SDL_Rect rect =
+    {
+        x, y,
+        surface->w, surface->h
+    };
+
+    SDL_BlitSurface(surface, nullptr, image->mSDLSurface, &rect);
+}
+
 #endif  // USE_SDL2
diff --git a/src/resources/sdlimagehelper.h b/src/resources/sdlimagehelper.h
index c80a7ba2b..9ab12368f 100644
--- a/src/resources/sdlimagehelper.h
+++ b/src/resources/sdlimagehelper.h
@@ -74,6 +74,11 @@ class SDLImageHelper final : public ImageHelper
                                  const float alpha)
                                  override final A_WARN_UNUSED;
 
+        void copySurfaceToImage(Image *const image,
+                                const int x, const int y,
+                                SDL_Surface *const surface)
+                                const override final;
+
         static void SDLSetEnableAlphaCache(const bool n)
         { mEnableAlphaCache = n; }