Force software decompression if OPENMW_DECOMPRESS_TEXTURES is set

components/sdlutil/sdlcursormanager.cpp

@@ -25,16 +25,15 @@
 USE_GRAPHICSWINDOW()
 #endif
 
+namespace CursorDecompression
+{
+    // macOS builds use the OSG fork that includes DXTC commit
     #if OSG_VERSION_GREATER_OR_EQUAL(3, 5, 8) || defined(__APPLE__)
-#define OPENMW_USE_SOFTWARE_CURSOR_DECOMPRESSION 1
+    static const bool DXTCSupported = true;
     #else
-#define OPENMW_USE_SOFTWARE_CURSOR_DECOMPRESSION 0
+    static const bool DXTCSupported = false;
     #endif
 
-#if !OPENMW_USE_SOFTWARE_CURSOR_DECOMPRESSION
-namespace
-{
-
     class MyGraphicsContext {
         public:
             MyGraphicsContext(int w, int h)
@@ -90,10 +89,8 @@ namespace
             osg::ref_ptr<osg::GraphicsContext> _gc;
     };
 
-    osg::ref_ptr<osg::Image> decompress (osg::ref_ptr<osg::Image> source, float rotDegrees)
+    SDLUtil::SurfaceUniquePtr hardwareDecompress (osg::ref_ptr<osg::Image> source, float rotDegrees)
     {
-        // TODO: use software decompression once S3TC patent expires
-
         int width = source->s();
         int height = source->t();
 
@@ -152,11 +149,55 @@ namespace
         source->releaseGLObjects();
         texture->releaseGLObjects();
 
-        return resultImage;
+        return SDLUtil::imageToSurface(resultImage, true);
+    }
+
+    SDLUtil::SurfaceUniquePtr softwareDecompress (osg::ref_ptr<osg::Image> source, float rotDegrees)
+    {
+        int width = source->s();
+        int height = source->t();
+        bool useAlpha = source->isImageTranslucent();
+
+        osg::ref_ptr<osg::Image> decompressedImage = new osg::Image;
+        decompressedImage->setFileName(source->getFileName());
+        decompressedImage->allocateImage(width, height, 1, useAlpha ? GL_RGBA : GL_RGB, GL_UNSIGNED_BYTE);
+        for (int s=0; s<width; ++s)
+            for (int t=0; t<height; ++t)
+                decompressedImage->setColor(source->getColor(s,t,0), s,t,0);
+
+        Uint32 redMask = 0x000000ff;
+        Uint32 greenMask = 0x0000ff00;
+        Uint32 blueMask = 0x00ff0000;
+        Uint32 alphaMask = useAlpha ? 0xff000000 : 0;
+
+        SDL_Surface *cursorSurface = SDL_CreateRGBSurfaceFrom(decompressedImage->data(),
+            width,
+            height,
+            decompressedImage->getPixelSizeInBits(),
+            decompressedImage->getRowSizeInBytes(),
+            redMask,
+            greenMask,
+            blueMask,
+            alphaMask);
+
+        SDL_Surface *targetSurface = SDL_CreateRGBSurface(0, width, height, 32, redMask, greenMask, blueMask, alphaMask);
+        SDL_Renderer *renderer = SDL_CreateSoftwareRenderer(targetSurface);
+
+        SDL_RenderClear(renderer);
+
+        SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "1");
+        SDL_Texture *cursorTexture = SDL_CreateTextureFromSurface(renderer, cursorSurface);
+
+        SDL_RenderCopyEx(renderer, cursorTexture, NULL, NULL, -rotDegrees, NULL, SDL_FLIP_VERTICAL);
+
+        SDL_DestroyTexture(cursorTexture);
+        SDL_FreeSurface(cursorSurface);
+        SDL_DestroyRenderer(renderer);
+
+        return SDLUtil::SurfaceUniquePtr(targetSurface, SDL_FreeSurface);
     }
 
 }
-#endif
 
 namespace SDLUtil
 {
@@ -220,77 +261,32 @@ namespace SDLUtil
 #endif
     }
 
-#if OPENMW_USE_SOFTWARE_CURSOR_DECOMPRESSION
-    SurfaceUniquePtr decompress(osg::Image* source, int rotDegrees)
-    {
-        int width = source->s();
-        int height = source->t();
-        bool useAlpha = source->isImageTranslucent();
-
-        osg::ref_ptr<osg::Image> decompressedImage = new osg::Image;
-        decompressedImage->setFileName(source->getFileName());
-        decompressedImage->allocateImage(width, height, 1, useAlpha ? GL_RGBA : GL_RGB, GL_UNSIGNED_BYTE);
-        for (int s=0; s<width; ++s)
-            for (int t=0; t<height; ++t)
-                decompressedImage->setColor(source->getColor(s,t,0), s,t,0);
-
-        Uint32 redMask = 0x000000ff;
-        Uint32 greenMask = 0x0000ff00;
-        Uint32 blueMask = 0x00ff0000;
-        Uint32 alphaMask = useAlpha ? 0xff000000 : 0;
-
-        SDL_Surface *cursorSurface = SDL_CreateRGBSurfaceFrom(decompressedImage->data(),
-            width,
-            height,
-            decompressedImage->getPixelSizeInBits(),
-            decompressedImage->getRowSizeInBytes(),
-            redMask,
-            greenMask,
-            blueMask,
-            alphaMask);
-
-        SDL_Surface *targetSurface = SDL_CreateRGBSurface(0, width, height, 32, redMask, greenMask, blueMask, alphaMask);
-        SDL_Renderer *renderer = SDL_CreateSoftwareRenderer(targetSurface);
-
-        SDL_RenderClear(renderer);
-
-        SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "1");
-        SDL_Texture *cursorTexture = SDL_CreateTextureFromSurface(renderer, cursorSurface);
-
-        SDL_RenderCopyEx(renderer, cursorTexture, NULL, NULL, -rotDegrees, NULL, SDL_FLIP_VERTICAL);
-
-        SDL_DestroyTexture(cursorTexture);
-        SDL_FreeSurface(cursorSurface);
-        SDL_DestroyRenderer(renderer);
-
-        return SurfaceUniquePtr(targetSurface, SDL_FreeSurface);
-    }
-#endif
-
     void SDLCursorManager::_createCursorFromResource(const std::string& name, int rotDegrees, osg::Image* image, Uint8 hotspot_x, Uint8 hotspot_y)
     {
         if (mCursorMap.find(name) != mCursorMap.end())
             return;
 
-#if !OPENMW_USE_SOFTWARE_CURSOR_DECOMPRESSION
+        static bool forceSoftwareDecompression = (getenv("OPENMW_DECOMPRESS_TEXTURES") != 0);
-        osg::ref_ptr<osg::Image> decompressed;
+
+        SurfaceUniquePtr (*decompressionFunction)(osg::ref_ptr<osg::Image>, float);
+        if (forceSoftwareDecompression || CursorDecompression::DXTCSupported) {
+            decompressionFunction = CursorDecompression::softwareDecompress;
+        } else {
+            decompressionFunction = CursorDecompression::hardwareDecompress;
+        }
 
         try {
-            decompressed = decompress(image, static_cast<float>(rotDegrees));
+            auto surface = decompressionFunction(image, static_cast<float>(rotDegrees));
+
+            //set the cursor and store it for later
+            SDL_Cursor* curs = SDL_CreateColorCursor(surface.get(), hotspot_x, hotspot_y);
+
+            mCursorMap.insert(CursorMap::value_type(std::string(name), curs));
         } catch (std::exception& e) {
             std::cerr << e.what() << std::endl;
             std::cerr <<"Using default cursor."<<std::endl;
             return;
         }
-
-        auto surf = SDLUtil::imageToSurface(decompressed, true);
-#else
-        auto surf = decompress(image, rotDegrees);
-#endif
-        //set the cursor and store it for later
-        SDL_Cursor* curs = SDL_CreateColorCursor(surf.get(), hotspot_x, hotspot_y);
-
-        mCursorMap.insert(CursorMap::value_type(std::string(name), curs));
     }
 
 }