Added some code to make my recent changes work with a software renderer

src/gui/core/canvas.cpp

@@ -1171,6 +1171,9 @@ void image_shape::draw(
 						  << image_->h << " to " << w << ',' << h << ".\n";
 
 				// Textures are automatically scaled to size.
+#ifdef SW_RENDERING_LEGACY_MODE
+				surf = scale_surface(image_, w, h);
+#endif
 			}
 		}
 	}
@@ -1179,6 +1182,13 @@ void image_shape::draw(
 		surf = image_;
 	}
 
+#ifdef SW_RENDERING_LEGACY_MODE
+	/* HACK: not sure why, but SW rendering has some problems with copying the surface to the texture and
+	 * corrupts certain semi-transparent pixels. This is a hacky workaround.
+	 */
+	SDL_SetSurfaceAlphaMod(surf, 254);
+#endif
+
 	dst_clip.w = w ? w : surf->w;
 	dst_clip.h = h ? h : surf->h;
 

src/gui/widgets/widget.cpp

@@ -385,12 +385,14 @@ class viewport_and_clip_rect_setter
 
 		SDL_Rect clip_rect = widget.calculate_clipping_rectangle(x_offset, y_offset);
 
+#ifndef SW_RENDERING_LEGACY_MODE
 		// Adjust clip rect origin to match the viewport origin. Currently, the both rects are mapped to
 		// absolute screen coordinates. However, setting the viewport essentially moves the screen origin,
 		// meaning if both the viewport rect and clip rect have x = 100, then clipping will actually
 		// happen at x = 200.
 		clip_rect.x -= dst_rect.x;
 		clip_rect.y -= dst_rect.y;
+#endif
 
 		SDL_RenderSetClipRect(renderer_, &clip_rect);
 	}

src/video.cpp

@@ -226,7 +226,11 @@ void CVideo::init_window()
 	}
 
 	// Initialize window
+#ifdef SW_RENDERING_LEGACY_MODE
+	window.reset(new sdl::window("", x, y, w, h, video_flags, SDL_RENDERER_SOFTWARE | SDL_RENDERER_TARGETTEXTURE));
+#else
 	window.reset(new sdl::window("", x, y, w, h, video_flags, SDL_RENDERER_ACCELERATED | SDL_RENDERER_TARGETTEXTURE));
+#endif
 
 	std::cerr << "Setting mode to " << w << "x" << h << std::endl;