BACKENDS: Fix window sizing of games that switch between multiple resolutions

2 files changed, 99 insertions, 4 deletions

diff --git a/backends/graphics/sdl/sdl-graphics.cpp b/backends/graphics/sdl/sdl-graphics.cpp
index aa6087beae..a181582235 100644
--- a/backends/graphics/sdl/sdl-graphics.cpp
+++ b/backends/graphics/sdl/sdl-graphics.cpp
@@ -23,12 +23,14 @@
 #include "backends/graphics/sdl/sdl-graphics.h"
 #include "backends/platform/sdl/sdl-sys.h"
 #include "backends/events/sdl/sdl-events.h"
+#include "common/config-manager.h"
 #include "common/textconsole.h"
+#include "graphics/scaler/aspect.h"
 
 SdlGraphicsManager::SdlGraphicsManager(SdlEventSource *source, SdlWindow *window)
 	: _eventSource(source), _window(window)
 #if SDL_VERSION_ATLEAST(2, 0, 0)
-	, _allowWindowSizeReset(false), _lastFlags(0)
+	, _allowWindowSizeReset(false), _hintedWidth(0), _hintedHeight(0), _lastFlags(0)
 #endif
 	  {
 }
@@ -63,7 +65,7 @@ bool SdlGraphicsManager::setState(const State &state) {
 #ifdef USE_RGB_COLOR
 		initSize(state.screenWidth, state.screenHeight, &state.pixelFormat);
 #else
-		initSize(state.screenWidth, state.screenHeight, 0);
+		initSize(state.screenWidth, state.screenHeight, nullptr);
 #endif
 		setFeatureState(OSystem::kFeatureAspectRatioCorrection, state.aspectRatio);
 		setFeatureState(OSystem::kFeatureFullscreenMode, state.fullscreen);
@@ -76,8 +78,82 @@ bool SdlGraphicsManager::setState(const State &state) {
 	}
 }
 
+bool SdlGraphicsManager::defaultGraphicsModeConfig() const {
+	const Common::ConfigManager::Domain *transientDomain = ConfMan.getDomain(Common::ConfigManager::kTransientDomain);
+	if (transientDomain && transientDomain->contains("gfx_mode")) {
+		const Common::String &mode = transientDomain->getVal("gfx_mode");
+		if (!mode.equalsIgnoreCase("normal") && !mode.equalsIgnoreCase("default")) {
+			return false;
+		}
+	}
+
+	const Common::ConfigManager::Domain *gameDomain = ConfMan.getActiveDomain();
+	if (gameDomain && gameDomain->contains("gfx_mode")) {
+		const Common::String &mode = gameDomain->getVal("gfx_mode");
+		if (!mode.equalsIgnoreCase("normal") && !mode.equalsIgnoreCase("default")) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+int SdlGraphicsManager::getGraphicsModeIdByName(const Common::String &name) const {
+	const OSystem::GraphicsMode *mode = getSupportedGraphicsModes();
+	while (mode && mode->name != nullptr) {
+		if (name.equalsIgnoreCase(mode->name)) {
+			return mode->id;
+		}
+		++mode;
+	}
+	return -1;
+}
+
+void SdlGraphicsManager::initSizeHint(const Graphics::ModeList &modes) {
 #if SDL_VERSION_ATLEAST(2, 0, 0)
-bool SdlGraphicsManager::createOrUpdateWindow(const int width, const int height, const Uint32 flags) {
+	const bool useDefault = defaultGraphicsModeConfig();
+
+	int scale = getGraphicsModeScale(getGraphicsModeIdByName(ConfMan.get("gfx_mode")));
+	if (scale == -1) {
+		warning("Unknown scaler; defaulting to 1");
+		scale = 1;
+	}
+
+	int16 bestWidth = 0, bestHeight = 0;
+	const Graphics::ModeList::const_iterator end = modes.end();
+	for (Graphics::ModeList::const_iterator it = modes.begin(); it != end; ++it) {
+		int16 width = it->width, height = it->height;
+
+		// TODO: Normalize AR correction by passing a PAR in the mode list
+		// instead of checking the dimensions here like this, since not all
+		// 320x200/640x400 uses are with non-square pixels (e.g. DreamWeb).
+		if (ConfMan.getBool("aspect_ratio")) {
+			if ((width == 320 && height == 200) || (width == 640 && height == 400)) {
+				height = real2Aspect(height);
+			}
+		}
+
+		if (!useDefault || width <= 320) {
+			width *= scale;
+			height *= scale;
+		}
+
+		if (bestWidth < width) {
+			bestWidth = width;
+		}
+
+		if (bestHeight < height) {
+			bestHeight = height;
+		}
+	}
+
+	_hintedWidth = bestWidth;
+	_hintedHeight = bestHeight;
+#endif
+}
+
+#if SDL_VERSION_ATLEAST(2, 0, 0)
+bool SdlGraphicsManager::createOrUpdateWindow(int width, int height, const Uint32 flags) {
 	if (!_window) {
 		return false;
 	}
@@ -88,6 +164,13 @@ bool SdlGraphicsManager::createOrUpdateWindow(const int width, const int height,
 	// size or pixel format of the internal game surface (since a user may have
 	// resized the game window)
 	if (!_window->getSDLWindow() || _lastFlags != flags || _allowWindowSizeReset) {
+		if (_hintedWidth) {
+			width = _hintedWidth;
+		}
+		if (_hintedHeight) {
+			height = _hintedHeight;
+		}
+
 		if (!_window->createOrUpdateWindow(width, height, flags)) {
 			return false;
 		}
diff --git a/backends/graphics/sdl/sdl-graphics.h b/backends/graphics/sdl/sdl-graphics.h
index 937beef9b4..74ee2838ea 100644
--- a/backends/graphics/sdl/sdl-graphics.h
+++ b/backends/graphics/sdl/sdl-graphics.h
@@ -122,14 +122,26 @@ public:
 	 */
 	SdlWindow *getWindow() const { return _window; }
 
+	virtual void initSizeHint(const Graphics::ModeList &modes) override;
+
 protected:
+	virtual int getGraphicsModeScale(int mode) const = 0;
+
+	bool defaultGraphicsModeConfig() const;
+	int getGraphicsModeIdByName(const Common::String &name) const;
+
 #if SDL_VERSION_ATLEAST(2, 0, 0)
 public:
-	void unlockWindowSize() { _allowWindowSizeReset = true; }
+	void unlockWindowSize() {
+		_allowWindowSizeReset = true;
+		_hintedWidth = 0;
+		_hintedHeight = 0;
+	}
 
 protected:
 	Uint32 _lastFlags;
 	bool _allowWindowSizeReset;
+	int _hintedWidth, _hintedHeight;
 
 	bool createOrUpdateWindow(const int width, const int height, const Uint32 flags);
 #endif