Fix live resizing, implement setting on all platforms.

Common/System/Display.cpp

@@ -56,22 +56,23 @@ DisplayProperties::DisplayProperties() {
 
 bool DisplayProperties::Recalculate(int new_pixel_xres, int new_pixel_yres, float new_scale, float customScale) {
 	bool px_changed = false;
-	if (pixel_xres != new_pixel_xres) {
+	if (new_pixel_xres > 0 && pixel_xres != new_pixel_xres) {
 		pixel_xres = new_pixel_xres;
 		px_changed = true;
 	}
-	if (pixel_yres != new_pixel_yres) {
+	if (new_pixel_yres > 0 && pixel_yres != new_pixel_yres) {
 		pixel_yres = new_pixel_yres;
 		px_changed = true;
 	}
 
-	dpi_scale_real = new_scale;
+	if (new_scale > 0) {
-	dpi_scale = new_scale / customScale;
+		dpi_scale_real = new_scale;
+	}
+	dpi_scale = dpi_scale_real / customScale;
 	pixel_in_dps = 1.0f / dpi_scale;
 
-	int new_dp_xres = (int)(new_pixel_xres * dpi_scale);
+	int new_dp_xres = (int)(pixel_xres * dpi_scale);
-	int new_dp_yres = (int)(new_pixel_yres * dpi_scale);
+	int new_dp_yres = (int)(pixel_yres * dpi_scale);
-
 	if (new_dp_xres != dp_xres || new_dp_yres != dp_yres || px_changed) {
 		dp_xres = new_dp_xres;
 		dp_yres = new_dp_yres;

Common/System/Display.h

@@ -41,6 +41,7 @@ struct DisplayProperties {
 	void Print();
 
 	// Returns true if the dimensions changed.
+	// The first three parameters can take -1 to signify "unchanged".
 	bool Recalculate(int new_pixel_xres, int new_pixel_yres, float new_scale, float customScale);
 };
 

Qt/QtMain.cpp

@@ -549,7 +549,7 @@ QString MainUI::InputBoxGetQString(QString title, QString defaultValue) {
 }
 
 void MainUI::resizeGL(int w, int h) {
-	if (Native_UpdateScreenScale(w, h, 1.0f)) {
+	if (Native_UpdateScreenScale(w, h, UIScaleFactorToMultiplier(g_Config.iUIScaleFactor))) {
 		System_PostUIMessage(UIMessage::GPU_RENDER_RESIZED);
 	}
 	xscale = w / this->width();
@@ -842,7 +842,7 @@ int main(int argc, char *argv[])
 
 	// We assume physicalDotsPerInchY is the same as PerInchX.
 	float dpi_scale = screen->logicalDotsPerInchX() / screen->physicalDotsPerInchX();
-	g_display.Recalculate(res.width(), res.height(), dpi_scale, 1.0f);
+	g_display.Recalculate(res.width(), res.height(), dpi_scale, UIScaleFactorToMultiplier(g_Config.iUIScaleFactor));
 
 	refreshRate = screen->refreshRate();
 

SDL/SDLMain.cpp

@@ -780,7 +780,7 @@ static void ProcessSDLEvent(SDL_Window *window, const SDL_Event &event, InputSta
 			bool fullscreen = (window_flags & SDL_WINDOW_FULLSCREEN);
 
 			// This one calls NativeResized if the size changed.
-			Native_UpdateScreenScale(new_width_px, new_height_px, 1.0f);
+			Native_UpdateScreenScale(new_width_px, new_height_px, UIScaleFactorToMultiplier(g_Config.iUIScaleFactor));
 
 			// Set variable here in case fullscreen was toggled by hotkey
 			if (g_Config.UseFullScreen() != fullscreen) {
@@ -1437,7 +1437,7 @@ int main(int argc, char *argv[]) {
 
 	float dpi_scale = 1.0f / (g_ForcedDPI == 0.0f ? g_DesktopDPI : g_ForcedDPI);
 
-	Native_UpdateScreenScale(w * g_DesktopDPI, h * g_DesktopDPI, 1.0f);
+	Native_UpdateScreenScale(w * g_DesktopDPI, h * g_DesktopDPI, UIScaleFactorToMultiplier(g_Config.iUIScaleFactor));
 
 	bool mainThreadIsRender = g_Config.iGPUBackend == (int)GPUBackend::OPENGL;
 

UI/GameSettingsScreen.cpp

@@ -1129,6 +1129,12 @@ void GameSettingsScreen::CreateSystemSettings(UI::ViewGroup *systemSettings) {
 #endif
 
 	PopupSliderChoice *uiScale = systemSettings->Add(new PopupSliderChoice(&g_Config.iUIScaleFactor, -8, 8, 0, "UI scale factor (DPI adjustment)", screenManager()));
+	uiScale->SetZeroLabel(sy->T("Off"));
+	uiScale->OnChange.Add([](UI::EventParams &e) {
+		g_display.Recalculate(-1, -1, -1, UIScaleFactorToMultiplier(g_Config.iUIScaleFactor));
+		NativeResized();
+		return UI::EVENT_DONE;
+	});
 
 	const Path bgPng = GetSysDirectory(DIRECTORY_SYSTEM) / "background.png";
 	const Path bgJpg = GetSysDirectory(DIRECTORY_SYSTEM) / "background.jpg";

UWP/App.cpp

@@ -330,7 +330,7 @@ void App::OnWindowSizeChanged(CoreWindow^ sender, WindowSizeChangedEventArgs^ ar
 
 	PSP_CoreParameter().pixelWidth = (int)(width * scale);
 	PSP_CoreParameter().pixelHeight = (int)(height * scale);
-	if (Native_UpdateScreenScale((int)width, (int)height, 1.0f)) {
+	if (Native_UpdateScreenScale((int)width, (int)height, UIScaleFactorToMultiplier(g_Config.iUIScaleFactor))) {
 		System_PostUIMessage(UIMessage::GPU_DISPLAY_RESIZED);
 	}
 }

android/jni/app-android.cpp

@@ -1001,7 +1001,7 @@ extern "C" jboolean Java_org_ppsspp_ppsspp_NativeRenderer_displayInit(JNIEnv * e
 }
 
 static bool recalculateDpi(int pixel_xres, int pixel_yres) {
-	bool retval = g_display.Recalculate(pixel_xres, pixel_yres, 240.0f / (float)display_dpi, 1.0f);
+	bool retval = g_display.Recalculate(pixel_xres, pixel_yres, 240.0f / (float)display_dpi, UIScaleFactorToMultiplier(g_Config.iUIScaleFactor));
 
 	INFO_LOG(Log::G3D, "RecalcDPI: display_xres=%d display_yres=%d pixel_xres=%d pixel_yres=%d", display_xres, display_yres, g_display.pixel_xres, g_display.pixel_yres);
 	INFO_LOG(Log::G3D, "RecalcDPI: g_dpi=%d g_dpi_scale=%f dp_xres=%d dp_yres=%d", display_dpi, g_display.dpi_scale, g_display.dp_xres, g_display.dp_yres);

ios/DisplayManager.mm

@@ -13,6 +13,9 @@
 #include "Common/System/System.h"
 #include "Common/System/NativeApp.h"
 #include "Core/System.h"
+#include "Core/Config.h"
+#include "Core/ConfigValues.h"
+
 #import <AVFoundation/AVFoundation.h>
 
 #define IS_IPAD() ([UIDevice currentDevice].userInterfaceIdiom == UIUserInterfaceIdiomPad)
@@ -151,7 +154,7 @@
 	}
 
 	float dpi_scale = 240.0f / dpi;
-	g_display.Recalculate(size.width * scale, size.height * scale, dpi_scale, 1.0f);
+	g_display.Recalculate(size.width * scale, size.height * scale, dpi_scale, UIScaleFactorToMultiplier(g_Config.iUIScaleFactor));
 
 	[[sharedViewController getView] setContentScaleFactor:scale];