Android get the display Density

android-project/app/src/main/java/org/libsdl/app/SDLActivity.java

@@ -311,7 +311,7 @@ public class SDLActivity extends Activity implements View.OnSystemUiVisibilityCh
         mNextNativeState = NativeState.INIT;
         mCurrentNativeState = NativeState.INIT;
     }
-    
+
     protected SDLSurface createSDLSurface(Context context) {
         return new SDLSurface(context);
     }
@@ -909,7 +909,7 @@ public class SDLActivity extends Activity implements View.OnSystemUiVisibilityCh
     public static native void nativeResume();
     public static native void nativeFocusChanged(boolean hasFocus);
     public static native void onNativeDropFile(String filename);
-    public static native void nativeSetScreenResolution(int surfaceWidth, int surfaceHeight, int deviceWidth, int deviceHeight, float rate);
+    public static native void nativeSetScreenResolution(int surfaceWidth, int surfaceHeight, int deviceWidth, int deviceHeight, float density, float rate);
     public static native void onNativeResize();
     public static native void onNativeKeyDown(int keycode);
     public static native void onNativeKeyUp(int keycode);

android-project/app/src/main/java/org/libsdl/app/SDLSurface.java

@@ -114,6 +114,7 @@ public class SDLSurface extends SurfaceView implements SurfaceHolder.Callback,
         mHeight = height;
         int nDeviceWidth = width;
         int nDeviceHeight = height;
+        float density = 1.0f;
         try
         {
             if (Build.VERSION.SDK_INT >= 17) {
@@ -121,6 +122,7 @@ public class SDLSurface extends SurfaceView implements SurfaceHolder.Callback,
                 mDisplay.getRealMetrics( realMetrics );
                 nDeviceWidth = realMetrics.widthPixels;
                 nDeviceHeight = realMetrics.heightPixels;
+                density = realMetrics.density;
             }
         } catch(Exception ignored) {
         }
@@ -132,7 +134,7 @@ public class SDLSurface extends SurfaceView implements SurfaceHolder.Callback,
 
         Log.v("SDL", "Window size: " + width + "x" + height);
         Log.v("SDL", "Device size: " + nDeviceWidth + "x" + nDeviceHeight);
-        SDLActivity.nativeSetScreenResolution(width, height, nDeviceWidth, nDeviceHeight, mDisplay.getRefreshRate());
+        SDLActivity.nativeSetScreenResolution(width, height, nDeviceWidth, nDeviceHeight, density, mDisplay.getRefreshRate());
         SDLActivity.onNativeResize();
 
         // Prevent a screen distortion glitch,

src/core/android/SDL_android.c

@@ -74,7 +74,7 @@ JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(onNativeDropFile)(
 JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(nativeSetScreenResolution)(
     JNIEnv *env, jclass jcls,
     jint surfaceWidth, jint surfaceHeight,
-    jint deviceWidth, jint deviceHeight, jfloat rate);
+    jint deviceWidth, jint deviceHeight, jfloat density, jfloat rate);
 
 JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(onNativeResize)(
     JNIEnv *env, jclass cls);
@@ -168,7 +168,7 @@ static JNINativeMethod SDLActivity_tab[] = {
     { "nativeSetupJNI", "()I", SDL_JAVA_INTERFACE(nativeSetupJNI) },
     { "nativeRunMain", "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/Object;)I", SDL_JAVA_INTERFACE(nativeRunMain) },
     { "onNativeDropFile", "(Ljava/lang/String;)V", SDL_JAVA_INTERFACE(onNativeDropFile) },
-    { "nativeSetScreenResolution", "(IIIIF)V", SDL_JAVA_INTERFACE(nativeSetScreenResolution) },
+    { "nativeSetScreenResolution", "(IIIIFF)V", SDL_JAVA_INTERFACE(nativeSetScreenResolution) },
     { "onNativeResize", "()V", SDL_JAVA_INTERFACE(onNativeResize) },
     { "onNativeSurfaceCreated", "()V", SDL_JAVA_INTERFACE(onNativeSurfaceCreated) },
     { "onNativeSurfaceChanged", "()V", SDL_JAVA_INTERFACE(onNativeSurfaceChanged) },
@@ -870,11 +870,11 @@ retry:
 JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(nativeSetScreenResolution)(
     JNIEnv *env, jclass jcls,
     jint surfaceWidth, jint surfaceHeight,
-    jint deviceWidth, jint deviceHeight, jfloat rate)
+    jint deviceWidth, jint deviceHeight, jfloat density, jfloat rate)
 {
     SDL_LockMutex(Android_ActivityMutex);
 
-    Android_SetScreenResolution(surfaceWidth, surfaceHeight, deviceWidth, deviceHeight, rate);
+    Android_SetScreenResolution(surfaceWidth, surfaceHeight, deviceWidth, deviceHeight, density, rate);
 
     SDL_UnlockMutex(Android_ActivityMutex);
 }

src/video/android/SDL_androidvideo.c

@@ -62,6 +62,7 @@ static int Android_DeviceWidth = 0;
 static int Android_DeviceHeight = 0;
 static Uint32 Android_ScreenFormat = SDL_PIXELFORMAT_RGB565; /* Default SurfaceView format, in case this is queried before being filled */
 static float Android_ScreenRate = 0.0f;
+static float Android_ScreenDensity = 1.0f;
 SDL_sem *Android_PauseSem = NULL;
 SDL_sem *Android_ResumeSem = NULL;
 SDL_mutex *Android_ActivityMutex = NULL;
@@ -213,13 +214,14 @@ int Android_GetDisplayPhysicalDPI(_THIS, SDL_VideoDisplay *display, float *ddpi,
     return Android_JNI_GetDisplayPhysicalDPI(ddpi, hdpi, vdpi);
 }
 
-void Android_SetScreenResolution(int surfaceWidth, int surfaceHeight, int deviceWidth, int deviceHeight, float rate)
+void Android_SetScreenResolution(int surfaceWidth, int surfaceHeight, int deviceWidth, int deviceHeight, float density, float rate)
 {
     Android_SurfaceWidth = surfaceWidth;
     Android_SurfaceHeight = surfaceHeight;
     Android_DeviceWidth = deviceWidth;
     Android_DeviceHeight = deviceHeight;
     Android_ScreenRate = rate;
+    Android_ScreenDensity = density;
 }
 
 static Uint32 format_to_pixelFormat(int format)

src/video/android/SDL_androidvideo.h

@@ -26,7 +26,7 @@
 #include "../SDL_sysvideo.h"
 
 /* Called by the JNI layer when the screen changes size or format */
-extern void Android_SetScreenResolution(int surfaceWidth, int surfaceHeight, int deviceWidth, int deviceHeight, float rate);
+extern void Android_SetScreenResolution(int surfaceWidth, int surfaceHeight, int deviceWidth, int deviceHeight, float density, float rate);
 extern void Android_SetFormat(int format_wanted, int format_got);
 extern void Android_SendResize(SDL_Window *window);