Fixed getting dpi scale in Linux.

.gitignore

@@ -5,3 +5,4 @@ local.properties
 run.sh
 .idea
 deploy.sh
+skiko/src/jvmMain/java/

skiko/src/jvmMain/cpp/linux/drawlayer.cc

@@ -4,6 +4,8 @@
 #include <GL/glx.h>
 #include <X11/X.h>
 #include <X11/Xlib.h>
+#include <X11/Xresource.h>
+#include <cstdlib>
 #include <unistd.h>
 #include <stdio.h>
 #include <set>
@@ -230,4 +232,46 @@ extern "C"
 
         return (jlong)window;
     }
+
+    double getDpiScaleByDisplay(Display *display)
+    {
+        char *resourceManager = XResourceManagerString(display);
+        if (resourceManager != nullptr)
+        {
+            XrmDatabase db = XrmGetStringDatabase(resourceManager);
+            if (db != nullptr)
+            {
+                XrmValue value;
+
+                char *type;
+                XrmGetResource(db, "Xft.dpi", "Xft.dpi", &type, &value);
+
+                if (value.addr != nullptr)
+                {
+                    return atof(value.addr) / 96.0;
+                }
+            }
+        }
+        return 1;
+    }
+
+    double getDpiScale()
+    {
+        Display *display = XOpenDisplay(nullptr);
+        if (display != nullptr)
+        {
+            double result = getDpiScaleByDisplay(display);
+            XCloseDisplay(display);
+            return result;
+        }
+        else
+        {
+            return 1;
+        }
+    }
+
+    JNIEXPORT jfloat JNICALL Java_org_jetbrains_skiko_PlatformOperationsKt_linuxGetDpiScaleNative(JNIEnv *env, jobject properties)
+    {
+        return (float)getDpiScale();
+    }
 } // extern "C"
\ No newline at end of file

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/HardwareLayer.kt

@@ -34,7 +34,7 @@ abstract class HardwareLayer : Canvas(), Drawable {
         external get
 
     override val contentScale: Float
-        get() = graphicsConfiguration.defaultTransform.scaleX.toFloat()
+        get() = platformOperations.getDpiScale(this)
 
     val absoluteX: Int
         get() = convertPoint(this, x, y, getRootPane(this)).x

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/PlatformOperations.kt

@@ -7,6 +7,7 @@ import javax.swing.SwingUtilities
 internal interface PlatformOperations {
     fun isFullscreen(component: Component): Boolean
     fun setFullscreen(component: Component, value: Boolean)
+    fun getDpiScale(component: Component): Float
 }
 
 internal val platformOperations: PlatformOperations by lazy {
@@ -19,8 +20,12 @@ internal val platformOperations: PlatformOperations by lazy {
                 override fun setFullscreen(component: Component, value: Boolean) {
                     osxSetFullscreenNative(component, value)
                 }
+
+                override fun getDpiScale(component: Component): Float {
+                    return component.graphicsConfiguration.defaultTransform.scaleX.toFloat()
+                }
         }
-        else -> {
+        OS.Windows -> {
             object: PlatformOperations {
                 override fun isFullscreen(component: Component): Boolean {
                     val window = SwingUtilities.getRoot(component) as Window
@@ -33,10 +38,37 @@ internal val platformOperations: PlatformOperations by lazy {
                     val device = window.graphicsConfiguration.device
                     device.setFullScreenWindow(if (value) window else null)
                 }
+
+                override fun getDpiScale(component: Component): Float {
+                    return component.graphicsConfiguration.defaultTransform.scaleX.toFloat()
+                }
+            }
+        }
+        OS.Linux -> {
+            object: PlatformOperations {
+                override fun isFullscreen(component: Component): Boolean {
+                    val window = SwingUtilities.getRoot(component) as Window
+                    val device = window.graphicsConfiguration.device
+                    return device.getFullScreenWindow() == window
+                }
+
+                override fun setFullscreen(component: Component, value: Boolean) {
+                    val window = SwingUtilities.getRoot(component) as Window
+                    val device = window.graphicsConfiguration.device
+                    device.setFullScreenWindow(if (value) window else null)
+                }
+
+                override fun getDpiScale(component: Component): Float {
+                    return linuxGetDpiScaleNative()
+                }
             }
         }
     }
 }
 
+// OSX
 external private fun osxIsFullscreenNative(component: Component): Boolean
 external private fun osxSetFullscreenNative(component: Component, value: Boolean)
+
+// Linux
+external private fun linuxGetDpiScaleNative(): Float