Fixed rendering flickering on Linux and Windows

.gitignore

@@ -5,3 +5,4 @@ local.properties
 .DS_Store
 run.sh
 .idea
+deploy.sh
\ No newline at end of file

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

@@ -33,15 +33,8 @@ public:
     }
 
 private:
-    bool isDrawing = false;
-
     void draw()
     {
-        if (isDrawing)
-        {
-            return;
-        }
-        isDrawing = true;
         if (jvm != NULL)
         {
             JNIEnv *env;
@@ -83,17 +76,13 @@ private:
                     return;
                 }
                 env->CallVoidMethod(canvasRef, drawMethod);
-
+                glFinish();
                 glXSwapBuffers(display, window);
-                glXMakeCurrent(display, 0, 0);
-
-                jvm->DetachCurrentThread();
             }
             ds->FreeDrawingSurfaceInfo(dsi);
             ds->Unlock(ds);
             awt.FreeDrawingSurface(ds);
         }
-        isDrawing = false;
     }
 };
 
@@ -111,10 +100,11 @@ LayersSet *findByObject(JNIEnv *env, jobject object)
     return NULL;
 }
 
-extern "C" {
-
-JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_updateLayer(JNIEnv *env, jobject canvas)
+extern "C"
 {
+
+    JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_updateLayer(JNIEnv *env, jobject canvas)
+    {
         if (windowsSet != NULL)
         {
             LayersSet *layer = findByObject(env, canvas);
@@ -165,7 +155,7 @@ JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_updateLayer(JNIEnv
         Window window = dsi_x11->drawable;
         if (dsi != NULL)
         {
-        GLint att[] = {GLX_RGBA, GLX_DOUBLEBUFFER, None};
+            GLint att[] = {GLX_RGBA, GLX_DOUBLEBUFFER, True, None};
 
             XVisualInfo *vi = glXChooseVisual(display, 0, att);
             GLXContext context = glXCreateContext(display, vi, NULL, GL_TRUE);
@@ -181,29 +171,28 @@ JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_updateLayer(JNIEnv
         ds->FreeDrawingSurfaceInfo(dsi);
         ds->Unlock(ds);
         awt.FreeDrawingSurface(ds);
-}
+    }
 
-JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_redrawLayer(JNIEnv *env, jobject canvas)
-{
+    JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_redrawLayer(JNIEnv *env, jobject canvas)
+    {
         LayersSet *layer = findByObject(env, canvas);
         if (layer != NULL)
         {
             layer->update();
         }
-}
+    }
 
-JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_disposeLayer(JNIEnv *env, jobject canvas)
-{
+    JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_disposeLayer(JNIEnv *env, jobject canvas)
+    {
         LayersSet *layer = findByObject(env, canvas);
         if (layer != NULL)
         {
             layer->dispose();
         }
-}
+    }
 
-JNIEXPORT jfloat JNICALL Java_org_jetbrains_skiko_HardwareLayer_getContentScale(JNIEnv *env, jobject canvas)
-{
+    JNIEXPORT jfloat JNICALL Java_org_jetbrains_skiko_HardwareLayer_getContentScale(JNIEnv *env, jobject canvas)
+    {
         return 1.0f;
-}
-
+    }
 } // extern "C"
\ No newline at end of file

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

@@ -16,54 +16,83 @@ using namespace std;
 JavaVM *jvm = NULL;
 extern "C" jboolean Skiko_GetAWT(JNIEnv *env, JAWT *awt);
 
-class LayersSet {
+class LayersSet
+{
 public:
     jobject windowRef;
     HGLRC context;
-	HWND glLayer;
+    HWND handler;
 
-	void update() {
+    void update()
+    {
         draw();
     }
 
-	void dispose() {
-		glLayer = NULL;
+    void dispose()
+    {
         context = NULL;
+        handler = NULL;
     }
 
 private:
-	bool isDrawing = false;
-	void draw() {
-		if (isDrawing) {
+    void draw()
+    {
+        if (jvm != NULL)
+        {
+            JNIEnv *env;
+            jvm->GetEnv((void **)&env, JNI_VERSION_10);
+            JAWT awt;
+            JAWT_DrawingSurface *ds = NULL;
+            JAWT_DrawingSurfaceInfo *dsi = NULL;
+            jboolean result = JNI_FALSE;
+            jint lock = 0;
+            JAWT_Win32DrawingSurfaceInfo *dsi_win;
+            awt.version = (jint)JAWT_VERSION_9;
+            result = Skiko_GetAWT(env, &awt);
+            if (result == JNI_FALSE)
+            {
+                fprintf(stderr, "JAWT_GetAWT failed! Result is JNI_FALSE\n");
                 return;
             }
 
-		isDrawing = true;
-		HDC handler = GetDC(glLayer);
-		wglMakeCurrent(handler, context);
+            ds = awt.GetDrawingSurface(env, windowRef);
+            lock = ds->Lock(ds);
+            dsi = ds->GetDrawingSurfaceInfo(ds);
+            dsi_win = (JAWT_Win32DrawingSurfaceInfo *)dsi->platformInfo;
 
-		if (jvm != NULL) {
-			JNIEnv *env;
+            HWND hwnd = dsi_win->hwnd;
+            HDC hdc = GetDC(hwnd);
+            if (dsi != NULL)
+            {
                 jvm->AttachCurrentThread((void **)&env, NULL);
 
+                wglMakeCurrent(hdc, context);
+
                 jclass wndClass = env->GetObjectClass(windowRef);
                 jmethodID drawMethod = env->GetMethodID(wndClass, "draw", "()V");
-			if (NULL == drawMethod) {
+                if (NULL == drawMethod)
+                {
                     fprintf(stderr, "The method Window.draw() not found!\n");
                     return;
                 }
                 env->CallVoidMethod(windowRef, drawMethod);
+                glFinish();
+                SwapBuffers(hdc);
+            }
+            ds->FreeDrawingSurfaceInfo(dsi);
+            ds->Unlock(ds);
+            awt.FreeDrawingSurface(ds);
         }
-
-		wglMakeCurrent(handler, NULL);
-		isDrawing = false;
     }
 };
 
-set<LayersSet*> *windowsSet = NULL;
-LayersSet *findByObject(JNIEnv *env, jobject object) {
-	for (auto &layer : *windowsSet) {
-		if (env->IsSameObject(object, layer->windowRef) == JNI_TRUE) {
+set<LayersSet *> *windowsSet = NULL;
+LayersSet *findByObject(JNIEnv *env, jobject object)
+{
+    for (auto &layer : *windowsSet)
+    {
+        if (env->IsSameObject(object, layer->windowRef) == JNI_TRUE)
+        {
             return layer;
         }
     }
@@ -71,8 +100,10 @@ LayersSet *findByObject(JNIEnv *env, jobject object) {
     return NULL;
 }
 
-float getScaleFloatFromEnum(DEVICE_SCALE_FACTOR scaleFactor) {
-    switch (scaleFactor) {
+float getScaleFloatFromEnum(DEVICE_SCALE_FACTOR scaleFactor)
+{
+    switch (scaleFactor)
+    {
     case SCALE_100_PERCENT:
         return 1.0f;
     case SCALE_120_PERCENT:
@@ -111,14 +142,18 @@ float getScaleFloatFromEnum(DEVICE_SCALE_FACTOR scaleFactor) {
     return 1.0f;
 }
 
-extern "C" {
-
-JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_updateLayer(JNIEnv *env, jobject window)
+extern "C"
 {
-	if (windowsSet != NULL) {
+
+    JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_updateLayer(JNIEnv *env, jobject window)
+    {
+        if (windowsSet != NULL)
+        {
             LayersSet *layer = findByObject(env, window);
-		if (layer != NULL) {
-			if (layer->glLayer == NULL && layer->context == NULL) {
+            if (layer != NULL)
+            {
+                if (layer->context == NULL)
+                {
                     env->DeleteGlobalRef(layer->windowRef);
                     layer->windowRef = NULL;
                     windowsSet->erase(layer);
@@ -126,40 +161,40 @@ JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_updateLayer(JNIEnv
                 }
                 return;
             }
-	} else {
-		windowsSet = new set<LayersSet*>();
+        }
+        else
+        {
+            windowsSet = new set<LayersSet *>();
         }
 
         JAWT awt;
-	JAWT_DrawingSurface* ds = NULL;
-	JAWT_DrawingSurfaceInfo* dsi = NULL;
+        JAWT_DrawingSurface *ds = NULL;
+        JAWT_DrawingSurfaceInfo *dsi = NULL;
         PIXELFORMATDESCRIPTOR pixFormatDscr;
         HGLRC context = NULL;
 
         jboolean result = JNI_FALSE;
         jint lock = 0;
-	JAWT_Win32DrawingSurfaceInfo* dsi_win;
+        JAWT_Win32DrawingSurfaceInfo *dsi_win;
 
         awt.version = (jint)JAWT_VERSION_9;
         result = Skiko_GetAWT(env, &awt);
 
-	if (result == JNI_FALSE) {
+        if (result == JNI_FALSE)
+        {
             fprintf(stderr, "JAWT_GetAWT failed! Result is JNI_FALSE\n");
             return;
         }
 
-	if (jvm == NULL) {
+        if (jvm == NULL)
+        {
             env->GetJavaVM(&jvm);
         }
 
         ds = awt.GetDrawingSurface(env, window);
-
         lock = ds->Lock(ds);
-
         dsi = ds->GetDrawingSurfaceInfo(ds);
-
-	// Get the platform-specific drawing info
-	dsi_win = (JAWT_Win32DrawingSurfaceInfo*)dsi->platformInfo;
+        dsi_win = (JAWT_Win32DrawingSurfaceInfo *)dsi->platformInfo;
 
         HWND hwnd = dsi_win->hwnd;
         HDC wndHandler = GetDC(hwnd);
@@ -169,7 +204,8 @@ JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_updateLayer(JNIEnv
             memset(&pixFormatDscr, 0, sizeof(PIXELFORMATDESCRIPTOR));
             pixFormatDscr.nSize = sizeof(PIXELFORMATDESCRIPTOR);
             pixFormatDscr.nVersion = 1;
-		pixFormatDscr.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER_DONTCARE;
+            pixFormatDscr.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
+
             pixFormatDscr.iPixelType = PFD_TYPE_RGBA;
             pixFormatDscr.cColorBits = 32;
             int iPixelFormat = ChoosePixelFormat(wndHandler, &pixFormatDscr);
@@ -177,46 +213,49 @@ JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_updateLayer(JNIEnv
             DescribePixelFormat(wndHandler, iPixelFormat, sizeof(PIXELFORMATDESCRIPTOR), &pixFormatDscr);
             context = wglCreateContext(wndHandler);
 
-		LayersSet* layer = new LayersSet();
+            LayersSet *layer = new LayersSet();
             windowsSet->insert(layer);
 
             jobject windowRef = env->NewGlobalRef(window);
 
             layer->windowRef = windowRef;
-		layer->glLayer = hwnd;
             layer->context = context;
+            layer->handler = hwnd;
         }
 
         ds->FreeDrawingSurfaceInfo(dsi);
-
         ds->Unlock(ds);
-
         awt.FreeDrawingSurface(ds);
-}
+    }
 
-JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_redrawLayer(JNIEnv *env, jobject window) {
+    JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_redrawLayer(JNIEnv *env, jobject window)
+    {
         LayersSet *layer = findByObject(env, window);
-	if (layer != NULL) {
+        if (layer != NULL)
+        {
             layer->update();
         }
-}
+    }
 
-JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_disposeLayer(JNIEnv *env, jobject window) {
+    JNIEXPORT void JNICALL Java_org_jetbrains_skiko_HardwareLayer_disposeLayer(JNIEnv *env, jobject window)
+    {
         LayersSet *layer = findByObject(env, window);
-	if (layer != NULL) {
+        if (layer != NULL)
+        {
             layer->dispose();
         }
-}
+    }
 
-JNIEXPORT jfloat JNICALL Java_org_jetbrains_skiko_HardwareLayer_getContentScale(JNIEnv *env, jobject window) {
+    JNIEXPORT jfloat JNICALL Java_org_jetbrains_skiko_HardwareLayer_getContentScale(JNIEnv *env, jobject window)
+    {
         LayersSet *layer = findByObject(env, window);
-	if (layer != NULL) {
+        if (layer != NULL)
+        {
             // get scale dpi factor of current monitor
             DEVICE_SCALE_FACTOR scaleFactor;
-		GetScaleFactorForMonitor(MonitorFromWindow(layer->glLayer, MONITOR_DEFAULTTOPRIMARY), &scaleFactor);
+            GetScaleFactorForMonitor(MonitorFromWindow(layer->handler, MONITOR_DEFAULTTOPRIMARY), &scaleFactor);
             return getScaleFloatFromEnum(scaleFactor);
         }
         return 1.0f;
-}
-
+    }
 } // extern "C"
\ No newline at end of file

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

@@ -57,15 +57,9 @@ open class SkiaLayer : HardwareLayer() {
         }
 
         skijaState.apply {
-            val gl = OpenGLApi.instance
-            gl.glClearColor(1.0f, 1.0f, 1.0f, 1.0f)
-            gl.glClear(gl.GL_COLOR_BUFFER_BIT)
-
             canvas!!.clear(-1)
             renderer?.onRender(canvas!!, width, height)
             context!!.flush()
-
-            gl.glFinish()
         }
     }
 
@@ -98,6 +92,8 @@ open class SkiaWindow : JFrame() {
     companion object {
         init {
             Library.load("/", "skiko")
+            // we have to set this property to avoid render flickering.
+            System.setProperty("sun.awt.noerasebackground", "true")
         }
     }