Bug 1156: GBM: Bring up incl GL rendering (TODO: GBM working page flip / sync)

- EGLSurface: Factor out 'eglCreate[Platform]WindowSurface'

NEWT egl.gbm.WindowDriver
-- Properly use GBM fourcc format and use as visualID
   for GBM surface creation and EGL config selection
-- Create eglSurface within this class
-- Hook up GBM/DRM page flip (not working yet, no visible artifacts - no swap)

- ProxySurfaceImpl.surfaceSwap() call upstreamSurface's implementation if available

TODO: 'Permission denied' calling:
- drmSetMaster (optional)
- drmModeSetCrtc
- drmModePageFlip

3 files changed, 399 insertions, 67 deletions

diff --git a/src/newt/native/egl_gbm.c b/src/newt/native/egl_gbm.c
index d4b56378c..afbab9ef2 100644
--- a/src/newt/native/egl_gbm.c
+++ b/src/newt/native/egl_gbm.c
@@ -1,39 +1,12 @@
-#include <stdlib.h>
-#include <errno.h>
-#include <string.h>
-
-#include "jogamp_newt_driver_egl_gbm_DisplayDriver.h"
-#include "jogamp_newt_driver_egl_gbm_ScreenDriver.h"
-#include "jogamp_newt_driver_egl_gbm_WindowDriver.h"
-
-#include <xf86drm.h>
-#include <xf86drmMode.h>
-#include <gbm.h>
-
-#define VERBOSE_ON 1
-
-#ifdef VERBOSE_ON
-    #define DBG_PRINT(...) fprintf(stderr, __VA_ARGS__); fflush(stderr) 
-#else
-    #define DBG_PRINT(...)
-#endif
-#define ERR_PRINT(...) fprintf(stderr, __VA_ARGS__); fflush(stderr) 
-
-typedef struct {
-    int fd; // drmClose
-    drmModeRes *resources; // drmModeFreeResources
-    drmModeConnector *connector; // drmModeFreeConnector
-    drmModeEncoder *encoder; // drmModeFreeEncoder
-    drmModeModeInfo *current_mode;
-} DRM_HANDLE;
-
-typedef struct {
-    struct gbm_bo *bo;
-    uint32_t fb_id;
-} DRM_GBM_FB;
+#include "egl_gbm.h"
 
 static jmethodID notifyScreenModeID = NULL;
 
+static jmethodID sizeChangedID = NULL;
+static jmethodID positionChangedID = NULL;
+static jmethodID visibleChangedID = NULL;
+static jmethodID windowDestroyNotifyID = NULL;
+
 /**
  * Display
  */
@@ -48,10 +21,6 @@ static void freeDrm(DRM_HANDLE *drm) {
             drmModeFreeConnector(drm->connector);
             drm->connector = NULL;
         }
-        if( NULL != drm->resources ) {
-            drmModeFreeResources(drm->resources);
-            drm->resources = NULL;
-        }
         if( 0 <= drm->fd ) {
             drmClose(drm->fd);
             drm->fd = -1;
@@ -70,23 +39,35 @@ JNIEXPORT jboolean JNICALL Java_jogamp_newt_driver_egl_gbm_DisplayDriver_initIDs
 JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_DisplayDriver_initDrm
   (JNIEnv *env, jclass clazz, jboolean verbose)
 {
+    static const char *linux_dri_card0 = "/dev/dri/card0";
     static const char *modules[] = {
-            "/dev/dri/card0", "i915", "radeon", "nouveau", "vmwgfx", "omapdrm", "exynos", "msm"
+            "i915", "radeon", "nouveau", "vmwgfx", "omapdrm", "exynos", "msm"
     };
     int module_count = sizeof(modules) / sizeof(const char*);
     const char * module_used = NULL;
-    int i, j, area;
+    int ret, i, j, area;
     DRM_HANDLE *drm = calloc(1, sizeof(DRM_HANDLE));
+    drmModeRes *resources = NULL;
 
 #ifdef VERBOSE_ON
     verbose = JNI_TRUE;
 #endif
 
     if( verbose ) {
-        ERR_PRINT( "EGL_GBM.Display initDrm start (testing %d modules)\n", module_count );
+        ERR_PRINT( "EGL_GBM.Display initDrm start\n");
     }
 
-    for (i = 0; i < module_count; i++) {
+    drm->fd = -1;
+
+#if 1
+    // try linux_dri_card0 first
+    drm->fd = open(linux_dri_card0, O_RDWR);
+    ERR_PRINT("EGL_GBM.Display trying to open '%s': success %d\n", 
+        linux_dri_card0, 0<=drm->fd);
+#endif
+
+    // try drm modules
+    for (i = 0; 0>drm->fd && i < module_count; i++) {
         if( verbose ) {
             ERR_PRINT("EGL_GBM.Display trying to load module[%d/%d] %s...", 
                 i, module_count, modules[i]);
@@ -101,7 +82,6 @@ JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_DisplayDriver_initDrm
                 ERR_PRINT("success.\n");
             }
             module_used = modules[i];
-            break;
         }
     }
     if (drm->fd < 0) {
@@ -109,27 +89,38 @@ JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_DisplayDriver_initDrm
         goto error;
     }
 
-    drm->resources = drmModeGetResources(drm->fd);
-    if ( NULL == drm->resources ) {
+#if 1
+    ret = drmSetMaster(drm->fd);
+    if(ret) {
+        //drmDropMaster(int fd);
+        DBG_PRINT( "EGL_GBM.Display drmSetMaster fd %d: FAILED: %d %s\n", 
+            drm->fd, ret, strerror(errno));
+    } else {
+        DBG_PRINT( "EGL_GBM.Display drmSetMaster fd %d: OK\n", drm->fd);
+    }
+#endif
+
+    resources = drmModeGetResources(drm->fd);
+    if ( NULL == resources ) {
         ERR_PRINT("EGL_GBM.Display drmModeGetResources failed on module %s: %s\n", 
             module_used, strerror(errno));
         goto error;
     }
 
     if( verbose ) {
-        for (i = 0; i < drm->resources->count_connectors; i++) {
-            drmModeConnector * c = drmModeGetConnector(drm->fd, drm->resources->connectors[i]);
+        for (i = 0; i < resources->count_connectors; i++) {
+            drmModeConnector * c = drmModeGetConnector(drm->fd, resources->connectors[i]);
             int chosen = DRM_MODE_CONNECTED == c->connection;
-            ERR_PRINT( "EGL_GBM.Display Connector %d/%d chosen %d: id[con 0x%X, enc 0x%X], type %d[id 0x%X], connection %d, dim %dx%x mm, modes %d, encoders %d\n",
-                i, drm->resources->count_connectors, chosen,
+            ERR_PRINT( "EGL_GBM.Display Connector %d/%d chosen %d: id[con 0x%x, enc 0x%x], type %d[id 0x%x], connection %d, dim %dx%x mm, modes %d, encoders %d\n",
+                i, resources->count_connectors, chosen,
                 c->connector_id, c->encoder_id, c->connector_type, c->connector_type_id, 
                 c->connection, c->mmWidth, c->mmHeight, c->count_modes, c->count_encoders);
             drmModeFreeConnector(c);
         }
     }
     /* find a connected connector: */
-    for (i = 0; i < drm->resources->count_connectors; i++) {
-        drm->connector = drmModeGetConnector(drm->fd, drm->resources->connectors[i]);
+    for (i = 0; i < resources->count_connectors; i++) {
+        drm->connector = drmModeGetConnector(drm->fd, resources->connectors[i]);
         if( DRM_MODE_CONNECTED == drm->connector->connection ) {
             break;
         } else {
@@ -137,12 +128,12 @@ JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_DisplayDriver_initDrm
             drm->connector = NULL;
         }
     }
-    if( i >= drm->resources->count_connectors ) {
+    if( i >= resources->count_connectors ) {
         /* we could be fancy and listen for hotplug events and wait for
          * a connector..
          */
         ERR_PRINT("EGL_GBM.Display no connected connector (connector count %d, module %s)!\n", 
-            drm->resources->count_connectors, module_used);
+            resources->count_connectors, module_used);
         goto error;
     }
 
@@ -168,19 +159,19 @@ JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_DisplayDriver_initDrm
     }
 
     if( verbose ) {
-        for (i = 0; i < drm->resources->count_encoders; i++) {
-            drmModeEncoder * e = drmModeGetEncoder(drm->fd, drm->resources->encoders[i]);
+        for (i = 0; i < resources->count_encoders; i++) {
+            drmModeEncoder * e = drmModeGetEncoder(drm->fd, resources->encoders[i]);
             int chosen = e->encoder_id == drm->connector->encoder_id;
-            ERR_PRINT( "EGL_GBM.Display Encoder %d/%d chosen %d: id 0x%X, type %d, crtc_id 0x%X, possible[crtcs %d, clones %d]\n",
-                i, drm->resources->count_encoders, chosen,
+            ERR_PRINT( "EGL_GBM.Display Encoder %d/%d chosen %d: id 0x%x, type %d, crtc_id 0x%x, possible[crtcs %d, clones %d]\n",
+                i, resources->count_encoders, chosen,
                 e->encoder_id, e->encoder_type, e->crtc_id,
                 e->possible_crtcs, e->possible_clones);
             drmModeFreeEncoder(e);
         }
     }
     /* find encoder: */
-    for (i = 0; i < drm->resources->count_encoders; i++) {
-        drm->encoder = drmModeGetEncoder(drm->fd, drm->resources->encoders[i]);
+    for (i = 0; i < resources->count_encoders; i++) {
+        drm->encoder = drmModeGetEncoder(drm->fd, resources->encoders[i]);
         if( drm->encoder->encoder_id == drm->connector->encoder_id ) {
             break;
         } else {
@@ -188,13 +179,23 @@ JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_DisplayDriver_initDrm
             drm->encoder = NULL;
         }
     }
-    if ( i >= drm->resources->count_encoders ) {
+    if ( i >= resources->count_encoders ) {
         ERR_PRINT("EGL_GBM.Display no encoder (module %s)!\n", module_used);
         goto error;
     }
+    for (i = 0; i < resources->count_crtcs; i++) {
+        if (resources->crtcs[i] == drm->encoder->crtc_id) {
+            drm->crtc_index = i;
+            break;
+        }
+    }
+
+    drmModeFreeResources(resources);
+    resources = NULL;
 
     if( verbose ) {
-        DBG_PRINT( "EGL_GBM.Display initDrm end.X0 OK\n");
+        DBG_PRINT( "EGL_GBM.Display initDrm end.X0 OK: fd %d, enc_id 0x%x, crtc_id 0x%x, conn_id 0x%x, curMode %s\n",
+            drm->fd, drm->encoder->encoder_id, drm->encoder->crtc_id, drm->connector->connector_id, drm->current_mode->name);
     }
 
     // drm->crtc_id = encoder->crtc_id;
@@ -205,6 +206,8 @@ error:
     if( verbose ) {
         DBG_PRINT( "EGL_GBM.Display initDrm end.X2 ERROR\n");
     }
+    drmModeFreeResources(resources);
+    resources = NULL;
     freeDrm(drm);
     return 0;
 }
@@ -219,6 +222,7 @@ JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_DisplayDriver_OpenGBMDis
 {
     DRM_HANDLE *drm = (DRM_HANDLE*) (intptr_t) jdrm;
     struct gbm_device * dev = gbm_create_device(drm->fd);
+    DBG_PRINT( "EGL_GBM.Display OpenGBMDisplay0 handle %p\n", dev);
     return (jlong) (intptr_t) dev;
 }
 
@@ -226,6 +230,7 @@ JNIEXPORT void JNICALL Java_jogamp_newt_driver_egl_gbm_DisplayDriver_CloseGBMDis
   (JNIEnv *env, jclass clazz, jlong jgbm)
 {
     struct gbm_device * dev = (struct gbm_device *) (intptr_t) jgbm;
+    DBG_PRINT( "EGL_GBM.Display CloseGBMDisplay0 handle %p\n", dev);
     gbm_device_destroy(dev);
 }
 
@@ -283,24 +288,58 @@ JNIEXPORT void JNICALL Java_jogamp_newt_driver_egl_gbm_ScreenDriver_initNative
 JNIEXPORT jboolean JNICALL Java_jogamp_newt_driver_egl_gbm_WindowDriver_initIDs
   (JNIEnv *env, jclass clazz)
 {
+    sizeChangedID = (*env)->GetMethodID(env, clazz, "sizeChanged", "(ZIIZ)V");
+    positionChangedID = (*env)->GetMethodID(env, clazz, "positionChanged", "(ZII)V");
+    visibleChangedID = (*env)->GetMethodID(env, clazz, "visibleChanged", "(Z)V");
+    windowDestroyNotifyID = (*env)->GetMethodID(env, clazz, "windowDestroyNotify", "(Z)Z");
+    if (sizeChangedID == NULL ||
+        positionChangedID == NULL ||
+        visibleChangedID == NULL ||
+        windowDestroyNotifyID == NULL) {
+        DBG_PRINT( "initIDs failed\n" );
+        return JNI_FALSE;
+    }
     DBG_PRINT( "EGL_GBM.Window initIDs ok\n" );
     return JNI_TRUE;
 }
 
+#ifndef DRM_FORMAT_MOD_LINEAR
+    #define DRM_FORMAT_MOD_LINEAR 0
+#endif
+
+WEAK struct gbm_surface *
+gbm_surface_create_with_modifiers(struct gbm_device *gbm,
+                                  uint32_t width, uint32_t height,
+                                  uint32_t format,
+                                  const uint64_t *modifiers,
+                                  const unsigned int count);
+
 JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_WindowDriver_CreateWindow0
-  (JNIEnv *env, jobject obj, jlong jdrm, jlong jgbm, jint x, jint y, jint width, jint height, jboolean opaque, jint alphaBits)
+  (JNIEnv *env, jobject obj, jlong jdrm, jlong jgbm, jint x, jint y, jint width, jint height, jint visual_id)
 {
     DRM_HANDLE *drm = (DRM_HANDLE*) (intptr_t) jdrm;
     struct gbm_device *dev = (struct gbm_device *) (intptr_t) jgbm;
+    uint64_t modifier = DRM_FORMAT_MOD_LINEAR;
+    struct gbm_surface *surface = NULL;
 
-    struct gbm_surface *surface = gbm_surface_create(dev,
-              drm->current_mode->hdisplay, drm->current_mode->vdisplay,
-              opaque ? GBM_FORMAT_XRGB8888 : GBM_BO_FORMAT_ARGB8888,
-              GBM_BO_USE_SCANOUT | GBM_BO_USE_RENDERING);
+    if( gbm_surface_create_with_modifiers ) {
+        surface = gbm_surface_create_with_modifiers(dev, width, height, visual_id, &modifier, 1);
+    }
+    if( NULL == surface ) {
+        if( gbm_surface_create_with_modifiers ) {
+            DBG_PRINT( "EGL_GBM.Window CreateWindow0 gbm_surface_create_with_modifiers failed\n");
+        }
+        surface = gbm_surface_create(dev, width, height, visual_id, GBM_BO_USE_SCANOUT | GBM_BO_USE_RENDERING);
+    }
     if ( NULL == surface ) {
-        DBG_PRINT("failed to create gbm surface\n");
-        return -1;
+        DBG_PRINT( "EGL_GBM.Window CreateWindow0 gbm_surface_create failed\n");
+        return 0;
     }
+
+    // Done in Java code ..
+    // (*env)->CallVoidMethod(env, obj, visibleChangedID, JNI_TRUE);
+
+    DBG_PRINT( "EGL_GBM.Window CreateWindow0 handle %p\n", surface);
     return (jlong) (intptr_t) surface;
 }
 
@@ -308,6 +347,7 @@ JNIEXPORT void JNICALL Java_jogamp_newt_driver_egl_gbm_WindowDriver_CloseWindow0
   (JNIEnv *env, jobject obj, jlong display, jlong window)
 {
     struct gbm_surface *surface = (struct gbm_surface *) (intptr_t) window;
+    DBG_PRINT( "EGL_GBM.Window CloseWindow0 handle %p\n", surface);
     gbm_surface_destroy(surface);
 }
 
diff --git a/src/newt/native/egl_gbm.h b/src/newt/native/egl_gbm.h
new file mode 100644
index 000000000..ae7c9121f
--- /dev/null
+++ b/src/newt/native/egl_gbm.h
@@ -0,0 +1,62 @@
+/**
+ * Copyright 2019 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ * 
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ * 
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#include <inttypes.h>
+
+#include "jogamp_newt_driver_egl_gbm_DisplayDriver.h"
+#include "jogamp_newt_driver_egl_gbm_ScreenDriver.h"
+#include "jogamp_newt_driver_egl_gbm_WindowDriver.h"
+
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+#include <gbm.h>
+
+#define WEAK __attribute__((weak))
+
+#define VERBOSE_ON 1
+
+#ifdef VERBOSE_ON
+    #define DBG_PRINT(...) fprintf(stderr, __VA_ARGS__); fflush(stderr) 
+#else
+    #define DBG_PRINT(...)
+#endif
+#define ERR_PRINT(...) fprintf(stderr, __VA_ARGS__); fflush(stderr) 
+
+typedef struct {
+    int fd; // drmClose
+    drmModeConnector *connector; // drmModeFreeConnector
+    drmModeEncoder *encoder; // drmModeFreeEncoder
+    int crtc_index;
+
+    drmModeModeInfo *current_mode;
+} DRM_HANDLE;
+
diff --git a/src/newt/native/egl_gbm_drmflip.c b/src/newt/native/egl_gbm_drmflip.c
new file mode 100644
index 000000000..4dda026a0
--- /dev/null
+++ b/src/newt/native/egl_gbm_drmflip.c
@@ -0,0 +1,230 @@
+#include "egl_gbm.h"
+
+#include <EGL/egl.h>
+
+WEAK uint64_t
+gbm_bo_get_modifier(struct gbm_bo *bo);
+
+WEAK int
+gbm_bo_get_plane_count(struct gbm_bo *bo);
+
+WEAK uint32_t
+gbm_bo_get_stride_for_plane(struct gbm_bo *bo, int plane);
+
+WEAK uint32_t
+gbm_bo_get_offset(struct gbm_bo *bo, int plane);
+
+typedef struct {
+    struct gbm_bo *bo;
+    uint32_t fb_id;
+} DRM_FB;
+
+static void page_flip_handler(int fd, unsigned int frame,
+          unsigned int sec, unsigned int usec, void *data)
+{
+    /* suppress 'unused parameter' warnings */
+    (void)fd, (void)frame, (void)sec, (void)usec;
+
+    int *waiting_for_flip = data;
+    *waiting_for_flip = 0;
+}
+
+static drmEventContext drm_event_ctx = {
+            .version = 2,
+            .page_flip_handler = page_flip_handler,
+    };
+
+static void drm_fb_destroy_callback(struct gbm_bo *bo, void *data)
+{
+    struct gbm_device * gbmDev = gbm_bo_get_device(bo);
+	int drm_fd = gbm_device_get_fd(gbmDev);
+	DRM_FB *fb = data;
+
+	if (fb->fb_id)
+		drmModeRmFB(drm_fd, fb->fb_id);
+
+	free(fb);
+}
+
+static DRM_FB * drm_fb_get_from_bo(struct gbm_bo *bo)
+{
+    struct gbm_device * gbmDev = gbm_bo_get_device(bo);
+	int drm_fd = gbm_device_get_fd(gbmDev);
+	DRM_FB *fb = gbm_bo_get_user_data(bo);
+	uint32_t width, height, format,
+		 strides[4] = {0}, handles[4] = {0},
+		 offsets[4] = {0}, flags = 0;
+	int ret = -1;
+
+	if (fb)
+		return fb;
+
+	fb = calloc(1, sizeof *fb);
+	fb->bo = bo;
+
+	width = gbm_bo_get_width(bo);
+	height = gbm_bo_get_height(bo);
+	format = gbm_bo_get_format(bo);
+
+	if (gbm_bo_get_modifier && gbm_bo_get_plane_count &&
+	    gbm_bo_get_stride_for_plane && gbm_bo_get_offset) {
+
+		uint64_t modifiers[4] = {0};
+		modifiers[0] = gbm_bo_get_modifier(bo);
+		const int num_planes = gbm_bo_get_plane_count(bo);
+		for (int i = 0; i < num_planes; i++) {
+			strides[i] = gbm_bo_get_stride_for_plane(bo, i);
+			handles[i] = gbm_bo_get_handle(bo).u32;
+			offsets[i] = gbm_bo_get_offset(bo, i);
+			modifiers[i] = modifiers[0];
+		}
+
+		if (modifiers[0]) {
+			flags = DRM_MODE_FB_MODIFIERS;
+			DBG_PRINT("Using modifier %" PRIx64 "\n", modifiers[0]);
+        }
+
+        ret = drmModeAddFB2WithModifiers(drm_fd, width, height,
+                format, handles, strides, offsets,
+                modifiers, &fb->fb_id, flags);
+        if(ret) {
+            ERR_PRINT("drmModeAddFB2WithModifiers failed!\n");
+        } else {
+            ERR_PRINT("drmModeAddFB2WithModifiers OK!\n");
+        }
+	}
+
+	if (ret) {
+		memcpy(handles, (uint32_t [4]){gbm_bo_get_handle(bo).u32,0,0,0}, 16);
+		memcpy(strides, (uint32_t [4]){gbm_bo_get_stride(bo),0,0,0}, 16);
+		memset(offsets, 0, 16);
+		ret = drmModeAddFB2(drm_fd, width, height, format,
+				handles, strides, offsets, &fb->fb_id, 0);
+        if(ret) {
+            ERR_PRINT("drmModeAddFB2 failed!\n");
+        } else {
+            ERR_PRINT("drmModeAddFB2 OK!\n");
+        }
+	}
+
+	if (ret) {
+		ERR_PRINT("failed to create fb: %s\n", strerror(errno));
+		free(fb);
+		return NULL;
+	}
+
+	gbm_bo_set_user_data(bo, fb, drm_fb_destroy_callback);
+
+	return fb;
+}
+
+JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_WindowDriver_FirstSwapSurface0
+  (JNIEnv *env, jobject obj, jlong jdrm, jlong jgbmSurface, jlong jeglDisplay, jlong jeglSurface)
+{
+    DRM_HANDLE *drm = (DRM_HANDLE*) (intptr_t) jdrm;
+    struct gbm_surface *gbmSurface = (struct gbm_surface *) (intptr_t) jgbmSurface;
+    EGLDisplay eglDisplay  = (EGLDisplay) (intptr_t) jeglDisplay;
+    EGLSurface eglSurface = (EGLSurface) (intptr_t) jeglSurface;
+    struct gbm_bo *nextBO = NULL;
+    DRM_FB *fb = NULL;
+    int ret;
+
+    if ( EGL_TRUE != eglSwapBuffers(eglDisplay, eglSurface) ) {
+        EGLint err = eglGetError(); 
+        ERR_PRINT("Failed eglSwapBuffers, err 0x%x\n", err);
+        return 0;
+    }
+    nextBO = gbm_surface_lock_front_buffer(gbmSurface);
+    fb = drm_fb_get_from_bo(nextBO);
+    if (!fb) {
+        ERR_PRINT("Failed to get a new framebuffer BO\n");
+        return 0;
+    }
+    /* set mode: */
+    ret = drmModeSetCrtc(drm->fd, drm->encoder->crtc_id, fb->fb_id, 0, 0,
+            &drm->connector->connector_id, 1, drm->current_mode);
+            /**
+            int drmModeSetCrtc(int fd, uint32_t crtcId, uint32_t bufferId,
+                   uint32_t x, uint32_t y, uint32_t *connectors, int count,
+                   drmModeModeInfoPtr mode);
+              */
+
+    if (ret) {
+        ERR_PRINT("drmModeSetCrtc failed to set mode: fd %d, enc_id 0x%x, crtc_id 0x%x, fb_id 0x%x, conn_id 0x%x, curMode %s: %d %s\n", 
+            drm->fd, drm->encoder->encoder_id, drm->encoder->crtc_id, fb->fb_id, 
+            drm->connector->connector_id, drm->current_mode->name, ret, strerror(errno));
+        return 0;
+    }
+    DBG_PRINT( "EGL_GBM.Window FirstSwapSurface0 nextBO %p, fd %d, enc_id 0x%x, crtc_id 0x%x, fb_id 0x%x, conn_id 0x%x, curMode %s\n", 
+        nextBO,
+        drm->fd, drm->encoder->encoder_id, drm->encoder->crtc_id, fb->fb_id, 
+        drm->connector->connector_id, drm->current_mode->name);
+    return (jlong) (intptr_t) nextBO;
+}
+
+JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_WindowDriver_NextSwapSurface0
+  (JNIEnv *env, jobject obj, jlong jdrm, jlong jgbmSurface, jlong jlastBO, jlong jeglDisplay, jlong jeglSurface)
+{
+    DRM_HANDLE *drm = (DRM_HANDLE*) (intptr_t) jdrm;
+    struct gbm_surface *gbmSurface = (struct gbm_surface *) (intptr_t) jgbmSurface;
+    struct gbm_bo *lastBO = (struct gbm_bo*) (intptr_t) jlastBO, *nextBO = NULL;
+    EGLDisplay eglDisplay  = (EGLDisplay) (intptr_t) jeglDisplay;
+    EGLSurface eglSurface = (EGLSurface) (intptr_t) jeglSurface;
+    DRM_FB *fb = NULL;
+    int ret, waiting_for_flip = 1;
+    fd_set fds;
+
+    if ( EGL_TRUE != eglSwapBuffers(eglDisplay, eglSurface) ) {
+        EGLint err = eglGetError(); 
+        ERR_PRINT("Failed eglSwapBuffers, err 0x%x\n", err);
+        return 0;
+    }
+    nextBO = gbm_surface_lock_front_buffer(gbmSurface);
+    fb = drm_fb_get_from_bo(nextBO);
+    if (!fb) {
+        ERR_PRINT("Failed to get a new framebuffer BO\n");
+        return 0;
+    }
+
+    /**
+     * Here you could also update drm plane layers if you want
+     * hw composition
+     */
+    ret = drmModePageFlip(drm->fd, drm->encoder->crtc_id, fb->fb_id,
+            DRM_MODE_PAGE_FLIP_EVENT, &waiting_for_flip);
+    if (ret) {
+        ERR_PRINT("drmModePageFlip failed to queue page flip: fd %d, enc_id 0x%x, crtc_id 0x%x, fb_id 0x%x, conn_id 0x%x, curMode %s: %p -> %p: %d %s\n", 
+            drm->fd, drm->encoder->encoder_id, drm->encoder->crtc_id, fb->fb_id, 
+            drm->connector->connector_id, drm->current_mode->name, 
+            lastBO, nextBO, ret, strerror(errno));
+        return 0;
+    }
+
+    while (waiting_for_flip) {
+        FD_ZERO(&fds);
+        FD_SET(0, &fds);
+        FD_SET(drm->fd, &fds);
+
+        ret = select(drm->fd + 1, &fds, NULL, NULL, NULL);
+        if (ret < 0) {
+            ERR_PRINT("select err: %s\n", strerror(errno));
+            return ret;
+        } else if (ret == 0) {
+            ERR_PRINT("select timeout!\n");
+            return -1;
+        } else if (FD_ISSET(0, &fds)) {
+            ERR_PRINT("user interrupted!\n");
+            return 0;
+        }
+        drmHandleEvent(drm->fd, &drm_event_ctx);
+    }
+
+    /* release last buffer to render on again: */
+    if( NULL != lastBO ) {
+        gbm_surface_release_buffer(gbmSurface, lastBO);
+    }
+
+    DBG_PRINT( "EGL_GBM.Window NextSwapSurface0 %p -> %p\n", lastBO, nextBO);
+    return (jlong) (intptr_t) nextBO;
+}
+