Bug 1156: DRM/GBM NEWT: Clarify drmModeSetCrtc(..)'s x/y parameter and earmark spanning across monitors

drmModeSetCrtc(..)'s x/y parameter are the surface's offset to be scanned out from one CRT!

2 files changed, 84 insertions, 160 deletions

diff --git a/src/newt/classes/jogamp/newt/driver/egl/gbm/WindowDriver.java b/src/newt/classes/jogamp/newt/driver/egl/gbm/WindowDriver.java
index ce1ffc1da..6d9940b95 100644
--- a/src/newt/classes/jogamp/newt/driver/egl/gbm/WindowDriver.java
+++ b/src/newt/classes/jogamp/newt/driver/egl/gbm/WindowDriver.java
@@ -33,8 +33,6 @@ import com.jogamp.common.nio.Buffers;
 import com.jogamp.nativewindow.AbstractGraphicsScreen;
 import com.jogamp.nativewindow.NativeWindowException;
 import com.jogamp.nativewindow.util.Point;
-import com.jogamp.nativewindow.util.Rectangle;
-import com.jogamp.nativewindow.util.RectangleImmutable;
 import com.jogamp.newt.Display;
 import com.jogamp.newt.event.MouseEvent;
 import com.jogamp.opengl.GLCapabilitiesChooser;
@@ -70,95 +68,24 @@ public class WindowDriver extends WindowImpl {
         windowHandleClose = 0;
     }
 
-    /**
-     * Clamp given rectangle to given screen bounds.
-     *
-     * @param screen
-     * @param rect the {@link RectangleImmutable} in pixel units
-     * @param definePosSize if {@code true} issue {@link #definePosition(int, int)} and {@link #defineSize(int, int)}
-     *                      if either has changed.
-     * @return If position or size has been clamped a new {@link RectangleImmutable} instance w/ clamped values
-     *         will be returned, otherwise the given {@code rect} is returned.
-     */
-    private RectangleImmutable clampRect(final ScreenDriver screen, final RectangleImmutable rect, final boolean definePosSize) {
-        int x = rect.getX();
-        int y = rect.getY();
-        int w = rect.getWidth();
-        int h = rect.getHeight();
-        final int s_w = screen.getWidth();
-        final int s_h = screen.getHeight();
+    private void zeroPosition(final ScreenDriver screen, int x, int y) {
         boolean modPos = false;
-        boolean modSize = false;
-        if( 0 > x ) {
+        if( 0 != x ) {
             x = 0;
             modPos = true;
         }
-        if( 0 > y ) {
+        if( 0 != y ) {
             y = 0;
             modPos = true;
         }
-        if( s_w < x + w ) {
-            if( 0 < x ) {
-                x = 0;
-                modPos = true;
-            }
-            if( s_w < w ) {
-                w = s_w;
-                modSize = true;
-            }
-        }
-        if( s_h < y + h ) {
-            if( 0 < y ) {
-                y = 0;
-                modPos = true;
-            }
-            if( s_h < h ) {
-                h = s_h;
-                modSize = true;
-            }
-        }
-        if( modPos || modSize ) {
-            if( definePosSize ) {
-                if( modPos ) {
-                    definePosition(x, y);
-                }
-                if( modSize ) {
-                    defineSize(w, h);
-                }
-            }
-            return new Rectangle(x, y, w, h);
-        } else {
-            return rect;
+        if( modPos ) {
+            definePosition(x, y);
         }
     }
-
-    /**
-     * Align given rectangle to given screen bounds.
-     *
-     * @param screen
-     * @param rect the {@link RectangleImmutable} in pixel units
-     * @param definePosSize if {@code true} issue {@link #definePosition(int, int)} and {@link #defineSize(int, int)}
-     *                      if either has changed.
-     * @return If position or size has been aligned a new {@link RectangleImmutable} instance w/ clamped values
-     *         will be returned, otherwise the given {@code rect} is returned.
-     */
-    private RectangleImmutable alignRect2Screen(final ScreenDriver screen, final RectangleImmutable rect, final boolean definePosSize) {
-        int x = rect.getX();
-        int y = rect.getY();
-        int w = rect.getWidth();
-        int h = rect.getHeight();
+    private void adjustSize(final ScreenDriver screen, int w, int h) {
         final int s_w = screen.getWidth();
         final int s_h = screen.getHeight();
-        boolean modPos = false;
         boolean modSize = false;
-        if( 0 != x ) {
-            x = 0;
-            modPos = true;
-        }
-        if( 0 != y ) {
-            y = 0;
-            modPos = true;
-        }
         if( s_w != w ) {
             w = s_w;
             modSize = true;
@@ -167,29 +94,15 @@ public class WindowDriver extends WindowImpl {
             h = s_h;
             modSize = true;
         }
-        if( modPos || modSize ) {
-            if( definePosSize ) {
-                if( modPos ) {
-                    definePosition(x, y);
-                }
-                if( modSize ) {
-                    defineSize(w, h);
-                }
-            }
-            return new Rectangle(x, y, w, h);
-        } else {
-            return rect;
+        if( modSize ) {
+            defineSize(w, h);
         }
     }
 
     @Override
     protected boolean canCreateNativeImpl() {
-        // clamp if required incl. redefinition of position and size
-        // clampRect((ScreenDriver) getScreen(), new Rectangle(getX(), getY(), getWidth(), getHeight()), true);
-
-        // Turns out DRM / GBM can only handle full screen size FB and crtc-modesetting (?)
-        alignRect2Screen((ScreenDriver) getScreen(), new Rectangle(getX(), getY(), getWidth(), getHeight()), true);
-
+        zeroPosition((ScreenDriver) getScreen(), getX(), getY());
+        adjustSize((ScreenDriver) getScreen(), getWidth(), getHeight());
         return true; // default: always able to be created
     }
 
@@ -292,15 +205,19 @@ public class WindowDriver extends WindowImpl {
         final GLContext ctx = GLContext.getCurrent();
         final int swapInterval = ctx.getSwapInterval();
 
-        ctx.getGL().glFinish(); // FIXME: Poor man's SYNC: glFenceSync () with glWaitSync() (remove later!)
+        ctx.getGL().glFinish(); // Poor man's SYNC: glFenceSync () with glWaitSync() (remove later!)
         if(!EGL.eglSwapBuffers(display.getHandle(), eglSurface)) {
             throw new GLException("Error swapping buffers, eglError "+toHexString(EGL.eglGetError())+", "+this);
         }
         if( 0 == lastBO ) {
-            lastBO = FirstSwapSurface(d.drmFd, d.getCrtcIDs()[0], getX(), getY(), d.getConnectors()[0].getConnector_id(),
-                                       d.getModes()[0], nativeWindowHandle, swapInterval);
+            // FIXME: Support spanning across multiple CRTC (surface tiling)
+            final int surfaceOffsetX = 0;
+            final int surfaceOffsetY = 0;
+            lastBO = FirstSwapSurface(d.drmFd, d.getCrtcIDs()[0], surfaceOffsetX, surfaceOffsetY,
+                                      d.getConnectors()[0].getConnector_id(),
+                                      d.getModes()[0], nativeWindowHandle);
         } else {
-            lastBO = NextSwapSurface(d.drmFd, d.getCrtcIDs()[0], getX(), getY(), d.getConnectors()[0].getConnector_id(),
+            lastBO = NextSwapSurface(d.drmFd, d.getCrtcIDs()[0], d.getConnectors()[0].getConnector_id(),
                                      d.getModes()[0], nativeWindowHandle, lastBO, swapInterval);
         }
         return true; // eglSwapBuffers done!
@@ -382,33 +299,59 @@ public class WindowDriver extends WindowImpl {
     protected static native boolean initIDs();
     // private native void reconfigure0(long eglWindowHandle, int x, int y, int width, int height, int flags);
 
-    private long FirstSwapSurface(final int drmFd, final int crtc_id, final int x, final int y,
+    /**
+     * First surface swap, actually initial surface/crtc setup.
+     * <p>
+     * {@code surfaceOffsetX} and {@code surfaceOffsetY} explained here
+     * <https://lists.freedesktop.org/archives/dri-devel/2014-February/053826.html>,
+     * useful to span surface across multiple monitors.
+     * </p>
+     * @param drmFd
+     * @param crtc_id the crtc to map to
+     * @param surfaceOffsetX the x-offset of the surface, which could span cross multiple crtc
+     * @param surfaceOffsetY the x-offset of the surface, which could span cross multiple crtc
+     * @param connector_id
+     * @param drmMode
+     * @param gbmSurface the surface to set on the crtc_id
+     * @return
+     */
+    private long FirstSwapSurface(final int drmFd, final int crtc_id, final int surfaceOffsetX, final int surfaceOffsetY,
                                   final int connector_id, final drmModeModeInfo drmMode,
-                                  final long gbmSurface, final int swapInterval) {
+                                  final long gbmSurface) {
         final ByteBuffer bb = drmMode.getBuffer();
         if(!Buffers.isDirect(bb)) {
             throw new IllegalArgumentException("drmMode's buffer is not direct (NIO)");
         }
-        return FirstSwapSurface0(drmFd, crtc_id, x, y, connector_id,
+        return FirstSwapSurface0(drmFd, crtc_id, surfaceOffsetX, surfaceOffsetY, connector_id,
                                  bb, Buffers.getDirectBufferByteOffset(bb),
-                                 gbmSurface, swapInterval);
+                                 gbmSurface);
     }
-    private native long FirstSwapSurface0(int drmFd, int crtc_id, int x, int y,
+    private native long FirstSwapSurface0(int drmFd, int crtc_id, int surfaceOffsetX, int surfaceOffsetY,
                                           int connector_id, Object mode, int mode_byte_offset,
-                                          long gbmSurface, int swapInterval);
+                                          long gbmSurface);
 
-    private long NextSwapSurface(final int drmFd, final int crtc_id, final int x, final int y,
+    /**
+     * @param drmFd
+     * @param crtc_id the crtc to swap
+     * @param connector_id
+     * @param drmMode
+     * @param gbmSurface the surface to swap on the given crtc_id
+     * @param lastBO
+     * @param swapInterval the desired swap interval. Zero implies no vsync, otherwise vsync.
+     * @return
+     */
+    private long NextSwapSurface(final int drmFd, final int crtc_id,
                                  final int connector_id, final drmModeModeInfo drmMode,
                                  final long gbmSurface, final long lastBO, final int swapInterval) {
         final ByteBuffer bb = drmMode.getBuffer();
         if(!Buffers.isDirect(bb)) {
             throw new IllegalArgumentException("drmMode's buffer is not direct (NIO)");
         }
-        return NextSwapSurface0(drmFd, crtc_id, x, y, connector_id,
+        return NextSwapSurface0(drmFd, crtc_id, connector_id,
                                 bb, Buffers.getDirectBufferByteOffset(bb),
                                 gbmSurface, lastBO, swapInterval);
     }
-    private native long NextSwapSurface0(int drmFd, int crtc_id, int x, int y,
+    private native long NextSwapSurface0(int drmFd, int crtc_id,
                                          int connector_id, Object mode, int mode_byte_offset,
                                          long gbmSurface, long lastBO, int swapInterval);
 }
diff --git a/src/newt/native/drm_gbm_legacy.c b/src/newt/native/drm_gbm_legacy.c
index cec3297a8..9c4e19dc3 100644
--- a/src/newt/native/drm_gbm_legacy.c
+++ b/src/newt/native/drm_gbm_legacy.c
@@ -43,7 +43,6 @@ gbm_bo_get_offset(struct gbm_bo *bo, int plane);
 typedef struct {
     struct gbm_bo *bo;
     uint32_t fb_id;
-    uint32_t x, y;
 } DRM_FB;
 
 static void page_flip_handler(int fd, unsigned int frame,
@@ -180,11 +179,12 @@ static DRM_FB * drm_fb_get_from_bo(int drmFd, struct gbm_bo *bo)
 }
 
 JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_WindowDriver_FirstSwapSurface0
-  (JNIEnv *env, jobject obj, jint drmFd, jint jcrtc_id, jint jx, jint jy, 
-   jint jconnector_id, jobject jmode, jint jmode_byte_offset, 
-   jlong jgbmSurface, jint swapInterval)
+  (JNIEnv *env, jobject obj, jint drmFd, jint jcrtc_id, jint jsurfaceOffsetX, jint jsurfaceOffsetY, 
+   jint jconnector_id, jobject jmode, jint jmode_byte_offset, jlong jgbmSurface)
 {
-    uint32_t crtc_id = (uint32_t)jcrtc_id;
+    const uint32_t crtc_id = (uint32_t)jcrtc_id;
+    const uint32_t surfaceOffsetX = (uint32_t)jsurfaceOffsetX;
+    const uint32_t surfaceOffsetY = (uint32_t)jsurfaceOffsetY;
     uint32_t connector_id = (uint32_t)jconnector_id;
     drmModeModeInfo *drmMode = NULL;
     struct gbm_surface *gbmSurface = (struct gbm_surface *) (intptr_t) jgbmSurface;
@@ -202,23 +202,34 @@ JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_WindowDriver_FirstSwapSu
         ERR_PRINT("Failed to get a new framebuffer BO (0)\n");
         return 0;
     }
-    fb->x = (uint32_t)jx;
-    fb->y = (uint32_t)jy;
     /**
      * Set Mode 
      *
      * Fails with x/y != 0: -28 No space left on device
      *   drmModeSetCrtc.0 failed to set mode: fd 26, crtc_id 0x27, fb_id 0x54, pos 10/10, conn_id 0x4d, curMode 1920x1080: -28 No space left on device
+     *
+     * See https://lists.freedesktop.org/archives/dri-devel/2014-February/053826.html:
+     *
+     * - The X,Y in drmModeSetCrtc does in fact specify the "source" offset into
+     *   your framebuffer (not the destination on the CRTC) which is what I was looking for.
+     *
+     * - We were able to allocate both a Dumb buffer, and a GBM buffer the size of
+     *   6 1920x1200 monitors in a 1x6 configuration, so basically we didn't have
+     *   any memory issues with a single buffer that big.
+     *
+     * - drmModeSetCrtc worked with both Dumb and GBM buffers, and we didn't have
+     *   to do anything special on our end, so it clearly is handling the tiling
+     *   issues behind the scenes (woot).
      */
-    ret = drmModeSetCrtc(drmFd, crtc_id, fb->fb_id, fb->x, fb->y,
+    ret = drmModeSetCrtc(drmFd, crtc_id, fb->fb_id, surfaceOffsetX, surfaceOffsetY,
                          &connector_id, 1, drmMode);
     if (ret) {
-        ERR_PRINT("drmModeSetCrtc.0 failed to set mode: fd %d, crtc_id 0x%x, fb_id 0x%x, pos %d/%d, conn_id 0x%x, curMode %s: %d %s\n", 
-            drmFd, crtc_id, fb->fb_id, jx, jy, connector_id, drmMode->name, ret, strerror(errno));
+        ERR_PRINT("drmModeSetCrtc.0 failed to set mode: fd %d, crtc_id 0x%x, fb_id 0x%x (offset %d/%d), conn_id 0x%x, curMode %s: %d %s\n", 
+            drmFd, crtc_id, fb->fb_id, surfaceOffsetX, surfaceOffsetY, connector_id, drmMode->name, ret, strerror(errno));
         return 0;
     }
-    DBG_PRINT( "EGL_GBM.Window FirstSwapSurface0 swapInterval %d, nextBO %p, fd %d, crtc_id 0x%x, fb_id 0x%x, pos %d/%d, conn_id 0x%x, curMode %s\n", 
-        swapInterval, nextBO, drmFd, crtc_id, fb->fb_id, jx, jy, connector_id, drmMode->name);
+    DBG_PRINT( "EGL_GBM.Window FirstSwapSurface0 nextBO %p, fd %d, crtc_id 0x%x, fb_id 0x%x (offset %d/%d), conn_id 0x%x, curMode %s\n", 
+        nextBO, drmFd, crtc_id, fb->fb_id, surfaceOffsetX, surfaceOffsetY, connector_id, drmMode->name);
     return (jlong) (intptr_t) nextBO;
 }
 
@@ -227,17 +238,16 @@ static int nextSwapVerboseOnce = 1;
 #endif
 
 JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_WindowDriver_NextSwapSurface0
-  (JNIEnv *env, jobject obj, jint drmFd, jint jcrtc_id, jint jx, jint jy, 
+  (JNIEnv *env, jobject obj, jint drmFd, jint jcrtc_id, 
    jint jconnector_id, jobject jmode, jint jmode_byte_offset, 
    jlong jgbmSurface, jlong jlastBO, jint swapInterval)
 {
-    uint32_t crtc_id = (uint32_t)jcrtc_id;
-    uint32_t x = (uint32_t)jx;
-    uint32_t y = (uint32_t)jy;
-    uint32_t connector_id = (uint32_t)jconnector_id;
+    const uint32_t crtc_id = (uint32_t)jcrtc_id;
+    const uint32_t connector_id = (uint32_t)jconnector_id;
     drmModeModeInfo *drmMode = NULL;
     struct gbm_surface *gbmSurface = (struct gbm_surface *) (intptr_t) jgbmSurface;
-    struct gbm_bo *lastBO = (struct gbm_bo*) (intptr_t) jlastBO, *nextBO = NULL;
+    struct gbm_bo *lastBO = (struct gbm_bo*) (intptr_t) jlastBO;
+    struct gbm_bo *nextBO = NULL;
     DRM_FB *fbNext = NULL;
     int ret, waiting_for_flip = 1;
     fd_set fds;
@@ -252,30 +262,8 @@ JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_WindowDriver_NextSwapSur
         ERR_PRINT("Failed to get a new framebuffer BO (1)\n");
         return 0;
     }
-#if 0
-    if( fbNext->x != x || fbNext->y != y ) {
-        // position changed, hard drmModeSetCrtc(..) w/o vsync
-        fbNext->x = x;
-        fbNext->y = y;
-
-        /**
-         * Set Mode 
-         *
-         * Fails with x/y != 0: -28 No space left on device
-         *   drmModeSetCrtc.0 failed to set mode: fd 26, crtc_id 0x27, fb_id 0x54, pos 10/10, conn_id 0x4d, curMode 1920x1080: -28 No space left on device
-         */
-        ret = drmModeSetCrtc(drmFd, crtc_id, fbNext->fb_id, fbNext->x, fbNext->y,
-                &connector_id, 1, drmMode);
-
-        if (ret) {
-            ERR_PRINT("drmModeSetCrtc.1 failed to set mode: fd %d, crtc_id 0x%x, fb_id 0x%x, pos %d/%d, conn_id 0x%x, curMode %s: %d %s\n", 
-                drmFd, crtc_id, fbNext->fb_id, jx, jy, connector_id, drmMode->name, ret, strerror(errno));
-            return 0;
-        }
-    } else
-#endif
     if( 0 != swapInterval) {
-        // same position, use vsync
+        // https://github.com/dvdhrm/docs/blob/master/drm-howto/modeset-vsync.c#L614
         ret = drmModePageFlip(drmFd, crtc_id, fbNext->fb_id,
                 DRM_MODE_PAGE_FLIP_EVENT, &waiting_for_flip);
         if (ret) {
@@ -286,9 +274,6 @@ JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_WindowDriver_NextSwapSur
 
         while (waiting_for_flip) {
             FD_ZERO(&fds);
-#if 0
-            FD_SET(0, &fds); // STDIN_FILENO: We don't want to listen to 
-#endif
             FD_SET(drmFd, &fds);
 
             ret = select(drmFd + 1, &fds, NULL, NULL, NULL);
@@ -298,10 +283,6 @@ JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_WindowDriver_NextSwapSur
             } else if (ret == 0) {
                 ERR_PRINT("drm.select: select timeout!\n");
                 return -1;
-#if 0
-            } else if (FD_ISSET(0, &fds)) {
-                DBG_PRINT("drm.select: stdin carriage return pressed!\n");
-#endif
             }
             drmHandleEvent(drmFd, &drm_event_ctx);
         }
@@ -315,8 +296,8 @@ JNIEXPORT jlong JNICALL Java_jogamp_newt_driver_egl_gbm_WindowDriver_NextSwapSur
 #ifdef VERBOSE_ON
     if( nextSwapVerboseOnce ) {
         nextSwapVerboseOnce = 0;
-        DBG_PRINT( "EGL_GBM.Window NextSwapSurface0 swapInterval %d, bo %p -> %p, fd %d, crtc_id 0x%x, fb_id 0x%x, pos %d/%d, conn_id 0x%x, curMode %s\n", 
-            swapInterval, lastBO, nextBO, drmFd, crtc_id, fbNext->fb_id, jx, jy, connector_id, drmMode->name);
+        DBG_PRINT( "EGL_GBM.Window NextSwapSurface0 swapInterval %d, bo %p -> %p, fd %d, crtc_id 0x%x, fb_id 0x%x, conn_id 0x%x, curMode %s\n", 
+            swapInterval, lastBO, nextBO, drmFd, crtc_id, fbNext->fb_id, connector_id, drmMode->name);
     }
 #endif
     return (jlong) (intptr_t) nextBO;