* Source/cairo/GNUmakefile:

* Source/cairo/CairoContext.m:
* Source/cairo/CairoSurface.m:
* Source/cairo/XGCairoModernSurface.m:
* Headers/cairo/XGCairoModernSurface.h:
* Headers/cairo/CairoSurface.h: New cairo surface which uses
cairo_surface_create_similar to create a back buffer which
has an alpha channel, even if the X server doesn't support
surfaces with alpha. This new surface is also made the default
since this seems to be the recommended way to double buffer
with cairo.


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/back/trunk@33978 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,17 @@
+2011-10-13  Eric Wasylishen  <ewasylishen@gmail.com>
+
+	* Source/cairo/GNUmakefile:
+	* Source/cairo/CairoContext.m:
+	* Source/cairo/CairoSurface.m:
+	* Source/cairo/XGCairoModernSurface.m:
+	* Headers/cairo/XGCairoModernSurface.h:
+	* Headers/cairo/CairoSurface.h: New cairo surface which uses
+	cairo_surface_create_similar to create a back buffer which
+	has an alpha channel, even if the X server doesn't support
+	surfaces with alpha. This new surface is also made the default
+	since this seems to be the recommended way to double buffer
+	with cairo.
+
 2011-09-18  Eric Wasylishen  <ewasylishen@gmail.com>
 
 	* Source/cairo/CairoContext.m: revert the last change for now

Headers/cairo/CairoSurface.h

@@ -42,6 +42,8 @@
 
 - (cairo_surface_t *) surface;
 
+- (void) handleExposeRect: (NSRect)rect;
+
 @end
 
 #endif

Headers/cairo/XGCairoModernSurface.h

@@ -0,0 +1,38 @@
+/*
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   Author: Eric Wasylishen <ewasylishen@gmail.com>
+
+   This file is part of GNUstep.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; see the file COPYING.LIB.
+   If not, see <http://www.gnu.org/licenses/> or write to the 
+   Free Software Foundation, 51 Franklin Street, Fifth Floor, 
+   Boston, MA 02110-1301, USA.
+*/
+
+#ifndef XGCairoXModernSurface_h
+#define XGCairoXModernSurface_h
+
+#include "cairo/CairoSurface.h"
+
+@interface XGCairoModernSurface : CairoSurface
+{
+  @private
+    cairo_surface_t *_windowSurface;
+}
+@end
+
+#endif
+

Source/cairo/CairoContext.m

@@ -47,8 +47,10 @@
 #  else
 //#    define _CAIRO_SURFACE_CLASSNAME XGCairoSurface
 //#    include "cairo/XGCairoSurface.h"
-#    define _CAIRO_SURFACE_CLASSNAME XGCairoXImageSurface
-#    include "cairo/XGCairoXImageSurface.h"
+//#    define _CAIRO_SURFACE_CLASSNAME XGCairoXImageSurface
+//#    include "cairo/XGCairoXImageSurface.h"
+#    define _CAIRO_SURFACE_CLASSNAME XGCairoModernSurface
+#    include "cairo/XGCairoModernSurface.h"
 #  endif /* USE_GLITZ */
 #  include "x11/XGServerWindow.h"
 #  include "x11/XWindowBuffer.h"
@@ -103,6 +105,7 @@
 
 - (void) flushGraphics
 {
+  // FIXME: Why is this here? When is it called?
 #if BUILD_SERVER == SERVER_x11
   XFlush([(XGServer *)server xDisplay]);
 #endif // BUILD_SERVER = SERVER_x11
@@ -113,7 +116,16 @@
 /* Private backend methods */
 + (void) handleExposeRect: (NSRect)rect forDriver: (void *)driver
 {
-  [(XWindowBuffer *)driver _exposeRect: rect];
+  if ([(id)driver isKindOfClass: [XWindowBuffer class]])
+    {
+      // For XGCairoXImageSurface
+      [(XWindowBuffer *)driver _exposeRect: rect];
+    }
+  else if ([(id)driver isKindOfClass: [CairoSurface class]])
+    {
+      // For XGCairoModernSurface
+      [(CairoSurface *)driver handleExposeRect: rect];
+    }
 }
 
 #ifdef XSHM

Source/cairo/CairoSurface.m

@@ -65,4 +65,8 @@
   return _surface;
 }
 
+- (void) handleExposeRect: (NSRect)rect
+{
+}
+
 @end

Source/cairo/GNUmakefile

@@ -42,7 +42,7 @@ ifeq ($(BUILD_SERVER),x11)
   ifeq ($(WITH_GLITZ),yes)
     cairo_OBJC_FILES += XGCairoGlitzSurface.m
   else
-    cairo_OBJC_FILES += XGCairoSurface.m XGCairoXImageSurface.m
+    cairo_OBJC_FILES += XGCairoSurface.m XGCairoXImageSurface.m XGCairoModernSurface.m
   endif
 else
   ifeq ($(BUILD_GRAPHICS),cairo)

Source/cairo/XGCairoModernSurface.m

@@ -0,0 +1,148 @@
+/*
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   Author: Eric Wasylishen <ewasylishen@gmail.com>
+
+   This file is part of GNUstep.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; see the file COPYING.LIB.
+   If not, see <http://www.gnu.org/licenses/> or write to the 
+   Free Software Foundation, 51 Franklin Street, Fifth Floor, 
+   Boston, MA 02110-1301, USA.
+*/
+
+#include "config.h"
+#include "x11/XGServer.h"
+#include "x11/XGServerWindow.h"
+#include "cairo/XGCairoModernSurface.h"
+#include <cairo-xlib.h>
+
+#define GSWINDEVICE ((gswindow_device_t *)gsDevice)
+
+@implementation XGCairoModernSurface
+
+- (id) initWithDevice: (void *)device
+{
+  cairo_surface_t *windowsurface;
+
+  gsDevice = device;
+
+  // Create a cairo xlib surface for the window
+  {
+    Display *dpy = GSWINDEVICE->display;
+    Visual *visual;
+    XWindowAttributes attributes;
+    
+    if (!XGetWindowAttributes(dpy, GSWINDEVICE->ident, &attributes))
+      {
+	visual = DefaultVisual(dpy, DefaultScreen(dpy));
+      }
+    else
+      {
+	visual = attributes.visual;
+      }
+    
+    windowsurface = cairo_xlib_surface_create(GSWINDEVICE->display,
+					      GSWINDEVICE->ident,
+					      visual,
+					      GSWINDEVICE->xframe.size.width,
+					      GSWINDEVICE->xframe.size.height);
+  }
+
+
+  if (GSWINDEVICE->type == NSBackingStoreNonretained)
+    {
+      // Don't double-buffer:
+      // use the window surface as the drawing destination.
+
+      _surface = windowsurface;
+    }
+  else
+    {
+      // Do double-buffer:
+      // Create a similar surface to the window which supports alpha
+
+      // Ask XGServerWindow to call +[CairoContext handleExposeRect:forDriver:]
+      // to let us handle the back buffer -> front buffer copy using cairo.
+      GSWINDEVICE->gdriverProtocol |= GDriverHandlesExpose | GDriverHandlesBacking;
+      GSWINDEVICE->gdriver = self;
+
+      _windowSurface = windowsurface;
+      _surface = cairo_surface_create_similar(windowsurface,
+					      CAIRO_CONTENT_COLOR_ALPHA,
+					      GSWINDEVICE->xframe.size.width,
+					      GSWINDEVICE->xframe.size.height);
+
+      /*NSLog(@"Window surface type %d, back buffer type %d, w %d h %d",
+	(int) cairo_surface_get_type(_windowSurface),
+	(int) cairo_surface_get_type(_surface),
+	(int) GSWINDEVICE->xframe.size.width,
+	(int) GSWINDEVICE->xframe.size.height);
+      */
+    }
+  
+  return self;
+}
+
+- (void) dealloc
+{
+  if (_windowSurface != NULL)
+    {
+      cairo_surface_destroy(_windowSurface);
+    }
+  [super dealloc];
+}
+
+- (NSSize) size
+{
+  return GSWINDEVICE->xframe.size;
+}
+
+- (void) handleExposeRect: (NSRect)rect
+{
+  cairo_t *windowCtx = cairo_create(_windowSurface);
+
+  double backupOffsetX, backupOffsetY;
+
+  // Temporairly cancel the device offset on the back buffer since
+  // we want to work with raw X11 pixel coordinates
+
+  cairo_surface_get_device_offset(_surface, &backupOffsetX, &backupOffsetY);
+  cairo_surface_set_device_offset(_surface, 0, 0);
+
+  // Copy the desired rectangle from the back buffer to the
+  // front buffer
+
+  // FIXME: should round
+  cairo_rectangle(windowCtx, rect.origin.x, rect.origin.y, rect.size.width, rect.size.height);
+  cairo_clip(windowCtx);
+  cairo_set_source_surface(windowCtx, _surface, 0, 0);
+  cairo_set_operator(windowCtx, CAIRO_OPERATOR_SOURCE);
+  cairo_paint(windowCtx);
+
+  // Debugging
+  // cairo_reset_clip(windowCtx);
+  // cairo_set_source_rgba(windowCtx, 1.0, 0.0, 0.0, 0.5);
+  // cairo_rectangle(windowCtx, rect.origin.x, rect.origin.y, rect.size.width, rect.size.height);
+  // cairo_stroke(windowCtx);
+  //  NSLog(@"Exposing rect %@ with cairo. Status: '%s'", NSStringFromRect(rect), cairo_status_to_string(cairo_status(windowCtx)));
+
+  cairo_destroy(windowCtx);
+  
+  // Restore device offset
+  cairo_surface_set_device_offset(_surface, backupOffsetX, backupOffsetY);
+}
+
+@end
+