Merge pull request #1 from theiostream/opal-bridge

[WIP] Implement methods for bridge between GUI and Opal

ChangeLog

@@ -1,3 +1,22 @@
+2017-07-17  Daniel Ferreira <dtf@stanford.edu>
+
+	* Source/opal/GNUmakefile: add OpalBridge.m to project.
+	* Source/opal/OpalBridge.m:	
+	Implement a bridge between NSColor and CGColorRef and a stub for a
+	bridge between NSImage and CGImageRef. This improves compatibility with
+	Quartz.
+
+2017-07-17  Daniel Ferreira <dtf@stanford.edu>
+
+	* Headers/opal/OpalSurface.h
+	* Source/opal/OpalContext.m
+	* Source/opal/OpalSurface.m:	
+	In Quartz, the "graphics port" bound to an NSGraphicsContext (subclassed
+	by OpalContext) is a CGContext. We currently initialize one in
+	OpalSurface if it does not exist, however we do not allow the client to
+	initialize a graphics context with a custom graphics port, which should
+	be allowed. We have enabled this feature.
+
 2017-07-31  Fred Kiefer <FredKiefer@gmx.de>
 
 	* Source/cairo/CairoGState.m (-DPSshow:): Get DPSshow: to work on

Headers/opal/OpalSurface.h

@@ -35,7 +35,7 @@
   CGContextRef _x11CGContext;
 }
 
-- (id) initWithDevice: (void *)device;
+- (id) initWithDevice: (void *)device context: (CGContextRef)ctx;
 - (void *)device;
 - (CGContextRef) CGContext;
 - (NSSize) size;

Source/opal/GNUmakefile

@@ -37,6 +37,7 @@ opal_OBJC_FILES = OpalSurface.m \
   OpalFaceInfo.m \
   OpalPSSurface.m \
   OpalPDFSurface.m \
+  OpalBridge.m \
   ../fontconfig/FCFaceInfo.m \
   ../fontconfig/FCFontEnumerator.m \
   ../fontconfig/FCFontInfo.m \

Source/opal/OpalBridge.m

@@ -0,0 +1,116 @@
+/*
+   OpalBridge.m
+
+   Copyright (C) 2017 Free Software Foundation, Inc.
+
+   Author: Daniel Ferreira <dtf@stanford.edu>
+   Date: July 2017
+
+   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.
+*/
+
+#import <AppKit/NSColor.h>
+#import <AppKit/NSImage.h>
+#import <AppKit/NSColorSpace.h>
+#import <AppKit/NSGraphics.h>
+#import <CoreGraphics/CGColor.h>
+#import <CoreGraphics/CGImage.h>
+#import <objc/runtime.h>
+
+@implementation NSColor (GSQuartz)
+/*
+ * FIXME:
+ * NOTE 1: GNUstep-GUI does not allow an NSColor to be created with a custom
+ * NSColorSpace. If this were allowed, we'd have to:
+ *   1) implement a bridge for -[NSColorSpace CGColorSpace]
+ *   2) for each color, extract that color space and generate a CGColorRef.
+ * NOTE 2: GNUstep-GUI makes no distinction of device and generic color spaces.
+ * If this ever ceases to be the case, some adjustment might be necessary here.
+ */
+- (CGColorRef)CGColor
+{
+  NSString *name = [self colorSpaceName];
+  
+  // FIXME: we should handle black color spaces here, which we currently
+  // ignore in the implementation.
+  CFStringRef cgColorSpaceName = NULL;
+  if ([name isEqualToString: NSCalibratedRGBColorSpace]
+    || [name isEqualToString: NSDeviceRGBColorSpace])
+    cgColorSpaceName = kCGColorSpaceSRGB;
+  else if ([name isEqualToString: NSCalibratedBlackColorSpace]
+    || [name isEqualToString: NSCalibratedWhiteColorSpace]
+    || [name isEqualToString: NSDeviceBlackColorSpace]
+    || [name isEqualToString: NSDeviceWhiteColorSpace])
+    cgColorSpaceName = kCGColorSpaceGenericGray;
+  else if ([name isEqualToString: NSDeviceCMYKColorSpace])
+    cgColorSpaceName = kCGColorSpaceGenericCMYK;
+  else if ([name isEqualToString: NSNamedColorSpace])
+    return [[self colorUsingColorSpaceName: NSDeviceRGBColorSpace] CGColor];
+
+  if (cgColorSpaceName == NULL)
+    return NULL;
+
+  CGColorSpaceRef colorSpace = CGColorSpaceCreateWithName(cgColorSpaceName);
+  CGFloat values[10];
+  [self getComponents: values];
+
+  CGColorRef color = CGColorCreate(colorSpace, values);
+  CFRelease(colorSpace);
+
+  return (CGColorRef)[(id)color autorelease];
+}
+@end
+
+@implementation NSImageRep (GSQuartz)
+- (CGImageRef)CGImageForProposedRect: (NSRect *)proposedDestRect 
+                             context: (NSGraphicsContext *)referenceContext 
+                               hints: (NSDictionary *)hints
+{
+  /*
+   * FIXME Must implement this.
+   * A note for future implementors:
+    > Apparently each NSImageRep subclass implements this method, with the
+    > base implementation being[1], as I understand it (which may be wrong):
+    > i. create a new blank context with *proposedDestRect.size and set it
+    > as the current context. This context should theoretically be
+    > constructed with properties extracted from `referenceContext` and/or
+    > `hints`, although I suppose our first implementation can go without
+    > that.
+    > ii. call [self draw];
+    > iii. adjust *proposedDestRect to round half-pixels
+    > iv. extract a CGImage from the bitmap context
+    > If NSImage.size == *proposedDestRect.size, we should just CGImageCreate
+    > directly from our representation data.
+   */
+
+  return NULL;
+}
+@end
+
+@implementation NSImage (GSQuartz)
+- (CGImageRef)CGImageForProposedRect: (NSRect *)proposedDestRect 
+                             context: (NSGraphicsContext *)referenceContext 
+                               hints: (NSDictionary *)hints
+{
+  // FIXME: Must implement this.
+  // This should pick the best NSImageRep for this NSImage and call
+  // -[NSImageRep CGImageForProposedRect:...].
+  return NULL;
+}
+@end

Source/opal/OpalContext.m

@@ -167,8 +167,20 @@
                     : (int)y
 {
   OpalSurface *surface;
-
-  surface = [[OpalSurface alloc] initWithDevice: device];
+  
+  /*
+   * The "graphics port" associated to an OpalContext is necessarily a
+   * CGContextRef supplied by the client to back the OpalContext, instead
+   * of having us create the CGContextRef ourselves.
+   *
+   * Since -graphicsPort is overriden from NSGraphicsContext to compute the
+   * CGContextRef for an OpalSurface (which is not initialized yet), we
+   * get the _graphicsPort ivar directly to obtain the supplied CGContextRef
+   * on initialization, and use that to init our surface.
+   */
+  CGContextRef suppliedContext = self->_graphicsPort;
+  surface = [[OpalSurface alloc] initWithDevice: device
+                                        context: suppliedContext];
 
   [OGSTATE GSSetSurface: surface
                        : x

Source/opal/OpalSurface.m

@@ -70,7 +70,7 @@ static CGContextRef createCGBitmapContext(int pixelsWide,
 
 @implementation OpalSurface
 
-- (void) createCGContexts
+- (void) createCGContextsWithSuppliedBackingContext: (CGContextRef)ctx
 {
   // FIXME: this method and class presumes we are being passed
   // a window device.
@@ -83,7 +83,7 @@ static CGContextRef createCGBitmapContext(int pixelsWide,
   Display * display = _gsWindowDevice->display;
   Window window = _gsWindowDevice->ident;
 
-  _x11CGContext = OPX11ContextCreate(display, window);
+  _x11CGContext = ctx ?: OPX11ContextCreate(display, window);
 
 #if 0
   if (_gsWindowDevice->type == NSBackingStoreNonretained)
@@ -114,7 +114,9 @@ static CGContextRef createCGBitmapContext(int pixelsWide,
 
 }
 
-- (id) initWithDevice: (void *)device
+// FIXME: *VERY* bad things will happen if a non-bitmap
+// context is passed here.
+- (id) initWithDevice: (void *)device context: (CGContextRef)ctx
 {
   self = [super init];
   if (!self)
@@ -124,7 +126,7 @@ static CGContextRef createCGBitmapContext(int pixelsWide,
   // a window device.
   _gsWindowDevice = (gswindow_device_t *) device;
 
-  [self createCGContexts];
+  [self createCGContextsWithSuppliedBackingContext: ctx];
 
   return self;
 }