Added OPGStateRef tracking and switching at appropriate times. Added OpalGState's -copyWithZone:.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/back/trunk@37119 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,26 @@
+2013-09-19  Ivan Vucica <ivan@vucica.net>
+
+	* Source/opal/OpalContext.m:
+	Added GState switcher -DPSsetgstate:. See description of 
+	_opGState in OpalGState.h. 
+
+	* Headers/opal/OpalGState.h:
+	Added _opGState i-var and relevant accessors.
+
+	* Source/opal/OpalGState.m:
+	Instead of yellow rectangle, -compositeGState:... method *should*
+	now be painting doublebuffered content from the 'other' GState,
+	but sadly does not. This needs debugging.
+
+	Implemented -copyWithZone:. See description of _opGState in
+	OpalGState.h to see how and why is _opGState used in this class,
+	how it is being copied and why it's alright to keep it nil during
+	-init and even after -DPSinitgraphics, but needs to be set in
+	-copyWithZone:.
+
+	Added -setOPGState: and -OPGState accessors for the _opGState
+	field.
+
 2013-09-18  Ivan Vucica <ivan@vucica.net>
 
 	* Source/opal/OpalSurface.m:

Headers/opal/OpalGState.h

@@ -25,6 +25,7 @@
    Boston, MA 02110-1301, USA.
 */
 
+#import <CoreGraphics/CoreGraphics.h>
 #import "gsc/GSGState.h"
 
 @class OpalSurface;
@@ -32,6 +33,30 @@
 @interface OpalGState : GSGState
 {
   OpalSurface * _opalSurface;
+
+  /** When a surface's gstate is being switched away from,
+      we store the current gstate in _opGState.
+
+      When a surface's gstate is being switched back to,
+      if _opGState is not nil, we apply the stored gstate.
+
+      To facilitate OpalGState class instance copying, we 
+      also store a copy of the gstate inside _opGState when
+      gstate's -copyWithZone: is being run. This is because
+      the same _opalSurface should be used in both new and
+      old OpalGState. 
+
+      The same is done in Cairo backend, with one key 
+      difference: since all graphics state operations in 
+      Cairo are done directly on cairo_t and are unrelated
+      to the surface, Opal mixes the concepts of a gstate
+      and a surface into a context. Hence, when gstate is
+      switched, it's OpalContext's duty to apply the stored
+      copy of a gstate from _opGState. No such trickery
+      is needed with Cairo, as Cairo backend can simply
+      have a different cairo_t with the same surface.
+   **/
+  OPGStateRef _opGState;
 }
 
 - (void) DPSinitclip;
@@ -63,4 +88,6 @@
 
 @interface OpalGState (Accessors)
 - (CGContextRef) cgContext;
+- (OPGStateRef) OPGState;
+- (void) setOPGState: (OPGStateRef) opGState;
 @end

Source/opal/OpalContext.m

@@ -84,6 +84,25 @@
   [OGSTATE DPSgrestore];
 }
 
+/** For information about this method, please see description of
+    i-var '_opGState' in OpalGState.h.
+ **/
+- (void) DPSsetgstate: (int)gstateID
+{
+  
+  OPGStateRef previousGState = OPContextCopyGState([OGSTATE cgContext]);
+  [OGSTATE setOPGState: previousGState];
+  [previousGState release]; // FIXME
+  
+  [super DPSsetgstate: gstateID];
+
+  OPGStateRef newGState = [OGSTATE OPGState];
+  if (newGState)
+    {
+      OPContextSetGState([OGSTATE cgContext], newGState);
+      [OGSTATE setOPGState: nil];
+    }
+}
 /*
 // FIXME: we should add this as soon as we implement -drawGState:...
 - (BOOL) supportsDrawGState

Source/opal/OpalGState.m

@@ -153,7 +153,7 @@ NSLog(@"                   : samplesperpixel = %d", samplesPerPixel);
                 fraction: (CGFloat)delta
 {
   NSDebugLLog(@"OpalGState", @"%p (%@): %s", self, [self class], __PRETTY_FUNCTION__);
-#if 1
+#if 0
   CGContextSaveGState(CGCTX);
   CGContextSetRGBFillColor(CGCTX, 1, 1, 0, 1);
   CGContextFillRect(CGCTX, CGRectMake(destPoint.x, destPoint.y, srcRect.size.width, srcRect.size.height));
@@ -225,6 +225,16 @@ NSLog(@"                   : samplesperpixel = %d", samplesPerPixel);
 
 @implementation OpalGState (InitializationMethods)
 
+- (id)copyWithZone: (NSZone *)zone
+{
+  OpalGState * theCopy = (OpalGState *) [super copyWithZone: zone];
+
+  [_opalSurface retain];
+  theCopy->_opGState = OPContextCopyGState(CGCTX);
+
+  return theCopy;
+}
+
 /* SOME NOTES:
    - GState approximates a cairo context: a drawing state.
    - Surface approximates a cairo surface: a place to draw things.
@@ -303,6 +313,20 @@ NSLog(@"                   : samplesperpixel = %d", samplesPerPixel);
   return [_opalSurface cgContext];
 }
 
+- (OPGStateRef) OPGState
+{
+  return _opGState;
+}
+- (void) setOPGState: (OPGStateRef)opGState
+{
+  if (opGState == _opGState)
+    return;
+
+  [opGState retain];
+  [_opGState release];
+  _opGState = opGState;
+}
+
 @end
 
 // MARK: Non-required methods
@@ -468,7 +492,7 @@ static CGFloat theAlpha = 1.; // TODO: removeme
 {
   NSDebugLLog(@"OpalGState", @"%p (%@): %s", self, [self class], __PRETTY_FUNCTION__);
   CGContextFlush(CGCTX);
-  [_opalSurface handleExpose:CGRectMake(0, 0, 1024, 1024)];
+  [_opalSurface handleExpose:CGRectMake(0, 0, 1024, 1024)]; // FIXME
 }
 - (void) DPSgsave
 {