Add simple gradient implementation for the cairo backend.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/back/trunk@28873 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,10 @@
+2009-10-23 Fred Kiefer <FredKiefer@gmx.de>
+
+	* Source/gsc/GSContext.m,
+	* Headers/gsc/GSGStateOps.h,
+	* Source/gsc/GSGState.m: Empty definitions of gradient methods.
+	* Source/cairo/CairoGState.m: Simple cairo gradient implementation.
+
 2009-10-20 Fred Kiefer <FredKiefer@gmx.de>
 
 	* Source/winlib/WIN32GState.m: Small correction of last change.

Headers/gsc/GSGStateOps.h

@@ -27,6 +27,8 @@
 #ifndef _GSGStateOps_h_INCLUDE
 #define _GSGStateOps_h_INCLUDE
 
+@class NSGradient;
+
 @interface GSGState (Ops)
 /* ----------------------------------------------------------------------- */
 /* Color operations */
@@ -166,4 +168,20 @@
 
 @end
 
+@interface GSGState (NSGradient)
+
+- (void) drawGradient: (NSGradient*)gradient
+           fromCenter: (NSPoint)startCenter
+               radius: (CGFloat)startRadius
+             toCenter: (NSPoint)endCenter 
+               radius: (CGFloat)endRadius
+              options: (NSUInteger)options;
+
+- (void) drawGradient: (NSGradient*)gradient
+            fromPoint: (NSPoint)startPoint
+              toPoint: (NSPoint)endPoint
+              options: (NSUInteger)options;
+
+@end
+
 #endif

Source/cairo/CairoGState.m

@@ -30,6 +30,7 @@
 #include <AppKit/NSAffineTransform.h>
 #include <AppKit/NSBezierPath.h>
 #include <AppKit/NSColor.h>
+#include <AppKit/NSGradient.h>
 #include <AppKit/NSGraphics.h>
 #include "cairo/CairoGState.h"
 #include "cairo/CairoFontInfo.h"
@@ -1413,3 +1414,86 @@ _set_op(cairo_t *ct, NSCompositingOperation op)
 }
 
 @end
+
+@implementation CairoGState (NSGradient)
+
+- (void) drawGradient: (NSGradient*)gradient
+           fromCenter: (NSPoint)startCenter
+               radius: (CGFloat)startRadius
+             toCenter: (NSPoint)endCenter 
+               radius: (CGFloat)endRadius
+              options: (NSUInteger)options
+{
+  int i;
+  int stops = [gradient numberOfColorStops];
+  NSPoint startP = [ctm transformPoint: startCenter];
+  NSPoint endP = [ctm transformPoint: endCenter];
+  cairo_pattern_t *cpattern = cairo_pattern_create_radial(startP.x, startP.y, 
+                                                          floatFromUserSpace(ctm, startRadius),
+                                                          endP.x, endP.y, 
+                                                          floatFromUserSpace(ctm, endRadius));
+  for (i = 0; i < stops; i++)
+    {
+      NSColor *color;
+      CGFloat location;
+      double red;
+      double green;
+      double blue;
+      double alpha;
+
+      [gradient getColor: &color
+                location: &location
+                atIndex: i];
+      red = [color redComponent];
+      green = [color greenComponent];
+      blue = [color blueComponent];
+      alpha = [color alphaComponent];
+      cairo_pattern_add_color_stop_rgba(cpattern, location,
+                                        red, green, blue, alpha);
+    }
+  cairo_save(_ct);
+  cairo_set_source(_ct, cpattern);
+  cairo_pattern_destroy(cpattern);
+  cairo_paint(_ct);
+  cairo_restore(_ct);
+}
+
+- (void) drawGradient: (NSGradient*)gradient
+            fromPoint: (NSPoint)startPoint
+              toPoint: (NSPoint)endPoint
+              options: (NSUInteger)options
+{
+  int i;
+  int stops = [gradient numberOfColorStops];
+  NSPoint startP = [ctm transformPoint: startPoint];
+  NSPoint endP = [ctm transformPoint: endPoint];
+  cairo_pattern_t *cpattern = cairo_pattern_create_linear(startP.x, startP.y,
+                                                          endP.x, endP.y);
+
+  for (i = 0; i < stops; i++)
+    {
+      NSColor *color;
+      CGFloat location;
+      double red;
+      double green;
+      double blue;
+      double alpha;
+
+      [gradient getColor: &color
+                location: &location
+                atIndex: i];
+      red = [color redComponent];
+      green = [color greenComponent];
+      blue = [color blueComponent];
+      alpha = [color alphaComponent];
+      cairo_pattern_add_color_stop_rgba(cpattern, location,
+                                        red, green, blue, alpha);
+    }
+  cairo_save(_ct);
+  cairo_set_source(_ct, cpattern);
+  cairo_pattern_destroy(cpattern);
+  cairo_paint(_ct);
+  cairo_restore(_ct);
+}
+
+@end

Source/gsc/GSContext.m

@@ -1001,3 +1001,32 @@ static NSMapTable *gtable;
   ctxt_pop(obj, opstack, NSObject);
 }
 @end
+
+@implementation GSContext (NSGradient)
+- (void) drawGradient: (NSGradient*)gradient
+           fromCenter: (NSPoint)startCenter
+               radius: (CGFloat)startRadius
+             toCenter: (NSPoint)endCenter 
+               radius: (CGFloat)endRadius
+              options: (NSUInteger)options
+{
+  [gstate drawGradient: gradient
+          fromCenter: startCenter
+          radius: startRadius
+          toCenter: endCenter 
+          radius: endRadius
+          options: options];
+}
+
+- (void) drawGradient: (NSGradient*)gradient
+            fromPoint: (NSPoint)startPoint
+              toPoint: (NSPoint)endPoint
+              options: (NSUInteger)options
+{
+  [gstate drawGradient: gradient
+          fromPoint: startPoint
+          toPoint: endPoint
+          options: options];
+}
+
+@end

Source/gsc/GSGState.m

@@ -1304,3 +1304,25 @@ typedef enum {
 }
 
 @end
+
+@implementation GSGState (NSGradient)
+
+- (void) drawGradient: (NSGradient*)gradient
+           fromCenter: (NSPoint)startCenter
+               radius: (CGFloat)startRadius
+             toCenter: (NSPoint)endCenter 
+               radius: (CGFloat)endRadius
+              options: (NSUInteger)options
+{
+  [self subclassResponsibility: _cmd];
+}
+
+- (void) drawGradient: (NSGradient*)gradient
+            fromPoint: (NSPoint)startPoint
+              toPoint: (NSPoint)endPoint
+              options: (NSUInteger)options
+{
+  [self subclassResponsibility: _cmd];
+}
+
+@end