Add support for top-left and bottom-left coordinate systems.

Author: bjhomer

BezierView.m

@@ -38,12 +38,22 @@ @implementation BezierView
 - (void) awakeFromNib {
 	bezierPoints = [[NSMutableArray alloc] init];
 	editingPoint = NSMakePoint(-1, -1);
+	
+	[[NSNotificationCenter defaultCenter] addObserver:self
+											 selector:@selector(frameChanged:)
+												 name:NSViewFrameDidChangeNotification
+											   object:self];
 }
 
 - (BOOL)acceptsFirstResponder {
 	return YES;
 }
 
+- (void)frameChanged:(NSNotification *)note {
+	[[self delegate] elementsDidChangeInBezierView:self];
+}
+
+
 #define NEAR_THRESHOLD 10
 
 - (NSPoint) locationOfPathElementNearPoint:(NSPoint)aPoint {
@@ -177,7 +187,9 @@ - (void)mouseDown:(NSEvent *)theEvent {
 			NSPoint trajectory = NSPointSubtractPoint(prevMain, prevC2);
 			control1 = NSPointAddToPoint(prevMain, trajectory);
 
-			control2 = NSInterpolatePoints(control1, local_point, 0.5);
+			NSPoint thingToPointBackAt = NSPointAddToPoint(control1, NSScaledPoint(trajectory, 0.5));
+			
+			control2 = NSInterpolatePoints(thingToPointBackAt, local_point, 0.33);
 		}
 
 		BezierPoint *newPoint = [[BezierPoint alloc] init];
@@ -251,7 +263,9 @@ - (void)drawRect:(NSRect)dirtyRect {
 	[extra release];
 
 	[[NSColor blackColor] set];
-	NSBezierPath * path = [NSBezierPathCodeBuilder objectForBezierPoints:bezierPoints];
+	NSBezierPathCodeBuilder *builder = [[NSBezierPathCodeBuilder alloc] init];
+	[builder setBezierPoints:bezierPoints];
+	NSBezierPath * path = [builder objectForBezierPoints];
 	[path stroke];
 }
 

CGPathRefCodeBuilder.m

@@ -12,7 +12,8 @@
 
 @implementation CGPathRefCodeBuilder
 
-+ (NSString *) codeForBezierPoints:(NSArray *)points {
+- (NSString *) codeForBezierPoints {
+	NSArray *points = [self effectiveBezierPoints];
 	NSMutableArray *lines = [NSMutableArray array];
 
 	[lines addObject:@"CGMutablePathRef path = CGPathCreateMutable();"];

CodeBuilder.h

@@ -10,10 +10,21 @@
 
 
 @interface CodeBuilder : NSObject {
-
+	NSArray *bezierPoints;
 }
 
-+ (NSString *) codeForBezierPoints:(NSArray *)points;
-+ (id) objectForBezierPoints:(NSArray *)points;
+// If yOrigin == 0, a bottom-left coordinate system is used.
+// If yOrigin != 0, a top-left coordinate system is used, and bezier
+// points (which always use bottom-left are converted before generating
+// code.
+@property (assign) CGFloat yOrigin;
+
+@property (copy) NSArray *bezierPoints;
+
+- (NSString *) codeForBezierPoints;
+- (id) objectForBezierPoints;
+
+// Bezier Points converted for the yOrigin
+- (NSArray *)effectiveBezierPoints;
 
 @end

CodeBuilder.m

@@ -7,18 +7,51 @@
 //
 
 #import "CodeBuilder.h"
+#import "BezierPoint.h"
 
 
 @implementation CodeBuilder
+@synthesize yOrigin, bezierPoints;
 
-+ (NSString *) codeForBezierPoints:(NSArray *)points {
+- (NSArray *)effectiveBezierPoints {
+	if (yOrigin == 0.0) {
+		return bezierPoints;
+	}
+	else {
+		NSMutableArray *effectivePoints = [NSMutableArray array];
+		for (BezierPoint *point in bezierPoints) {
+			CGPoint mainPoint = [point mainPoint];
+			CGPoint control1 = [point controlPoint1];
+			CGPoint control2 = [point controlPoint2];
+			
+			CGPoint newMain = CGPointMake(mainPoint.x, yOrigin - mainPoint.y);
+			CGPoint newC1 = CGPointMake(control1.x, yOrigin - control1.y);
+			CGPoint newC2 = CGPointMake(control2.x, yOrigin - control2.y);
+			
+			BezierPoint *newPoint = [[BezierPoint alloc] init];
+			[newPoint setMainPoint:newMain];
+			[newPoint setControlPoint1:newC1];
+			[newPoint setControlPoint2:newC2];
+			[effectivePoints addObject:newPoint];
+			[newPoint release];
+		}
+		return effectivePoints;
+	}
+}
+
+- (NSString *) codeForBezierPoints {
 	NSLog(@"SUBCLASSES MUST OVERRIDE");
 	return nil;
 }
 
-+ (id) objectForBezierPoints:(NSArray *)points {
+- (id) objectForBezierPoints {
 	NSLog(@"SUBCLASSES MUST OVERRIDE");
 	return nil;
 }
 
+- (void)dealloc {
+	[bezierPoints release];
+	[super dealloc];
+}
+
 @end