I have created a view and in my draw rect method I create paths depending on what a user does with sliders. Using standard colors , everything works and looks very nice. I am trying to follow a code snippet from apple that shows how to draw patterns into a rect at this link:
Apple Drawing Guide
The example shows how to create a function callback with the pattern desired and then an additional method call to draw the rect. If I call the code as it is written from my rect it will draw my pattern as I would expect, however, I do not want to fill my rect , I want to fill a specified path in the rect. If I change the call in the drawing method from CGContextFillRect to CGContextFillPath, it doesn't work. I'm sure there is something I am overlooking to modify this code to get it to do what I want.
My callback pattern is a simple checkerboard:
code:
// Call Back function for Graphics Pattern
#define PATTERN_SIZE 10
void patternSpec(void *info , CGContextRef pContext){
NSLog(@"patternSpec Callback Called");
CGFloat subUnit = PATTERN_SIZE / 2;
CGRect square1 = {{0,0}, {subUnit, subUnit}},
square2 = {{subUnit, subUnit}, {subUnit, subUnit}},
square3 = {{0 , subUnit}, {subUnit, subUnit}},
square4 = {{subUnit , 0}, {subUnit, subUnit}};
CGContextSetRGBFillColor(pContext, 1.0, 0.0, 0.0, 1.0 );
CGContextFillRect(pContext, square1);
CGContextSetRGBFillColor(pContext, 1.0, 0.0, 0.0, 1.0 );
CGContextFillRect(pContext, square2);
CGContextSetRGBFillColor(pContext, 0.0, 0.0, 0.0, 1.0 );
CGContextFillRect(pContext, square3);
CGContextSetRGBFillColor(pContext, 0.0, 0.0, 0.0, 1.0 );
CGContextFillRect(pContext, square4);
}
// Method that draws the pattern
static void drawPattern (CGContextRef myContext)
{
NSLog(@"drawPattern Called ");
CGPatternRef pattern;
CGColorSpaceRef patternSpace;
CGFloat alpha = 1.0;
//width, height;
static const CGPatternCallbacks callbacks = {0, &patternSpec, NULL};
CGContextSaveGState (myContext);
patternSpace = CGColorSpaceCreatePattern (NULL);// 6
CGContextSetFillColorSpace (myContext, patternSpace);// 7
CGColorSpaceRelease (patternSpace);// 8
pattern = CGPatternCreate (NULL,CGRectMake (0, 0, PATTERN_SIZE, PATTERN_SIZE),
CGAffineTransformIdentity, PATTERN_SIZE, PATTERN_SIZE,
kCGPatternTilingConstantSpacing true, &callbacks);
CGContextSetFillPattern (myContext, pattern, &alpha);// 17
CGPatternRelease (pattern);// 18
//CGContextFillRect(myContext, rect);
CGContextDrawPath(myContext, kCGPathFill);
CGContextRestoreGState (myContext);
}
Here is a snippet of the code where I would like to call the routine:
CGContextSetLineWidth(context, .7);
CGContextSetRGBStrokeColor(context, 0.0, 0.0, 0.0, 1.0);
// Standard non-inverted view scenario.
CGContextBeginPath(context);
CGContextMoveToPoint(context, 0.00 , bMargin);
CGContextAddLineToPoint(context, highPX - curveSP , bMargin);
[self addCurve:context startX:highPX startY:bMargin radius:bo curveSp:curveSP curveDir:FL_BL];
CGContextAddLineToPoint(context, highPX, ((h - tMargin) - curveSP) );
[self addCurve:context startX:highPX startY: (h - tMargin) radius:bo curveSp:curveSP curveDir:FL_TL];
CGContextAddLineToPoint(context, (lowPX - curveSP), (h - tMargin) );
[self addCurve:context startX: lowPX startY: (h - tMargin) radius:bo curveSp:curveSP curveDir:FL_TR];
CGContextAddLineToPoint(context, lowPX, (bMargin + curveSP) );
[self addCurve:context startX:lowPX startY: bMargin radius:bo curveSp:curveSP curveDir:FL_BR];
CGContextAddLineToPoint(context, w, bMargin);
//CGContextDrawPath(context, nonInvertedView);
CGContextDrawPath(context, kCGPathStroke);
// fill with pattern
drawPattern(context);
The actual apple example also includes an NSRect arg in the drawing method, but since I don't want to fill a rect, I figured I could omit that. not sure though.
Thanks