Question

UPDATE:
I tried implementing the method specified by Peter and am getting incorrect shadowing. What is wrong?

alt text http://grab.by/2XyP

CGContextSetShadowWithColor(c, CGSizeMake(4, 4), kAudioThumbShadowBlur, [[UAColor blackColor] CGColor]);
    CGContextFillPath(c);

    CGMutablePathRef path = CGPathCreateMutable();
    CGPathMoveToPoint(path, NULL, minx, midy);
    CGPathAddArcToPoint(path, NULL, minx, miny, midx, miny, kDefaultMargin);
    CGPathAddArcToPoint(path, NULL, maxx, miny, maxx, midy, kDefaultMargin);
    CGPathAddArcToPoint(path, NULL, maxx, maxy, midx, maxy, kDefaultMargin);
    CGPathAddArcToPoint(path, NULL, minx, maxy, minx, midy, kDefaultMargin);
    CGPathCloseSubpath(path);


    // Fill and stroke the path
    CGContextSaveGState(c);
    CGContextAddPath(c, path);
    CGContextClip(c);


    myGradient = CGGradientCreateWithColorComponents(myColorspace, components, locations, 2);
    CGContextDrawLinearGradient(c, myGradient, CGPointMake(minx,miny), CGPointMake(minx,maxy), 0);

    CGContextAddPath(c, path);
    CGPathRelease(path);
    CGContextStrokePath(c);
    CGContextRestoreGState(c);

ORIGINAL QUESTION:
I am looking to draw a natural looking shadow around the bottom of a custom rounded cell item I make in CoreGraphics using this code:

...
    CGMutablePathRef path = CGPathCreateMutable();
    CGPathMoveToPoint(path, NULL, minx, miny);
    CGPathAddArcToPoint(path, NULL, minx, maxy, midx, maxy, kDefaultMargin);
    CGPathAddArcToPoint(path, NULL, maxx, maxy, maxx, miny, kDefaultMargin);
    CGPathAddLineToPoint(path, NULL, maxx, miny);
    CGPathAddLineToPoint(path, NULL, minx, miny);
    CGPathCloseSubpath(path);

    // Fill and stroke the path
    CGContextSaveGState(c);
    CGContextAddPath(c, path);
    CGContextClip(c);

    myGradient = CGGradientCreateWithColorComponents(myColorspace, components, locations, 2);
    CGContextDrawLinearGradient(c, myGradient, CGPointMake(minx,miny), CGPointMake(minx,maxy), 0);

    CGContextAddPath(c, path);
    CGPathRelease(path);
    CGContextStrokePath(c);
    CGContextRestoreGState(c);
...

I want to apply the shadow around the outside of this path, either before or after the gradient fill. What is the best way to go about doing this?

Answer 1

A gradient draw doesn’t count as a fill, so, first, set the shadow and do a solid-color fill. Then, draw over the solid-color fill with the gradient and clipped stroke.