CODEWITHSUNDEEP
iosobjective-ccore-graphics
Surya Subenthiran
Surya Subenthiran

Reputation: 2217

CoreGraphics - Gap visible between two Quadrilaterals shaped path

I have drawn two Quadrilaterals(4 sides) shaped paths using CoreGraphics. There are 6 points totally, path1 uses the first 4 points and path2 uses the last 4 points thus both sharing 2 points.

The code is follows

- (void)drawRect:(CGRect)rect {

    CGPoint topLeft = CGPointMake(121, 116);
    CGPoint topRight = CGPointMake(221, 216);

    CGPoint middleLeft = CGPointMake(121, 180);
    CGPoint middleRight = CGPointMake(221, 280);

    CGPoint bottomLeft = CGPointMake(121, 244);
    CGPoint bottomRight = CGPointMake(221, 344);

    CGMutablePathRef subpath1 = CGPathCreateMutable();
    CGPathMoveToPoint(subpath1, NULL, topLeft.x, topLeft.y);
    CGPathAddLineToPoint(subpath1, NULL, topRight.x, topRight.y);
    CGPathAddLineToPoint(subpath1, NULL, middleRight.x, middleRight.y);
    CGPathAddLineToPoint(subpath1, NULL, middleLeft.x, middleLeft.y);
    CGPathAddLineToPoint(subpath1, NULL, topLeft.x, topLeft.y);

    CGMutablePathRef subpath2 = CGPathCreateMutable();
    CGPathMoveToPoint(subpath2, NULL, middleLeft.x, middleLeft.y);
    CGPathAddLineToPoint(subpath2, NULL, middleRight.x, middleRight.y);
    CGPathAddLineToPoint(subpath2, NULL, bottomRight.x, bottomRight.y);
    CGPathAddLineToPoint(subpath2, NULL, bottomLeft.x, bottomLeft.y);
    CGPathAddLineToPoint(subpath2, NULL, middleLeft.x, middleLeft.y);

    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetFillColorWithColor(context, [UIColor colorWithRed:0.19 green:0.42 blue:0.09 alpha:1.0].CGColor);
    CGContextSetBlendMode(context, kCGBlendModeMultiply);
    CGContextSetAlpha(context, 1.0);

    CGContextAddPath(context, subpath1);
    CGContextFillPath(context);

    CGContextAddPath(context, subpath2);
    CGContextFillPath(context);
}

The output image is

enter image description here

But in the screen there is a odd white line appears in the joining edge. I want to remove the white line.

Can anyone help how to avoid this white line?

Upvotes: 1

Views: 69

Answers (1)

bevoy
bevoy

Reputation: 751

Add both paths to the context first and then fill it.

- (void)drawRect:(CGRect)rect {

    CGPoint topLeft = CGPointMake(121, 116);
    CGPoint topRight = CGPointMake(221, 216);

    CGPoint middleLeft = CGPointMake(121, 180);
    CGPoint middleRight = CGPointMake(221, 280);

    CGPoint bottomLeft = CGPointMake(121, 244);
    CGPoint bottomRight = CGPointMake(221, 344);

    CGMutablePathRef subpath1 = CGPathCreateMutable();
    CGPathMoveToPoint(subpath1, NULL, topLeft.x, topLeft.y);
    CGPathAddLineToPoint(subpath1, NULL, topRight.x, topRight.y);
    CGPathAddLineToPoint(subpath1, NULL, middleRight.x, middleRight.y);
    CGPathAddLineToPoint(subpath1, NULL, middleLeft.x, middleLeft.y);
    CGPathAddLineToPoint(subpath1, NULL, topLeft.x, topLeft.y);

    CGMutablePathRef subpath2 = CGPathCreateMutable();
    CGPathMoveToPoint(subpath2, NULL, middleLeft.x, middleLeft.y);
    CGPathAddLineToPoint(subpath2, NULL, middleRight.x, middleRight.y);
    CGPathAddLineToPoint(subpath2, NULL, bottomRight.x, bottomRight.y);
    CGPathAddLineToPoint(subpath2, NULL, bottomLeft.x, bottomLeft.y);
    CGPathAddLineToPoint(subpath2, NULL, middleLeft.x, middleLeft.y);

    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetFillColorWithColor(context, [UIColor colorWithRed:0.19 green:0.42 blue:0.09 alpha:1.0].CGColor);
    CGContextSetBlendMode(context, kCGBlendModeMultiply);
    CGContextSetAlpha(context, 1.0);

    // Changes start here...
    CGContextAddPath(context, subpath1);
    CGContextAddPath(context, subpath2);
    CGContextFillPath(context);
}

Upvotes: 2

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