How to draw trapezoid shape in iOS? - ios

I need help to draw trapezoid shapes in iOS.
I am using the following code to draw the Pink shape, but it is not working:
UIBezierPath* trianglePath = [UIBezierPath bezierPath];
[trianglePath moveToPoint:CGPointMake(0, 0)];
[trianglePath addLineToPoint:CGPointMake(topView.frame.size.width, topView.frame.size.height/2)];
[trianglePath addLineToPoint:CGPointMake(100, topView.frame.size.height/2)];
CAShapeLayer *triangleMaskLayer = [CAShapeLayer layer];
[triangleMaskLayer setPath:trianglePath.CGPath];
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0,topView.frame.size.height-150, 200, 150)];
view.layer.mask = triangleMaskLayer;
[self.view addSubview:view];
How can I draw the pink-colored shape?

-(void)TriangularPinkView{
UIBezierPath *path = [UIBezierPath bezierPath];
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.strokeColor = [[UIColor redColor] CGColor];
shapeLayer.lineWidth = 0.5;
CGPoint start = CGPointMake(CGRectGetMinX(self.pinkView.frame), CGRectGetMidY(self.pinkView.frame)+CGRectGetHeight(self.pinkView.frame)*.25);
[path moveToPoint:start];
[path addLineToPoint:CGPointMake(CGRectGetMaxX(self.pinkView.frame), CGRectGetMidY(self.pinkView.frame))];
[path addLineToPoint:CGPointMake(CGRectGetMaxX(self.pinkView.frame), CGRectGetMaxY(self.pinkView.frame))];
[path addLineToPoint:CGPointMake(CGRectGetMinX(self.pinkView.frame), CGRectGetMaxY(self.pinkView.frame))];
shapeLayer.path = [path CGPath];
// shapeLayer.fillRule = kCAFillRuleEvenOdd;
shapeLayer.fillColor = [[UIColor redColor] CGColor];
[self.view.layer addSublayer:shapeLayer];
}

Related

UIBezierPath - Rectangle with rounded corners

I'm using dr-Charts API to draw bar graphs in my application. I'm drawing the bar graph:
BarChart *barChartView = [[BarChart alloc] initWithFrame:CGRectMake(0, 150, WIDTH(self.view), HEIGHT(self.view) - 600)];
[barChartView setDataSource:self];
[barChartView setDelegate:self];
[barChartView setLegendViewType:LegendTypeHorizontal];
[barChartView setShowCustomMarkerView:TRUE];
[barChartView drawBarGraph];
[barChartView setDrawGridY:TRUE];
[barChartView setDrawGridX:FALSE];
[self.view addSubview:barChartView];
Actually, I want my bar chart rectangles to be rounded rect, something similar to this:
So, In BarChart.m, I started playing with API CAShapeLayer & UIBezierPath:
- (UIBezierPath *)drawBarPathWithStartPoint:(CGPoint)startPoint endPoint:(CGPoint)endPoint{
UIBezierPath *path = [UIBezierPath bezierPathWithRect:CGRectMake(startPoint.x, startPoint.y, endPoint.x - startPoint.x, endPoint.y - startPoint.y)];
//UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(startPoint.x, startPoint.y, endPoint.x - startPoint.x, endPoint.y - startPoint.y) byRoundingCorners:UIRectCornerAllCorners cornerRadii:CGSizeMake(10, 10)];
[path stroke];
return path;
}
CAShapeLayer *shapeLayer = [[CAShapeLayer alloc] init];
[shapeLayer setPath:[[self drawBarPathWithStartPoint:endPoint endPoint:startPoint] CGPath]];
[shapeLayer setStrokeColor:[barData.barColor CGColor]];
[shapeLayer setFillColor:[barData.barColor CGColor]];
[shapeLayer setFillRule:kCAFillRuleEvenOdd];
[shapeLayer setLineWidth:0.5f];
[shapeLayer setOpacity:0.7f];
[shapeLayer setShadowRadius:0.0f];
[shapeLayer setShadowColor:[[UIColor clearColor] CGColor]];
[shapeLayer setShadowOpacity:0.0f];
[shapeLayer setValue:[barData.yAxisArray objectAtIndex:i] forKey:#"data"];
After following many answers on StackOverflow, I couldn't succeed.
I tried many answers like shapeLayer.cornerRadius = 10;
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(startPoint.x, startPoint.y, endPoint.x - startPoint.x, endPoint.y - startPoint.y) byRoundingCorners:UIRectCornerAllCorners cornerRadii:CGSizeMake(10, 10)];
Could you please help.
Try to draw wide line with rounded corners, for example
UIBezierPath *linePath = [UIBezierPath bezierPath];
[linePath moveToPoint:CGPointMake(topX, topY)];
[linePath addLineToPoint:CGPointMake(bottomX, bottomY)];
CAShapeLayer *line = [CAShapeLayer layer];
line.frame = some_frame;
line.lineCap = kCALineCapRound;
line.path = linePath.CGPath;
line.fillColor = nil;
line.lineWidth = 6.0;
line.cornerRadius = 3.0;
line.opacity = 1.0;
line.strokeColor = [UIColor greenColor].CGColor;
[line setMasksToBounds:YES];

Draw on UIView or GLKView?

I need to draw a separator line with some dots on it. I have decided I will do this using the draw method, as opposed to including images of the separator. I will do this for performance and for customisability, as the separator changes sometimes.
Now I have looked into the draw() method on UIView and I have noticed that Apple suggests using GLKView when drawing using OpenGL.
For a simple separator, won't it be too much of a hassle to call OpenGL? Or is the OpenGL overhead negligible? When would I want to use the native UIKit draw() then?
FYI I don't know either method, but want to learn both methods, so don't reply "what you know best". I am simply asking about performance.
OpenGL uses GPU instead of CPU for computation. If you are making something like a gaming app, then you can think of using OpenGL. I believe you want to draw a line in an iOS App. For that you can either use drawRect method in UIView or create a shapeLayer and add it as a sublayer.
The following examples will show you:
CAShapeLayer *simpleLine = [CAShapeLayer layer];
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(0, 80)];
[path addLineToPoint:CGPointMake(300, 80)];
simpleLine.lineWidth = 1.0;
simpleLine.path = path.CGPath;
simpleLine.strokeColor = [[UIColor blackColor] CGColor];
[[self.view layer] addSublayer:simpleLine];
For using drawRect, you are supposed to do this inside a Custom UIView as opposed to the above method.
- (void)drawRect:(CGRect)rect {
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(0, 80)];
[path addLineToPoint:CGPointMake(300, 80)];
path.lineWidth = 1.0;
[[UIColor blueColor] setStroke];
[path stroke];
}
If your separator parameters changes and if you are making an app, it's better to use drawRect method. You can call this method anytime by using [CustomUIView setNeedsDisplay:YES]
Edit
What you're asking for is circle over line. You can do that by drawing UIBezierPath for line first and then add UIBezierPath for circle later.
Normal Line
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(10.0, 10.0)];
[path addLineToPoint:CGPointMake(100.0, 100.0)];
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.path = [path CGPath];
shapeLayer.strokeColor = [[UIColor redColor] CGColor];
shapeLayer.lineWidth = 3.0;
shapeLayer.fillColor = [[UIColor clearColor] CGColor];
[self.view.layer addSublayer:shapeLayer];
Dotted Line
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(10.0, 10.0)];
[path addLineToPoint:CGPointMake(100.0, 100.0)];
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.path = [path CGPath];
shapeLayer.strokeColor = [[UIColor redColor] CGColor];
shapeLayer.lineWidth = 3.0;
shapeLayer.fillColor = [[UIColor clearColor] CGColor];
shapeLayer.lineDashPattern = #[#4, #2];
[self.view.layer addSublayer:shapeLayer];

How to create a circular dotted line as a CALayer?

I read this post Draw dotted (not dashed!) line, with IBDesignable in 2017 about drawing a dotted line (rather than a dashed line). However, I am not too familiar with graphics generally and I'm wondering how I can do this with a CALayer (so I don't have to do the whole get current graphics context thing).
I am trying to produce a dotted line that looks like this (the white part, ignore the background):
Here's the code I have working to produce a dotted line:
CAShapeLayer *shapelayer = [CAShapeLayer layer];
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:startPoint];
[path addLineToPoint:endPoint];
[path setLineCapStyle:kCGLineCapRound];
UIColor *fill = [UIColor whiteColor];
shapelayer.strokeStart = 0.0;
shapelayer.strokeColor = fill.CGColor;
shapelayer.lineWidth = 4.0;
shapelayer.lineJoin = kCALineJoinRound;
shapelayer.lineDashPattern = [NSArray arrayWithObjects:[NSNumber numberWithInt:4],[NSNumber numberWithInt:6 ], nil];
shapelayer.path = path.CGPath;
return shapelayer;
How can I mirror the code in the SO post I referenced but continue using a CALayer?
I tried modifying the code from that post like so:
UIBezierPath * path = [[UIBezierPath alloc] init];
[path moveToPoint:startPoint];
[path addLineToPoint:endPoint];
[path setLineWidth:8.0];
CGFloat dashes[] = { path.lineWidth, path.lineWidth * 2 };
[path setLineDash:dashes count:2 phase:0];
[path setLineCapStyle:kCGLineCapRound];
[path stroke];
CAShapeLayer *returnLayer = [CAShapeLayer layer];
returnLayer.path = path.CGPath;
return returnLayer;
However, this ends up drawing nothing.
I hope this will help you.
CAShapeLayer *circleLayer = [CAShapeLayer layer];
[circleLayer setPath:[[UIBezierPath bezierPathWithOvalInRect:CGRectMake(50, 50, 100, 100)] CGPath]];
circleLayer.lineWidth = 2.0;
[circleLayer setStrokeColor:[[UIColor redColor] CGColor]];
[circleLayer setFillColor:[[UIColor clearColor] CGColor]];
circleLayer.lineJoin = kCALineJoinRound;
circleLayer.lineDashPattern = [NSArray arrayWithObjects:[NSNumber numberWithInt:2],[NSNumber numberWithInt:3 ], nil];
// self.bgImage is parentView
[[self.bgImage layer] addSublayer:circleLayer];
self.bgImage.layer.borderWidth = 1.0f;
self.bgImage.layer.borderColor = [[UIColor blueColor]CGColor];
I have attached the output of the image
In my case I had to set the lineCapStyle rather than the lineJoinStyle.

How to remove CAShapeLayer along user drag?

I am new to painting app ,so please suggest me is there any way to remove.
i was googled i am only getting
CGContextSetBlendMode(_context, kCGBlendModeClear);
but not for CAShape layer
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(touchPoint.x,touchPoint.y)];
[path addLineToPoint:CGPointMake(startingPoint.x,startingPoint.y)];
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.path = [path CGPath];
// shapeLayer.strokeColor =kCGBlendModeClear;
if([UIDevice currentDevice].userInterfaceIdiom ==UIUserInterfaceIdiomPad)
{
shapeLayer.lineWidth = 7.0;
}
else
{
shapeLayer.lineWidth = 5.0;
}
shapeLayer.fillColor = [[UIColor clearColor] CGColor];
[self.layer addSublayer:shapeLayer];
[clearBeizer addObject:shapeLayer];
please help me to remove that layer thanks.

[iOS]Layer on UILabel, why is not full?

I custom a BWLabel to draw the label's border.
- (void)drawRect:(CGRect)rect {
CGRect frame = self.frame;
UIBezierPath *linePath = [UIBezierPath bezierPath];
[linePath moveToPoint:CGPointMake(0,0)];
[linePath addLineToPoint:CGPointMake(frame.size.width, 0)];
[linePath addLineToPoint:CGPointMake(frame.size.width, frame.size.height)];
[linePath addLineToPoint:CGPointMake(0, frame.size.height)];
CAShapeLayer *lineLayer = [CAShapeLayer layer];
lineLayer.lineWidth = 3.0f;
lineLayer.strokeColor = [[UIColor whiteColor] CGColor];
lineLayer.path = linePath.CGPath;
[self.layer addSublayer:lineLayer];
}
I use Debug View Hierarchy to see the BWLabel.
I have a question, why the CAShapeLayer is not full?
your draw rect should look like this
- (void)drawRect:(CGRect)rect
{
CGRect frame = self.frame;
UIBezierPath *linePath = [UIBezierPath bezierPath];
[linePath moveToPoint:CGPointMake(0,0)];
[linePath addLineToPoint:CGPointMake(frame.size.width, 0)];
[linePath addLineToPoint:CGPointMake(frame.size.width, frame.size.height)];
[linePath addLineToPoint:CGPointMake(0, frame.size.height)];
[linePath addLineToPoint:CGPointMake(0, 0)];
CAShapeLayer *lineLayer = [CAShapeLayer layer];
lineLayer.lineWidth = 3.0f;
lineLayer.strokeColor = [[UIColor whiteColor] CGColor];
lineLayer.path = linePath.CGPath;
[self.layer addSublayer:lineLayer];
}

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