I have a curve which is drawn by using Bezier curve. Now i am moving this particular object and placing it in another location. How can i get the new points for the curve of that object.
- (void)drawRect:(CGRect)rect
{
[myPath moveToPoint:CGPointMake(100, 100)];
[myPath addLineToPoint:CGPointMake(100, 400)];
[myPath addLineToPoint:CGPointMake(400, 400)];
[myPath addLineToPoint:CGPointMake(400, 100)];
[myPath addLineToPoint:CGPointMake(100, 100)];
[myPath closePath];
[[UIColor redColor] setStroke];
[myPath strokeWithBlendMode:kCGBlendModeNormal alpha:1.0];
[self setNeedsDisplay];
}
This is my code to draw the rectangle. Now by using touches i am moving the rectangle, after moving how can i get the new points of the rectangle.In this particular case i am using a rectangle but there may be a polygon of indefinite points, in that case how can i get those points.
For a simple linear transformation you only need to apply dx and dy to each control point of your curve (aka add your change in x and y to all the points you defined for the curve).
Related
I'm drawing some simple bezier paths, but I'm finding it impossible to remove the spikes created when the angle between line segments is small:
(Note: The circle is from a separate drawing operation, but I'm trying to make sure the line does not spike past the circle...).
I've tried all kinds of variations of lineCapStyle and lineJoinStyle but nothing seems to work.
In addition to what is shown below I have tried using a Miter Join with 'setMiterLimit'.
Here's my line drawing code snip:
CAShapeLayer *myShapeLayer=[CAShapeLayer layer];
UIBezierPath *myPath=[UIBezierPath bezierPath];
[myPath moveToPoint:tmpPoint];
[myPath addLineToPoint:tmpPoint];
[myPath setLineCapStyle:kCGLineCapRound];
[myPath setLineJoinStyle:kCGLineJoinRound];
myShapeLayer.path=[myPath CGPath];
myShapeLayer.strokeColor = [[UIColor yellowColor] CGColor];
myShapeLayer.fillColor = [[UIColor clearColor] CGColor];
myShapeLayer.lineWidth = 3.0;
Just in case - here's the Miter code I've used, varying the value rom 0.0 to 100.0 - all with no effect:
[myPath setLineCapStyle:kCGLineCapRound];
[myPath setLineJoinStyle:kCGLineJoinMiter];
[myPath setMiterLimit:1.0];
You should be setting lineJoin on the shape layer instead of the path:
myShapeLayer.lineJoin = kCALineJoinRound;
The confusion comes from the fact that UIBezierPath has the ability to draw the path (by calling fill and stroke on the path). The configuration of line joins and line caps on the path is only affecting this drawing.
However, since you are drawing the path using a CAShapeLayer, the configurations of both line joins and line caps should be done on the shape layer.
The short story is that I would like the bounds (I think I mean bounds instead of frame) of a NSBezierPath to fill a view. Something like this:
To generate the above image I scaled/translated each point in my created path using the information from Covert latitude/longitude point to a pixels (x,y) on mercator projection. The problem is that this isn't scalable (I will be adding many more paths) and I want to easily add pan/zoom functionality to my view. Additionally, I want the stroke to remain the same regardless of scale (i.e. no fat boundaries when I zoom).
I think I want to generate a reusable path in some arbitrary reference frame (e.g. longitude and modified latitude) instead of generating a new path every time the window changes. Then I can translate/scale my view's coordinate system to fill the view with the path.
So I used Apple's geometry guide to to modify the view's frame. I got the translation right but scaling failed.
[self setBoundsOrigin:self.path.bounds.origin];
[self scaleUnitSquareToSize:NSMakeSize(1.5, 1.5)];
Then I tried a coordinate system transformation in my drawRect: method only to end up with a similar result.
NSAffineTransform* xform = [NSAffineTransform transform];
[xform translateXBy:(-self.path.bounds.origin.x) yBy:(-self.path.bounds.origin.y)];
[xform scaleXBy:1.5 yBy:1.5];
[xform concat];
Finally I tried manually setting the view bounds in drawRect: but the result was ugly and very slow!
I know I can also transform the NSBezierPath object and I think that would work, but I'd rather transform the view once instead of looping through and transforming each path every update. I think there's about three lines of code I'm missing that will do exactly what I'm looking for.
Edit:
Here's the drawRect: method I'm using:
- (void)drawRect:(NSRect)dirtyRect
{
// NSAffineTransform* xform = [NSAffineTransform transform];
// [xform translateXBy:-self.path.bounds.origin.x yBy:-self.path.bounds.origin.y];
// [xform scaleXBy:1.5 yBy:1.5];
// [xform concat];
[self drawBoundaries];
NSRect bounds = [self bounds];
[[NSColor blackColor] set];
[NSBezierPath fillRect:bounds];
// Draw the path in white
[[NSColor whiteColor] set];
[self.path stroke];
[[NSColor redColor] set];
[NSBezierPath strokeRect:self.path.bounds];
NSLog(#"path origin %f x %f",self.path.bounds.origin.x, self.path.bounds.origin.y);
NSLog(#"path bounds %f x %f",self.path.bounds.size.width, self.path.bounds.size.height);
}
I was able to get it to work using two transformations. I was trying to avoid this to reduce complexity and computation when I have many paths to transform and a window that zooms/pans.
- (void)transformPath:(NSBezierPath *)path
{
NSAffineTransform *translateTransform = [NSAffineTransform transform];
NSAffineTransform *scaleTransform = [NSAffineTransform transform];
[translateTransform translateXBy:(-self.path.bounds.origin.x)
yBy:(-self.path.bounds.origin.y)];
float scale = MIN(self.bounds.size.width / self.path.bounds.size.width,
self.bounds.size.height / self.path.bounds.size.height);
[scaleTransform scaleBy:scale];
[path transformUsingAffineTransform: translateTransform];
[path transformUsingAffineTransform: scaleTransform];
}
What I am trying to do is draw a frame around a view using the UIBezierPath drawRectWithRounderCorners method. So what I decided to do was take the rect from the draw rect method, apply a UIEdgesInset object with values that are negative and try to draw it like that. So far the UIBezierPath object is not drawing outside the bounds of the rect passed to draw rect. When I apply the same rect to a CALayer object the layer gets drawn as I would need. So how come I can't get the UIBezierPath object to draw the same rectangle as the CALayer object?
- (void)drawRect:(CGRect)rect {
[super drawRect:rect];
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:
UIEdgeInsetsInsetRect(rect, UIEdgeInsetsMake(-5,-5, -5, -5))
byRoundingCorners:UIRectCornerTopLeft|UIRectCornerBottomLeft
cornerRadii:CGSizeMake(5, 5)];
[[UIColor blueColor]setFill];
[[UIColor blueColor]setStroke];
[path stroke];
[path fill];
CALayer *backGround = [CALayer layer];
[backGround setOpacity:.2];
[backGround setFrame:UIEdgeInsetsInsetRect(rect,
UIEdgeInsetsMake(-5,-5, -5, -5))];
[backGround setBackgroundColor:[UIColor greenColor].CGColor];
[self.layer addSublayer:backGround];
}
A view cannot draw outside of its own bounds. That's why your UIBezierPath doesn't show up.
A layer can draw outside of its superlayer's bounds if the superlayer's maskstoBounds property is NO. The masksToBounds property corresponds to the view's clipsToBounds property, and the default value is NO.
I am drawing a custom window by setting a custom content view for the window. When I draw the custom view I give it rounded corners and a nice outline to mimic a proper window.
However, I see another 1 px outline around the window which strays from the edge at the corners. I have found that if I turn off the shadow it goes away, but obviously as this wants to act like a window I need the shadow. Here's what I mean about the 1px outline:
How can I prevent this?
EDIT
Code for drawing the custom window's content view:
NSBezierPath *path = [NSBezierPath bezierPathWithRoundedRect:[self bounds] cornerRadius:5];
NSGradient* aGradient = [[[NSGradient alloc] initWithColorsAndLocations:
[NSColor colorWithDeviceRed:0.5569 green:0.5137 blue:0.4588 alpha:1.0000], 0.0,
[NSColor colorWithDeviceRed:0.5569 green:0.5137 blue:0.4588 alpha:1.0000], 1.0,
nil] autorelease];
[aGradient drawInBezierPath:path angle:90];
[path setLineWidth:4];
[[NSColor colorWithDeviceRed:0.4235 green:0.3922 blue:0.3451 alpha:0.9000] setStroke];
[path strokeInside];
[path setLineWidth:3];
[[NSColor colorWithDeviceRed:0.8431 green:0.8314 blue:0.8078 alpha:1.0000] setStroke];
[path strokeInside];
[path setLineWidth:1];
[[NSColor colorWithDeviceRed:0.4235 green:0.3922 blue:0.3451 alpha:0.9000] setStroke];
[path strokeInside];
Don't ask me how I got this, but this will solve your problem.
Define a category for NSWindow with the following content:
#implementation NSWindow(NoShadowRim)
- (id)_shadowRimInfo {
return #{
#"kCUIMeasureWindowFrameRimDensity": [NSNumber numberWithInt:0]
};
}
#end
DISCLAIMER: This overrides the internal method of NSWindow, so use it at your own risk. It may break with any OS X update.
You need to tell the window to recompute its shadow by sending it -invalidateShadow.
Try:
[[self window] display];
[[self window] setHasShadow:NO];
[[self window] setHasShadow:YES];
This line contouring the window area is drawn automatically. I have a window which has this line running accurately around bottom rounded corners. You have to setup the window as non-opaque and the background color to transparent:
[self setOpaque:NO];
[self setBackgroundColor:[NSColor clearColor]];
The somewhere in the contentView -drawRect: you do
[NSGraphicsContext saveGraphicsState];
[pathWithBottomRoundedCorner addClip];
// your drawing here...
[NSGraphicsContext restoreGraphicsState];
That should work.
As I understand correctly, shadows are drawn by windows server. When you draw custom NSWindow with rounded corners or other not rectangular shapes, window server don't count those transparent pixels and dont drop shadow under them.
I developed some hack to avoid such behavior. Just drop additional shadow under your path, something like this:
NSShadow *headShadow = [[NSShadow alloc] init];
[headShadow setShadowColor:[NSColor colorWithSRGBRed:0.0
green:0.0
blue:0.0
alpha:0.16]];
[headShadow setShadowBlurRadius:0.0f];
[headShadow setShadowOffset:NSMakeSize(0.0f, 0.0f)];
[headShadow set];
Ideally for perfect result i fink shadow must be equal to window servers.
Can anyone guide me in the correct way to build a colored bubble/circle programmatically?
I can't use images as I need it to be able to be any color depending on user interaction.
My thought was maybe to make a white circle image and then overlay a color on top of it.
However I am not sure if this would work, or how to really go about it.
If someone could point me the right direction I would appreciate it.
There are a couple steps to drawing something in Cocoa.
First you need a path that will be used to define the object that you are going to be drawing. Take a look here Drawing Fundamental Shapes for a guide on creating paths in Cocoa. You will be most interested in sending the "appendBezierPathWithOvalInRect" message to an "NSBezierPath" object, this takes a rectangle that bounds the circle you want to draw.
This code will create a 10x10 circle at coordinates 10,10:
NSRect rect = NSMakeRect(10, 10, 10, 10);
NSBezierPath* circlePath = [NSBezierPath bezierPath];
[circlePath appendBezierPathWithOvalInRect: rect];
Once you have your path you want to set the color for the current drawing context. There are two colors, stroke and fill; stroke is the outline of the path and the fill is the interior color. To set a color you send "set" to an "NSColor" object.
This sets the stroke to black and the fill to red:
[[NSColor blackColor] setStroke];
[[NSColor redColor] setFill];
Now that you have your path and you have your colors set just fill the path and then draw it:
[path stroke];
[path fill];
All of this will need to be done in a graphics context like in drawRect of a view perhaps. All of this together with a graphics context would look like this:
- (void)drawRect:(NSRect)rect
{
// Get the graphics context that we are currently executing under
NSGraphicsContext* gc = [NSGraphicsContext currentContext];
// Save the current graphics context settings
[gc saveGraphicsState];
// Set the color in the current graphics context for future draw operations
[[NSColor blackColor] setStroke];
[[NSColor redColor] setFill];
// Create our circle path
NSRect rect = NSMakeRect(10, 10, 10, 10);
NSBezierPath* circlePath = [NSBezierPath bezierPath];
[circlePath appendBezierPathWithOvalInRect: rect];
// Outline and fill the path
[circlePath stroke];
[circlePath fill];
// Restore the context to what it was before we messed with it
[gc restoreGraphicsState];
}
You may use simple UIView to create perfect circle with only parameter radius:
// Add framework CoreGraphics.framework
#import <QuartzCore/QuartzCore.h>
-(UIView *)circleWithColor:(UIColor *)color radius:(int)radius {
UIView *circle = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 2 * radius, 2 * radius)];
circle.backgroundColor = color;
circle.layer.cornerRadius = radius;
circle.layer.masksToBounds = YES;
return circle;
}
Create an NSView subclass that holds an NSColor as an ivar. In the drawRect method, create an NSBezierPath of the appropriate size, using the view's bounds. Then set the color [myColor set] and fill the path [myPath fill]. There's a lot more you can do, such as set transparency, a border, and so on and so on, but I'll leave that to the docs unless you have a specific question.
To use the NSView subclass, just drag a view object onto your nib, and choose the name of your subclass in custom class in IB's inspector. You'll need to also set an outlet to it in your controller, so you can change the color as needed.
CGContextRef c = UIGraphicsGetCurrentContext();
CGContextSetRGBFillColor(c, 40, 0, 255, 0.1);
CGContextSetRGBStrokeColor(c, 0, 40, 255, 0.5);
// Draw a green solid circle
CGContextSetRGBFillColor(c, 0, 255, 0, 1);
CGContextFillEllipseInRect(c, CGRectMake(100, 100, 25, 25));
Download sketch from apple. http://developer.apple.com/library/mac/#samplecode/Sketch
It can do a lot more, but one of the things is draw circles.