I am trying to draw a drop shadow underneath an image to which I apply rounded corners, but I have 2 problems:
The drop shadow only appears underneath the non-rounded area of the rounded image and not underneath the bottom rounded corners as one would get if applying a drop shadow in photoshop.
Using the same settings as in photoshop (a 2 y-axis offset, 1 blur and 85% black) results in a much darker shadow which does not appear as blurred as it should.
Any help would be appreciated please.
float myColorValues[] = {0, 0, 0, 0.85};
CGColorRef myColor = CGColorCreate(colorSpace, myColorValues);
CGContextSetShadowWithColor(context, CGSizeMake(0, -2), 2, myColor);
// Draw a round corner path
CGContextBeginPath(context);
CGRect rect = CGRectMake(0, 0, 68, 68);
addRoundedRectToPath(context, rect, cornerWidth, cornerHeight);
CGContextClosePath(context);
CGContextClip(context);
CGContextDrawImage(context, CGRectMake(1, 2, 70, 70), imageScaledAndCropped);
The solution is to draw a rounded bezier path underneath the image and to apply the shadow to that.
Related
I am trying to draw rounded corners on rectangle in drawRect method using bezier path, but somehow the rounded corner is being shown on inner side of rectangle, instead of both inner and outer sides. Code is given below. Also attached herewith is border that is currently being drawn (outer side of border is not rounded)
- (void)drawRect:(CGRect)rect
{
// Drawing code
CGContextRef context=UIGraphicsGetCurrentContext();
//Set gray color to whole context
[[UIColor lightGrayColor] set];
CGContextSetAlpha(context,0.7);
UIRectFill(rect);
// Configure the context colors and line
CGContextSetStrokeColorWithColor(context, [UIColor colorWithRed:131./255. green:148./255. blue:219./255. alpha:1.0].CGColor);
CGContextSetFillColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextSetLineWidth(context, 10.0);
CGSize size=self.bounds.size;
CGFloat radius = 10.0;
CGSize guideSize=CGSizeMake(330, 130);
CGRect guideCoords= CGRectMake(size.width*.5-guideSize.width*.5, size.height*.5-guideSize.height*.5, guideSize.width , guideSize.height);
// Guide drawing
CGContextStrokeRect(context,guideCoords);
// Draw the Text
[kVinGuideMessage drawInRect:CGRectMake(guideCoords.origin.x+kSideMessageMargin, guideCoords.origin.y+guideSize.height+kMarginFromGuide, guideCoords.size.width-2*kSideMessageMargin,40) withFont:[UIFont systemFontOfSize:16.0] lineBreakMode:NSLineBreakByWordWrapping alignment:NSTextAlignmentLeft];
//Get instersection and clear color of inner overlay
CGRect holeRectIntersection = CGRectIntersection(rect,guideCoords);
//----------ADDING ROUNDED CORNERS HERE-----------//
CGPathRef clippath = [UIBezierPath bezierPathWithRoundedRect:guideCoords cornerRadius:radius].CGPath;
CGContextAddPath(context, clippath);
CGContextClip(context);
//------------------------------------------------//
[[UIColor clearColor] setFill];
UIRectFill(holeRectIntersection);
}
The outer corners are being drawn by the CGContextStrokeRect(context,guideCoords); I think. At that point you haven't set a clipping path and your line width is 10 points, so why would the outer corners be rounded? I think you'll have better luck if you set a clipping path (probably not exactly the same clipping path you've got at the bottom) before calling stroke rect on the guideCoords rectangle.
I'm trying to draw a rectangle, which should have black color border of width 5.0, I am getting the rectangle as seen below,
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextStrokePath(context);
CGContextSetRGBFillColor(context, 0.0, 1.0, 0.0, 0.5);
CGContextFillRect(context, rect);
I can make it clear / transparent (white) background instead the green one showing right now with [UIColor whiteColor].CGColor but then it should have black border also.
How do I set the customized border to rectangle?
Set the stroke color and width as desired, for example:
CGContextSetStrokeColorWithColor(context, [UIColor blackColor].CGColor);
CGContextSetLineWidth(context, 5.0f);
CGContextStrokeRect(context, rect);
If you are also filling the rectangle, do this after filling so the fill doesn't cover up the stroke.
I would like to draw a circle like those in the picture in objective-c :
(source: hostingpics.net)
I just want to draw the blue circle filled with the corresponding percentage starting from the bottom. (NB : the range of the percentage is between 0 and 100) Don't worry about the tick in the center, it's just an imageView added over the circle view.
You could make 2 image views. One would contain your circle with the check mark, and the rest transparent. The other image would be below that, with a light blue rectangle. As the percentage increases, you raise the blue rectangle more and more by modifying it's frame. It would be visible of course through the transparent part of the image on top.
Hope this helps!
// Draw circle of radius r and center X,Y
CGRect r;
r.origin.y = Y-radius;
r.origin.x = X-radius;
r.size.width = 2*radius;
r.size.height 2*radius;
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextAddEllipseInRect(ctx, r);
CGContextSetFillColor(ctx, CGColorGetComponents([[UIColor lightGray] CGColor]));
CGContextFillPath(ctx);
// Draw a blue color filled path. Below is half circle filled with blue color.
CGContextBeginPath(ctx);
CGContextAddArc(ctx, X, Y, r, -M_PI_2, M_PI_2, 1);
CGContextClosePath(ctx); // could be omitted
CGContextSetFillColorWithColor(ctx, [UIColor blueColor].CGColor);
CGContextFillPath(ctx);
Idea is to draw a circle and fill it with light gray color and than draw and close path from arc of the circle (whatever angle is required) and fill it with blue color.
Adding to Levi's suggestion.
You can scale the rect image using CGAffineTransformScale.
e.g:
CGAffineTransform transform = self.rectImageView.transform;
float scale = 0.5;
self.rectImageView.transform = CGAffineTransformScale(transform, 1, scale);
This will scale the image to 50%
to set it back to 100%, just set scale = 2.
So I have the following code:
CGContextDrawImage(context, CGRectMake(100, 0, 220, self.image.size.height), self.image.CGImage);
basically I am asking CG to draw the image 100 px to the right.. now this works fine.. however to the left of the image I see a white background. How do I change this background to some other color? Say I want a black blackground
Before drawing the image, fill the rect with the desired color:
CGContextSetFillColorWithColor(context, [UIColor blackColor].CGColor);
CGContextFillRect(context, CGRectMake(0, 0, self.image.size.width + 100, self.image.size.height)); //I suppose your rect's width is as much as image's width +100
//Then draw your image
CGContextDrawImage(context, CGRectMake(100, 0, 220, self.image.size.height), self.image.CGImage);
Note: Make sure the rect's you're drawing into width is at least the image's width + 100
I've got a weird issue with quartz. The first time I run the piece of code below, the line will be drawn like the line to the right in the image. The second time (and every time after) these lines are executed, the line will look like the line to the left. Why does it look like that? It's all jaggy and seems to have a dark border. If you'd draw the curve with opacity, it would be rather bright the first time, and very dark the second.
CGContextSetRGBFillColor(context, 0.0,0.0,0.0,0.0);
CGContextClearRect(context, CGRectMake( 0, 0, 320, 480));
CGContextSetRGBFillColor(context, 0, 0, 0, 0);
CGContextSetBlendMode(context, kCGBlendModeNormal);
CGContextSetRGBStrokeColor(context, 1.0, 1.0, 1.0, 1.0);
CGContextSetLineWidth(context, 4.0);
CGContextMoveToPoint(context, p1.x, p1.y);
CGContextAddCurveToPoint(context, cp1.x, cp1.y, cp2.x, cp2.y, p2.x, p2.y);
CGContextDrawPath(context, kCGPathStroke);
(source: pici.se)
antialiasing OFF?
also, you might want to make sure the x and y values are rounded as the Quartz Framework doesn't handle well the half point.