I have been trying to measure glyph bounds precisely but this code prints out 916!!! The real width of this is 69.
- (void)drawRect:(NSRect)dirtyRect {
CGContextRef main = [[NSGraphicsContext currentContext] graphicsPort];
CGContextSetTextMatrix(main, CGAffineTransformIdentity);
CGGlyph g;
CGPoint p = CGPointMake(100, 100);
CGRect rect = CGRectMake(0, 0, 0, 0);
CGFontRef font = CGFontCreateWithFontName((CFStringRef)#"Arial");
g = CGFontGetGlyphWithGlyphName(font, CFSTR("L"));
CGContextSetFont(main, font);
CGContextSetTextPosition(main, 0, 0);
CGContextSetFontSize(main, 200);
CGContextSetRGBFillColor(main, 0, 0, 1, 1);
CGContextShowGlyphsAtPositions(main, &g, &p, 1);
CGFontGetGlyphBBoxes(font, &g, 1, &rect);
printf("%f", rect.size.width);
}
You are using CGFontGetGlyphBBoxes, which returns the size in glyph space units. To use this, you need to scale it with the units per em and the font size.
CGRect rect;
CGFontRef font = CGFontCreateWithFontName((CFStringRef)#"Arial");
CGFloat fontSize = 200.0;
CGGlyph g = CGFontGetGlyphWithGlyphName(font, CFSTR("L"));
CGFontGetGlyphBBoxes(font, &g, 1, &rect);
CGFloat width = rect.size.Width / CGFontGetUnitsPerEm(font) * fontSize;
An alternate way to do it to use [NSFont boundingRectForCGGlyph:].
NSFont *font = [NSFont fontWithName:#"Arial" size:200];
NSRect rect = [font boundingRectForCGGlyph:g];
boundingRectForCGGlyph
Returns the bounding rectangle for the specified glyph, scaled to the receiver’s size.
Related
I am Rotating the image by using this code
- (CGImageRef)CGImageRotatedByAngle:(CGImageRef)imgRef angle:(CGFloat)angle
{
CGFloat angleInRadians = angle * (M_PI / 360);
CGFloat width = CGImageGetWidth(imgRef);
CGFloat height = CGImageGetHeight(imgRef);
CGRect imgRect = CGRectMake(0, 0, width, height);
CGAffineTransform transform = CGAffineTransformMakeRotation(angleInRadians);
CGRect rotatedRect = CGRectApplyAffineTransform(imgRect, transform);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef bmContext = CGBitmapContextCreate(NULL,
rotatedRect.size.width,
rotatedRect.size.height,
8,
0,
colorSpace,
kCGImageAlphaPremultipliedFirst);
CGContextSetAllowsAntialiasing(bmContext, YES);
CGContextSetShouldAntialias(bmContext, YES);
CGContextSetInterpolationQuality(bmContext, kCGInterpolationHigh);
CGColorSpaceRelease(colorSpace);
CGContextTranslateCTM(bmContext,
+(rotatedRect.size.width/2),
+(rotatedRect.size.height/2));
CGContextRotateCTM(bmContext, angleInRadians);
CGContextTranslateCTM(bmContext,
-(rotatedRect.size.width/2),
-(rotatedRect.size.height/2));
CGContextDrawImage(bmContext, CGRectMake(0, 0,
rotatedRect.size.width,
rotatedRect.size.height),
imgRef);
CGImageRef rotatedImage = CGBitmapContextCreateImage(bmContext);
CFRelease(bmContext);
// [(id)rotatedImage autorelease];
return rotatedImage;
}
By this i am having the resultant image like this..
those white spaces should not be there and it should follow the same pattern of that size with out that white spaces around..the rotated image....
Please help..Thanks in advance
I have succeeded in drawing a rectangle which has a hole inside of the shape of a rounded rectangle using CGContextEOFillPath. I can change the colour of my shape. However, I would like to use a gradient, I suppose that I have got to use CGContextDrawLinearGradient, however, I can't make it work. It keep painting the entire rectangle, hole included.
Here is the code that I am using
- (void)drawRect:(CGRect)rect
{
[super drawRect:rect];
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
CGFloat frameWidth = 1; //[CQMFloatingContentOverlayView frameWidth];
CGFloat radius = [self cornerRadius];
CGSize viewSize = [self frame].size;
CGPathRef path = CQMPathCreateRoundingRect(CGRectMake(frameWidth, frameWidth,
viewSize.width - frameWidth * 2,
viewSize.height - frameWidth * 2),
radius, radius, radius, radius);
CGContextAddRect(context, CGRectMake(0, 0, viewSize.width, viewSize.height));
CGContextAddPath(context, path);
CGContextEOFillPath(context);
CGPathRelease(path);
CGContextRestoreGState(context);
}
CGPathRef CQMPathCreateRoundingRect(CGRect rect, CGFloat blRadius, CGFloat brRadius, CGFloat trRadius, CGFloat tlRadius) {
CGPoint tlPoint = rect.origin;
CGPoint brPoint = CGPointMake(rect.origin.x + rect.size.width,
rect.origin.y + rect.size.height);
CGMutablePathRef path = CGPathCreateMutable();
CGPathMoveToPoint(path, NULL, tlPoint.x + tlRadius, tlPoint.y);
CGPathAddArcToPoint(path, NULL,
brPoint.x, tlPoint.y,
brPoint.x, tlPoint.y + trRadius,
trRadius);
CGPathAddArcToPoint(path, NULL,
brPoint.x, brPoint.y,
brPoint.x - brRadius, brPoint.y,
brRadius);
CGPathAddArcToPoint(path, NULL,
tlPoint.x, brPoint.y,
tlPoint.x, brPoint.y - blRadius,
blRadius);
CGPathAddArcToPoint(path, NULL,
tlPoint.x, tlPoint.y,
tlPoint.x + tlRadius, tlPoint.y,
tlRadius);
CGPathCloseSubpath(path);
return path;
}
I don't know where to put the gradient code, I have tried before and after the CGContextEOFillPath but could not reach my objective.
This code should make what you want (check for syntax and typos, code is directly written in answer)
- (void)drawRect:(CGRect)rect {
CGContextRef context = UIGraphicsGetCurrentContext();
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGFloat gradientColors[] =
{
0.1, 0.1, 0.5, 1.00,
0.9, 0.9, 1.0, 1.00,
};
CGGradientRef gradient = CGGradientCreateWithColorComponents(colorSpace, gradientColors, NULL, sizeof(gradientColors)/(sizeof(gradientColors[0])*4));
CGColorSpaceRelease(colorSpace);
CGContextSaveGState(context);
CGFloat frameWidth = 1; //[CQMFloatingContentOverlayView frameWidth];
CGFloat radius = [self cornerRadius];
CGSize viewSize = [self frame].size;
CGPathRef path = CQMPathCreateRoundingRect(CGRectMake(frameWidth, frameWidth,
viewSize.width - frameWidth * 2,
viewSize.height - frameWidth * 2),
radius, radius, radius, radius);
CGContextAddRect(context, CGRectMake(0, 0, viewSize.width, viewSize.height));
CGContextAddPath(context, path);
CGContextEOClip(context);
CGContextDrawLinearGradient(context, gradient, CGPointMake(0, 0), CGPointMake(viewSize.width, viewSize.height), kCGGradientDrawsBeforeStartLocation);
CGPathRelease(path);
CGContextRestoreGState(context);
}
I have this chunk of code here that draws a block with a one-character string on it:
CGContextDrawImage(context, CGRectMake([blok getLocation].x * xunit, [blok getLocation].y * yunit, 40, 40), [blok getImage].CGImage);
[[blok getSymbol] drawAtPoint:CGPointMake([blok getLocation].x * xunit+15, [blok getLocation].y * yunit) withFont:[UIFont fontWithName:#"Helvetica" size:24]];
It's working fine, but I've been doing some layout changes, and now I need it so that the string drawn will be white. Using the methods for setting the fill color and the stroke color haven't done anything. Is there some other way to do this?
Set the foregroundcolor in the attributes and use the draw withAttributes functions
NSDictionary *attributes = [NSDictionary dictionaryWithObjects:
#[font, [UIColor whiteColor]]
forKeys:
#[NSFontAttributeName, NSForegroundColorAttributeName]];
[string drawInRect:frame withAttributes:attributes];
Have you tried:
CGContextSetFillColorWithColor(UIGraphicsGetCurrentContext(), textColor);
For example:
CGContextDrawImage(context, CGRectMake([blok getLocation].x * xunit, [blok getLocation].y * yunit, 40, 40), [blok getImage].CGImage);
CGContextSetFillColorWithColor(UIGraphicsGetCurrentContext(), textColor);
[[blok getSymbol] drawAtPoint:CGPointMake([blok getLocation].x * xunit+15, [blok getLocation].y * yunit) withFont:[UIFont fontWithName:#"Helvetica" size:24]];
This is what I use for drawing labels:
- (void)_drawLabel:(NSString *)label withFont:(UIFont *)font forWidth:(CGFloat)width
atPoint:(CGPoint)point withAlignment:(UITextAlignment)alignment color:(UIColor *)color
{
// obtain current context
CGContextRef context = UIGraphicsGetCurrentContext();
// save context state first
CGContextSaveGState(context);
// obtain size of drawn label
CGSize size = [label sizeWithFont:font
forWidth:width
lineBreakMode:UILineBreakModeClip];
// determine correct rect for this label
CGRect rect = CGRectMake(point.x, point.y - (size.height / 2),
width, size.height);
// set text color in context
CGContextSetFillColorWithColor(context, color.CGColor);
// draw text
[label drawInRect:rect
withFont:font
lineBreakMode:UILineBreakModeClip
alignment:alignment];
// restore context state
CGContextRestoreGState(context);
}
In theory, these should be the same size, but they're not:
The text in blue is from Core Text, in black is from -[NSString drawInRect:]. Here is the code:
//Some formatting to get the correct frame
int y = MESSAGE_FRAME.origin.y + 8;
if (month) y = y + 27;
int height = [JHomeViewCellContentView heightOfMessage:self.entry.message];
CGRect rect = CGRectMake(MESSAGE_FRAME.origin.x + 8, y, MESSAGE_FRAME.size.width - 16, height);
//Draw in rect method
UIFont *font = [UIFont fontWithName:#"Crimson" size:15.0f];
[[UIColor colorWithWhite:0.2 alpha:1.0] setFill];
[self.entry.message drawInRect:rect withFont:font lineBreakMode:UILineBreakModeWordWrap alignment:UITextAlignmentLeft];
//Frame change to suit CoreText
CGRect rect2 = CGRectMake(MESSAGE_FRAME.origin.x + 8, self.bounds.size.height - y - height, MESSAGE_FRAME.size.width - 16, height);
//Core text method
CTFontRef fontRef = CTFontCreateWithName((CFStringRef)#"Crimson", 15.0f, NULL);
NSDictionary *attDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
(__bridge_transfer id)fontRef, (NSString *)kCTFontAttributeName,
(id)[[UIColor blueColor] CGColor], (NSString *)kCTForegroundColorAttributeName,
nil];
NSAttributedString *attString = [[NSAttributedString alloc] initWithString:self.entry.message attributes:attDictionary];
//Flip the coordinate system
CGContextSetTextMatrix(context, CGAffineTransformIdentity);
CGContextTranslateCTM(context, 0, self.bounds.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
CGMutablePathRef path = CGPathCreateMutable();
CGPathAddRect(path, NULL, rect2);
CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((__bridge_retained CFAttributedStringRef)attString);
CTFrameRef theFrame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, [attString length]), path, NULL);
CFRelease(framesetter);
CFRelease(path);
CTFrameDraw(theFrame, context);
CFRelease(theFrame);
The font is the same. I don't understand why one is being rendered differently.
It’s because NSLayoutManager uses some unusual heuristics to cope with certain fonts.
See How does line spacing work in Core Text? (and why is it different from NSLayoutManager?) for more detail.
I try to Draw a pdf with CoreGraphics, everything work fine but in instrument there is a 100% leak on : CGContextDrawPDFPage(ctx, page2);
I release with CGPDFDocumentRelease(); everytime i use CGPDFDocumentCreateWithURL();
There is any solution to release : CGContextDrawPDFPage ?
- (void)drawRect:(CGRect)rect
{
if (state == 0) {
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextSaveGState(ctx);
[[UIColor whiteColor] set];
CGContextFillRect(ctx, CGRectMake(0, 0, rect.size.width, rect.size.height));
CGContextGetCTM(ctx);
CGContextScaleCTM(ctx, 1, -1);
CGContextTranslateCTM(ctx, 45, -rect.size.height);
CGPDFDocumentRef pdf = CGPDFDocumentCreateWithURL(((CFURLRef)url));
CGPDFPageRef page = CGPDFDocumentGetPage(pdf, currentPage);
CGRect mediaRect = CGPDFPageGetBoxRect(page, kCGPDFCropBox);
CGContextScaleCTM(ctx, (678) / mediaRect.size.width,
(rect.size.height ) / (mediaRect.size.height));
CGContextSetInterpolationQuality(ctx, kCGInterpolationHigh);
CGContextSetRenderingIntent(ctx, kCGRenderingIntentDefault);
CGContextDrawPDFPage(ctx, page);
CGPDFDocumentRelease(pdf);
CGContextRestoreGState(ctx);
}
else
{
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextSaveGState(ctx);
[[UIColor whiteColor] set];
CGContextFillRect(ctx, CGRectMake(0, 0, rect.size.width, rect.size.height));
CGContextGetCTM(ctx);
CGContextScaleCTM(ctx, 1, -1);
CGContextTranslateCTM(ctx, 6, -rect.size.height);
CGPDFDocumentRef pdf = CGPDFDocumentCreateWithURL(((CFURLRef)url));
CGPDFPageRef page = CGPDFDocumentGetPage(pdf, currentPage);
CGRect mediaRect = CGPDFPageGetBoxRect(page, kCGPDFCropBox);
CGContextScaleCTM(ctx, (497) / mediaRect.size.width,
(rect.size.height ) / (mediaRect.size.height));
// draw it
CGContextSetInterpolationQuality(ctx, kCGInterpolationHigh);
CGContextSetRenderingIntent(ctx, kCGRenderingIntentDefault);
CGContextDrawPDFPage(ctx, page);
CGPDFDocumentRelease(pdf);
CGContextRestoreGState(ctx);
//
CGContextSaveGState(ctx);
CGContextGetCTM(ctx);
CGContextScaleCTM(ctx, 1, -1);
CGContextTranslateCTM(ctx, 506, -rect.size.height);
CGPDFDocumentRef pdf2 = CGPDFDocumentCreateWithURL(((CFURLRef)url));
CGPDFPageRef page2 = CGPDFDocumentGetPage(pdf2, (currentPage + 1));
CGContextScaleCTM(ctx, (497) / mediaRect.size.width,
(rect.size.height ) / (mediaRect.size.height));
CGContextSetInterpolationQuality(ctx, kCGInterpolationHigh);
CGContextSetRenderingIntent(ctx, kCGRenderingIntentDefault);
//Leak 100%
CGContextDrawPDFPage(ctx, page2);
CGPDFDocumentRelease(pdf2);
CGContextRestoreGState(ctx);
}
}
And I don't know why. Any idea?
This is the only leak of my app :(
I don't see where the leak come from :s
PS : state = 0 = portrait orientation
state = 1 = landscape so I draw 2 pages in landscape orientation.
Looks like you're not releasing the CGPDFPageRef instances you're getting from CGPDFDocumentGetPage.
CGPDFPageRelease(page);
Add that for page and page2 at the appropriate locations.