On 18 Aug 2013, at 16:27, Simone Tellini <cocoa-...@tellini.info> wrote:
> > Il giorno 18/ago/2013, alle ore 15:03, "Gerriet M. Denkmann" > <gerr...@mdenkmann.de> ha scritto: > >> I just noticed that the program I use to create Png files creates files with >> twice the number of pixels in each dimension. >> Obviously because since I last used it, I have switched to a Retina Mac Book. >> >> Ok, so I have to fix this program. >> > > you can do something like this: > > NSSize size = ...; > NSBitmapImageRep *bitmapRep = [[NSBitmapImageRep alloc] > initWithBitmapDataPlanes: NULL > > > pixelsWide: size.width > > > pixelsHigh: size.height > > > bitsPerSample: 8 > > > samplesPerPixel: 4 > > > hasAlpha: YES > > > isPlanar: NO > > > colorSpaceName: NSCalibratedRGBColorSpace > > > bitmapFormat: NSAlphaFirstBitmapFormat > > > bytesPerRow: 0 > > > bitsPerPixel: 0]; > NSGraphicsContext *bmCtx; > NSAffineTransform *transform = [NSAffineTransform transform]; > > [bitmapRep setSize: size]; > > bmCtx = [NSGraphicsContext graphicsContextWithBitmapImageRep: > bitmapRep]; > bmCtx = [NSGraphicsContext graphicsContextWithGraphicsPort: [bmCtx > graphicsPort] > > flipped: YES]; > > [NSGraphicsContext saveGraphicsState]; > [NSGraphicsContext setCurrentContext: bmCtx]; > > [transform translateXBy: 0 > yBy: size.height]; > [transform scaleXBy: 1 > yBy: -1]; > [transform set]; > > ...do some drawing... > > [NSGraphicsContext restoreGraphicsState]; > > data = [bitmapRep representationUsingType: NSPNGFileType properties: > nil]; > > [bitmapRep release]; No need for the complex cocoa to CG manoeuvrings there, this will do fine: NSSize size = …; CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef ctx = CGBitmapContextCreate(NULL, size.width, size.height, 8, 8 * 4 * size.width, rgbColorSpace, kCGBitmapAlphaInfoMask & kCGAlphaLast); CFRelease(rgbColorSpace); … do some drawing … CGImageRef img = CGBitmapContextCreateImage(ctx); CGContextRelease(ctx); return [[[NSImage alloc] initWithCGImage:img size:size] autorelease]; Thanks Tom Davie _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
