Question

I have a method that returns NSData from a CGPathRef like so …

+ (NSData *) createPDFDataWithCGPath: (CGPathRef) path mediaBox: (CGRect) mediaBox
{
  CFMutableDataRef data = NULL;
  if (path) {
    CFAllocatorRef allocator = NULL;
    data = CFDataCreateMutable(allocator, 0);
    CGDataConsumerRef consumer = CGDataConsumerCreateWithCFData(data);
    CGContextRef context = CGPDFContextCreate(consumer, &mediaBox, NULL);
    CFTypeRef keys[1] = { kCGPDFContextMediaBox };
    CFTypeRef values[1] = { CFDataCreate(allocator, (const UInt8 *)&mediaBox, sizeof(CGRect)) };
    CFDictionaryRef pageInfo = CFDictionaryCreate(allocator, keys, values, 1, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);

    CGPDFContextBeginPage(context, pageInfo);
    CGContextScaleCTM(context, 1, -1);
    CGContextTranslateCTM(context, 0, -mediaBox.size.height);
    CGContextAddPath(context, path);
    CGContextSetRGBFillColor(context, 0, 0, 0, 1);
    CGContextFillPath(context);
    CGPDFContextEndPage(context);

    CFRelease(pageInfo);
    CFRelease(values[0]);
    CGPDFContextClose(context);
    CGContextRelease(context);
    CGDataConsumerRelease(consumer);
  }
  return (NSData *)data;
}

When I attempt to use this and write a PDF file from the data I get my file at the correct size but the paths are not drawn into the PDF … it’s an empty document basically.

Is it enough to just write the file like so …

[maskData writeToFile: DOCUMENTS_PATH_WITH_STRING(@"maskData.pdf") atomically: YES];

or are their more hoops to jump though to write it as a PDF?

Answer 1

This was a bit of a red herring. The paths were being drawn but had no strokes or fills. The code in my question above is sound and works as expected.