text: /* CoreGraphics - CGGradient.h
     Copyright (c) 2006-2011 Apple Inc.
     All rights reserved. */
  
  #ifndef CGGRADIENT_H_
  #define CGGRADIENT_H_
  
  #include <CoreFoundation/CFBase.h>
  #include <CoreFoundation/CFAvailability.h>
  #include <stdint.h>
  
  typedef struct CF_BRIDGED_TYPE(id) CGGradient *CGGradientRef;
  
  typedef CF_OPTIONS (uint32_t, CGGradientDrawingOptions) {
    kCGGradientDrawsBeforeStartLocation = (1 << 0),
    kCGGradientDrawsAfterEndLocation = (1 << 1)
  };
  
  #include <CoreGraphics/CGBase.h>
  #include <CoreGraphics/CGColorSpace.h>
  #include <CoreGraphics/CGContext.h>
  
  CF_IMPLICIT_BRIDGING_ENABLED
  
  CF_ASSUME_NONNULL_BEGIN
  
  /* A CGGradient defines a transition between colors. The transition is
     defined over a range from 0 to 1 inclusive. A gradient specifies a color
     at location 0, one at location 1, and possibly additional colors assigned
     to locations between 0 and 1.
  
     A CGGradient has a color space. When a gradient is created, all colors
     specified are converted to that color space, and interpolation of colors
     occurs using the components of that color space. See the documentation of
     each creation function for more details. */
  
  /* Return the CFTypeID for CGGradients. */
  
  CG_EXTERN CFTypeID CGGradientGetTypeID(void)
      CG_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
  
  /* Creates a gradient by pairing the color components provided in
     `components' with locations provided in `locations'. If `locations' is
     NULL, the first color in `colors' will be at location 0, the last color
     in `colors' will be at location 1, and intervening colors will be at
     equal intervals in between. Otherwise, each location in `locations'
     should be a CGFloat between 0 and 1. Each set of color components should
     specify a color in the color space `space' (which may not be a pattern or
     indexed color space). The number of locations is specified by `count';
     the number of color components is the product of `count' and the number
     of color components of `space'. If no color is provided for 0 or 1, the
     gradient will use the color provided at the locations closest to 0 and 1
     for those values. */
  
  CG_EXTERN CGGradientRef __nullable CGGradientCreateWithColorComponents(
      CGColorSpaceRef cg_nullable space, const CGFloat * cg_nullable components,
      const CGFloat * __nullable locations, size_t count)
      CG_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
  
  /* Creates a gradient by pairing the colors provided in `colors' with the
     locations provided in `locations'. `colors' should be a non-empty array
     of CGColor objects. The colors may be in any color space other than a
     pattern or indexed color space. If `space' is non-NULL, each color will
     be converted to that color space and the gradient will drawn in that
     space; otherwise, each color will be converted to and drawn in the
     "Generic" RGB color space. If `space' is specified, it may not be a
     pattern or indexed color space. If `locations' is NULL, the first color
     in `colors' will be at location 0, the last color in `colors' will be at
     location 1, and intervening colors will be at equal intervals in between.
     Otherwise, each location in `locations' should be a CGFloat between 0 and
     1; the array of locations should should contain the same number of items
     as `colors'. If no color is provided for 0 or 1, the gradient will use
     the color provided at the locations closest to 0 and 1 for those
     values. */
  
  CG_EXTERN CGGradientRef __nullable CGGradientCreateWithColors(
      CGColorSpaceRef __nullable space, CFArrayRef cg_nullable colors,
      const CGFloat * __nullable locations)
      CG_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
  
  /* Equivalent to `CFRetain' except that it doesn't crash (as `CFRetain'
     does) if `gradient' is NULL. */
  
  CG_EXTERN CGGradientRef cg_nullable CGGradientRetain(
      CGGradientRef cg_nullable gradient)
      CG_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
  
  /* Equivalent to `CFRelease' except that it doesn't crash (as `CFRelease'
     does) if `gradient' is NULL. */
  
  CG_EXTERN void CGGradientRelease(CGGradientRef cg_nullable gradient)
      CG_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0);
  
  CF_ASSUME_NONNULL_END
  
  CF_IMPLICIT_BRIDGING_DISABLED
  
  #endif /* CGGRADIENT_H_ */
  