From 2c4725b1b4d926c8b8f73e5f5ee693802db92522 Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Sun, 6 Aug 2017 07:05:36 +1000
Subject: [PATCH 01/13] CGContext: correctly export CGContextDrawShading() stub

In CGContext.m we had CGContextDrawShading()'s definition repeated from
the header; we did not, however, have an actual stub for this function,
which caused linking errors with Opal clients. This turns this still
unimplemented function into an actual stub.
---
 Source/OpalGraphics/CGContext.m | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/Source/OpalGraphics/CGContext.m b/Source/OpalGraphics/CGContext.m
index 7ae42ed..cfdb807 100644
--- a/Source/OpalGraphics/CGContext.m
+++ b/Source/OpalGraphics/CGContext.m
@@ -1526,8 +1526,11 @@ void CGContextDrawRadialGradient(
 
 void CGContextDrawShading(
   CGContextRef ctx,
-  CGShadingRef shading
-);
+  CGShadingRef shading)
+{
+  // FIXME: unimplemented
+  return;
+}
 
 void CGContextSetFont(CGContextRef ctx, CGFontRef font)
 {

From dca7c1188b54076cbcc012f2d9558491a4ce9228 Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Sun, 6 Aug 2017 07:15:08 +1000
Subject: [PATCH 02/13] CGContext: properly implement ellipse-related functions

Add an actual implementation for CGContextAddEllipseInRect() which makes
use of CGPath APIs. Implement CGContextFillEllipseInRect() and
CGContextStrokeEllipseInRect() as well.
---
 Source/OpalGraphics/CGContext.m | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/Source/OpalGraphics/CGContext.m b/Source/OpalGraphics/CGContext.m
index cfdb807..65af125 100644
--- a/Source/OpalGraphics/CGContext.m
+++ b/Source/OpalGraphics/CGContext.m
@@ -772,7 +772,11 @@ void CGContextAddPath(CGContextRef ctx, CGPathRef path)
 void CGContextAddEllipseInRect(CGContextRef ctx, CGRect rect)
 {
   OPLOGCALL("ctx /*%p*/, CGRectMake(%g, %g, %g, %g)", ctx, rect.origin.x, rect.origin.y,
-            rect.size.width, rect.size.height)
+            rect.size.width, rect.size.height);
+  CGPathRef path = CGPathCreateMutable();
+  CGPathAddEllipseInRect(path, NULL, rect);
+  CGContextAddPath(ctx, path);
+  CGPathRelease(path);
   OPRESTORELOGGING()
 }
 
@@ -953,6 +957,20 @@ void CGContextClearRect(CGContextRef ctx, CGRect rect)
   OPRESTORELOGGING()
 }
 
+void CGContextFillEllipseInRect(CGContextRef ctx, CGRect rect)
+{
+  CGContextBeginPath(ctx);
+  CGContextAddEllipseInRect(ctx, rect);
+  CGContextFillPath(ctx);
+}
+
+void CGContextStrokeEllipseInRect(CGContextRef ctx, CGRect rect)
+{
+  CGContextBeginPath(ctx);
+  CGContextAddEllipseInRect(ctx, rect);
+  CGContextStrokePath(ctx);
+}
+
 void CGContextStrokeLineSegments(
   CGContextRef ctx,
   const CGPoint points[],

From e8271a98a99e234698fa8975563d492822829780 Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Sun, 6 Aug 2017 07:23:51 +1000
Subject: [PATCH 03/13] CGContext: define some private getter functions

CoreGraphics posesses the private getter counterparts for some setter
functions, such as antialiasing and font smoothing. This implements
those getters.
---
 Headers/CoreGraphics/CGContext.h | 12 +++++++++---
 Source/OpalGraphics/CGContext.m  | 10 ++++++++++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/Headers/CoreGraphics/CGContext.h b/Headers/CoreGraphics/CGContext.h
index 131445e..f9b8e2c 100644
--- a/Headers/CoreGraphics/CGContext.h
+++ b/Headers/CoreGraphics/CGContext.h
@@ -562,6 +562,15 @@ CGRect CGContextConvertRectToDeviceSpace(CGContextRef ctx, CGRect rect);
 
 CGRect CGContextConvertRectToUserSpace(CGContextRef ctx, CGRect rect);
 
+bool CGContextPathContainsPoint(CGContextRef c,
+    CGPoint point, CGPathDrawingMode mode);
+
+/* CoreGraphics Private APIs */
+
+bool CGContextGetShouldSmoothFonts(CGContextRef ctx);
+
+bool CGContextGetShouldAntialias(CGContextRef ctx);
+
 /* Opal Extensions */
 
 // FIXME: Move extensions to a separate header?
@@ -583,9 +592,6 @@ OPGStateRef OPContextCopyGState(CGContextRef ctx);
 
 void OPContextSetGState(CGContextRef ctx, OPGStateRef gstate);
 
-bool CGContextPathContainsPoint(CGContextRef c,
-    CGPoint point, CGPathDrawingMode mode);
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/Source/OpalGraphics/CGContext.m b/Source/OpalGraphics/CGContext.m
index 65af125..aee5d5d 100644
--- a/Source/OpalGraphics/CGContext.m
+++ b/Source/OpalGraphics/CGContext.m
@@ -377,6 +377,11 @@ void CGContextSetShouldAntialias(CGContextRef ctx, int shouldAntialias)
   OPRESTORELOGGING()
 }
 
+bool CGContextGetShouldAntialias(CGContextRef ctx)
+{
+  return cairo_get_antialias(ctx->ct) != CAIRO_ANTIALIAS_NONE;
+}
+
 void CGContextSetLineWidth(CGContextRef ctx, CGFloat width)
 {
   OPLOGCALL("ctx /*%p*/, %g", ctx, width)
@@ -480,6 +485,11 @@ void CGContextSetShouldSmoothFonts(CGContextRef ctx, int shouldSmoothFonts)
   OPRESTORELOGGING()
 }
 
+bool CGContextGetShouldSmoothFonts(CGContextRef ctx)
+{
+  return false;
+}
+
 void CGContextSetAllowsFontSmoothing(CGContextRef ctx, bool allowsFontSmoothing)
 {
   OPLOGCALL("ctx /*%p*/, %s", ctx, allowsFontSmoothing ? "true" : "false")

From 879e4f36c6a67d04a6fe86d88015afbbc457fcf5 Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Sun, 6 Aug 2017 07:31:12 +1000
Subject: [PATCH 04/13] CGContext: define CGContextGetType()

Define the private CoreGraphics CGContextGetType() API, which determines
the type of a CGContextRef (a bitmap context, PostScript context, PDF
context etc.).
---
 Headers/CoreGraphics/CGContext.h | 18 ++++++++++++++++++
 Source/OpalGraphics/CGContext.m  |  7 +++++++
 2 files changed, 25 insertions(+)

diff --git a/Headers/CoreGraphics/CGContext.h b/Headers/CoreGraphics/CGContext.h
index f9b8e2c..da2e8bf 100644
--- a/Headers/CoreGraphics/CGContext.h
+++ b/Headers/CoreGraphics/CGContext.h
@@ -138,6 +138,22 @@ enum {
 };
 typedef int CGTextEncoding;
 
+// NOTE: This `typedef enum` in opposition to defining enum constants and
+// their types as integers is here to maintain compatibility with the original
+// CoreGraphics API, although this is *NOT* an ideal way to define these types.
+typedef enum {
+  kCGContextTypeUnknown,
+  kCGContextTypePDF,
+  kCGContextTypePostScript,
+  kCGContextTypeWindow,
+  kCGContextTypeBitmap,
+  kCGContextTypeGL,
+  kCGContextTypeDisplayList,
+  kCGContextTypeKSeparation,
+  kCGContextTypeIOSurface,
+  kCGContextTypeCount
+} CGContextType;
+
 /* Functions */
 
 /* Managing Graphics Contexts */
@@ -571,6 +587,8 @@ bool CGContextGetShouldSmoothFonts(CGContextRef ctx);
 
 bool CGContextGetShouldAntialias(CGContextRef ctx);
 
+CGContextType CGContextGetType(CGContextRef ctx);
+
 /* Opal Extensions */
 
 // FIXME: Move extensions to a separate header?
diff --git a/Source/OpalGraphics/CGContext.m b/Source/OpalGraphics/CGContext.m
index aee5d5d..e7fc2bf 100644
--- a/Source/OpalGraphics/CGContext.m
+++ b/Source/OpalGraphics/CGContext.m
@@ -1987,6 +1987,13 @@ CGRect CGContextConvertRectToUserSpace(CGContextRef ctx, CGRect rect)
     CGAffineTransformInvert(CGContextGetUserSpaceToDeviceSpaceTransform(ctx)));
 }
 
+CGContextType CGContextGetType(CGContextRef ctx)
+{
+  // NOTE: This is not wrong, since Opal does not currently seem to support
+  // any other context type.
+  return kCGContextTypeBitmap;
+}
+
 void OpalContextSetScaleFactor(CGContextRef ctx, CGFloat scale)
 {
   if (scale == 0)

From ffa5d7f65435d8474a1c1ac0938d0a6aa2aa69ee Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Sun, 6 Aug 2017 07:41:38 +1000
Subject: [PATCH 05/13] CGContext: implement CGContextSetCTM()

Implement the private function CGContextSetCTM(), which allows clients
to set the current transformation matrix of a context.
---
 Headers/CoreGraphics/CGContext.h |  2 ++
 Source/OpalGraphics/CGContext.m  | 10 ++++++++++
 2 files changed, 12 insertions(+)

diff --git a/Headers/CoreGraphics/CGContext.h b/Headers/CoreGraphics/CGContext.h
index da2e8bf..5fd2934 100644
--- a/Headers/CoreGraphics/CGContext.h
+++ b/Headers/CoreGraphics/CGContext.h
@@ -589,6 +589,8 @@ bool CGContextGetShouldAntialias(CGContextRef ctx);
 
 CGContextType CGContextGetType(CGContextRef ctx);
 
+void CGContextSetCTM(CGContextRef ctx, CGAffineTransform m);
+
 /* Opal Extensions */
 
 // FIXME: Move extensions to a separate header?
diff --git a/Source/OpalGraphics/CGContext.m b/Source/OpalGraphics/CGContext.m
index e7fc2bf..7e795ce 100644
--- a/Source/OpalGraphics/CGContext.m
+++ b/Source/OpalGraphics/CGContext.m
@@ -290,6 +290,16 @@ CGAffineTransform CGContextGetCTM(CGContextRef ctx)
   return CGAffineTransformMake(result.xx, result.yx, result.xy, result.yy, result.x0, result.y0);
 }
 
+void CGContextSetCTM(CGContextRef ctx, CGAffineTransform m)
+{
+  // FIXME: it looks like we do not need to do anything related to the
+  // flip transformation here like in GetCTM() above, but we may be wrong
+  // here.
+  cairo_matrix_t cairoMatrix;
+  cairo_matrix_init(&cairoMatrix, m.a, m.b, m.c, m.d, m.tx, m.ty);
+  cairo_set_matrix(ctx->ct, &cairoMatrix);
+}
+
 void OPContextSetCairoDeviceOffset(CGContextRef ctx, CGFloat x, CGFloat y)
 {
   OPLOGCALL("ctx /*%p*/, %g, %g", ctx, x, y)

From 8454a24bc4cd82190e277bb1139eb3b79614b3be Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Thu, 10 Aug 2017 13:37:38 +1000
Subject: [PATCH 06/13] CGContext: create CGContext private function stubs

Create stubs for yet unimplemented private CoreGraphics functions, for
increased compatibility with CG.
---
 Headers/CoreGraphics/CGContext.h | 12 +++++++++++
 Source/OpalGraphics/CGContext.m  | 34 ++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/Headers/CoreGraphics/CGContext.h b/Headers/CoreGraphics/CGContext.h
index 5fd2934..b30b382 100644
--- a/Headers/CoreGraphics/CGContext.h
+++ b/Headers/CoreGraphics/CGContext.h
@@ -591,6 +591,18 @@ CGContextType CGContextGetType(CGContextRef ctx);
 
 void CGContextSetCTM(CGContextRef ctx, CGAffineTransform m);
 
+CGAffineTransform CGContextGetBaseCTM(CGContextRef);
+
+void CGContextSetBaseCTM(CGContextRef, CGAffineTransform);
+
+CGColorSpaceRef CGContextCopyDeviceColorSpace(CGContextRef);
+
+void CGContextSetShouldAntialiasFonts(CGContextRef, bool shouldAntialiasFonts);
+
+bool CGDisplayUsesInvertedPolarity(void);
+
+bool CGDisplayUsesForceToGray(void);
+
 /* Opal Extensions */
 
 // FIXME: Move extensions to a separate header?
diff --git a/Source/OpalGraphics/CGContext.m b/Source/OpalGraphics/CGContext.m
index 7e795ce..97955f5 100644
--- a/Source/OpalGraphics/CGContext.m
+++ b/Source/OpalGraphics/CGContext.m
@@ -2004,6 +2004,40 @@ CGContextType CGContextGetType(CGContextRef ctx)
   return kCGContextTypeBitmap;
 }
 
+CGAffineTransform CGContextGetBaseCTM(CGContextRef ctx)
+{
+  // FIXME: unimplemented
+  return (CGAffineTransform){0, 0, 0, 0, 0, 0};
+}
+
+void CGContextSetBaseCTM(CGContextRef ctx, CGAffineTransform m)
+{
+  // FIXME: unimplemented
+}
+
+CGColorSpaceRef CGContextCopyDeviceColorSpace(CGContextRef ctx)
+{
+  // FIXME: unimplemented
+  return NULL;
+}
+
+void CGContextSetShouldAntialiasFonts(CGContextRef ctx, bool shouldAntialiasFonts)
+{
+  // FIXME: unimplemented
+}
+
+bool CGDisplayUsesInvertedPolarity(void)
+{
+  // FIXME: unimplemented
+  return false;
+}
+
+bool CGDisplayUsesForceToGray(void)
+{
+  // FIXME: unimplemented
+  return false;
+}
+
 void OpalContextSetScaleFactor(CGContextRef ctx, CGFloat scale)
 {
   if (scale == 0)

From f8677b0d3b57890870094c65518e7792f947844e Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Thu, 10 Aug 2017 13:39:50 +1000
Subject: [PATCH 07/13] CGFont: implement stub for
 CGFontGetGlyphAdvancesForStyle

Create a stub for the private function CGFontGetGlyphAdvancesForStyle
for increased compatibility.
---
 Headers/CoreGraphics/CGFont.h | 11 +++++++++++
 Source/OpalGraphics/CGFont.m  | 12 ++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/Headers/CoreGraphics/CGFont.h b/Headers/CoreGraphics/CGFont.h
index 7824a58..7677bbb 100644
--- a/Headers/CoreGraphics/CGFont.h
+++ b/Headers/CoreGraphics/CGFont.h
@@ -35,6 +35,7 @@ typedef struct CGFont* CGFontRef;
 #endif
 
 #include <CoreGraphics/CGBase.h>
+#include <CoreGraphics/CGAffineTransform.h>
 #include <CoreGraphics/CGGeometry.h>
 #include <CoreGraphics/CGDataProvider.h>
 
@@ -154,6 +155,16 @@ CGFontRef CGFontRetain(CGFontRef font);
 
 void CGFontRelease(CGFontRef font);
 
+/* Private Functions */
+
+bool CGFontGetGlyphAdvancesForStyle(
+  CGFontRef,
+  const CGAffineTransform*,
+  int,
+  const CGGlyph[],
+  size_t count,
+  CGSize advances[]);
+
 /* Extensions */
 
 #ifndef __MINGW__ // FIXME: proper check for fontconfig
diff --git a/Source/OpalGraphics/CGFont.m b/Source/OpalGraphics/CGFont.m
index ac67927..59d6aa7 100644
--- a/Source/OpalGraphics/CGFont.m
+++ b/Source/OpalGraphics/CGFont.m
@@ -351,3 +351,15 @@ CGGlyph OPFontGetGlyphWithCharacter(CGFontRef font, unichar character)
 {
   return [font glyphWithCharacter: character];
 }
+
+bool CGFontGetGlyphAdvancesForStyle(
+  CGFontRef font,
+  const CGAffineTransform *m,
+  int renderingStyle,
+  const CGGlyph glyphs[],
+  size_t count,
+  CGSize advances[])
+{
+  // FIXME: unimplemented
+  return false;
+}

From 627b030edac811675f9a2f653b9949325a97eca4 Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Thu, 10 Aug 2017 13:47:36 +1000
Subject: [PATCH 08/13] CGImageSource: add private stubs

Add private constant and function stubs for CGImageSource for increased
compatibility.
---
 Headers/CoreGraphics/CGImageSource.h |  9 +++++++++
 Source/OpalGraphics/CGImageSource.m  | 18 ++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/Headers/CoreGraphics/CGImageSource.h b/Headers/CoreGraphics/CGImageSource.h
index 9a4ad24..3937a1e 100644
--- a/Headers/CoreGraphics/CGImageSource.h
+++ b/Headers/CoreGraphics/CGImageSource.h
@@ -50,6 +50,11 @@ const extern CFStringRef kCGImageSourceCreateThumbnailFromImageAlways;
 const extern CFStringRef kCGImageSourceThumbnailMaxPixelSize;
 const extern CFStringRef kCGImageSourceCreateThumbnailWithTransform;
 
+const extern CFStringRef kCGImageSourceShouldPreferRGB32;
+const extern CFStringRef kCGImageSourceSkipMetadata;
+const extern CFStringRef kCGImageSourceSubsampleFactor;
+const extern CFStringRef kCGImageSourceShouldCacheImmediately;
+
 /* Data Types */
 
 #ifdef INTERNAL_BUILD_OBJC
@@ -139,6 +144,10 @@ void CGImageSourceUpdateDataProvider(
 
 CFTypeID CGImageSourceGetTypeID();
 
+/* Private APIs */
+
+CFStringRef CGImageSourceGetTypeWithData(CFDataRef, CFStringRef, bool*);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/Source/OpalGraphics/CGImageSource.m b/Source/OpalGraphics/CGImageSource.m
index 10849ee..839ceff 100644
--- a/Source/OpalGraphics/CGImageSource.m
+++ b/Source/OpalGraphics/CGImageSource.m
@@ -38,6 +38,15 @@
 const CFStringRef kCGImageSourceThumbnailMaxPixelSize = @"kCGImageSourceThumbnailMaxPixelSize";
 const CFStringRef kCGImageSourceCreateThumbnailWithTransform = @"kCGImageSourceCreateThumbnailWithTransform";
 
+const CFStringRef kCGImageSourceShouldPreferRGB32 =
+  @"kCGImageSourceShouldPreferRGB32";
+const CFStringRef kCGImageSourceSkipMetadata =
+  @"kCGImageSourceSkipMetadata";
+const CFStringRef kCGImageSourceSubsampleFactor =
+  @"kCGImageSourceSubsampleFactor";
+const CFStringRef kCGImageSourceShouldCacheImmediately =
+  @"kCGImageSourceShouldCacheImmediately";
+
 
 static NSMutableArray *sourceClasses = nil;
 
@@ -354,6 +363,15 @@ CFStringRef CGImageSourceGetType(CGImageSourceRef source)
   return [source type];
 }
 
+CFStringRef CGImageSourceGetTypeWithData(
+  CFDataRef data,
+  CFStringRef string,
+  bool* result)
+{
+  // FIXME: unimplemented
+  return NULL;
+}
+
 void CGImageSourceUpdateData(
   CGImageSourceRef source,
   CFDataRef data,

From 477c1a4c6924f51169b1edac4688ccb98096fae0 Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Thu, 10 Aug 2017 13:55:24 +1000
Subject: [PATCH 09/13] CTFont: add private function stubs

Add stubs for some private functions and constants in CTFont for
compatibility purposes.
---
 Headers/CoreText/CTFont.h | 31 +++++++++++++++++++++++++
 Source/OpalText/CTFont.m  | 49 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+)

diff --git a/Headers/CoreText/CTFont.h b/Headers/CoreText/CTFont.h
index 9725176..8d8f837 100644
--- a/Headers/CoreText/CTFont.h
+++ b/Headers/CoreText/CTFont.h
@@ -486,6 +486,37 @@ CFTypeID CTFontGetTypeID();
 CTFontDescriptorRef CTFontManagerCreateFontDescriptorFromData(
   CFDataRef data);
 
+/* Private APIs */
+
+bool CTFontGetVerticalGlyphsForCharacters(
+  CTFontRef,
+  const UniChar characters[],
+  CGGlyph glyphs[],
+  CFIndex count);
+
+bool CTFontTransformGlyphs(
+  CTFontRef,
+  CGGlyph glyphs[],
+  CGSize advances[],
+  CFIndex count,
+  int);
+
+CTFontRef CTFontCreateForCSS(
+  CFStringRef name,
+  uint16_t weight,
+  CTFontSymbolicTraits,
+  CGFloat size);
+
+CTFontRef CTFontCreateForCharactersWithLanguage(
+  CTFontRef currentFont,
+  const UTF16Char *characters,
+  CFIndex length,
+  CFStringRef language, CFIndex *coveredLength);
+
+extern const CFStringRef kCTFontReferenceURLAttribute;
+extern const CFStringRef kCTFontOpticalSizeAttribute;
+extern const CFStringRef kCTFontPostScriptNameAttribute;
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/Source/OpalText/CTFont.m b/Source/OpalText/CTFont.m
index 9905d82..e718c73 100644
--- a/Source/OpalText/CTFont.m
+++ b/Source/OpalText/CTFont.m
@@ -66,6 +66,13 @@
 const CFStringRef kCTFontOpenTypeFeatureTag = (CFStringRef)@"kCTFontOpenTypeFeatureTag";
 const CFStringRef kCTFontOpenTypeFeatureValue = (CFStringRef)@"kCTFontOpenTypeFeatureValue";
 
+const CFStringRef kCTFontReferenceURLAttribute =
+  @"kCTFontReferenceURLAttribute";
+const CFStringRef kCTFontOpticalSizeAttribute =
+  @"kCTFontOpticalSizeAttribute";
+const CFStringRef kCTFontPostScriptNameAttribute =
+  @"kCTFontPostScriptNameAttribute";
+
 /* Classes */
 
 
@@ -552,3 +559,45 @@ CTFontDescriptorRef CTFontManagerCreateFontDescriptorFromData(
   // FIXME: unimplemented
   return NULL;
 }
+
+bool CTFontGetVerticalGlyphsForCharacters(
+  CTFontRef font,
+  const UniChar characters[],
+  CGGlyph glyphs[],
+  CFIndex count)
+{
+  // FIXME: unimplemented
+  return false;
+}
+
+bool CTFontTransformGlyphs(
+  CTFontRef font,
+  CGGlyph glyphs[],
+  CGSize advances[],
+  CFIndex count,
+  int options)
+{
+  // FIXME: unimplemented
+  return false;
+}
+
+CTFontRef CTFontCreateForCSS(
+  CFStringRef name,
+  uint16_t weight,
+  CTFontSymbolicTraits traits,
+  CGFloat size)
+{
+  // FIXME: unimplemented
+  return NULL;
+}
+
+CTFontRef CTFontCreateForCharactersWithLanguage(
+  CTFontRef currentFont,
+  const UTF16Char *characters,
+  CFIndex length,
+  CFStringRef language,
+  CFIndex *coveredLength)
+{
+  // FIXME: unimplemented
+  return NULL;
+}

From dc4592fcaea4b1cda7731c345a3992b3620912c7 Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Thu, 10 Aug 2017 13:56:38 +1000
Subject: [PATCH 10/13] CTFontDescriptor: add stub for
 CTFontDescriptorIsSystemUIFont()

Create a stub for the CTFontDescriptorIsSystemUIFont() private function
for increased compatibility.
---
 Headers/CoreText/CTFontDescriptor.h | 2 ++
 Source/OpalText/CTFontDescriptor.m  | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/Headers/CoreText/CTFontDescriptor.h b/Headers/CoreText/CTFontDescriptor.h
index 95d65f3..859d161 100644
--- a/Headers/CoreText/CTFontDescriptor.h
+++ b/Headers/CoreText/CTFontDescriptor.h
@@ -152,6 +152,8 @@ CFTypeRef CTFontDescriptorCopyLocalizedAttribute(
 
 CFTypeID CTFontDescriptorGetTypeID();
 
+bool CTFontDescriptorIsSystemUIFont(CTFontDescriptorRef);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/Source/OpalText/CTFontDescriptor.m b/Source/OpalText/CTFontDescriptor.m
index 983265c..55b23a2 100644
--- a/Source/OpalText/CTFontDescriptor.m
+++ b/Source/OpalText/CTFontDescriptor.m
@@ -177,3 +177,8 @@ CFTypeID CTFontDescriptorGetTypeID()
   return (CFTypeID)[OPFontDescriptor class];
 }
 
+bool CTFontDescriptorIsSystemUIFont(CTFontDescriptorRef desc)
+{
+  // FIXME: unimplemented
+  return false;
+}

From dac2a33409e84927c183dff259d84db79cd0ee6b Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Thu, 10 Aug 2017 13:58:45 +1000
Subject: [PATCH 11/13] CTLine: add stub for CTLineCreateWithUniCharProvider()

Add a stub for the CTLineCreateWithUniCharProvider() private function
for increased compatibility purposes.
---
 Headers/CoreText/CTLine.h | 14 ++++++++++++++
 Source/OpalText/CTLine.m  |  8 ++++++++
 2 files changed, 22 insertions(+)

diff --git a/Headers/CoreText/CTLine.h b/Headers/CoreText/CTLine.h
index ea9c6dc..51f4b65 100644
--- a/Headers/CoreText/CTLine.h
+++ b/Headers/CoreText/CTLine.h
@@ -125,6 +125,20 @@ CGRect CTLineGetBoundsWithOptions(
   CTLineRef line,
   CTLineBoundsOptions options);
 
+/* Private APIs */
+
+typedef const UniChar* (*CTUniCharProviderCallback)(
+  CFIndex stringIndex,
+  CFIndex* charCount,
+  CFDictionaryRef* attributes,
+  void* refCon);
+typedef void (*CTUniCharDisposeCallback)(const UniChar* chars, void* refCon);
+
+CTLineRef CTLineCreateWithUniCharProvider(
+  CTUniCharProviderCallback provide,
+  CTUniCharDisposeCallback dispose,
+  void* refCon);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/Source/OpalText/CTLine.m b/Source/OpalText/CTLine.m
index 0e8b051..7c9e6c9 100644
--- a/Source/OpalText/CTLine.m
+++ b/Source/OpalText/CTLine.m
@@ -191,3 +191,11 @@ CGRect CTLineGetBoundsWithOptions(
 {
   return CGRectZero;
 }
+
+CTLineRef CTLineCreateWithUniCharProvider(
+  CTUniCharProviderCallback provide,
+  CTUniCharDisposeCallback dispose,
+  void* refCon)
+{
+  return NULL;
+}

From 8faeac45415faf04a4fd8279e1fb80be145d20ee Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Thu, 10 Aug 2017 14:00:32 +1000
Subject: [PATCH 12/13] CTRun: add private function stubs

Add stubs for private functions in CTRun for increased compatibility.
---
 Headers/CoreText/CTRun.h | 10 ++++++++++
 Source/OpalText/CTRun.m  | 14 ++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/Headers/CoreText/CTRun.h b/Headers/CoreText/CTRun.h
index 27cf886..647e530 100644
--- a/Headers/CoreText/CTRun.h
+++ b/Headers/CoreText/CTRun.h
@@ -119,6 +119,16 @@ void CTRunDraw(
 
 CFTypeID CTRunGetTypeID();
 
+/* Private APIs */
+
+CGSize CTRunGetInitialAdvance(CTRunRef run);
+
+void CTRunGetBaseAdvancesAndOrigins(
+  CTRunRef,
+  CFRange,
+  CGSize baseAdvances[],
+  CGPoint origins[]);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/Source/OpalText/CTRun.m b/Source/OpalText/CTRun.m
index 2f30170..67624d5 100644
--- a/Source/OpalText/CTRun.m
+++ b/Source/OpalText/CTRun.m
@@ -223,3 +223,17 @@ CFTypeID CTRunGetTypeID()
   return (CFTypeID)[CTRun class];
 }
 
+CGSize CTRunGetInitialAdvance(CTRunRef run)
+{
+  // FIXME: unimplemented
+  return CGSizeZero;
+}
+
+void CTRunGetBaseAdvancesAndOrigins(
+  CTRunRef run,
+  CFRange range,
+  CGSize baseAdvances[],
+  CGPoint origins[])
+{
+  // FIXME: unimplemented
+}

From 0593b06b4c1367b023034b7e73ba93ea548aef68 Mon Sep 17 00:00:00 2001
From: Daniel Ferreira <dtf@stanford.edu>
Date: Thu, 10 Aug 2017 14:02:25 +1000
Subject: [PATCH 13/13] CTTypesetter: add stub for
 CTTypesetterCreateWithUniCharProviderAndOptions()

Add stub for CTTypesetterCreateWithUniCharProviderAndOptions(), a
private function, for increased compatibility.
---
 Headers/CoreText/CTTypesetter.h | 6 ++++++
 Source/OpalText/CTTypesetter.m  | 9 +++++++++
 2 files changed, 15 insertions(+)

diff --git a/Headers/CoreText/CTTypesetter.h b/Headers/CoreText/CTTypesetter.h
index 72044a0..6aec39b 100644
--- a/Headers/CoreText/CTTypesetter.h
+++ b/Headers/CoreText/CTTypesetter.h
@@ -74,6 +74,12 @@ CFIndex CTTypesetterSuggestLineBreak(
 
 CFTypeID CTTypesetterGetTypeID();
 
+CTTypesetterRef CTTypesetterCreateWithUniCharProviderAndOptions(
+  CTUniCharProviderCallback provide,
+  CTUniCharDisposeCallback dispose,
+  void* refCon,
+  CFDictionaryRef options);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/Source/OpalText/CTTypesetter.m b/Source/OpalText/CTTypesetter.m
index eb9d047..fa39d10 100644
--- a/Source/OpalText/CTTypesetter.m
+++ b/Source/OpalText/CTTypesetter.m
@@ -143,3 +143,12 @@ CFTypeID CTTypesetterGetTypeID()
   return (CFTypeID)[CTTypesetter class];
 }
 
+CTTypesetterRef CTTypesetterCreateWithUniCharProviderAndOptions(
+  CTUniCharProviderCallback provide,
+  CTUniCharDisposeCallback dispose,
+  void* refCon,
+  CFDictionaryRef options)
+{
+  // FIXME: unimplemented
+  return NULL;
+}