From ff02c2c2684d9eecb2f5fefe689fe60ff8e98280 Mon Sep 17 00:00:00 2001
From: Emmanuele Bassi <ebassi@gnome.org>
Date: Sun, 13 Aug 2023 15:47:20 +0100
Subject: [PATCH] Add surface-to-png in the quartz boilerplate

The cairo-boilerplate static library cannot use private API defined in
the main Cairo shared library, because it has no access to those
symbols.

Since the code is small, we can just dump it into the boilerplate
library.
---
 boilerplate/cairo-boilerplate-quartz.c | 80 +++++++++++++++++++++++++-
 1 file changed, 78 insertions(+), 2 deletions(-)

diff --git a/boilerplate/cairo-boilerplate-quartz.c b/boilerplate/cairo-boilerplate-quartz.c
index 1a1417c75..dd2452c0a 100644
--- a/boilerplate/cairo-boilerplate-quartz.c
+++ b/boilerplate/cairo-boilerplate-quartz.c
@@ -28,6 +28,40 @@
 
 #include <cairo-quartz-private.h>
 
+#include <dlfcn.h>
+
+#ifndef RTLD_DEFAULT
+#define RTLD_DEFAULT ((void *) 0)
+#endif
+
+/*
+ * macOS Private functions
+ */
+typedef enum {
+    kCGContextTypeUnknown,
+    kCGContextTypePDF,
+    kCGContextTypePostScript,
+    kCGContextTypeWindow,
+    kCGContextTypeBitmap,
+    kCGContextTypeGL,
+    kCGContextTypeDisplayList,
+    kCGContextTypeKSeparation,
+    kCGContextTypeIOSurface,
+    kCGContextTypeCount
+} CGContextType;
+
+
+static unsigned int (*CGContextGetTypePtr) (CGContextRef) = NULL;
+static void
+quartz_ensure_symbols (void)
+{
+    static cairo_bool_t symbol_lookup_done = FALSE;
+    if (!symbol_lookup_done) {
+	CGContextGetTypePtr = dlsym (RTLD_DEFAULT, "CGContextGetType");
+	symbol_lookup_done = TRUE;
+    }
+}
+
 static cairo_surface_t *
 _cairo_boilerplate_quartz_create_surface (const char		    *name,
 					  cairo_content_t	     content,
@@ -47,6 +81,48 @@ _cairo_boilerplate_quartz_create_surface (const char		    *name,
     return cairo_quartz_surface_create (format, width, height);
 }
 
+static bool
+cg_context_is_bitmap (CGContextRef context)
+{
+    quartz_ensure_symbols ();
+
+    if (likely (CGContextGetTypePtr)) {
+	return CGContextGetTypePtr (context) == kCGContextTypeBitmap;
+    }
+
+    return CGBitmapContextGetBitsPerPixel (context) != 0;
+}
+
+static cairo_status_t
+_cairo_boilerplate_quartz_surface_to_png (cairo_surface_t *surface,
+                                          const char      *dest)
+{
+    CGContextRef context = cairo_quartz_surface_get_cg_context (surface);
+    if (!context || !cg_context_is_bitmap (context)) {
+        return CAIRO_STATUS_SURFACE_TYPE_MISMATCH;
+    }
+
+    CGImageRef image = CGBitmapContextCreateImage (context);
+    CFStringRef png_utti = CFSTR("public.png");
+    CFStringRef path;
+    CFURLRef url;
+
+    CGImageDestinationRef image_dest;
+
+    path = CFStringCreateWithCString (NULL, dest, kCFStringEncodingUTF8);
+    url = CFURLCreateWithFileSystemPath (NULL, path, kCFURLPOSIXPathStyle, FALSE);
+    image_dest = CGImageDestinationCreateWithURL (url, png_utti, 1, NULL);
+
+    CGImageDestinationAddImage (image_dest, image, NULL);
+    CGImageDestinationFinalize (image_dest);
+
+    CFRelease (url);
+    CFRelease (path);
+
+    CGImageRelease (image);
+    return CAIRO_STATUS_SUCCESS;
+}
+
 static const cairo_boilerplate_target_t targets[] = {
     {
 	"quartz", "quartz", NULL, NULL,
@@ -56,7 +132,7 @@ static const cairo_boilerplate_target_t targets[] = {
 	cairo_surface_create_similar,
 	NULL, NULL,
 	_cairo_boilerplate_get_image_surface,
-	_cairo_quartz_surface_to_png,
+	_cairo_boilerplate_quartz_surface_to_png,
 	NULL, NULL, NULL,
 	TRUE, FALSE, FALSE
     },
@@ -68,7 +144,7 @@ static const cairo_boilerplate_target_t targets[] = {
 	cairo_surface_create_similar,
 	NULL, NULL,
 	_cairo_boilerplate_get_image_surface,
-	_cairo_quartz_surface_to_png,
+	_cairo_boilerplate_quartz_surface_to_png,
 	NULL, NULL, NULL,
         FALSE, FALSE, FALSE
     },