fix: move orientation FFI bindings out of generated file; fix bool.toNSNumber

lib/src/darwin/native.dart

@@ -4,6 +4,7 @@ import 'dart:typed_data';
 import 'package:ffi/ffi.dart';
 import 'package:objective_c/objective_c.dart';
 import 'package:platform_image_converter/src/darwin/bindings.g.dart';
+import 'package:platform_image_converter/src/darwin/orientation_bindings.dart';
 import 'package:platform_image_converter/src/image_conversion_exception.dart';
 import 'package:platform_image_converter/src/image_converter_platform_interface.dart';
 import 'package:platform_image_converter/src/output_format.dart';

lib/src/darwin/orientation_bindings.dart

@@ -0,0 +1,98 @@
+// Hand-written FFI bindings for EXIF/CGImageSource orientation APIs.
+//
+// These supplement the auto-generated bindings.g.dart without modifying it.
+// They bind the CoreFoundation / ImageIO symbols needed to read and apply
+// the EXIF orientation tag when converting images on Darwin (iOS/macOS).
+//
+// Relevant Apple documentation:
+// - CGImageSourceCopyPropertiesAtIndex:
+//   https://developer.apple.com/documentation/imageio/cgimagesourcecopypropertiesatindex
+// - CGImageSourceCreateThumbnailAtIndex:
+//   https://developer.apple.com/documentation/imageio/cgimagesourcecreatethumbnailatindex
+// - kCGImagePropertyOrientation:
+//   https://developer.apple.com/documentation/imageio/kcgimagepropertyorientation
+// - kCGImageSourceCreateThumbnailWithTransform:
+//   https://developer.apple.com/documentation/imageio/kcgimagesourcecreatethumbnailwithtransform
+
+// ignore_for_file: type=lint, non_constant_identifier_names
+import 'dart:ffi' as ffi;
+
+import 'package:objective_c/objective_c.dart' as objc;
+
+import 'bindings.g.dart';
+
+// ─── CGImageSource properties ────────────────────────────────────────────────
+
+/// Copies the properties dictionary for the image at [index] inside [isrc].
+///
+/// Returns a retained `CFDictionaryRef` — the caller must `CFRelease` it.
+/// Returns `nullptr` if the source or image is invalid.
+@ffi.Native<CFDictionaryRef Function(CGImageSourceRef, ffi.Size, CFDictionaryRef)>()
+external CFDictionaryRef CGImageSourceCopyPropertiesAtIndex(
+  CGImageSourceRef isrc,
+  int index,
+  CFDictionaryRef options,
+);
+
+/// Creates an orientation-corrected image for the entry at [index].
+///
+/// With `kCGImageSourceCreateThumbnailWithTransform = kCFBooleanTrue` in
+/// [options], ImageIO bakes the EXIF rotation and/or flip into the returned
+/// pixel data, giving correctly-oriented pixels for any orientation value.
+///
+/// Returns a retained `CGImageRef` — the caller must `CFRelease` it.
+@ffi.Native<CGImageRef Function(CGImageSourceRef, ffi.Size, CFDictionaryRef)>()
+external CGImageRef CGImageSourceCreateThumbnailAtIndex(
+  CGImageSourceRef isrc,
+  int index,
+  CFDictionaryRef options,
+);
+
+// ─── CFDictionary / CFNumber lookup ──────────────────────────────────────────
+
+/// Returns the value associated with [key] in [theDict], or `nullptr`.
+///
+/// The returned pointer is not retained — do not `CFRelease` it.
+@ffi.Native<ffi.Pointer<ffi.Void> Function(CFDictionaryRef, ffi.Pointer<ffi.Void>)>()
+external ffi.Pointer<ffi.Void> CFDictionaryGetValue(
+  CFDictionaryRef theDict,
+  ffi.Pointer<ffi.Void> key,
+);
+
+/// Extracts the numeric value from a `CFNumber` into a native Dart pointer.
+///
+/// [theType] selects the C numeric type; 9 = `kCFNumberSInt32Type` (int32).
+/// Returns `true` on success.
+@ffi.Native<ffi.Bool Function(ffi.Pointer<ffi.Void>, ffi.Int32, ffi.Pointer<ffi.Void>)>()
+external bool CFNumberGetValue(
+  ffi.Pointer<ffi.Void> number,
+  int theType,
+  ffi.Pointer<ffi.Void> valuePtr,
+);
+
+// ─── ImageIO option keys ──────────────────────────────────────────────────────
+
+/// Key: EXIF/CGImage orientation tag in CGImageSource properties dicts.
+///
+/// Value is a `CFNumberRef` (int32) matching `CGImagePropertyOrientation`:
+/// 1=Up, 2=UpMirrored, 3=Down, 4=DownMirrored,
+/// 5=LeftMirrored, 6=Right, 7=RightMirrored, 8=Left.
+@ffi.Native<ffi.Pointer<objc.CFString>>()
+external ffi.Pointer<objc.CFString> kCGImagePropertyOrientation;
+
+/// Key: when `kCFBooleanTrue`, creates a thumbnail from the full image even
+/// when no embedded thumbnail is present.
+@ffi.Native<ffi.Pointer<objc.CFString>>()
+external ffi.Pointer<objc.CFString> kCGImageSourceCreateThumbnailFromImageIfAbsent;
+
+/// Key: when `kCFBooleanTrue`, rotates/flips the thumbnail to match the EXIF
+/// orientation tag, producing pixel-correct upright image data.
+@ffi.Native<ffi.Pointer<objc.CFString>>()
+external ffi.Pointer<objc.CFString> kCGImageSourceCreateThumbnailWithTransform;
+
+/// Key: maximum pixel size (longest edge) for the thumbnail.
+///
+/// Set this to the source image's longest edge to get full-resolution output
+/// from `CGImageSourceCreateThumbnailAtIndex`.
+@ffi.Native<ffi.Pointer<objc.CFString>>()
+external ffi.Pointer<objc.CFString> kCGImageSourceThumbnailMaxPixelSize;