RGBA -> RGB now happens in C

example/ios/Flutter/AppFrameworkInfo.plist

@@ -21,6 +21,6 @@
   <key>CFBundleVersion</key>
   <string>1.0</string>
   <key>MinimumOSVersion</key>
-  <string>11.0</string>
+  <string>12.0</string>
 </dict>
 </plist>

example/ios/Podfile

@@ -1,5 +1,5 @@
 # Uncomment this line to define a global platform for your project
-# platform :ios, '11.0'
+# platform :ios, '12.0'
 
 # CocoaPods analytics sends network stats synchronously affecting flutter build latency.
 ENV['COCOAPODS_DISABLE_STATS'] = 'true'

example/ios/Podfile.lock

@@ -15,8 +15,8 @@ EXTERNAL SOURCES:
 
 SPEC CHECKSUMS:
   blurhash_ffi: 4831b96320d4273876c9a2fd3f7d50b8a3a53509
-  Flutter: f04841e97a9d0b0a8025694d0796dd46242b2854
+  Flutter: e0871f40cf51350855a761d2e70bf5af5b9b5de7
 
-PODFILE CHECKSUM: 70d9d25280d0dd177a5f637cdb0f0b0b12c6a189
+PODFILE CHECKSUM: 819463e6a0290f5a72f145ba7cde16e8b6ef0796
 
-COCOAPODS: 1.12.1
+COCOAPODS: 1.15.2

example/ios/Runner.xcodeproj/project.pbxproj

@@ -219,7 +219,7 @@
 		97C146E61CF9000F007C117D /* Project object */ = {
 			isa = PBXProject;
 			attributes = {
-				LastUpgradeCheck = 1430;
+				LastUpgradeCheck = 1510;
 				ORGANIZATIONNAME = "";
 				TargetAttributes = {
 					331C8080294A63A400263BE5 = {
@@ -457,7 +457,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SUPPORTED_PLATFORMS = iphoneos;
@@ -584,7 +584,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
@@ -633,7 +633,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SUPPORTED_PLATFORMS = iphoneos;

example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1430"
+   LastUpgradeVersion = "1510"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"

example/pubspec.lock

@@ -23,7 +23,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "1.2.3"
+    version: "1.2.4"
   boolean_selector:
     dependency: transitive
     description:

lib/blurhash.dart

@@ -176,8 +176,8 @@ class BlurhashFFI {
       ImageProvider imageProvider) async {
     final completer = Completer<BlurHashImageInfo>();
     final listener = ImageStreamListener((imageInfo, _) async {
-      final ByteData? bytes =
-          await imageInfo.image.toByteData(format: ui.ImageByteFormat.rawRgba);
+      final ByteData? bytes = await imageInfo.image
+          .toByteData(format: ui.ImageByteFormat.rawRgba);
       if (bytes == null) {
         completer.completeError(BlurhashFFIException(
             'Could not decode Image from Image provider',
@@ -186,15 +186,10 @@ class BlurhashFFI {
         return;
       }
       final Uint8List list = bytes.buffer.asUint8List();
-      final rgbBytes = Uint8List(list.length ~/ 4 * 3);
-      for (var i = 0, j = 0; i < list.length; i += 4, j += 3) {
-        rgbBytes[j] = list[i];
-        rgbBytes[j + 1] = list[i + 1];
-        rgbBytes[j + 2] = list[i + 2];
-      }
+
       if (!completer.isCompleted) {
         completer.complete(BlurHashImageInfo(imageInfo.image.height,
-            imageInfo.image.width, imageInfo.image.width * 3, rgbBytes));
+            imageInfo.image.width, imageInfo.image.width * 4, list));
       }
     }, onError: (dynamic exception, StackTrace? stackTrace) {
       completer.completeError(exception, stackTrace);
@@ -356,7 +351,6 @@ class BlurhashFFI {
             data.pixelsPointer,
             data.rowStride,
           );
-          data.free();
           final String resultString = result.cast<Utf8>().toDartString();
           final _EncodeResponse response =
               _EncodeResponse(data.id, resultString);
@@ -365,7 +359,6 @@ class BlurhashFFI {
         } else if (data is _DecodeRequest) {
           final Pointer<Uint8> result = _bindings.decode(data.blurHashPointer,
               data.width, data.height, data.punch, data.channels);
-          data.free();
           final Uint8List resultImage = result.asTypedList(
             data.width * data.height * data.channels,
             // preffer way but works only from dart 3.1.0, and requre to change generated bindings
@@ -402,7 +395,7 @@ class BlurhashFFI {
         final stackTrace = StackTrace.current;
         throw BlurhashFFIException(
             'ERORR: ${Isolate.current.debugName}', stackTrace, e);
-      }
+      } 
     }
 
     final ReceivePort helperReceivePort = ReceivePort()..listen(onSend);
@@ -423,7 +416,11 @@ class BlurhashFFIException extends Error {
       [this.level = Level.SEVERE]);
 }
 
-class _DecodeToArrayRequest {
+mixin Freeable {
+  void free();
+}
+
+class _DecodeToArrayRequest with Freeable{
   final int id;
   final String blurHash;
   final int width;
@@ -444,6 +441,7 @@ class _DecodeToArrayRequest {
     return _bhptr!.cast<Char>();
   }
 
+  @override
   void free() {
     if (_bhptr != null) {
       malloc.free(_bhptr!);
@@ -452,7 +450,7 @@ class _DecodeToArrayRequest {
   }
 }
 
-class _DecodeRequest {
+class _DecodeRequest with Freeable{
   final int id;
   final String blurHash;
   final int width;
@@ -471,7 +469,7 @@ class _DecodeRequest {
     }
     return _bhptr!.cast<Char>();
   }
-
+  @override
   void free() {
     if (_bhptr != null) {
       malloc.free(_bhptr!);
@@ -480,7 +478,7 @@ class _DecodeRequest {
   }
 }
 
-class _EncodeRequest {
+class _EncodeRequest with Freeable{
   final int id;
   final Uint8List pixels;
   final int width;
@@ -501,6 +499,7 @@ class _EncodeRequest {
     return pixelsPtr!;
   }
 
+  @override
   void free() {
     if (pixelsPtr != null) {
       calloc.free(pixelsPtr!);

lib/blurhash_ffi_bindings_generated.dart

@@ -34,7 +34,7 @@ class BlurhashFfiBindings {
   /// `yComponents` - The number of components in the Y direction. Must be between 1 and 9. 3 to 5 is usually a good range for this.
   /// `width` - The width in pixels of the supplied image.
   /// `height` - The height in pixels of the supplied image.
-  /// `rgb` - A pointer to the pixel data. This is supplied in RGB order, with 3 bytes per pixels.
+  /// `rgb` - A pointer to the pixel data. This is supplied in RGBA format, with 4 bytes per pixels.
   /// `bytesPerRow` - The number of bytes per row of the RGB pixel data.
   ffi.Pointer<ffi.Char> blurHashForPixels(
     int xComponents,
@@ -166,22 +166,4 @@ class BlurhashFfiBindings {
           'freePixelArray');
   late final _freePixelArray =
       _freePixelArrayPtr.asFunction<void Function(ffi.Pointer<ffi.Uint8>)>();
-
-  /// freeBlurhash : Frees the blurhash string
-  /// Parameters :
-  /// blurhash : Blurhash string pointer which will be freed.
-  /// Returns : void (None)
-  void freeString(
-    ffi.Pointer<ffi.Char> blurhash,
-  ) {
-    return _freeString(
-      blurhash,
-    );
-  }
-
-  late final _freeStringPtr =
-      _lookup<ffi.NativeFunction<ffi.Void Function(ffi.Pointer<ffi.Char>)>>(
-          'freeString');
-  late final _freeString =
-      _freeStringPtr.asFunction<void Function(ffi.Pointer<ffi.Char>)>();
 }

src/blurhash_ffi.c

@@ -48,6 +48,8 @@ const char *blurHashForPixels(int xComponents, int yComponents, int width, int h
 		}
 	}
 
+	free(rgb);
+
 	float *dc = &factors[0];
 	float *ac = dc + 3;
 	int acCount = xComponents * yComponents - 1;
@@ -88,12 +90,14 @@ static float *multiplyBasisFunction(int xComponent, int yComponent, int width, i
 	float r = 0, g = 0, b = 0;
 	float normalisation = (xComponent == 0 && yComponent == 0) ? 1 : 2;
 
+	int channels = (int)bytesPerRow / width;
+
 	for(int y = 0; y < height; y++) {
 		for(int x = 0; x < width; x++) {
 			float basis = cosf(M_PI * xComponent * x / width) * cosf(M_PI * yComponent * y / height);
-			r += basis * sRGBToLinear(rgb[3 * x + 0 + y * bytesPerRow]);
-			g += basis * sRGBToLinear(rgb[3 * x + 1 + y * bytesPerRow]);
-			b += basis * sRGBToLinear(rgb[3 * x + 2 + y * bytesPerRow]);
+			r += basis * sRGBToLinear(rgb[channels * x + 0 + y * bytesPerRow]);
+			g += basis * sRGBToLinear(rgb[channels * x + 1 + y * bytesPerRow]);
+			b += basis * sRGBToLinear(rgb[channels * x + 2 + y * bytesPerRow]);
 		}
 	}
 

src/blurhash_ffi.h

@@ -28,7 +28,7 @@
 		`yComponents` - The number of components in the Y direction. Must be between 1 and 9. 3 to 5 is usually a good range for this.
 		`width` - The width in pixels of the supplied image.
 		`height` - The height in pixels of the supplied image.
-		`rgb` - A pointer to the pixel data. This is supplied in RGB order, with 3 bytes per pixels.
+		`rgb` - A pointer to the pixel data. This is supplied in RGBA format, with 4 bytes per pixels.
 		`bytesPerRow` - The number of bytes per row of the RGB pixel data.
 */