add internal info decoding back to PSD format

brendan-duncan · Nov 10, 2024 · 91915a7 · 91915a7
1 parent 71e1d16
commit 91915a7
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Showing 3 changed files with 41 additions and 30 deletions.
diff --git a/lib/src/formats/psd/psd_channel.dart b/lib/src/formats/psd/psd_channel.dart
@@ -1,3 +1,4 @@
+import 'dart:math';
 import 'dart:typed_data';
 
 import '../../util/image_exception.dart';
@@ -19,7 +20,7 @@ class PsdChannel {
 
   int id;
   int? dataLength;
-  late Uint8List data;
+  Uint8List? data;
 
   PsdChannel(this.id, this.dataLength);
 
@@ -38,6 +39,9 @@ class PsdChannel {
 
   void readPlane(InputBuffer input, int width, int height, int? bitDepth,
       [int? compression, Uint16List? lineLengths, int planeNum = 0]) {
+    if (input.length < 2) {
+      return;
+    }
     compression ??= input.readUint16();
 
     switch (compression) {
@@ -70,7 +74,7 @@ class PsdChannel {
     }
     if (len > input.length) {
       data = Uint8List(len);
-      data.fillRange(0, len, 255);
+      data!.fillRange(0, len, 255);
       return;
     }
 
@@ -88,23 +92,27 @@ class PsdChannel {
     var pos = 0;
     var lineIndex = planeNum * height;
     if (lineIndex >= lineLengths.length) {
-      data.fillRange(0, data.length, 255);
+      data!.fillRange(0, data!.length, 255);
       return;
     }
 
     for (var i = 0; i < height; ++i) {
       final len = lineLengths[lineIndex++];
       final s = input.readBytes(len);
-      _decodeRLE(s, data, pos);
+      _decodeRLE(s, data!, pos);
       pos += width;
     }
   }
 
   void _decodeRLE(InputBuffer src, Uint8List dst, int dstIndex) {
     while (!src.isEOS) {
-      var n = src.readInt8();
+      var n = 0;
+      n = src.readInt8();
       if (n < 0) {
         n = 1 - n;
+        if (src.isEOS) {
+          break;
+        }
         final b = src.readByte();
         if ((dstIndex + n) > dst.length) {
           n = dst.length - dstIndex;
@@ -117,6 +125,7 @@ class PsdChannel {
         if ((dstIndex + n) > dst.length) {
           n = dst.length - dstIndex;
         }
+        n = min(n, src.length);
         for (var i = 0; i < n; ++i) {
           dst[dstIndex++] = src.readByte();
         }

diff --git a/lib/src/formats/psd/psd_image.dart b/lib/src/formats/psd/psd_image.dart
@@ -41,6 +41,15 @@ class PsdImage implements DecodeInfo {
   final imageResources = <int, PsdImageResource>{};
   bool hasAlpha = false;
 
+  static const resourceBlockSignature = 0x3842494d; // '8BIM'
+
+  late InputBuffer? _input;
+
+  //InputBuffer? _colorData;
+  InputBuffer? _imageResourceData;
+  InputBuffer? _layerAndMaskData;
+  InputBuffer? _imageData;
+
   @override
   Color? get backgroundColor => null;
 
@@ -53,14 +62,13 @@ class PsdImage implements DecodeInfo {
     }
 
     var len = _input!.readUint32();
-    /*_colorData =*/
-    _input!.readBytes(len);
+    /*_colorData =*/ _input!.readBytes(len);
 
     len = _input!.readUint32();
-    /*_imageResourceData =*/ _input!.readBytes(len);
+    _imageResourceData = _input!.readBytes(len);
 
     len = _input!.readUint32();
-    /*_layerAndMaskData =*/ _input!.readBytes(len);
+    _layerAndMaskData = _input!.readBytes(len);
 
     _imageData = _input!.readBytes(_input!.length);
   }
@@ -85,16 +93,16 @@ class PsdImage implements DecodeInfo {
     // Image Resource Block:
     // Image resources are used to store non-pixel data associated with images,
     // such as pen tool paths.
-    //_readImageResources();
+    _readImageResources();
 
-    //_readLayerAndMaskData();
+    _readLayerAndMaskData();
 
     _readMergeImageData();
 
     _input = null;
     //_colorData = null;
-    //_imageResourceData = null;
-    //_layerAndMaskData = null;
+    _imageResourceData = null;
+    _layerAndMaskData = null;
     _imageData = null;
 
     return true;
@@ -408,7 +416,7 @@ class PsdImage implements DecodeInfo {
     // TODO support indexed and duotone images.
   }
 
-  /*void _readImageResources() {
+  void _readImageResources() {
     _imageResourceData!.rewind();
     while (!_imageResourceData!.isEOS) {
       final blockSignature = _imageResourceData!.readUint32();
@@ -433,9 +441,9 @@ class PsdImage implements DecodeInfo {
             PsdImageResource(blockId, blockName, blockData);
       }
     }
-  }*/
+  }
 
-  /*void _readLayerAndMaskData() {
+  void _readLayerAndMaskData() {
     _layerAndMaskData!.rewind();
     var len = _layerAndMaskData!.readUint32();
     if ((len & 1) != 0) {
@@ -484,7 +492,7 @@ class PsdImage implements DecodeInfo {
         /*int kind =*/
         ..readByte();
     }
-  }*/
+  }
 
   void _readMergeImageData() {
     _imageData!.rewind();
@@ -509,8 +517,8 @@ class PsdImage implements DecodeInfo {
         colorMode, depth, width, height, mergeImageChannels);
   }
 
-  static int _ch(List<int> data, int si, int ns) =>
-      ns == 1 ? data[si] : ((data[si] << 8) | data[si + 1]) >> 8;
+  static int _ch(List<int>? data, int si, int ns) =>
+      data == null ? 0 : ns == 1 ? data[si] : ((data[si] << 8) | data[si + 1]) >> 8;
 
   static Image createImageFromChannels(PsdColorMode? colorMode, int? bitDepth,
       int width, int height, List<PsdChannel> channelList) {
@@ -596,13 +604,4 @@ class PsdImage implements DecodeInfo {
 
     return output;
   }
-
-  static const resourceBlockSignature = 0x3842494d; // '8BIM'
-
-  late InputBuffer? _input;
-
-  //InputBuffer _colorData;
-  //late InputBuffer? _imageResourceData;
-  //late InputBuffer? _layerAndMaskData;
-  late InputBuffer? _imageData;
 }
diff --git a/lib/src/util/input_buffer.dart b/lib/src/util/input_buffer.dart
@@ -1,4 +1,5 @@
 import 'dart:convert';
+import 'dart:math';
 import 'dart:typed_data';
 
 import 'bit_utils.dart';
@@ -16,14 +17,16 @@ class InputBuffer {
   InputBuffer(this.buffer,
       {this.bigEndian = false, this.offset = 0, int? length})
       : start = offset,
-        end = (length == null) ? buffer.length : offset + length;
+        end = min(
+            buffer.length, (length == null) ? buffer.length : offset + length);
 
   /// Create a copy of [other].
   InputBuffer.from(InputBuffer other, {int offset = 0, int? length})
       : buffer = other.buffer,
         offset = other.offset + offset,
         start = other.start,
-        end = (length == null) ? other.end : other.offset + offset + length,
+        end = min(other.buffer.length,
+            (length == null) ? other.end : other.offset + offset + length),
         bigEndian = other.bigEndian;
 
   ///  The current read position relative to the start of the buffer.