fix(tbinaryreader): fix skipBitOffsetOf and skipBitOffsetTo in case t…

…hey are first statement
Itee · Mar 3, 2022 · 74542e4 · 74542e4
1 parent 9134c0c
commit 74542e4
Showing 1 changed file with 46 additions and 14 deletions.
diff --git a/sources/loaders/TBinaryReader.js b/sources/loaders/TBinaryReader.js
@@ -79,8 +79,8 @@ class TBinaryReader {
         // For bit reading use same approche than byte
         this._bits = {
             buffer: null,
-            offset: null,
-            length: null
+            offset: 0,
+            length: 0
         }
 
         this._updateDataView()
@@ -283,6 +283,21 @@ class TBinaryReader {
     _isOutOfRangeBitOffset( offset ) {
         return offset > this._bits.length
     }
+    _readBit8() {
+        this._bits.buffer = this.getUint8()
+        this._bits.length = 8
+        this._bits.offset = 0
+    }
+    _readBit16() {
+        this._bits.buffer = this.getUint16()
+        this._bits.length = 16
+        this._bits.offset = 0
+    }
+    _readBit32() {
+        this._bits.buffer = this.getUint32()
+        this._bits.length = 32
+        this._bits.offset = 0
+    }
     _getBitAt ( bitOffset ) {
 
         return ( this._bits.buffer & ( 1 << bitOffset ) ) === 0 ? 0 : 1
@@ -295,8 +310,31 @@ class TBinaryReader {
     }
 
     skipBitOffsetTo ( bitOffset ) {
+        //todo is positive bitoffset
+
+        // In case we start directly by a skip offset try to determine which kind of data is expected
+        if ( this._isNullBitBuffer() ) {
+
+            if (bitOffset <= 8) {
+
+                this._readBit8()
+
+            } else if (8 < bitOffset && bitOffset <= 16 ){
 
-        if ( this._isOutOfRangeBitOffset(bitOffset) ) { throw new RangeError( 'Bit offset is out of range of the current bits field.' ) }
+                this._readBit16()
+
+            } else if (16 < bitOffset && bitOffset <= 32 ){
+
+                this._readBit32()
+
+            } else {
+
+                throw new RangeError( 'You cannot skip more than 32 bits. Please use skipOffsetOf instead !' )
+
+            }
+
+        }
+        else if ( this._isOutOfRangeBitOffset(bitOffset) ) { throw new RangeError( 'Bit offset is out of range of the current bits field.' ) }
 
         this._bits.offset = bitOffset
         if(this._isEndOfBitBuffer()) {
@@ -314,9 +352,7 @@ class TBinaryReader {
     getBit8 ( moveNext = true ) {
 
         if ( this._isNullBitBuffer() ) {
-            this._bits.buffer = this.getUint8()
-            this._bits.length = 8
-            this._bits.offset = 0
+            this._readBit8()
         }
 
         const bitValue = this._getBitAt( this._bits.offset )
@@ -358,10 +394,8 @@ class TBinaryReader {
 
     getBit16 ( moveNext = true ) {
 
-        if ( this._isNullBitBuffer() || this._isEndOfBitBuffer() ) {
-            this._bits.buffer = this.getUint16()
-            this._bits.length = 16
-            this._bits.offset = 0
+        if ( this._isNullBitBuffer() ) {
+            this._readBit16()
         }
 
         const bitValue = this._getBitAt( this._bits.offset )
@@ -403,10 +437,8 @@ class TBinaryReader {
 
     getBit32 ( moveNext = true ) {
 
-        if ( this._isNullBitBuffer() || this._isEndOfBitBuffer() ) {
-            this._bits.buffer = this.getUint32()
-            this._bits.length = 32
-            this._bits.offset = 0
+        if ( this._isNullBitBuffer() ) {
+            this._readBit32()
         }
 
         const bitValue = this._getBitAt( this._bits.offset )