Reuse all lists in linebreaker, remove lineBaseLines.

Author: Yuncong Zhang

Runtime/ui/txt/linebreaker.cs

@@ -108,7 +108,9 @@ public static int[] newLinePositions(string text, out int count) {
         TextBuff _textBuf;
         float[] _charWidths;
         List<int> _breaks = new List<int>();
+        int _breaksCount = 0;
         List<float> _widths = new List<float>();
+        int _widthsCount = 0;
         WordBreaker _wordBreaker = new WordBreaker();
         float _width = 0.0f;
         float _preBreak;
@@ -120,19 +122,28 @@ public static int[] newLinePositions(string text, out int count) {
         TabStops _tabStops;
         int mFirstTabIndex;
         List<Candidate> _candidates = new List<Candidate>();
+        int _candidatesCount = 0;
 
         public int computeBreaks() {
-            int nCand = this._candidates.Count;
+            int nCand = this._candidatesCount;
             if (nCand > 0 && (nCand == 1 || this._lastBreak != nCand - 1)) {
-                var cand = this._candidates.last();
+                var cand = this._candidates[this._candidatesCount - 1];
                 this._pushBreak(cand.offset, (cand.postBreak - this._preBreak));
             }
 
-            return this._breaks.Count;
+            return this._breaksCount;
         }
 
-        public List<int> getBreaks() {
-            return this._breaks;
+        public int getBreaksCount() {
+            return this._breaksCount;
+        }
+
+        public int getBreak(int i) {
+            return this._breaks[i];
+        }
+
+        public float getWidth(int i) {
+            return this._widths[i];
         }
 
         public void resize(int size) {
@@ -145,11 +156,11 @@ public void setText(string text, int textOffset, int textLength) {
             this._textBuf = new TextBuff(text, textOffset, textLength);
             this._wordBreaker.setText(this._textBuf);
             this._wordBreaker.next();
-            this._candidates.Clear();
+            this._candidatesCount = 0;
             Candidate can = new Candidate {
                 offset = 0, postBreak = 0, preBreak = 0, postSpaceCount = 0, preSpaceCount = 0, pre = 0
             };
-            this._candidates.Add(can);
+            this._addCandidateToList(can);
             this._lastBreak = 0;
             this._bestBreak = 0;
             this._bestScore = ScoreInfty;
@@ -208,14 +219,14 @@ public void addStyleRun(TextStyle style, int start, int end) {
         public void finish() {
             this._wordBreaker.finish();
             this._width = 0;
-            this._candidates.Clear();
-            this._widths.Clear();
-            this._breaks.Clear();
+            this._candidatesCount = 0;
+            this._breaksCount = 0;
+            this._widthsCount = 0;
             this._textBuf = default;
         }
 
-        public List<float> getWidths() {
-            return this._widths;
+        public int getWidthsCount() {
+            return this._widthsCount;
         }
 
         public void setTabStops(TabStops tabStops) {
@@ -225,7 +236,7 @@ public void setTabStops(TabStops tabStops) {
         void _addWordBreak(int offset, float preBreak, float postBreak, int preSpaceCount, int postSpaceCount,
             float penalty) {
 
-            float width = this._candidates.last().preBreak;
+            float width = this._candidates[this._candidatesCount - 1].preBreak;
             if (postBreak - width > this._lineWidth) {
                 this._addCandidatesInsideWord(width, offset, postSpaceCount);
             }
@@ -241,7 +252,7 @@ void _addWordBreak(int offset, float preBreak, float postBreak, int preSpaceCoun
         }
 
         void _addCandidatesInsideWord(float width, int offset, int postSpaceCount) {
-            int i = this._candidates.last().offset;
+            int i = this._candidates[this._candidatesCount - 1].offset;
             width += this._charWidths[i++];
             for (; i < offset; i++) {
                 float w = this._charWidths[i];
@@ -259,10 +270,19 @@ void _addCandidatesInsideWord(float width, int offset, int postSpaceCount) {
             }
         }
 
+        void _addCandidateToList(Candidate cand) {
+            if (this._candidates.Count == this._candidatesCount) {
+                this._candidates.Add(cand);
+                this._candidatesCount++;
+            }
+            else {
+                this._candidates[this._candidatesCount++] = cand;
+            }
+        }
 
         void _addCandidate(Candidate cand) {
-            int candIndex = this._candidates.Count;
-            this._candidates.Add(cand);
+            int candIndex = this._candidatesCount;
+            this._addCandidateToList(cand);
             if (cand.postBreak - this._preBreak > this._lineWidth) {
                 if (this._bestBreak == this._lastBreak) {
                     this._bestBreak = candIndex;
@@ -299,9 +319,22 @@ void _pushGreedyBreak() {
         }
 
         void _pushBreak(int offset, float width) {
-            if (this.lineLimit == 0 || this._breaks.Count < this.lineLimit) {
-                this._breaks.Add(offset);
-                this._widths.Add(width);
+            if (this.lineLimit == 0 || this._breaksCount < this.lineLimit) {
+                if (this._breaks.Count == this._breaksCount) {
+                    this._breaks.Add(offset);
+                    this._breaksCount++;
+                }
+                else {
+                    this._breaks[this._breaksCount++] = offset;
+                }
+
+                if (this._widths.Count == this._widthsCount) {
+                    this._widths.Add(width);
+                    this._widthsCount++;
+                }
+                else {
+                    this._widths[this._widthsCount++] = width;
+                }
             }
         }
     }

Runtime/ui/txt/paragraph.cs

@@ -188,7 +188,7 @@ public LineRange(int start, int end, int endExcludingWhitespace, int endIncludin
         ParagraphStyle _paragraphStyle;
         List<LineRange> _lineRanges = new List<LineRange>();
         List<float> _lineWidths = new List<float>();
-        float[] _lineBaseLines;
+        // float[] _lineBaseLines;
         GlyphLine[] _glyphLines;
         float _maxIntrinsicWidth;
         float _minIntrinsicWidth;
@@ -287,9 +287,9 @@ public void layout(ParagraphConstraints constraints) {
                 this._glyphLines = new GlyphLine[this._lineRanges.Count];
             }
 
-            if (this._lineBaseLines == null || this._lineBaseLines.Length < this._lineRanges.Count) {
-                this._lineBaseLines = new float[this._lineRanges.Count];
-            }
+            // if (this._lineBaseLines == null || this._lineBaseLines.Length < this._lineRanges.Count) {
+            //     this._lineBaseLines = new float[this._lineRanges.Count];
+            // }
 
             if (this._lineHeights == null || this._lineHeights.Length < this._lineRanges.Count) {
                 this._lineHeights = new float[this._lineRanges.Count];
@@ -536,7 +536,7 @@ void updateLineMetrics(FontMetrics metrics, float styleHeight) {
 
                 this._lineHeights[lineNumber] = ((lineNumber == 0 ? 0 : this._lineHeights[lineNumber - 1])
                                       + Mathf.Round(maxLineSpacing + maxDescent));
-                this._lineBaseLines[lineNumber] = this._lineHeights[lineNumber] - maxDescent;
+                // this._lineBaseLines[lineNumber] = this._lineHeights[lineNumber] - maxDescent;
                 yOffset += Mathf.Round(maxLineSpacing + preMaxDescent);
                 preMaxDescent = maxDescent;
                 float lineXOffset = this.getLineXOffset(runXOffset);
@@ -863,7 +863,7 @@ int _addStyleRuns(LineBreaker lineBreaker, ref int runIndex, int blockStart, int
                     break;
                 }
 
-                if (lineBreaker.lineLimit != 0 && lineBreaker.getBreaks().Count >= lineBreaker.lineLimit) {
+                if (lineBreaker.lineLimit != 0 && lineBreaker.getBreaksCount() >= lineBreaker.lineLimit) {
                     break;
                 }
 
@@ -888,12 +888,10 @@ int _addStyleRuns(LineBreaker lineBreaker, ref int runIndex, int blockStart, int
         }
 
         void _updateBreaks(LineBreaker lineBreaker, int breaksCount, int blockStart, int blockEnd) {
-            List<int> breaks = lineBreaker.getBreaks();
-            List<float> widths = lineBreaker.getWidths();
             for (int i = 0; i < breaksCount; ++i) {
-                var breakStart = i > 0 ? breaks[i - 1] : 0;
+                var breakStart = i > 0 ? lineBreaker.getBreak(i - 1) : 0;
                 var lineStart = breakStart + blockStart;
-                var lineEnd = breaks[i] + blockStart;
+                var lineEnd = lineBreaker.getBreak(i) + blockStart;
                 bool hardBreak = lineEnd == blockEnd;
                 var lineEndIncludingNewline =
                     hardBreak && lineEnd < this._text.Length ? lineEnd + 1 : lineEnd;
@@ -905,7 +903,7 @@ void _updateBreaks(LineBreaker lineBreaker, int breaksCount, int blockStart, int
 
                 this._lineRanges.Add(new LineRange(lineStart, lineEnd,
                     lineEndExcludingWhitespace, lineEndIncludingNewline, hardBreak));
-                this._lineWidths.Add(widths[i]);
+                this._lineWidths.Add(lineBreaker.getWidth(i));
             }
         }