Don't upscale already scaled ppem

SixLabors · Mar 26, 2022 · 7b3ec08 · 7b3ec08
1 parent 6c3d00b
commit 7b3ec08
Show file tree

Hide file tree

Showing 3 changed files with 13 additions and 17 deletions.
diff --git a/src/SixLabors.Fonts/GlyphMetrics.cs b/src/SixLabors.Fonts/GlyphMetrics.cs
@@ -239,15 +239,15 @@ internal void RenderTo(IGlyphRenderer surface, float pointSize, Vector2 location
         {
             float dpi = options.Dpi;
             location *= dpi;
-            float scaledPoint = dpi * pointSize;
+            float scaledPPEM = dpi * pointSize;
             bool forcePPEMToInt = (this.FontMetrics.HeadFlags & HeadTable.HeadFlags.ForcePPEMToInt) != 0;
 
             if (forcePPEMToInt)
             {
-                scaledPoint = MathF.Round(scaledPoint);
+                scaledPPEM = MathF.Round(scaledPPEM);
             }
 
-            FontRectangle box = this.GetBoundingBox(location, scaledPoint);
+            FontRectangle box = this.GetBoundingBox(location, scaledPPEM);
 
             // TextRun is never null here as rendering is only accessable via a Glyph which
             // uses the cloned metrics instance.
@@ -262,26 +262,20 @@ internal void RenderTo(IGlyphRenderer surface, float pointSize, Vector2 location
                         colorSurface.SetColor(this.GlyphColor.Value);
                     }
 
-                    if (!this.scaledVector.TryGetValue(scaledPoint, out GlyphVector scaledVector))
+                    if (!this.scaledVector.TryGetValue(scaledPPEM, out GlyphVector scaledVector))
                     {
                         // Scale and translate the glyph
-                        Vector2 scale = new Vector2(scaledPoint) / this.ScaleFactor;
+                        Vector2 scale = new Vector2(scaledPPEM) / this.ScaleFactor;
                         var transform = Matrix3x2.CreateScale(scale);
                         transform.Translation = this.offset * scale * MirrorScale;
                         scaledVector = GlyphVector.Transform(this.vector, transform);
 
                         if (options.ApplyHinting)
                         {
-                            float scaledPixel = scaledPoint * (dpi / 72F);
-                            if (forcePPEMToInt)
-                            {
-                                scaledPixel = MathF.Round(scaledPixel);
-                            }
-
-                            this.FontMetrics.ApplyHinting(this, ref scaledVector, scale, scaledPixel);
+                            this.FontMetrics.ApplyHinting(this, ref scaledVector, scale, scaledPPEM);
                         }
 
-                        this.scaledVector[scaledPoint] = scaledVector;
+                        this.scaledVector[scaledPPEM] = scaledVector;
                     }
 
                     GlyphOutline outline = scaledVector.GetOutline();
@@ -360,7 +354,7 @@ internal void RenderTo(IGlyphRenderer surface, float pointSize, Vector2 location
 
                 (Vector2 Start, Vector2 End, float Thickness) GetEnds(float thickness, float position)
                 {
-                    Vector2 scale = new Vector2(scaledPoint) / this.ScaleFactor * MirrorScale;
+                    Vector2 scale = new Vector2(scaledPPEM) / this.ScaleFactor * MirrorScale;
                     Vector2 offset = location + (this.offset * scale * MirrorScale);
 
                     // Calculate the correct advance for the line.

diff --git a/src/SixLabors.Fonts/StreamFontMetrics.cs b/src/SixLabors.Fonts/StreamFontMetrics.cs
@@ -478,7 +478,7 @@ public static StreamFontMetrics[] LoadFontCollection(Stream stream)
             return fonts;
         }
 
-        internal void ApplyHinting(GlyphMetrics metrics, ref GlyphVector glyphVector, Vector2 scaleXY, float scaledPixel)
+        internal void ApplyHinting(GlyphMetrics metrics, ref GlyphVector glyphVector, Vector2 scaleXY, float scaledPPEM)
         {
             if (this.interpreter == null)
             {
@@ -495,8 +495,8 @@ internal void ApplyHinting(GlyphMetrics metrics, ref GlyphVector glyphVector, Ve
                 }
             }
 
-            float scaleFactor = scaledPixel / this.UnitsPerEm;
-            this.interpreter.SetControlValueTable(this.cvt?.ControlValues, scaleFactor, scaledPixel, this.prep?.Instructions);
+            float scaleFactor = scaledPPEM / this.UnitsPerEm;
+            this.interpreter.SetControlValueTable(this.cvt?.ControlValues, scaleFactor, scaledPPEM, this.prep?.Instructions);
 
             Bounds bounds = glyphVector.GetBounds();
 

diff --git a/src/SixLabors.Fonts/Tables/General/Glyphs/GlyphVector.cs b/src/SixLabors.Fonts/Tables/General/Glyphs/GlyphVector.cs
@@ -133,6 +133,8 @@ public static void Hint(ref GlyphVector glyph, Interpreter interpreter, Vector2
             for (int i = 0; i < glyph.entries.Count; i++)
             {
                 GlyphTableEntry entry = glyph.entries[i];
+
+                // TODO: Figure out a way to pool this.
                 var controlPoints = new Vector2[entry.ControlPoints.Length + 4];
                 controlPoints[controlPoints.Length - 4] = pp1;
                 controlPoints[controlPoints.Length - 3] = pp2;