完成字符的正确渲染

Author: lindexi

src/MediaConverters/SkiaWmfRenderer/src/SkiaWmfRenderer/Rendering/RenderTextHelper.cs

@@ -21,6 +21,16 @@ public static void DrawText(this SKCanvas canvas, string text, float x, float y,
 
         font.Shape(buffer);
 
+        // 经过实验测试，发现这里的 GetGlyphInfoSpan 方法返回的 Codepoint 就是 GlyphIndex 的值
+        // 如 edd88c25d3b92b231df2ed5c7fc0ce9297b98d96 的实验，只要在 HarfBuzzSharp.Font 的 Shape 方法之后，那么获取的 Codepoint 就是 GlyphIndex 的值
+        // 如其控制台输出的如下内容：
+        // Typeface=Standard Symbols PS GlyphCount=191
+        // ContainsGlyph('p')=True 81
+        // TryGetGlyph=True 81
+        // (int) 'p' == 112
+        // Before HarfBuzzSharp.Font.Shape Codepoint=112
+        // After HarfBuzzSharp.Font.Shape Codepoint=81
+        // 可见在 StandardSymbolsPS.ttf 字体下，在 Shape 之前，获取到的 Codepoint 就是字符的 Codepoint 值，而不是 GlyphIndex 的值。在 Shape 之后，获取到的 Codepoint 就是 GlyphIndex 的值
         ReadOnlySpan<GlyphInfo> glyphInfoSpan = buffer.GetGlyphInfoSpan();
         Span<ushort> glyphsSpan = glyphInfoSpan.Length < 1024 ?
             stackalloc ushort[glyphInfoSpan.Length]
@@ -29,15 +39,7 @@ stackalloc ushort[glyphInfoSpan.Length]
         for (int i = 0; i < glyphInfoSpan.Length; i++)
         {
             var codepoint = glyphInfoSpan[i].Codepoint;
-            if (font.TryGetGlyph(codepoint, out uint glyphId))
-            {
-                glyphsSpan[i] = (ushort) glyphId;
-            }
-            else
-            {
-                // 暂时不知道怎么处理
-                glyphsSpan[i] = 0;
-            }
+            glyphsSpan[i] = (ushort) codepoint;
         }
 
         Span<byte> byteBuffer = MemoryMarshal.AsBytes(glyphsSpan);

src/MediaConverters/SkiaWmfRenderer/src/SkiaWmfRenderer/Rendering/WmfRenderStatus.cs

@@ -116,8 +116,6 @@ public void UpdateSkiaTextStatus(string text)
            SKFontStyleWidth.Normal, IsItalic ? SKFontStyleSlant.Italic : SKFontStyleSlant.Upright);
         }
 
-
-
         Console.WriteLine($"CurrentFontName='{CurrentFontName}' get the SKTypeface {(typeface is null ? "is null" : "not null")}. SKTypeface={typeface?.FamilyName} GlyphCount={typeface?.GlyphCount}. Text={text}");
 
         skFont.Typeface = typeface;