1

我正在为 Windows 编写化学分子编辑器。由于它必须在 Word 加载项中使用，因此我仅限于使用 WPF 来呈现结构。这工作得很好，除了一个小小的琐碎点。

带有未对齐标签的样本分子

我使用 GlyphRuns 来渲染原子标签，它们总是稍微向右移动。如果您查看屏幕截图，您会看到有一个前导空格，尤其是 H2N 和 Hg 原子标签。为什么？当您获得字形运行的轮廓几何图形时，您会得到白色背景。

GlyphRun 类的文档记录很差，以至于我看不到要修改哪些属性才能将文本精确定位到我想要的位置。因此，任何尝试的建议都将受到欢迎。

更新：我被要求提供一个样本。代码很复杂，但不是无缘无故的，所以我将其删减以专注于要点：

    public void MeasureAtCenter(Point center)
        {
            GlyphInfo = GlyphUtils.GetGlyphsAndInfo(Text, PixelsPerDip, out GlyphRun groupGlyphRun, center, _glyphTypeface, TypeSize);
            //compensate the main offset vector for any descenders
            Vector mainOffset = GlyphUtils.GetOffsetVector(groupGlyphRun, AtomShape.SymbolSize) + new Vector(0.0, -MaxBaselineOffset) + new Vector(-FirstBearing(groupGlyphRun), 0.0);



            TextRun = groupGlyphRun;
            TextMetrics = new AtomTextMetrics
            {
                BoundingBox = groupGlyphRun.GetBoundingBox(center + mainOffset),
                Geocenter = center,
                TotalBoundingBox = groupGlyphRun.GetBoundingBox(center + mainOffset),
                OffsetVector = mainOffset
            };
        }

  public static GlyphInfo GetGlyphs(string symbolText, GlyphTypeface glyphTypeFace, double size)
        {
            ushort[] glyphIndexes = new ushort[symbolText.Length];
            double[] advanceWidths = new double[symbolText.Length];
            double[] uprightBaselineOffsets = new double[symbolText.Length];
            double totalWidth = 0;

            for (int n = 0; n < symbolText.Length; n++)
            {
                ushort glyphIndex = glyphTypeFace.CharacterToGlyphMap[symbolText[n]];
                glyphIndexes[n] = glyphIndex;

                double width = glyphTypeFace.AdvanceWidths[glyphIndex] * size;
                advanceWidths[n] = width;

                double ubo = glyphTypeFace.DistancesFromHorizontalBaselineToBlackBoxBottom[glyphIndex] * size;
                uprightBaselineOffsets[n] = ubo;
                totalWidth += width;
            }
            return new GlyphInfo { AdvanceWidths = advanceWidths, Indexes = glyphIndexes, Width = totalWidth, UprightBaselineOffsets = uprightBaselineOffsets };
        }

        public static GlyphUtils.GlyphInfo GetGlyphsAndInfo(string symbolText, float pixelsPerDip, out GlyphRun hydrogenGlyphRun, Point point, GlyphTypeface glyphTypeFace, double symbolSize)
        {
            //measure the H atom first
            var glyphInfo = GlyphUtils.GetGlyphs(symbolText, glyphTypeFace, symbolSize);
            hydrogenGlyphRun = GlyphUtils.GetGlyphRun(glyphInfo, glyphTypeFace,
                symbolSize, pixelsPerDip, point);
            //work out exactly how much we should offset from the center to get to the bottom left
            return glyphInfo;
        }

 public static Vector GetOffsetVector(GlyphRun glyphRun, double symbolSize)
    {
        Rect rect = glyphRun.ComputeInkBoundingBox();

        //Vector offset = (rect.BottomLeft - rect.TopRight) / 2;
        Vector offset = new Vector(-rect.Width / 2, glyphRun.GlyphTypeface.CapsHeight * symbolSize / 2);
        return offset;
    }
4

0 回答 0