示例#1
0
        public static unsafe void CompareMetricsWithStb(Font f, DrawableFontAtlas atlas, StbTrueType.stbtt_fontinfo stbFont)
        {
            var pc = new StbTrueType.stbtt_pack_context();

            StbTrueType.stbtt_PackBegin(pc, (byte *)0, 512, 512, 512, 1, null);

            var cd = new StbTrueType.stbtt_packedchar[f.LastCharIndex + 1];

            StbTrueType.stbrp_rect[] rects;
            fixed(StbTrueType.stbtt_packedchar *charDataPtr = &cd[0])
            {
                var range = new StbTrueType.stbtt_pack_range
                {
                    first_unicode_codepoint_in_range = 0,
                    array_of_unicode_codepoints      = null,
                    num_chars          = (int)f.LastCharIndex + 1,
                    chardata_for_range = charDataPtr,
                    font_size          = -atlas.FontSize
                };

                rects = new StbTrueType.stbrp_rect[f.LastCharIndex + 1];
                fixed(StbTrueType.stbrp_rect *rectPtr = &rects[0])
                {
                    int n = StbTrueType.stbtt_PackFontRangesGatherRects(pc, stbFont, &range, 1, rectPtr);

                    StbTrueType.stbtt_PackFontRangesPackRects(pc, rectPtr, n);
                }
            }

            foreach ((char charIndex, DrawableGlyph atlasGlyph) in atlas.Glyphs)
            {
                FontGlyph glyph = atlasGlyph.FontGlyph;

                var advance = 0;
                var bearing = 0;
                StbTrueType.stbtt_GetCodepointHMetrics(stbFont, charIndex, &advance, &bearing);
                Assert.True(advance == glyph.AdvanceWidth);
                Assert.True(bearing == glyph.LeftSideBearing || glyph.LeftSideBearing == 0); // stb has junk data beyond valid

                var minX = 0;
                var maxX = 0;
                var minY = 0;
                var maxY = 0;
                StbTrueType.stbtt_GetCodepointBitmapBoxSubpixel(stbFont, charIndex, atlas.RenderScale, atlas.RenderScale, 0, 0, &minX, &minY, &maxX, &maxY);

                Rectangle bbox = glyph.GetBBox(atlas.RenderScale);

                Assert.Equal(minX, bbox.X);
                Assert.Equal(minY, bbox.Y);
                Assert.Equal(maxX, bbox.Width);
                Assert.Equal(maxY, bbox.Height);

                Rectangle drawBox = new Rectangle(0, 0, bbox.Width - bbox.X, bbox.Height - bbox.Y);
                drawBox.Size += Vector2.One; // Add padding from stb
                StbTrueType.stbrp_rect rect = rects[charIndex];
                Assert.Equal(rect.w, drawBox.Width);
                Assert.Equal(rect.h, drawBox.Height);
            }
        }