feat: add font configuration

Source/Data/Font/FontConfig.cs

@@ -0,0 +1,184 @@
+using ImGuiNET;
+using NumericsConverter;
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace UImGui
+{
+	[System.Serializable]
+	internal struct FontConfig
+	{
+		[Tooltip("TTF/OTF data ownership taken by the container ImFontAtlas (will delete memory itself). (default=true)")]
+		public bool FontDataOwnedByAtlas;
+
+		[Tooltip("Index of font within TTF/OTF file. (default=0)")]
+		public int FontNo;
+
+		[Tooltip("Size in pixels for rasterizer (more or less maps to the resulting font height).")]
+		public float SizeInPixels;
+
+		[Tooltip("Rasterize at higher quality for sub-pixel positioning. " +
+			"Note the difference between 2 and 3 is minimal so you can reduce this to 2 to save memory. " +
+			"Read https://github.com/nothings/stb/blob/master/tests/oversample/README.md for details. (default=3)")]
+		public int OversampleH;
+
+		[Tooltip("Rasterize at higher quality for sub-pixel positioning. " +
+			"This is not really useful as we don't use sub-pixel positions on the Y axis. (default=1)")]
+		public int OversampleV;
+
+		[Tooltip("Align every glyph to pixel boundary." +
+			" Useful e.g. if you are merging a non-pixel aligned font with the default font.  (default=false)" +
+			"If enabled, you can set OversampleH/V to 1.")]
+		public bool PixelSnapH;
+
+		[Tooltip("Extra spacing (in pixels) between glyphs. Only X axis is supported for now. (default=0, 0)")]
+		public Vector2 GlyphExtraSpacing;
+
+		[Tooltip("Offest all glyphs from this font input. (default=0, 0)")]
+		public Vector2 GlyphOffset;
+
+		[Tooltip("Glyph ranges for different writing systems.")]
+		public ScriptGlyphRanges GlyphRanges;
+
+		[Tooltip("Minimum AdvanceX for glyphs, set Min to align font icons, set both Min/Max to enforce mono-space font. (default=0, 0)")]
+		public float GlyphMinAdvanceX;
+
+		[Tooltip("Maximum AdvanceX for glyphs. (default=float_max)")]
+		public float GlyphMaxAdvanceX;
+
+		[Tooltip("Merge into previous ImFont, so you can combine multiple " +
+			"inputs font into one ImFont (e.g. ASCII font + icons + Japanese glyphs). " +
+			"You may want to use GlyphOffset.y when merge font of different heights. (default=false)")]
+		public bool MergeMode;
+
+		[Tooltip("Settings for custom font builder. THIS IS BUILDER IMPLEMENTATION DEPENDENT. Leave as zero if unsure. (default=0)")]
+		public uint FontBuilderFlags;
+
+		[Tooltip("Brighten (>1.0f) or darken (<1.0f) font output. " +
+			"Brightening small fonts may be a good workaround to make them more readable. (default=1.0f)")]
+		public float RasterizerMultiply;
+
+		[Tooltip("Explicitly specify unicode codepoint of ellipsis character. " +
+			"When fonts are being merged first specified ellipsis will be used. (default=-1)")]
+		public char EllipsisChar;
+
+		[Tooltip("User-provided list of Unicode range (2 value per range, values are inclusive).")]
+		public Range[] CustomGlyphRanges;
+
+		public void SetDefaults()
+		{
+			unsafe
+			{
+				ImFontConfig* imFontConfig = ImGuiNative.ImFontConfig_ImFontConfig();
+				SetFrom(imFontConfig);
+				ImGuiNative.ImFontConfig_destroy(imFontConfig);
+			}
+		}
+
+		public void ApplyTo(ImFontConfigPtr im)
+		{
+			im.FontDataOwnedByAtlas = FontDataOwnedByAtlas;
+			im.FontNo = FontNo;
+			im.SizePixels = SizeInPixels;
+			im.OversampleH = OversampleH;
+			im.OversampleV = OversampleV;
+			im.PixelSnapH = PixelSnapH;
+			im.GlyphExtraSpacing = GlyphExtraSpacing.ToSystem();
+			im.GlyphOffset = GlyphOffset.ToSystem();
+			im.GlyphMinAdvanceX = GlyphMinAdvanceX;
+			im.GlyphMaxAdvanceX = GlyphMaxAdvanceX;
+			im.MergeMode = MergeMode;
+			im.FontBuilderFlags = FontBuilderFlags;
+			im.RasterizerMultiply = RasterizerMultiply;
+			im.EllipsisChar = EllipsisChar;
+
+			// setting GlyphRanges requires allocating memory so it is not done here
+			// use BuildRanges to get a List with the values, then allocate memory and copy
+			// (see TextureManager)
+		}
+
+		public void SetFrom(ImFontConfigPtr im)
+		{
+			FontDataOwnedByAtlas = im.FontDataOwnedByAtlas;
+			FontNo = im.FontNo;
+			SizeInPixels = im.SizePixels;
+			OversampleH = im.OversampleH;
+			OversampleV = im.OversampleV;
+			PixelSnapH = im.PixelSnapH;
+			GlyphExtraSpacing = im.GlyphExtraSpacing.ToUnity();
+			GlyphOffset = im.GlyphOffset.ToUnity();
+			GlyphMinAdvanceX = im.GlyphMinAdvanceX;
+			GlyphMaxAdvanceX = im.GlyphMaxAdvanceX;
+			MergeMode = im.MergeMode;
+			FontBuilderFlags = im.FontBuilderFlags;
+			RasterizerMultiply = im.RasterizerMultiply;
+			EllipsisChar = (char)im.EllipsisChar;
+
+			// no good way to set GlyphRanges, do manually
+		}
+
+		public unsafe List<ushort> BuildRanges()
+		{
+			ImFontAtlas* atlas = null;
+			List<ushort> ranges = default;
+
+			void AddRangePtr(ushort* r)
+			{
+				while (*r != 0)
+				{
+					ranges.Add(*r++);
+				}
+			};
+
+			if ((GlyphRanges & ScriptGlyphRanges.Default) != 0)
+			{
+				AddRangePtr(ImGuiNative.ImFontAtlas_GetGlyphRangesDefault(atlas));
+			}
+
+			if ((GlyphRanges & ScriptGlyphRanges.Cyrillic) != 0)
+			{
+				AddRangePtr(ImGuiNative.ImFontAtlas_GetGlyphRangesCyrillic(atlas));
+			}
+
+			if ((GlyphRanges & ScriptGlyphRanges.Japanese) != 0)
+			{
+				AddRangePtr(ImGuiNative.ImFontAtlas_GetGlyphRangesJapanese(atlas));
+			}
+
+			if ((GlyphRanges & ScriptGlyphRanges.Korean) != 0)
+			{
+				AddRangePtr(ImGuiNative.ImFontAtlas_GetGlyphRangesKorean(atlas));
+			}
+
+			if ((GlyphRanges & ScriptGlyphRanges.Thai) != 0)
+			{
+				AddRangePtr(ImGuiNative.ImFontAtlas_GetGlyphRangesThai(atlas));
+			}
+
+			if ((GlyphRanges & ScriptGlyphRanges.Vietnamese) != 0)
+			{
+				AddRangePtr(ImGuiNative.ImFontAtlas_GetGlyphRangesVietnamese(atlas));
+			}
+
+			if ((GlyphRanges & ScriptGlyphRanges.ChineseSimplified) != 0)
+			{
+				AddRangePtr(ImGuiNative.ImFontAtlas_GetGlyphRangesChineseSimplifiedCommon(atlas));
+			}
+
+			if ((GlyphRanges & ScriptGlyphRanges.ChineseFull) != 0)
+			{
+				AddRangePtr(ImGuiNative.ImFontAtlas_GetGlyphRangesChineseFull(atlas));
+			}
+
+			if ((GlyphRanges & ScriptGlyphRanges.Custom) != 0)
+			{
+				foreach (Range range in CustomGlyphRanges)
+				{
+					ranges.AddRange(new[] { range.Start, range.End });
+				}
+			}
+
+			return ranges;
+		}
+	}
+}

Source/Data/Font/FontDefinition.cs

@@ -0,0 +1,15 @@
+using UnityEngine;
+
+namespace UImGui
+{
+	[System.Serializable]
+	internal struct FontDefinition
+	{
+		[Tooltip("Path relative to Application.streamingAssetsPath")]
+		public string Path;
+		public FontConfig Config;
+
+		[SerializeField]
+		private Object _fontAsset;
+	}
+}

Source/Data/Font/FontRasterizerType.cs

@@ -0,0 +1,8 @@
+namespace UImGui
+{
+	internal enum FontRasterizerType
+	{
+		StbTrueType,
+		FreeType,
+	}
+}

Source/Data/Font/ScriptGlyphRanges.cs

@@ -0,0 +1,18 @@
+using System;
+
+namespace UImGui
+{
+	[Flags]
+	internal enum ScriptGlyphRanges
+	{
+		Default = 1 << 0,
+		Cyrillic = 1 << 1,
+		Japanese = 1 << 2,
+		Korean = 1 << 3,
+		Thai = 1 << 4,
+		Vietnamese = 1 << 5,
+		ChineseSimplified = 1 << 6,
+		ChineseFull = 1 << 7,
+		Custom = 1 << 8,
+	}
+}