imgui_freetype: Added support for plutosvg to render OpenType SVG fonts. (#7927, #7187 + #6591, #6607)

See #7927 for details.

Author: pthom

docs/CHANGELOG.txt

@@ -93,6 +93,10 @@ Other changes:
   preventing use of external shortcuts not guarded by an ActiveId check. (#8048) [@geertbleyen]
 - InputText: ensure mouse cursor shape is set regardless of whether keyboard mode is 
   enabled or not. (#6417)
+- imgui_freetype: Added support for plutosvg (as an alternative to lunasvg) to render 
+  OpenType SVG fonts. Requires defining IMGUI_ENABLE_FREETYPE_PLUTOSVG along with IMGUI_ENABLE_FREETYPE.
+  Providing headers/librairies for plutosvg + plutovg is up to you (see #7927 for help).
+  (#7927, #7187, #6591, #6607) [@pthom]
 - Backends: DX11, DX12, SDLRenderer2/3. Vulkan, WGPU: expose selected state in
   ImGui_ImplXXXX_RenderState structures during render loop. (#6969, #5834, #7468, #3590)
 - Backends: DX9, DX10, DX11, DX12, OpenGL, Vulkan, WGPU: Changed default texture sampler

imconfig.h

@@ -83,10 +83,13 @@
 // On Windows you may use vcpkg with 'vcpkg install freetype --triplet=x64-windows' + 'vcpkg integrate install'.
 //#define IMGUI_ENABLE_FREETYPE
 
-//---- Use FreeType+lunasvg library to render OpenType SVG fonts (SVGinOT)
-// Requires lunasvg headers to be available in the include path + program to be linked with the lunasvg library (not provided).
+//---- Use FreeType + plutosvg or lunasvg to render OpenType SVG fonts (SVGinOT)
 // Only works in combination with IMGUI_ENABLE_FREETYPE.
-// (implementation is based on Freetype's rsvg-port.c which is licensed under CeCILL-C Free Software License Agreement)
+// - lunasvg is currently easier to acquire/install, as e.g. it is part of vcpkg.
+// - plutosvg will support more fonts and may load them faster. It currently requires to be built manually but it is fairly easy. See misc/freetype/README for instructions.
+// - Both require headers to be available in the include path + program to be linked with the library code (not provided).
+// - (note: lunasvg implementation is based on Freetype's rsvg-port.c which is licensed under CeCILL-C Free Software License Agreement)
+//#define IMGUI_ENABLE_FREETYPE_PLUTOSVG
 //#define IMGUI_ENABLE_FREETYPE_LUNASVG
 
 //---- Use stb_truetype to build and rasterize the font atlas (default)

misc/freetype/README.md

@@ -38,7 +38,25 @@ You can use the `ImGuiFreeTypeBuilderFlags_LoadColor` flag to load certain color
 
 ### Using OpenType SVG fonts (SVGinOT)
 - *SVG in Open Type* is a standard by Adobe and Mozilla for color OpenType and Open Font Format fonts. It allows font creators to embed complete SVG files within a font enabling full color and even animations.
-- Popular fonts such as [twemoji](https://github.com/13rac1/twemoji-color-font) and fonts made with [scfbuild](https://github.com/13rac1/scfbuild) is SVGinOT
-- Requires: [lunasvg](https://github.com/sammycage/lunasvg) v2.3.2 and above
-    1. Add `#define IMGUI_ENABLE_FREETYPE_LUNASVG` in your `imconfig.h`.
-    2. Get latest lunasvg binaries or build yourself. Under Windows you may use vcpkg with: `vcpkg install lunasvg --triplet=x64-windows`.
+- Popular fonts such as [twemoji](https://github.com/13rac1/twemoji-color-font) and fonts made with [scfbuild](https://github.com/13rac1/scfbuild) is SVGinOT 
+- Two alternatives are possible to render SVG fonts: use "lunasvg" or "plutosvg". plutosvg will support some more fonts (e.g. NotoColorEmoji-Regular) and may load them faster.
+
+#### Using lunasvg
+Requires: [lunasvg](https://github.com/sammycage/lunasvg) v2.3.2 and above
+- Add `#define IMGUI_ENABLE_FREETYPE_LUNASVG` in your `imconfig.h`.
+- Get latest lunasvg binaries or build yourself. Under Windows you may use vcpkg with: `vcpkg install lunasvg --triplet=x64-windows`.
+
+#### Using plutosvg (and plutovg)
+- Add `#define IMGUI_ENABLE_FREETYPE_PLUTOSVG` in your `imconfig.h`.
+- Compile and link with plutosvg *and* plutovg (which is required by plutosvg)
+
+_Compilation hints for plutovg_
+- Compile all source files in `plutovg/source/*.c`
+- Add include directory: `plutovg/include` + `plutovg/stb`
+
+_Compilation hints for plutosvg_
+- Compile `plutosvg/source/plutosvg.c`
+- Add include directory: `plutosvg/source`
+- Add define: `PLUTOSVG_HAS_FREETYPE`
+- Link with: plutovg, freetype
+

misc/freetype/imgui_freetype.cpp

@@ -6,8 +6,9 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2024/10/17: added plutosvg support for SVG Fonts (seems faster/better than lunasvg). Enable by using '#define IMGUI_ENABLE_FREETYPE_PLUTOSVG'. (#7927)
 //  2023/11/13: added support for ImFontConfig::RasterizationDensity field for scaling render density without scaling metrics.
-//  2023/08/01: added support for SVG fonts, enable by using '#define IMGUI_ENABLE_FREETYPE_LUNASVG' (#6591)
+//  2023/08/01: added support for SVG fonts, enable by using '#define IMGUI_ENABLE_FREETYPE_LUNASVG'. (#6591)
 //  2023/01/04: fixed a packing issue which in some occurrences would prevent large amount of glyphs from being packed correctly.
 //  2021/08/23: fixed crash when FT_Render_Glyph() fails to render a glyph and returns NULL.
 //  2021/03/05: added ImGuiFreeTypeBuilderFlags_Bitmap to load bitmap glyphs.
@@ -45,12 +46,21 @@
 #include FT_GLYPH_H             // <freetype/ftglyph.h>
 #include FT_SYNTHESIS_H         // <freetype/ftsynth.h>
 
-#ifdef IMGUI_ENABLE_FREETYPE_LUNASVG
+// Handle LunaSVG and PlutoSVG
+#if defined(IMGUI_ENABLE_FREETYPE_LUNASVG) && defined(IMGUI_ENABLE_FREETYPE_PLUTOSVG)
+#error "Cannot enable both IMGUI_ENABLE_FREETYPE_LUNASVG and IMGUI_ENABLE_FREETYPE_PLUTOSVG"
+#endif
+#ifdef  IMGUI_ENABLE_FREETYPE_LUNASVG
 #include FT_OTSVG_H             // <freetype/otsvg.h>
 #include FT_BBOX_H              // <freetype/ftbbox.h>
 #include <lunasvg.h>
+#endif
+#ifdef  IMGUI_ENABLE_FREETYPE_PLUTOSVG
+#include <plutosvg.h>
+#endif
+#if defined(IMGUI_ENABLE_FREETYPE_LUNASVG) || defined (IMGUI_ENABLE_FREETYPE_PLUTOSVG)
 #if !((FREETYPE_MAJOR >= 2) && (FREETYPE_MINOR >= 12))
-#error IMGUI_ENABLE_FREETYPE_LUNASVG requires FreeType version >= 2.12
+#error IMGUI_ENABLE_FREETYPE_PLUTOSVG or IMGUI_ENABLE_FREETYPE_LUNASVG requires FreeType version >= 2.12
 #endif
 #endif
 
@@ -269,11 +279,11 @@ namespace
 
         // Need an outline for this to work
         FT_GlyphSlot slot = Face->glyph;
-#ifdef IMGUI_ENABLE_FREETYPE_LUNASVG
+#if defined(IMGUI_ENABLE_FREETYPE_LUNASVG) || defined(IMGUI_ENABLE_FREETYPE_PLUTOSVG)
         IM_ASSERT(slot->format == FT_GLYPH_FORMAT_OUTLINE || slot->format == FT_GLYPH_FORMAT_BITMAP || slot->format == FT_GLYPH_FORMAT_SVG);
 #else
 #if ((FREETYPE_MAJOR >= 2) && (FREETYPE_MINOR >= 12))
-        IM_ASSERT(slot->format != FT_GLYPH_FORMAT_SVG && "The font contains SVG glyphs, you'll need to enable IMGUI_ENABLE_FREETYPE_LUNASVG in imconfig.h and install required libraries in order to use this font");
+        IM_ASSERT(slot->format != FT_GLYPH_FORMAT_SVG && "The font contains SVG glyphs, you'll need to enable IMGUI_ENABLE_FREETYPE_PLUTOSVG or IMGUI_ENABLE_FREETYPE_LUNASVG in imconfig.h and install required libraries in order to use this font");
 #endif
         IM_ASSERT(slot->format == FT_GLYPH_FORMAT_OUTLINE || slot->format == FT_GLYPH_FORMAT_BITMAP);
 #endif // IMGUI_ENABLE_FREETYPE_LUNASVG
@@ -810,6 +820,10 @@ static bool ImFontAtlasBuildWithFreeType(ImFontAtlas* atlas)
     SVG_RendererHooks hooks = { ImGuiLunasvgPortInit, ImGuiLunasvgPortFree, ImGuiLunasvgPortRender, ImGuiLunasvgPortPresetSlot };
     FT_Property_Set(ft_library, "ot-svg", "svg-hooks", &hooks);
 #endif // IMGUI_ENABLE_FREETYPE_LUNASVG
+#ifdef IMGUI_ENABLE_FREETYPE_PLUTOSVG
+    // With plutosvg, use provided hooks
+    FT_Property_Set(ft_library, "ot-svg", "svg-hooks", plutosvg_ft_svg_hooks());
+#endif // IMGUI_ENABLE_FREETYPE_PLUTOSVG
 
     bool ret = ImFontAtlasBuildWithFreeTypeEx(ft_library, atlas, atlas->FontBuilderFlags);
     FT_Done_Library(ft_library);

misc/freetype/imgui_freetype.h

@@ -5,6 +5,13 @@
 #include "imgui.h"      // IMGUI_API
 #ifndef IMGUI_DISABLE
 
+// Usage:
+// - Add '#define IMGUI_ENABLE_FREETYPE' in your imconfig to enable support for imgui_freetype in imgui.
+
+// Optional support for OpenType SVG fonts:
+// - Add '#define IMGUI_ENABLE_FREETYPE_PLUTOSVG' to use plutosvg (not provided). See #7927.
+// - Add '#define IMGUI_ENABLE_FREETYPE_LUNASVG' to use lunasvg (not provided). See #6591.
+
 // Forward declarations
 struct ImFontAtlas;
 struct ImFontBuilderIO;