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Fonts: Added support for OpenType SVG fonts using lunasvg (#6591, #6607)

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sakiodre 2023-08-01 09:27:08 +02:00 committed by ocornut
parent 19ae142bdd
commit 2ad8c60abc
3 changed files with 173 additions and 0 deletions
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8
imconfig.h
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@ -80,6 +80,14 @@
// The only purpose of this define is if you want force compilation of the stb_truetype backend ALONG with the FreeType backend.
//#define IMGUI_ENABLE_STB_TRUETYPE
//---- Use lunasvg library to render OpenType SVG fonts (SVGinOT)
// Requires lunasvg headers to be available in the include path. Requires program to be compiled with the lunasvg library (not provided).
// See https://github.com/ocornut/imgui/tree/master/misc/freetype
// Only works in combination with IMGUI_ENABLE_FREETYPE.
// The implementation is based on the demo https://gitlab.freedesktop.org/freetype/freetype-demos/-/blob/master/src/rsvg-port.c
// which is licensed under CeCILL-C Free Software License Agreement
//#define IMGUI_ENABLE_FREETYPE_LUNASVG
//---- Define constructor and implicit cast operators to convert back<>forth between your math types and ImVec2/ImVec4.
// This will be inlined as part of ImVec2 and ImVec4 class declarations.
/*

8
misc/freetype/README.md
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@ -35,3 +35,11 @@ You can use the `ImGuiFreeTypeBuilderFlags_LoadColor` flag to load certain color
["Using Colorful Glyphs/Emojis"](https://github.com/ocornut/imgui/blob/master/docs/FONTS.md#using-colorful-glyphsemojis) section of FONTS.md.
![colored glyphs](https://user-images.githubusercontent.com/8225057/106171241-9dc4ba80-6191-11eb-8a69-ca1467b206d1.png)
### 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_OTSVG` 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`.

157
misc/freetype/imgui_freetype.cpp
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@ -6,6 +6,7 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2023/07/12: added support for SVG fonts, enable by using '#define IMGUI_ENABLE_FREETYPE_LUNASVG'
// 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.
@ -44,6 +45,13 @@
#include FT_GLYPH_H // <freetype/ftglyph.h>
#include FT_SYNTHESIS_H // <freetype/ftsynth.h>
#ifdef IMGUI_ENABLE_FREETYPE_LUNASVG
#include FT_OTSVG_H // <freetype/otsvg.h>
#include FT_BBOX_H // <freetype/ftbbox.h>
#include <lunasvg.h>
#include <memory>
#endif
#ifdef _MSC_VER
#pragma warning (push)
#pragma warning (disable: 4505) // unreferenced local function has been removed (stb stuff)
@ -70,6 +78,14 @@ static void* (*GImGuiFreeTypeAllocFunc)(size_t size, void* user_data) = ImGuiFre
static void (*GImGuiFreeTypeFreeFunc)(void* ptr, void* user_data) = ImGuiFreeTypeDefaultFreeFunc;
static void* GImGuiFreeTypeAllocatorUserData = nullptr;
#ifdef IMGUI_ENABLE_FREETYPE_LUNASVG
FT_Error ImGuiLunasvgPortInit(FT_Pointer* state);
void ImGuiLunasvgPortFree(FT_Pointer* state);
FT_Error ImGuiLunasvgPortRender(FT_GlyphSlot slot, FT_Pointer* _state);
FT_Error ImGuiLunasvgPortPresetSlot(FT_GlyphSlot slot, FT_Bool cache, FT_Pointer* _state);
#endif
//-------------------------------------------------------------------------
// Code
//-------------------------------------------------------------------------
@ -244,7 +260,19 @@ namespace
// Need an outline for this to work
FT_GlyphSlot slot = Face->glyph;
#if ((FREETYPE_MAJOR >= 2) && (FREETYPE_MINOR >= 12))
#ifdef IMGUI_ENABLE_FREETYPE_LUNASVG
IM_ASSERT(slot->format == FT_GLYPH_FORMAT_OUTLINE || slot->format == FT_GLYPH_FORMAT_BITMAP || slot->format == FT_GLYPH_FORMAT_SVG);
#else
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_OUTLINE || slot->format == FT_GLYPH_FORMAT_BITMAP);
#endif // IMGUI_ENABLE_FREETYPE_LUNASVG
#else
IM_ASSERT(slot->format == FT_GLYPH_FORMAT_OUTLINE || slot->format == FT_GLYPH_FORMAT_BITMAP);
#endif // ((FREETYPE_MAJOR >= 2) && (FREETYPE_MINOR >= 12))
// Apply convenience transform (this is not picking from real "Bold"/"Italic" fonts! Merely applying FreeType helper transform. Oblique == Slanting)
if (UserFlags & ImGuiFreeTypeBuilderFlags_Bold)
@ -770,6 +798,18 @@ static bool ImFontAtlasBuildWithFreeType(ImFontAtlas* atlas)
// If you don't call FT_Add_Default_Modules() the rest of code may work, but FreeType won't use our custom allocator.
FT_Add_Default_Modules(ft_library);
#ifdef IMGUI_ENABLE_FREETYPE_LUNASVG
#if ((FREETYPE_MAJOR >= 2) && (FREETYPE_MINOR >= 12))
// Install svg hooks for FreeType
// https://freetype.org/freetype2/docs/reference/ft2-properties.html#svg-hooks
// https://freetype.org/freetype2/docs/reference/ft2-svg_fonts.html#svg_fonts
SVG_RendererHooks hooks = {ImGuiLunasvgPortInit, ImGuiLunasvgPortFree, ImGuiLunasvgPortRender, ImGuiLunasvgPortPresetSlot};
FT_Property_Set(ft_library, "ot-svg", "svg-hooks", &hooks);
#else
IM_ASSERT(!"IMGUI_ENABLE_FREETYPE_LUNASVG requires FreeType version >= 2.12");
#endif // ((FREETYPE_MAJOR >= 2) && (FREETYPE_MINOR >= 12))
#endif // IMGUI_ENABLE_FREETYPE_LUNASVG
bool ret = ImFontAtlasBuildWithFreeTypeEx(ft_library, atlas, atlas->FontBuilderFlags);
FT_Done_Library(ft_library);
@ -790,6 +830,123 @@ void ImGuiFreeType::SetAllocatorFunctions(void* (*alloc_func)(size_t sz, void* u
GImGuiFreeTypeAllocatorUserData = user_data;
}
#ifdef IMGUI_ENABLE_FREETYPE_LUNASVG
// For more details, see https://gitlab.freedesktop.org/freetype/freetype-demos/-/blob/master/src/rsvg-port.c
// The original code from the demo is licensed under CeCILL-C Free Software License Agreement
// https://gitlab.freedesktop.org/freetype/freetype/-/blob/master/LICENSE.TXT
typedef struct LunasvgPortState_
{
FT_Error err = FT_Err_Ok;
std::unique_ptr<lunasvg::Document> svg = nullptr;
lunasvg::Matrix matrix; // Scaled and translated matrix for rendering
} LunasvgPortState, *PLunasvgPortState;
FT_Error ImGuiLunasvgPortInit(FT_Pointer* _state)
{
*_state = new LunasvgPortState();
return FT_Err_Ok;
}
void ImGuiLunasvgPortFree(FT_Pointer* _state)
{
delete *_state;
}
FT_Error ImGuiLunasvgPortRender(FT_GlyphSlot slot, FT_Pointer* _state)
{
PLunasvgPortState state = *(PLunasvgPortState*)_state;
// If there was an error while loading the svg in
// `ImGuiLunasvgPortPresetSlot`, the renderer hook
// still get called, so just returns the error.
if (state->err != FT_Err_Ok) return state->err;
// rows is height, pitch (or stride) equals to width * sizeof(int32)
lunasvg::Bitmap bitmap((uint8_t*)slot->bitmap.buffer, slot->bitmap.width, slot->bitmap.rows, slot->bitmap.pitch);
state->svg->setMatrix(state->svg->matrix().identity()); // Reset the svg matrix to the default value
state->svg->render(bitmap, state->matrix); // state->matrix is already scaled and translated
state->err = FT_Err_Ok;
return state->err;
}
FT_Error ImGuiLunasvgPortPresetSlot(FT_GlyphSlot slot, FT_Bool cache, FT_Pointer* _state)
{
FT_SVG_Document document = (FT_SVG_Document)slot->other;
PLunasvgPortState state = *(PLunasvgPortState*)_state;
FT_Size_Metrics& metrics = document->metrics;
// This function is called twice, once in the `FT_Load_Glyph`
// and another right before `ImGuiLunasvgPortRender`.
// If it's the latter, don't do anything because it's
// already done in the former.
if (cache) return state->err;
state->svg = lunasvg::Document::loadFromData((const char*)document->svg_document, document->svg_document_length);
if (state->svg == nullptr)
{
state->err = FT_Err_Invalid_SVG_Document;
return state->err;
}
lunasvg::Box box = state->svg->box();
double scale = std::min(metrics.x_ppem / box.w, metrics.y_ppem / box.h);
double xx = (double)document->transform.xx / (1 << 16);
double xy = -(double)document->transform.xy / (1 << 16);
double yx = -(double)document->transform.yx / (1 << 16);
double yy = (double)document->transform.yy / (1 << 16);
double x0 = (double)document->delta.x / 64 * box.w / metrics.x_ppem;
double y0 = -(double)document->delta.y / 64 * box.h / metrics.y_ppem;
// This reset the matrix to its default value
state->matrix.identity();
// Scale and transform, we don't translate the svg yet
state->matrix.scale(scale, scale);
state->matrix.transform(xx, xy, yx, yy, x0, y0);
state->svg->setMatrix(state->matrix);
// Pre-translate the matrix for the rendering step
state->matrix.translate(-box.x, -box.y);
// Get the box again after the transformation
box = state->svg->box();
// Calculate the bitmap size
slot->bitmap_left = FT_Int(box.x);
slot->bitmap_top = FT_Int(-box.y);
slot->bitmap.rows = (unsigned int)(ceil(box.h));
slot->bitmap.width = (unsigned int)(ceil(box.w));
slot->bitmap.pitch = slot->bitmap.width * 4;
slot->bitmap.pixel_mode = FT_PIXEL_MODE_BGRA;
// Compute all the bearings and set them correctly. The outline is
// scaled already, we just need to use the bounding box.
double metrics_width = box.w;
double metrics_height = box.h;
double horiBearingX = box.x;
double horiBearingY = -box.y;
double vertBearingX = slot->metrics.horiBearingX / 64.0 - slot->metrics.horiAdvance / 64.0 / 2.0;
double vertBearingY = (slot->metrics.vertAdvance / 64.0 - slot->metrics.height / 64.0) / 2.0;
slot->metrics.width = FT_Pos(round(metrics_width * 64.0));
slot->metrics.height = FT_Pos(round(metrics_height * 64.0));
slot->metrics.horiBearingX = FT_Pos(horiBearingX * 64);
slot->metrics.horiBearingY = FT_Pos(horiBearingY * 64);
slot->metrics.vertBearingX = FT_Pos(vertBearingX * 64);
slot->metrics.vertBearingY = FT_Pos(vertBearingY * 64);
if (slot->metrics.vertAdvance == 0)
slot->metrics.vertAdvance = FT_Pos(metrics_height * 1.2 * 64.0);
state->err = FT_Err_Ok;
return state->err;
}
#endif // !IMGUI_ENABLE_FREETYPE_LUNASVG
//-----------------------------------------------------------------------------
#ifdef __GNUC__