OrbitEngine::Graphics::FontCollection class
#include <OE/Graphics/FontCollection.hpp>

A collection of Glyphs and metadata.

Contents

Example: create a collection of text and emojis (no SDF)

const FontSize size = 22;

Font* font = new Font("latin.ttf");
Font* font_emojis = new Font("emojis.ttf");

// create an empty collection
FontCollection* collection = new FontCollection();

// add all the glyphs available in the text font
collection->addGlyphs(font, font->getAvailableGlyphs(), size, GlyphRenderMode::COLOR);

// filter the emoji font to only keep true emojis
auto emojis = font_emojis->getAvailableGlyphs();
emojis.erase(std::remove_if(emojis.begin(), emojis.end(), [](const GlyphCodepoint& code) {
    return !Font::HasEmojiPresentation(code);
}), emojis.end());

// add the glyphs to the collection
collection->addGlyphs(emojis_font, emojis, size, GlyphRenderMode::COLOR);

// export
collection->exportToFiles("font-collection-fnt.json", "font-collection.json", "font-collection.png");

// cleanup
delete collection;

The resulting font-collection.png:

Image

Metadata format:

{
    "glyphs": [
        {
            "i": 87, // codepoint
            "m": 4, // render mode
            "s": 22, // original font size
            "w": 19, // width
            "h": 14, // height
            "ha": 19, // horizontal advance
            "va": 19, // vertical advance
            "hbx": 0, // horizontal bearing X
            "hby": 14, // horizontal bearing Y
            "vbx": -10, // vertical bearing X
            "vby":2, // vertical bearing Y
            "k": [ // kernings, can be missing
                {
                    "i": 228, // right codepoint
                    "d": -1 // kerning distance
                },
                ...
            ]
        },
        ...
    ]
}

Public static functions

static auto Load(const std::string& font_metadata, const std::string& atlas_metadata, const std::string& atlas_image) -> FontCollection*
Loads a font collection from disk.
static auto toIndex(GlyphCodepoint code, GlyphRenderMode mode) -> FrameIndex

Constructors, destructors, conversion operators

FontCollection()
Creates an empty collection.
~FontCollection()

Public functions

auto addGlyph(Font* font, GlyphCodepoint codepoint, FontSize size, GlyphRenderMode mode) -> bool
Add a single glyph to the collection.
auto addGlyphs(Font* font, const std::vector<GlyphCodepoint>& codepoints, FontSize size, GlyphRenderMode mode) -> int
Add a group of glyph to the collection.
auto exportToFiles(const std::string& font_metadata, const std::string& atlas_metadata, const std::string& atlas_image) -> bool
Export the font collection to disk.

Function documentation

static FontCollection* OrbitEngine::Graphics::FontCollection::Load(const std::string& font_metadata, const std::string& atlas_metadata, const std::string& atlas_image)

Loads a font collection from disk.

Parameters
font_metadata in path to the font metadata file to read (.json)
atlas_metadata in path to the atlas metadata fke to read (.json)
atlas_image in path to the atlas image file to read (.png)
Returns The FontCollection instance if the operation was successful, NULL otherwise

bool OrbitEngine::Graphics::FontCollection::addGlyph(Font* font, GlyphCodepoint codepoint, FontSize size, GlyphRenderMode mode)

Add a single glyph to the collection.

Parameters
font in Font to extract the glyph
codepoint in glyph unicode's codepoint
size in target size to generate the glyph
mode in mode used to render the glyph
Returns Whether the glyph has been generated and added successfully

int OrbitEngine::Graphics::FontCollection::addGlyphs(Font* font, const std::vector<GlyphCodepoint>& codepoints, FontSize size, GlyphRenderMode mode)

Add a group of glyph to the collection.

Parameters
font in Font to extract the glyphs
codepoints in list of the glyphs code points to add
size in target size to generate the glyphs
mode in mode used to render the glyphs
Returns The number of glyphs that have been generated and added successfully

bool OrbitEngine::Graphics::FontCollection::exportToFiles(const std::string& font_metadata, const std::string& atlas_metadata, const std::string& atlas_image)

Export the font collection to disk.

Parameters
font_metadata in path to write the font metadata file (.json)
atlas_metadata in path to write the atlas metadata file (.json)
atlas_image in path to write the atlas image file (.png)
Returns Whether the collection was exported correctly