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Fonts

ZenGin fonts are stored in a custom format which maps sections of an image to each character of the alphabet. To that end, each font contains 256 glyphs which correspond to the characters of the Windows-1252 character encoding.

Overview

Every font contains the name of the image containing the appearances of each glyph as well as a list of glyphs. Each glyph contains two coordinates which together form a rectangle around the glyph in the image. See Dealing with glyphs for more details

Loading Fonts

Example
#include <zenkit-capi/Font.h>

int main(int, char**) {
    // Load from a file on disk:
    ZkFont* font = ZkFont_loadPath("FONT_OLD_20.FNT");
    ZkFont_del(font);

    // ... or from a VFS:
    ZkVfs* vfs = ZkVfs_new();
    ZkVfs_mountDiskHost(vfs, "Textures.vdf", ZkVfsOverwriteBehavior_OLDER);
    font = ZkFont_loadVfs(vfs, "FONT_OLD_20.FNT");
    ZkFont_del(font);
    ZkVfs_del(vfs);

    return 0;
}
Example
#include <zenkit/Font.hh>
#include <zenkit/Stream.hh>
#include <zenkit/Vfs.hh>

int main(int, char const** argv) {
    zenkit::Font font {};

    // Load from a file on disk:
    auto r = zenkit::Read::from("FONT_OLD_20.FNT");
    font.load(r.get());

    // ... or from a VFS
    zenkit::Vfs vfs;
    vfs.mount_disk("Textures.vdf", zenkit::VfsOverwriteBehavior::OLDER)

    r = vfs->find("FONT_OLD_20.FNT")->open_read();
    font.load(r.get());

    return 0;
}
Example
using ZenKit;

// Load from a file on disk:
var font = new Font("FONT_OLD_20.FNT");

// ... or from a VFS:
var vfs = new Vfs();
vfs.MountDisk("Textures.vdf", VfsOverwriteBehavior.Older);
font = new Font(vfs, "FONT_OLD_20.FNT");
Example
import dev.gothickit.zenkit.fnt.Font;
import dev.gothickit.zenkit.vfs.Vfs;
import dev.gothickit.zenkit.vfs.VfsOverwriteBehavior;

// Load from a file on disk:
var fnt = Font.load("FONT_OLD_20.FNT");

// ... or from a VFS:
var vfs = new Vfs();
vfs.mountDisk("Textures.vdf", VfsOverwriteBehavior.OLDER)
fnt = Font.load(vfs, "FONT_OLD_20.FNT");
Example
from zenkit import Vfs, VfsOverwriteBehavior, Font

# Load from a file on disk:
fnt = Font.load("FONT_OLD_20.FNT")

# ... or from a VFS:
vfs = Vfs()
vfs.mount_disk("Textures.vdf", clobber=VfsOverwriteBehavior.OLDER)
fnt = Font.load(vfs.find("FONT_OLD_20.FNT"))

Dealing with glyphs

To render a font, first the font texture must be loaded. Its name is stored in the Font::name field. Each of the 256 glyphs of the font then contains two UV-coordinates denoting the top and bottom corner of a subsection of said texture. These UV-coordinates are between 0 and 1, so they have to be scaled to the actual width and height of the image by multiplying them. The subsection contains the actual image data for the glyph.

Since each glyph is saved at the same index as the number representation of its character in Windows-1252, to get the glyph for the character 'a', one can just font.glyphs[(int) 'a'] to get the correct glyph, assuming that 'a' follows Windows-1252 encoding.

Example
#include <zenkit-capi/Font.h>
#include <zenkit-capi/Texture.h>

int main(int, char**) {
    ZkFont* font = ZkFont_loadPath("FONT_OLD_20.FNT");

    // The texture (1) must be loaded from some other location,
    // most likely the `Textures.vdf` disk.
    ZkTexture* tex = ZkTexture_loadPath(ZkFont_getName(font));

    // The second parameter denotes the index of the glyph to get. There
    // are usually 256 glyphs in every font but the number of glyphs can
    // also be retrieved using `ZkFont_getGlyphCount()`.
    ZkFontGlyph glyph = ZkFont_getGlyph(font, 0);

    // To be able to determine the pixel offset of the glyph we
    // need to retrieve the size of the font texture.
    uint32_t texture_width = ZkTexture_getWidth(tex);
    uint32_t texture_height = ZkTexture_getHeight(tex);

    // Each UV coordinate contains a value from 0 to 1 which is
    // mapped to the actual with and height of the image
    int actual_top_x = glyph.topLeft.x * texture_width;
    int actual_top_y = glyph.topLeft.y * texture_height;

    int actual_bottom_x = glyph.bottomRight.x * texture_width;
    int actual_bottom_y = glyph.bottomRight.y * texture_height;

    // ...

    ZkTexture_del(tex);
    ZkFont_del(font);

    return 0;
}
  1. See Textures for information about loading texture files.
Example
#include <zenkit/Font.hh>
#include <zenkit/Stream.hh>

int main(int, char const** argv) {
    zenkit::Font font {};

    auto r = zenkit::Read::from("FONT_OLD_20.FNT");
    font.load(r.get());

    // The texture (1) must be loaded from some other location,
    // most likely the `Textures.vdf` disk.
    auto r_texture = zenkit::Read::from(font.name);
    zenkit::Texture font_texture {};
    font_texture.load(r_texture.get());

    zenkit::FontGlyph glyph0 = font.glyphs[0];

    // Each UV coordinate contains a value from 0 to 1 which is
    // mapped to the actual with and height of the image
    int actual_top_x = glyph0.uv[0].x * font_texture.width();
    int actual_top_y = glyph0.uv[0].y * font_texture.height();

    int actual_bottom_x = glyph0.uv[1].x * font_texture.width();
    int actual_bottom_y = glyph0.uv[1].y * font_texture.height();

    // ...

    return 0;
}
  1. See Textures for information about loading texture files.
Example
using ZenKit;

var font = new Font("FONT_OLD_20.FNT");

// The texture (1) must be loaded from some other location,
// most likely the `Textures.vdf` disk.
var tex = new Texture(font.Name);

// The second parameter denotes the index of the glyph to get. There
// are usually 256 glyphs in every font but the number of glyphs can
// also be retrieved using `Font.GlyphCount`. You can also access all
// glyphs at once through `Font.Glyphs`.
FontGlyph glyph = font.GetGlyph(0);

// Each UV coordinate contains a value from 0 to 1 which is
// mapped to the actual with and height of the image
float actual_top_x = glyph.topLeft.X * tex.Width;
float actual_top_y = glyph.topLeft.Y * tex.Height;

float actual_bottom_x = glyph.bottomRight.X * tex.Width;
float actual_bottom_y = glyph.bottomRight.Y * tex.Height;

// ...
  1. See Textures for information about loading texture files.
Example
import dev.gothickit.zenkit.fnt.Font;
import dev.gothickit.zenkit.fnt.FontGlyph;
import dev.gothickit.zenkit.tex.Texture;
import dev.gothickit.zenkit.vfs.Vfs;
import dev.gothickit.zenkit.vfs.VfsOverwriteBehavior;

var font = new Font("FONT_OLD_20.FNT");

// The texture (1) must be loaded from some other location,
// most likely the `Textures.vdf` disk.
var tex = new Texture(font.getName());

// The second parameter denotes the index of the glyph to get. There
// are usually 256 glyphs in every font but the number of glyphs can
// also be retrieved using `Font.GlyphCount`. You can also access all
// glyphs at once through `Font.Glyphs`.
FontGlyph glyph = font.getGlyph(0);

// Each UV coordinate contains a value from 0 to 1 which is
// mapped to the actual with and height of the image
float actualTopX = glyph.topLeft.x * tex.getWidth();
float actualTopY = glyph.topLeft.y * tex.getHeight();

float actualBottomX = glyph.bottomRight.x * tex.getWidth();
float actualBottomY = glyph.bottomRight.y * tex.getHeight();

// ...
  1. See Textures for information about loading texture files.