font.h File Reference

TrueType font loading, glyph rasterization and text measurement. More...

#include <scimesh/types.h>
#include <cstdint>
#include <memory>
#include <string>
#include <vector>

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Classes
struct	scimesh::FontMetrics
	Vertical metrics of a font at a given pixel size. More...
struct	scimesh::GlyphBitmap
	One rasterized glyph: an 8-bit coverage bitmap plus placement info. More...
class	scimesh::Font
	A TrueType font, loaded at a fixed pixel size, with a glyph cache. More...

Namespaces
namespace	scimesh

Functions
std::string	scimesh::resolve_font_path (const std::string &path)
	Turn a possibly empty font path into a path that exists.
std::string	scimesh::default_font_path ()
	Path of the bundled default font, or as overridden by the SCIMESH_FONT environment variable.
Font	scimesh::cached_font (const std::string &path, float pixel_size)
	Load a font, re-using an already loaded one when possible.
void	scimesh::clear_font_cache ()
	Drop all fonts from the process-wide font cache.

Detailed Description

TrueType font loading, glyph rasterization and text measurement.

scimesh draws text labels by rasterizing glyphs with stb_truetype (a single-header, public-domain TrueType parser) and blending the resulting 8-bit coverage bitmaps into the output image. No system font, font server or graphics stack is involved, so text rendering works headless exactly like the rest of the renderer.

The package bundles Inter-Regular.ttf (SIL Open Font License 1.1), see default_font_path(), so labels work out of the box. Any other .ttf file can be used instead — pass its path to TextLayer::font_file, or set the SCIMESH_FONT environment variable to override the default.

This header is the low-level font API: loading, metrics, glyph coverage bitmaps and text measurement. Text placement (world vs. screen space, anchoring, depth testing, halos) lives in TextLayer, see text.h.

Example

scimesh::Font font = scimesh::cached_font("", 18.0f);  // "" = bundled font
float w = font.measure("anterior");
const scimesh::GlyphBitmap *glyph = font.glyph('A');

Note

Font sizes are in output pixels of the final image. The renderer scales them internally by the supersampling factor, so a label keeps its physical size when anti-aliasing is enabled.

Warning

stb_truetype performs no range checking on the font data. Only load font files you trust, see the warning in the stb_truetype header.

See also

TextLayer, draw_text(), text.h

Since

0.4.0

Definition in file font.h.