A fixed-width Font's glyphs, baked into one sheet, drawn as one quad per glyph. More...

#include <Font+Bitmap.h>

Data Fields
int	advance
	The pen advance per glyph, in texels.

int	bearing
	The horizontal offset from the pen to a cell's left edge, in texels.

SDL_Size	cellSize
	The size of one cell, in texels.

SDL_Surface *	surface
	The glyph sheet: a grid of FONT_BITMAP_COLUMNS by FONT_BITMAP_COLUMNS cells of `cellSize`, in texels, or `NULL` if the Font is not fixed-width.

Detailed Description

A fixed-width Font's glyphs, baked into one sheet, drawn as one quad per glyph.

A Font rasterizes each string into its own surface and Texture, which costs hundreds of microseconds every time the string changes. A fixed-width Font therefore rasterizes a range of codepoints once, into a uniform grid of glyphs on a single surface, and Text draws it as one quad per glyph from that sheet. Unlike an ImageAtlas, nothing is packed: every glyph's position follows from its codepoint and the glyph size, so the grid is its own lookup table. Text that changes every frame becomes free.

Only fixed-width faces are supported, so there are no per-glyph metrics: a codepoint's cell is codepoint - FONT_BITMAP_FIRST, and overhang is baked by sizing every cell to the face's maximum ink bounds. This discards kerning and shaping (ligatures, joining, reordering), which is fine for a HUD or console and wrong for proportional prose; proportional Fonts never bake.

Cells are physical texels, rasterized at the Font's pixel density; sizes reported through sizeBitmapCharacters are logical, as Font's are. Like the Font that owns it, a FontBitmap is immutable and bound to that Font's pixel density.

This is a value embedded in Font, not an Object: surface == NULL means the Font is not fixed-width and has no bitmap.

Definition at line 82 of file Font+Bitmap.h.

Field Documentation

◆ advance

int FontBitmap::advance

The pen advance per glyph, in texels.

Definition at line 86 of file Font+Bitmap.h.

◆ bearing

int FontBitmap::bearing

The horizontal offset from the pen to a cell's left edge, in texels.

Negative when glyphs lean left of the pen, as a synthetic italic does.

Definition at line 92 of file Font+Bitmap.h.

◆ cellSize

SDL_Size FontBitmap::cellSize

The size of one cell, in texels.

Definition at line 97 of file Font+Bitmap.h.

◆ surface

SDL_Surface* FontBitmap::surface

The glyph sheet: a grid of FONT_BITMAP_COLUMNS by FONT_BITMAP_COLUMNS cells of cellSize, in texels, or NULL if the Font is not fixed-width.

Definition at line 103 of file Font+Bitmap.h.

The documentation for this struct was generated from the following file: