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#pragma once
#include <assert.h>
#include <stdint.h>
static const unsigned char FontGlyphStart = 32; // Space.
static const unsigned char FontGlyphEnd = 127; // One past tilde.
static const unsigned int FontAtlasNumGlyphs = FontGlyphEnd - FontGlyphStart;
/// Font atlas header.
typedef struct FontHeader {
uint16_t glyph_width;
uint16_t glyph_height;
uint16_t num_glyphs;
} FontHeader;
/// Font atlas.
///
/// Pixels are stored in "glyph-major" order. First the rows of the first glyph,
/// followed by the rows of the second glyph, etc. Thus, pixels should be viewed
/// as a linear array, not a 2d array. This arrangement allows an application to
/// render glyphs by scanning atlas memory linearly.
typedef struct FontAtlas {
FontHeader header;
unsigned char pixels[1];
} FontAtlas;
/// Load a font atlas from a file.
FontAtlas* LoadFontAtlas(const char* path);
/// Get the glyph into the atlas.
static inline const unsigned char* FontGetGlyph(
const FontAtlas* atlas, unsigned char c) {
assert(atlas);
unsigned index = c - FontGlyphStart;
if (index >= FontAtlasNumGlyphs) {
index = '?' - FontGlyphStart;
}
assert(index < FontAtlasNumGlyphs);
return atlas->pixels +
index * (atlas->header.glyph_width * atlas->header.glyph_height);
}
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