Skip to content

Commit

Permalink
TEST: PicoVector: alright-fonts bringup.
Browse files Browse the repository at this point in the history
  • Loading branch information
Gadgetoid committed Apr 18, 2024
1 parent 21e9817 commit 7cd9187
Show file tree
Hide file tree
Showing 6 changed files with 471 additions and 43 deletions.
16 changes: 16 additions & 0 deletions libraries/pico_vector/af-file-io.h
Original file line number Diff line number Diff line change
@@ -0,0 +1,16 @@
#include <stdlib.h>
#include <stdint.h>

extern "C" {
void* fileio_open(const char* filename);

void fileio_close(void* fhandle);

size_t fileio_read(void* fhandle, void *buf, size_t len);

int fileio_getc(void* fhandle);

size_t fileio_tell(void* fhandle);

size_t fileio_seek(void* fhandle, size_t pos);
}
5 changes: 5 additions & 0 deletions libraries/pico_vector/af-memory.h
Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
extern "C" {
void *af_malloc(size_t size);
void *af_realloc(void *p, size_t size);
void af_free(void *p);
}
361 changes: 361 additions & 0 deletions libraries/pico_vector/alright-fonts.h
Original file line number Diff line number Diff line change
@@ -0,0 +1,361 @@
/*
Alright Fonts 🖍 - a font format for embedded and low resource platforms.
Jonathan Williamson, August 2022
Examples, source, and more: https://github.com/lowfatcode/pretty-poly
MIT License https://github.com/lowfatcode/pretty-poly/blob/main/LICENSE
An easy way to render high quality text in embedded applications running
on resource constrained microcontrollers such as the Cortex M0 and up.
- OTF and TTF support: generate efficient packed fonts easily
- Minimal data: ~4kB (40 bytes per char) for printable ASCII set (Roboto)
- Tunable: trade off file size, contour complexity, and visual quality
- Metrics: advance and bounding box for fast layout
- UTF-8 or ASCII: support for non ASCII like Kanji or Cyrillic
- Fixed scale: coords scaled to ^2 bounds for fast scaling (no divide)
- C17 header only library: simply copy the header file into your project
- Customised font packs: include only the characters you need
- Simple outlines: all paths are simply polylines for easy rendering
- Easy antialiasing: combine with Pretty Poly for quick results!
*/

#ifndef AF_INCLUDE_H
#define AF_INCLUDE_H

#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <math.h>
#include <stdbool.h>
#include <wchar.h>

#ifdef AF_MALLOC
#ifndef PP_MALLOC
#define PP_MALLOC(size) AF_MALLOC(size)
#define PP_REALLOC(p, size) AF_REALLOC(p, size)
#define PP_FREE(p) AF_FREE(p)
#endif // PP_MALLOC
#endif // AF_MALLOC

#ifndef AF_MALLOC
#define AF_MALLOC(size) malloc(size)
#define AF_REALLOC(p, size) realloc(p, size)
#define AF_FREE(p) free(p)
#endif // AF_MALLOC

#ifndef AF_FILE
#define AF_FILE FILE*
#define AF_FREAD(p, size, nmemb, stream) fread(p, size, nmemb, stream)
#define AF_FGETC(stream) fgetc(stream)
#endif

#include "pretty-poly.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef struct {
int8_t x, y;
} af_point_t;
pp_point_t af_point_transform(pp_point_t *p, pp_mat3_t *m);

typedef struct {
uint8_t point_count;
af_point_t *points;
} af_path_t;

typedef struct {
char codepoint;
int8_t x, y, w, h;
int8_t advance;
uint8_t path_count;
af_path_t *paths;
} af_glyph_t;

typedef struct {
uint16_t flags;
uint16_t glyph_count;
af_glyph_t *glyphs;
} af_face_t;

typedef enum {
AF_H_ALIGN_LEFT = 0, AF_H_ALIGN_CENTER = 1, AF_H_ALIGN_RIGHT = 2,
AF_H_ALIGN_JUSTIFY = 4,
AF_V_ALIGN_TOP = 8, AF_V_ALIGN_MIDDLE = 16, AF_V_ALIGN_BOTTOM = 32
} af_align_t;

typedef struct {
af_face_t *face; // font
float size; // text size in pixels
float line_height; // spacing between lines (%)
float letter_spacing; // spacing between characters (%)
float word_spacing; // spacing between words (%)
af_align_t align; // horizontal and vertical alignment
pp_mat3_t *transform; // arbitrary transformation
} af_text_metrics_t;

bool af_load_font_file(AF_FILE file, af_face_t *face);
void af_render_character(af_face_t *face, wchar_t codepoint, af_text_metrics_t *tm);
void af_render(af_face_t *face, wchar_t *text, af_text_metrics_t *tm);
pp_rect_t af_measure(af_face_t *face, const wchar_t *text, af_text_metrics_t *tm);

#ifdef AF_USE_PRETTY_POLY
#endif

#ifdef __cplusplus
}
#endif

#ifdef AF_IMPLEMENTATION


/*
helper functions
*/

// big endian file reading helpers
uint16_t ru16(AF_FILE file) {uint8_t w[2]; AF_FREAD((char *) w, 1, 2, file); return (uint16_t)w[0] << 8 | w[1];}
int16_t rs16(AF_FILE file) {uint8_t w[2]; AF_FREAD((char *) w, 1, 2, file); return (uint16_t)w[0] << 8 | w[1];}
uint32_t ru32(AF_FILE file) {uint8_t dw[4]; AF_FREAD((char *)dw, 1, 4, file); return (uint32_t)dw[0] << 24 | (uint32_t)dw[1] << 16 | (uint32_t)dw[2] << 8 | dw[3];}
uint8_t ru8(AF_FILE file) {return AF_FGETC(file);}
int8_t rs8(AF_FILE file) {return AF_FGETC(file);}

bool af_load_font_file(AF_FILE file, af_face_t *face) {
// check header magic bytes are present
char marker[4]; AF_FREAD(marker, 1, 4, file);
if(memcmp(marker, "af!?", 4) != 0) {
return false; // doesn't start with magic marker
}

// extract flags and ensure none set
face->flags = ru16(file);
if(face->flags != 0) {
return false; // unknown flags set
}

// number of glyphs, paths, and points in font
uint16_t glyph_count = ru16(file);
uint16_t path_count = ru16(file);
uint16_t point_count = ru16(file);

// allocate buffer to store font glyph, path, and point data
void *buffer = AF_MALLOC(sizeof(af_glyph_t) * glyph_count + \
sizeof( af_path_t) * path_count + \
sizeof(af_point_t) * point_count);
af_glyph_t *glyphs = (af_glyph_t *) buffer;
af_path_t *paths = ( af_path_t *)(glyphs + (sizeof(af_glyph_t) * glyph_count));
af_point_t *points = (af_point_t *)( paths + (sizeof( af_path_t) * path_count));

// load glyph dictionary
face->glyph_count = glyph_count;
face->glyphs = glyphs;
for(int i = 0; i < glyph_count; i++) {
af_glyph_t *glyph = &face->glyphs[i];
glyph->codepoint = ru16(file);
glyph->x = rs8(file);
glyph->y = rs8(file);
glyph->w = ru8(file);
glyph->h = ru8(file);
glyph->advance = ru8(file);
glyph->path_count = ru8(file);
glyph->paths = paths;
paths += sizeof(af_path_t) * glyph->path_count;
}

// load the glyph paths
for(int i = 0; i < glyph_count; i++) {
af_glyph_t *glyph = &face->glyphs[i];
for(int j = 0; j < glyph->path_count; j++) {
af_path_t *path = &glyph->paths[j];
path->point_count = ru8(file);
path->points = points;
points += sizeof(af_point_t) * path->point_count;
}
}

// load the glyph points
for(int i = 0; i < glyph_count; i++) {
af_glyph_t *glyph = &face->glyphs[i];
for(int j = 0; j < glyph->path_count; j++) {
af_path_t *path = &glyph->paths[j];
for(int k = 0; k < path->point_count; k++) {
af_point_t *point = &path->points[k];
point->x = ru8(file);
point->y = ru8(file);
}
}
}

return true;
}

af_glyph_t *find_glyph(af_face_t *face, wchar_t c) {
for(int i = 0; i < face->glyph_count; i++) {
if(face->glyphs[i].codepoint == c) {
return &face->glyphs[i];
}
}
return NULL;
}

void af_render_glyph(af_glyph_t* glyph, af_text_metrics_t *tm) {
assert(glyph != NULL);

pp_poly_t poly;
poly.count = glyph->path_count;
poly.paths = (pp_path_t *)AF_MALLOC(poly.count * sizeof(pp_path_t));
for(uint32_t i = 0; i < poly.count; i++) {
pp_path_t *path = &poly.paths[i];
path->count = glyph->paths[i].point_count;
path->points = (pp_point_t *)AF_MALLOC(glyph->paths[i].point_count * sizeof(pp_point_t));
for(uint32_t j = 0; j < path->count; j++) {
pp_point_t *point = &path->points[j];
point->x = glyph->paths[i].points[j].x;
point->y = glyph->paths[i].points[j].y;
}
}

pp_render(&poly);

for(uint32_t i = 0; i < poly.count; i++) {
pp_path_t *path = &poly.paths[i];
free(path->points);
}
free(poly.paths);
}

void af_render_character(af_face_t *face, wchar_t c, af_text_metrics_t *tm) {
af_glyph_t *glyph = find_glyph(face, c);
if(!glyph) {
return;
}
af_render_glyph(glyph, tm);
}

int get_line_width(af_face_t *face, wchar_t *text, af_text_metrics_t *tm) {
int line_width = 0;
wchar_t *end = wcschr(text, L'\n');
for(wchar_t c = *text; text < end; text++, c = *text) {
af_glyph_t *glyph = find_glyph(face, c);
if(!glyph) {
continue;
}

if(c == L' ') {
line_width += (glyph->advance * tm->word_spacing) / 100.0f;
} else {
line_width += (glyph->advance * tm->letter_spacing) / 100.0f;
}
}
return line_width;
}

int get_max_line_width(af_face_t *face, wchar_t *text, af_text_metrics_t *tm) {
int max_width = 0;

wchar_t *end = wcschr(text, L'\n');
while(end) {
int width = get_line_width(face, text, tm);
max_width = max_width < width ? width : max_width;
text = end + 1;
end = wcschr(text, L'\n');
}

return max_width;
}


void af_render(af_face_t *face, wchar_t *text, af_text_metrics_t *tm) {
pp_mat3_t *old = pp_transform(NULL);

float line_height = (tm->line_height * 128.0f) / 100.0f;
float scale = tm->size / 128.0f;

// find maximum line length
int max_line_width = get_max_line_width(face, text, tm);

struct {
float x, y;
} caret;

caret.x = 0;
caret.y = 0;

wchar_t *end = wcschr(text, L'\n');
while(end) {
int line_width = get_line_width(face, text, tm);

for(wchar_t c = *text; text < end; text++, c = *text) {
af_glyph_t *glyph = find_glyph(face, c);
if(!glyph) {
continue;
}

pp_mat3_t caret_transform = *tm->transform;
pp_mat3_scale(&caret_transform, scale, scale);
pp_mat3_translate(&caret_transform, caret.x, caret.y);

if(tm->align == AF_H_ALIGN_CENTER) {
pp_mat3_translate(&caret_transform, (max_line_width - line_width) / 2, 0);
}

if(tm->align == AF_H_ALIGN_RIGHT) {
pp_mat3_translate(&caret_transform, (max_line_width - line_width), 0);
}

pp_transform(&caret_transform);

af_render_glyph(glyph, tm);

if(c == L' ') {
caret.x += (glyph->advance * tm->word_spacing) / 100.0f;
} else {
caret.x += (glyph->advance * tm->letter_spacing) / 100.0f;
}

}

text = end + 1;
end = wcschr(text, L'\n');

caret.x = 0;
caret.y += line_height;
}



pp_transform(old);
}

pp_rect_t af_measure(af_face_t *face, const wchar_t *text, af_text_metrics_t *tm) {
pp_rect_t result;
bool first = true;
pp_mat3_t t = *tm->transform;

for(size_t i = 0; i < wcslen(text); i++) {
af_glyph_t *glyph = find_glyph(face, text[i]);
if(!glyph) {
continue;
}
pp_rect_t r = {glyph->x, glyph->y, glyph->x + glyph->w, glyph->y + glyph->h};
r = pp_rect_transform(&r, &t);
pp_mat3_translate(&t, glyph->advance, 0);

if(first) {
result = r;
first = false;
}else{
result = pp_rect_merge(&result, &r);
}
}

return result;
}

#endif // AF_IMPLEMENTATION

#endif // AF_INCLUDE_H
Loading

0 comments on commit 7cd9187

Please sign in to comment.