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/*
TrueType to Adafruit_GFX font converter. Derived from Peter Jakobs'
Adafruit_ftGFX fork & makefont tool, and Paul Kourany's Adafruit_mfGFX.
NOT AN ARDUINO SKETCH. This is a command-line tool for preprocessing
fonts to be used with the Adafruit_GFX Arduino library.
For UNIX-like systems. Outputs to stdout; redirect to header file, e.g.:
./fontconvert ~/Library/Fonts/FreeSans.ttf 18 > FreeSans18pt7b.h
REQUIRES FREETYPE LIBRARY. www.freetype.org
Currently this only extracts the printable 7-bit ASCII chars of a font.
Will eventually extend with some int'l chars a la ftGFX, not there yet.
Keep 7-bit fonts around as an option in that case, more compact.
See notes at end for glyph nomenclature & other tidbits.
*/
#ifndef ARDUINO
#include <stdio.h>
#include <ctype.h>
#include <stdint.h>
#include <ft2build.h>
#include FT_GLYPH_H
#include "../gfxfont.h" // Adafruit_GFX font structures
#define DPI 141 // Approximate res. of Adafruit 2.8" TFT
// Accumulate bits for output, with periodic hexadecimal byte write
void enbit(uint8_t value) {
static uint8_t row = 0, sum = 0, bit = 0x80, firstCall = 1;
if(value) sum |= bit; // Set bit if needed
if(!(bit >>= 1)) { // Advance to next bit, end of byte reached?
if(!firstCall) { // Format output table nicely
if(++row >= 12) { // Last entry on line?
printf(",\n "); // Newline format output
row = 0; // Reset row counter
} else { // Not end of line
printf(", "); // Simple comma delim
}
}
printf("0x%02X", sum); // Write byte value
sum = 0; // Clear for next byte
bit = 0x80; // Reset bit counter
firstCall = 0; // Formatting flag
}
}
int main(int argc, char *argv[]) {
int i, j, err, size, first=' ', last='~',
bitmapOffset = 0, x, y, byte;
char *fontName, c, *ptr;
FT_Library library;
FT_Face face;
FT_Glyph glyph;
FT_Bitmap *bitmap;
FT_BitmapGlyphRec *g;
GFXglyph *table;
uint8_t bit;
// Parse command line. Valid syntaxes are:
// fontconvert [filename] [size]
// fontconvert [filename] [size] [last char]
// fontconvert [filename] [size] [first char] [last char]
// Unless overridden, default first and last chars are
// ' ' (space) and '~', respectively
if(argc < 3) {
fprintf(stderr, "Usage: %s fontfile size [first] [last]\n",
argv[0]);
return 1;
}
size = atoi(argv[2]);
if(argc == 4) {
last = atoi(argv[3]);
} else if(argc == 5) {
first = atoi(argv[3]);
last = atoi(argv[4]);
}
if(last < first) {
i = first;
first = last;
last = i;
}
ptr = strrchr(argv[1], '/'); // Find last slash in filename
if(ptr) ptr++; // First character of filename (path stripped)
else ptr = argv[1]; // No path; font in local dir.
// Allocate space for font name and glyph table
if((!(fontName = malloc(strlen(ptr) + 20))) ||
(!(table = (GFXglyph *)malloc((last - first + 1) *
sizeof(GFXglyph))))) {
fprintf(stderr, "Malloc error\n");
return 1;
}
// Derive font table names from filename. Period (filename
// extension) is truncated and replaced with the font size & bits.
strcpy(fontName, ptr);
ptr = strrchr(fontName, '.'); // Find last period (file ext)
if(!ptr) ptr = &fontName[strlen(fontName)]; // If none, append
// Insert font size and 7/8 bit. fontName was alloc'd w/extra
// space to allow this, we're not sprintfing into Forbidden Zone.
sprintf(ptr, "%dpt%db", size, (last > 127) ? 8 : 7);
// Space and punctuation chars in name replaced w/ underscores.
for(i=0; (c=fontName[i]); i++) {
if(isspace(c) || ispunct(c)) fontName[i] = '_';
}
// Init FreeType lib, load font
if((err = FT_Init_FreeType(&library))) {
fprintf(stderr, "FreeType init error: %d", err);
return err;
}
// Use TrueType engine version 35, without subpixel rendering.
// This improves clarity of fonts since this library does not
// support rendering multiple levels of gray in a glyph.
// See https://github.com/adafruit/Adafruit-GFX-Library/issues/103
FT_UInt interpreter_version = TT_INTERPRETER_VERSION_35;
FT_Property_Set( library, "truetype",
"interpreter-version",
&interpreter_version );
if((err = FT_New_Face(library, argv[1], 0, &face))) {
fprintf(stderr, "Font load error: %d", err);
FT_Done_FreeType(library);
return err;
}
// << 6 because '26dot6' fixed-point format
FT_Set_Char_Size(face, size << 6, 0, DPI, 0);
// Currently all symbols from 'first' to 'last' are processed.
// Fonts may contain WAY more glyphs than that, but this code
// will need to handle encoding stuff to deal with extracting
// the right symbols, and that's not done yet.
// fprintf(stderr, "%ld glyphs\n", face->num_glyphs);
printf("const uint8_t %sBitmaps[] PROGMEM = {\n ", fontName);
// Process glyphs and output huge bitmap data array
for(i=first, j=0; i<=last; i++, j++) {
// MONO renderer provides clean image with perfect crop
// (no wasted pixels) via bitmap struct.
if((err = FT_Load_Char(face, i, FT_LOAD_TARGET_MONO))) {
fprintf(stderr, "Error %d loading char '%c'\n",
err, i);
continue;
}
if((err = FT_Render_Glyph(face->glyph,
FT_RENDER_MODE_MONO))) {
fprintf(stderr, "Error %d rendering char '%c'\n",
err, i);
continue;
}
if((err = FT_Get_Glyph(face->glyph, &glyph))) {
fprintf(stderr, "Error %d getting glyph '%c'\n",
err, i);
continue;
}
bitmap = &face->glyph->bitmap;
g = (FT_BitmapGlyphRec *)glyph;
// Minimal font and per-glyph information is stored to
// reduce flash space requirements. Glyph bitmaps are
// fully bit-packed; no per-scanline pad, though end of
// each character may be padded to next byte boundary
// when needed. 16-bit offset means 64K max for bitmaps,
// code currently doesn't check for overflow. (Doesn't
// check that size & offsets are within bounds either for
// that matter...please convert fonts responsibly.)
table[j].bitmapOffset = bitmapOffset;
table[j].width = bitmap->width;
table[j].height = bitmap->rows;
table[j].xAdvance = face->glyph->advance.x >> 6;
table[j].xOffset = g->left;
table[j].yOffset = 1 - g->top;
for(y=0; y < bitmap->rows; y++) {
for(x=0;x < bitmap->width; x++) {
byte = x / 8;
bit = 0x80 >> (x & 7);
enbit(bitmap->buffer[
y * bitmap->pitch + byte] & bit);
}
}
// Pad end of char bitmap to next byte boundary if needed
int n = (bitmap->width * bitmap->rows) & 7;
if(n) { // Pixel count not an even multiple of 8?
n = 8 - n; // # bits to next multiple
while(n--) enbit(0);
}
bitmapOffset += (bitmap->width * bitmap->rows + 7) / 8;
FT_Done_Glyph(glyph);
}
printf(" };\n\n"); // End bitmap array
// Output glyph attributes table (one per character)
printf("const GFXglyph %sGlyphs[] PROGMEM = {\n", fontName);
for(i=first, j=0; i<=last; i++, j++) {
printf(" { %5d, %3d, %3d, %3d, %4d, %4d }",
table[j].bitmapOffset,
table[j].width,
table[j].height,
table[j].xAdvance,
table[j].xOffset,
table[j].yOffset);
if(i < last) {
printf(", // 0x%02X", i);
if((i >= ' ') && (i <= '~')) {
printf(" '%c'", i);
}
putchar('\n');
}
}
printf(" }; // 0x%02X", last);
if((last >= ' ') && (last <= '~')) printf(" '%c'", last);
printf("\n\n");
// Output font structure
printf("const GFXfont %s PROGMEM = {\n", fontName);
printf(" (uint8_t *)%sBitmaps,\n", fontName);
printf(" (GFXglyph *)%sGlyphs,\n", fontName);
if (face->size->metrics.height == 0) {
// No face height info, assume fixed width and get from a glyph.
printf(" 0x%02X, 0x%02X, %d };\n\n",
first, last, table[0].height);
} else {
printf(" 0x%02X, 0x%02X, %ld };\n\n",
first, last, face->size->metrics.height >> 6);
}
printf("// Approx. %d bytes\n",
bitmapOffset + (last - first + 1) * 7 + 7);
// Size estimate is based on AVR struct and pointer sizes;
// actual size may vary.
FT_Done_FreeType(library);
return 0;
}
/* -------------------------------------------------------------------------
Character metrics are slightly different from classic GFX & ftGFX.
In classic GFX: cursor position is the upper-left pixel of each 5x7
character; lower extent of most glyphs (except those w/descenders)
is +6 pixels in Y direction.
W/new GFX fonts: cursor position is on baseline, where baseline is
'inclusive' (containing the bottom-most row of pixels in most symbols,
except those with descenders; ftGFX is one pixel lower).
Cursor Y will be moved automatically when switching between classic
and new fonts. If you switch fonts, any print() calls will continue
along the same baseline.
...........#####.. -- yOffset
..........######..
..........######..
.........#######..
........#########.
* = Cursor pos. ........#########.
.......##########.
......#####..####.
......#####..####.
*.#.. .....#####...####.
.#.#. ....##############
#...# ...###############
#...# ...###############
##### ..#####......#####
#...# .#####.......#####
====== #...# ====== #*###.........#### ======= Baseline
|| xOffset
glyph->xOffset and yOffset are pixel offsets, in GFX coordinate space
(+Y is down), from the cursor position to the top-left pixel of the
glyph bitmap. i.e. yOffset is typically negative, xOffset is typically
zero but a few glyphs will have other values (even negative xOffsets
sometimes, totally normal). glyph->xAdvance is the distance to move
the cursor on the X axis after drawing the corresponding symbol.
There's also some changes with regard to 'background' color and new GFX
fonts (classic fonts unchanged). See Adafruit_GFX.cpp for explanation.
*/
#endif /* !ARDUINO */