PSF2PNG(1) General Commands Manual PSF2PNG(1)

psf2png — PSF2 to PNG renderer

psf2png [-b bg] [-c cols] [-f fg] [-s str] [file]

psf2png renders the PSF2 font file or standard input to PNG on standard output.

The arguments are as follows:

bg
Use bg (hexadecimal RGB) as background color. The default background color is black.
cols
Arrange glyphs in cols columns. The default number of columns is 32.
fg
Use fg (hexadecimal RGB) as foreground color. The default foreground color is white.
str
Render glyphs for string str rather than all glyphs.

pngo(1), psfed(1)

September 28, 2018 OpenBSD 7.3

psf2png.c in git 

/* Copyright (C) 2018  June McEnroe <june@causal.agency>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <err.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>

#include "png.h"

int main(int argc, char *argv[]) {
	uint32_t cols = 32;
	const char *str = NULL;
	uint32_t fg = 0xFFFFFF;
	uint32_t bg = 0x000000;

	int opt;
	while (0 < (opt = getopt(argc, argv, "b:c:f:s:"))) {
		switch (opt) {
			break; case 'b': bg = strtoul(optarg, NULL, 16);
			break; case 'c': cols = strtoul(optarg, NULL, 0);
			break; case 'f': fg = strtoul(optarg, NULL, 16);
			break; case 's': str = optarg;
			break; default:  return EX_USAGE;
		}
	}
	if (!cols && str) cols = strlen(str);
	if (!cols) return EX_USAGE;

	const char *path = NULL;
	if (optind < argc) path = argv[optind];
	
	FILE *file = path ? fopen(path, "r") : stdin;
	if (!file) err(EX_NOINPUT, "%s", path);
	if (!path) path = "(stdin)";

	struct {
		uint32_t magic;
		uint32_t version;
		uint32_t size;
		uint32_t flags;
		struct {
			uint32_t len;
			uint32_t size;
			uint32_t height;
			uint32_t width;
		} glyph;
	} header;
	size_t len = fread(&header, sizeof(header), 1, file);
	if (ferror(file)) err(EX_IOERR, "%s", path);
	if (len < 1) errx(EX_DATAERR, "%s: truncated header", path);

	uint32_t widthBytes = (header.glyph.width + 7) / 8;
	uint8_t glyphs[header.glyph.len][header.glyph.height][widthBytes];
	len = fread(glyphs, header.glyph.size, header.glyph.len, file);
	if (ferror(file)) err(EX_IOERR, "%s", path);
	if (len < header.glyph.len) {
		errx(EX_DATAERR, "%s: truncated glyphs", path);
	}
	fclose(file);

	uint32_t count = (str ? strlen(str) : header.glyph.len);
	uint32_t width = header.glyph.width * cols;
	uint32_t rows = (count + cols - 1) / cols;
	uint32_t height = header.glyph.height * rows;

	pngHead(stdout, width, height, 8, PNGIndexed);
	uint8_t pal[] = {
		bg >> 16, bg >> 8, bg,
		fg >> 16, fg >> 8, fg,
	};
	pngPalette(stdout, pal, sizeof(pal));

	uint8_t data[height][1 + width];
	memset(data, PNGNone, sizeof(data));

	for (uint32_t i = 0; i < count; ++i) {
		uint32_t row = header.glyph.height * (i / cols);
		uint32_t col = 1 + header.glyph.width * (i % cols);
		uint32_t g = (str ? str[i] : i);
		for (uint32_t y = 0; y < header.glyph.height; ++y) {
			for (uint32_t x = 0; x < header.glyph.width; ++x) {
				uint8_t bit = glyphs[g][y][x / 8] >> (7 - x % 8) & 1;
				data[row + y][col + x] = bit;
			}
		}
	}

	pngData(stdout, (uint8_t *)data, sizeof(data));
	pngTail(stdout);
}