/*
* Brother QL-570 thermal printing program
* It prints a mono PNG image directly to the printers block device
*
* Copyright 2011 Asbjørn Sloth Tønnesen <code@asbjorn.it>
*
* PNG reading based on:
* A simple libpng example program
* http://zarb.org/~gc/html/libpng.html
* Copyright 2002-2011 Guillaume Cottenceau and contributors.
*
* This software may be freely redistributed under the terms
* of the libpng license.
* http://libpng.org/pub/png/src/libpng-LICENSE.txt
*
* Example usage:
* ./ql570 /dev/usb/lp0 image.png
*/
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <stdarg.h>
#include <errno.h>
#define PNG_DEBUG 3
#include <png.h>
#define ESC 0x1b
#define DEBUG
FILE * fp;
struct {
int16_t w;
int16_t h;
uint8_t * data;
} typedef pngdata_t;
FILE * ql570_open(const char * path)
{
fp = fopen(path, "r+b");
if (fp == NULL) {
perror("fopen");
exit(EXIT_FAILURE);
}
return fp;
}
void check_img(pngdata_t * img)
{
int i, j;
int lb = (img->w / 8) + (img->w % 8 > 0);
printf("lb: %d\n", lb);
for (i=0;i<img->h;i++) {
for (j=img->w-1;j!=0;j--) {
if (img->data[i*lb+j/8] & (1 << (7-(j % 8)))) {
printf("#");
} else {
printf(" ");
}
}
printf("\n");
}
}
void ql570_print(pngdata_t * img)
{
/* Init */
fprintf(fp, "%c%c", ESC, '@');
/* Set media type */
fprintf(fp, "%c%c%c%c%c%c%c%c%c%c%c%c%c", ESC, 'i', 'z', 0xa6, 0x0a, 29, 0, img->h & 0xff, img->h >> 8, 0, 0, 0, 0);
/* Set cut type */
fprintf(fp, "%c%c%c", ESC, 'i', 'K', 8);
/* Enable cutter */
fprintf(fp, "%c%c%c", ESC, 'i', 'A', 1);
/* Set margin = 0 */
fprintf(fp, "%c%c%c%c%c", ESC, 'i', 'd', 0, 0);
int i, j;
int lb = (img->w / 8) + (img->w % 8 > 0);
for (i=0;i<img->h;i++) {
fprintf(fp, "%c%c%c", 'g', 0x00, 90);
for (j=0;j<lb;j++) {
fprintf(fp, "%c", img->data[i*lb+j]);
}
for (;j<90;j++) {
fprintf(fp, "%c", 0x00);
}
}
/* Print */
fprintf(fp, "%c", 0x1a);
}
void abort_(const char * s, ...)
{
va_list args;
va_start(args, s);
vfprintf(stderr, s, args);
fprintf(stderr, "\n");
va_end(args);
abort();
}
pngdata_t * loadpng(const char * path)
{
png_structp png_ptr;
png_infop info_ptr;
png_bytep * row_pointers;
int width, height, rowbytes;
int x, y;
unsigned char header[8]; // 8 is the maximum size that can be checked
png_byte* ptr;
FILE *fp;
int type = 0;
int lb;
uint8_t * bitmap;
/* open file and test for it being a png */
fp = fopen(path, "rb");
if (!fp)
abort_("[read_png_file] File %s could not be opened for reading", path);
fread(header, 1, 8, fp);
if (png_sig_cmp(header, 0, 8))
abort_("[read_png_file] File %s is not recognized as a PNG file", path);
/* initialize stuff */
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr)
abort_("[read_png_file] png_create_read_struct failed");
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
abort_("[read_png_file] png_create_info_struct failed");
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[read_png_file] Error during init_io");
png_init_io(png_ptr, fp);
png_set_sig_bytes(png_ptr, 8);
png_read_info(png_ptr, info_ptr);
if (png_get_channels(png_ptr, info_ptr) == 1
&& png_get_bit_depth(png_ptr, info_ptr) == 1) {
type = 1;
} else if (png_get_channels(png_ptr, info_ptr) == 4
&& png_get_bit_depth(png_ptr, info_ptr) == 8) {
type = 2;
}
if (type == 0) {
fprintf(stderr, "Invalid PNG! Only mono or 4x8-bit RGBA PNG files are allowed\n");
exit(1);
}
width = png_get_image_width(png_ptr, info_ptr);
height = png_get_image_height(png_ptr, info_ptr);
png_read_update_info(png_ptr, info_ptr);
/* read file */
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[read_png_file] Error during read_image");
row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * height);
rowbytes = type == 1 ? (width / 8) + (width % 8 > 0) : width << 2;
for (y=0; y<height; y++)
row_pointers[y] = (png_byte*) malloc(rowbytes);
png_read_image(png_ptr, row_pointers);
fclose(fp);
lb = (height / 8) + (height % 8 > 0);
bitmap = malloc(width*lb);
memset(bitmap, 0, width*lb);
#define heat_on(x, y) bitmap[(x*lb)+(y/8)] |= 1 << (7-(y%8))
for (y=0; y<height; y++) {
png_byte* row = row_pointers[y];
for (x=0; x<width; x++) {
if (type == 1) {
ptr = &(row[x/8]);
} else {
ptr = &(row[x<<2]);
}
if ((ptr[0] & (1 << (7-(x%8)))) == 0) {
heat_on(x, y);
}
}
}
pngdata_t * ret = malloc(sizeof(pngdata_t));
ret->w = height;
ret->h = width;
ret->data = bitmap;
return ret;
}
int main(int argc, const char ** argv)
{
if (argc <= 2) {
fprintf(stderr, "Usage: %s printer pngfile\n", argv[0]);
exit(EXIT_FAILURE);
}
ql570_open(argv[1]);
pngdata_t * data = loadpng(argv[2]);
//check_img(data);
printf("w: %d\th: %d\n", data->w, data->h);
//check_img(data);
ql570_print(data);
return EXIT_SUCCESS;
}
