gimptoglcd.c

/* Convert 1-bit GIMP .h file to GLCD-compatible bitmap .h-file.

   In essence it does the same as Michael Margolis's glcdBitmap sketch,
   however this program is written from scratch without looking at his code.

   Author: Kristian Gunstone

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU 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 General Public License for more details.
  
   You should have received a copy of the GNU General Public License
   along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

// GIMP 1-bit header file. header_data_cmap will be ignored.
#include "sgw/SGW_Bulk/gimp_sgw_noise_128x48.h"

int main(int argc, const char *argv[]) {

	assert(argc == 2);

	const char *file_out = argv[1];
	FILE *fp;

	fp = fopen(file_out, "wb");
	if(fp == NULL) {
		perror("fopen");
		return(EXIT_FAILURE);
	}

	if((float) width / 8 != abs(width / 8)) 
		printf("%d is not padded!\n", width);
	if((float) height / 8 != abs(height / 8))  {
		printf("%d is not padded!\n", height);
	}

	printf("%dx%d\n", width, height);

	fprintf(fp, 
		"// This file is autogenerated.\n"
		"#include <inttypes.h>\n"
		"#include <avr/pgmspace.h>\n\n"
		"static uint8_t bitmap[] PROGMEM = {\n"
		"\t%3d, // Width\n"
		"\t%3d, // height\n\n"
		"\t// Bit packed image data (%d bytes)\n",
		width, height, width * height / 8);

	size_t offset = 0;

	int x, y, page;

	// Page is the vertical bank
	for(page = 0; page < (height / 8); page ++) {

		fprintf(fp, "\n\t// Page %02d\n\t", page);

		// horizontal traversion in st
		for(x = 0; x < width; x++) {

			uint8_t byte = 0;

			// Packing (vertical pixels)
			for(y = 0; y < 8; y++) {
				long bit = x + (((page * 8) + y) * width);
				byte ^= header_data[bit] << y;
			}
		
			fprintf(fp, "0x%02x,", byte);

			if(x % 8 == 7)
				fprintf(fp, "\n\t");

			offset++;
		}
	}


	printf("%d bytes, %d pages.\n", (int) offset, page);

	fprintf(fp, "\n};\n");

	fclose(fp);
	
	return(EXIT_SUCCESS);
}