libfbx-ppm.c

libfxb是linux下只写操作framebuffer的一个轻量级的库。

/*
 *  libfbx-ppm.c -- PPM Image Functions
 *  (C)opyright 2000-2001 U4X Labs
 *
 *  Written by: Paul Mundt     <[e-mail]>
 *              Mike Bourgeous <[e-mail]>
 *              Sat Sep 2 01:45:15 EDT 2000
 *
 *  $Id: libfbx-ppm.c,v 1.12 2001/01/01 08:46:17 lethal Exp $
 *
 *       Originally part of fbgraph.c, now separate.  Handles the
 *  loading and saving of PPM format image files.
 *
 *  See ChangeLog for modifcations, CREDITS for credits.
 *  			
 *  All source herein is copyright U4X Labs and its original author. 
 *  Any code modifications or additions are (C)opyright the original 
 *  author and U4X Labs respectively.
 *
 *  libfbx is free software; you can redistribute it and/or modify it 
 *  under the terms of the GNU Lesser General Public License as 
 *  published by the Free Software Foundation; either version 2.1 of 
 *  the License, or (at your option) any later version.
 *
 *  libfbx 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with libfbx; if not, write to the Free Software 
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 *  USA
 */
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <signal.h>
#include <time.h>
#include <math.h>
#include <linux/fb.h>
#include <linux/kd.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <sys/user.h>
#include <termios.h>
#include <ctype.h>
#include <libfbx/libfbx.h>

/*
 * Function:	fb_load_ppm()
 * Arguments:	Filename of ppm image to load
 * Returns:	Image on an fb surface
 * Description: Attempts to load a ppm format image and 
 * 		place it in an fb_surface memory bitmap.  
 */
fb_surface *fb_load_ppm(char *filename)
{
	fb_surface *input_ppm;
	FILE *ppm_file;
	char buf[1024];
	char tmpc1, tmpc2;
	int num = 0, gonum = 0, i, w = 0, h = 0, m = 0, x, y, r, g, b;

/*
 * Reduces duplicate code. Trust me.
 */
#define tmpc1_if() \
{ \
	if (tmpc1 == '#') { \
		fgets(buf, 1024, ppm_file); \
		tmpc1 = fgetc(ppm_file); \
	} \
} 

	ppm_file = fopen(filename, "rb");
	
	if (ppm_file == NULL) {
		snprintf(buf, 1024, "Unable to open %s", filename);
		perror(buf);
		return NULL;
	}
	
	tmpc1 = fgetc(ppm_file);
	tmpc2 = fgetc(ppm_file);

	if (tmpc1 != 'P' || tmpc2 != '6') {
		fprintf(stderr, "This file isn't a proper format ppm. "
			  	"Can only handle RAWBITS format.\n");
		return NULL;
	}

	/* reduces duplicate code */
	goto first;

	/* HACK HACK HACK HACK!!!!!!! */
	for (num = 0; num < 3; num++) {
	    second:
		gonum++;

		while (isspace(tmpc1)) {
		    first:
			tmpc1 = fgetc(ppm_file);
			tmpc1_if();


			if (gonum == 0)
				goto second;
		}

		buf[0] = tmpc1;
		buf[1] = '\0';

		for (i = 1; !isspace(tmpc1); i++) {
			tmpc1 = fgetc(ppm_file);
			tmpc1_if();
			buf[i] = tmpc1;
			buf[i + 1] = '\0';
		}
	
		if (num == 0)	
			w = atoi(buf);
		else if (num == 1)
			h = atoi(buf);
		else
			m = atoi(buf);
	}
	
	input_ppm = fb_create_surface(w, h);

	for (y = 0; y < h && !feof(ppm_file); y++)
		for(x = 0; x < w && !feof(ppm_file); x++) {
			r = (unsigned char)fgetc(ppm_file);
			g = (unsigned char)fgetc(ppm_file);
			b = (unsigned char)fgetc(ppm_file);
			fb_putpixel(x, y, r, g, b, input_ppm);
		}

	fclose(ppm_file);

	return input_ppm;
}

/*
 * Function:	fb_save_ppm()
 * Arguments:	Name of file to save to, surface to save
 * Returns:	Zero on success, otherwise non zero
 * Description:	Saves the contents of the surface indicated to a ppm
 * 		RAWBITS format image file.
 */
int fb_save_ppm(char *filename, fb_surface *surface, int grayscale)
{
        int x, y;
        int r, g, b;
        FILE *output_image;

        output_image = fopen(filename, "wb");

        if (surface == NULL)
                return -1;
        if (output_image == NULL)
                return -1;

	fprintf(output_image, "P%d\n", grayscale ? 5 : 6);
        fprintf(output_image, "%i %i\n", surface->width, surface->height);
        fprintf(output_image, "255\n");

        for (y = 0; y < surface->width; y++)
                for (x = 0; x < surface->width; x++) {
                        fb_getpixel(x, y, &r, &g, &b, surface);
                        fputc(r & 0xFF, output_image);
                        fputc(g & 0xFF, output_image);
                        fputc(b & 0xFF, output_image);
                }

        if (fclose(output_image))
                return errno;

        return 0;
}