fbvis.c

   1 /*
   2  * fbvis - a framebuffer image viewer
   3  *
   4  * Copyright (C) 2013 Ali Gholami Rudi
   5  *
   6  * This file is released under the modified BSD license.
   7  */
   8 #include <ctype.h>
   9 #include <signal.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <unistd.h>
  14 #include <pty.h>
  15 #include "draw.h"
  16 #include "lodepng.h"
  17
  18 /* optimized version of fb_val() */
  19 #define FB_VAL(r, g, b) fb_val(r, g, b)
  20
  21 #define PAGESTEPS       8
  22 #define CTRLKEY(x)      ((x) - 96)
  23 #define MIN(a, b)       ((a) < (b) ? (a) : (b))
  24 #define MAX(a, b)       ((a) > (b) ? (a) : (b))
  25 #define REGION(a, b, x) (MIN(b, MAX(x, a)))
  26
  27 static unsigned char *obuf;     /* original image */
  28 static int ocols, orows;        /* obuf dimensions */
  29 static int ch;                  /* bytes per pixel */
  30 static unsigned char *buf;      /* zoomed image for framebuffer */
  31 static int cols, rows;          /* buf dimensions */
  32 static int czoom;               /* current zoom */
  33 static int head, left;          /* current viewing position */
  34 static int count;               /* command prefix */
  35 static struct termios termios;
  36 static char **files;
  37 static int curfile = -1;
  38
  39 #define ZOOM_ORIG       0
  40 #define ZOOM_FITHT      1
  41 #define ZOOM_FITWID     2
  42
  43 static void zoom(int z)
  44 {
  45         int bpp = FBM_BPP(fb_mode());
  46         int i, j;
  47         int c = 100;
  48         if (z == ZOOM_FITHT)
  49                 c = 100 * fb_rows() / orows;
  50         if (z == ZOOM_FITWID)
  51                 c = 100 * fb_cols() / ocols;
  52         czoom = z;
  53         cols = ocols * c / 100;
  54         rows = orows * c / 100;
  55         buf = malloc(rows * cols * bpp);
  56         for (i = 0; i < rows; i++) {
  57                 for (j = 0; j < cols; j++) {
  58                         unsigned char *src = obuf + (i * 100 / c * ocols +
  59                                                         j * 100 / c) * ch;
  60                         unsigned int *dst = (void *) buf + (i * cols + j) * bpp;
  61                         *dst = FB_VAL(src[0], src[1], src[2]);
  62                 }
  63         }
  64 }
  65
  66 static void draw(void)
  67 {
  68         int bpp = FBM_BPP(fb_mode());
  69         int rs = head;
  70         int re = rs + MIN(rows - rs, fb_rows());
  71         int cs = left;
  72         int ce = cs + MIN(cols - cs, fb_cols());
  73         int fbr = (fb_rows() - (re - rs)) >> 1;
  74         int fbc = (fb_cols() - (ce - cs)) >> 1;
  75         int i;
  76         for (i = rs; i < re; i++)
  77                 fb_set(fbr + i - rs, fbc, buf + (i * cols + cs) * bpp, ce - cs);
  78 }
  79
  80 unsigned char *stbi_load(char const *filename, int *x, int *y, int *comp, int req_comp);
  81 char *ppm_load(char *path, int *h, int *w);
  82
  83 static int loadfile(char *path)
  84 {
  85         FILE *fp = fopen(path, "r");
  86         obuf = NULL;
  87         if (!fp)
  88                 return 1;
  89         fclose(fp);
  90         ch = 4;
  91         lodepng_decode32_file(&obuf, (void *) &ocols, (void *) &orows, path);
  92         if (!obuf)
  93                 obuf = stbi_load(path, &ocols, &orows, &ch, 0);
  94         if (!obuf) {
  95                 ch = 3;
  96                 obuf = (void *) ppm_load(path, &orows, &ocols);
  97         }
  98         return !obuf;
  99 }
 100
 101 static void printinfo(void)
 102 {
 103         printf("\rFBVIS:     file:%s\x1b[K\r", files[curfile]);
 104         fflush(stdout);
 105 }
 106
 107 static void freebufs(void)
 108 {
 109         free(buf);
 110         free(obuf);
 111         buf = NULL;
 112         obuf = NULL;
 113 }
 114
 115 static int nextfile(int dir)
 116 {
 117         freebufs();
 118         head = 0;
 119         while (1) {
 120                 curfile += dir;
 121                 if (curfile < 0 || !files[curfile])
 122                         return 1;
 123                 if (!loadfile(files[curfile]))
 124                         break;
 125                 else
 126                         printf("failed to load image <%s>\n", files[curfile]);
 127         }
 128         zoom(czoom);
 129         printinfo();
 130         return 0;
 131 }
 132
 133 static int readkey(void)
 134 {
 135         unsigned char b;
 136         if (read(0, &b, 1) <= 0)
 137                 return -1;
 138         return b;
 139 }
 140
 141 static int getcount(int def)
 142 {
 143         int result = count ? count : def;
 144         count = 0;
 145         return result;
 146 }
 147
 148 static void term_setup(void)
 149 {
 150         struct termios newtermios;
 151         tcgetattr(0, &termios);
 152         newtermios = termios;
 153         newtermios.c_lflag &= ~ICANON;
 154         newtermios.c_lflag &= ~ECHO;
 155         tcsetattr(0, TCSAFLUSH, &newtermios);
 156 }
 157
 158 static void term_cleanup(void)
 159 {
 160         tcsetattr(0, 0, &termios);
 161 }
 162
 163 static void mainloop(void)
 164 {
 165         int step = fb_rows() / PAGESTEPS;
 166         int hstep = fb_cols() / PAGESTEPS;
 167         int c;
 168         term_setup();
 169         draw();
 170         while ((c = readkey()) != -1) {
 171                 switch (c) {
 172                 case 'j':
 173                         head += step * getcount(1);
 174                         break;
 175                 case 'k':
 176                         head -= step * getcount(1);
 177                         break;
 178                 case 'l':
 179                         left += hstep * getcount(1);
 180                         break;
 181                 case 'h':
 182                         left -= hstep * getcount(1);
 183                         break;
 184                 case 'H':
 185                         head = 0;
 186                         break;
 187                 case 'L':
 188                         head = MAX(0, rows - fb_rows());
 189                         break;
 190                 case 'M':
 191                         head = MAX(0, (rows - fb_rows()) >> 1);
 192                         break;
 193                 case ' ':
 194                 case CTRL('d'):
 195                         head += fb_rows() * getcount(1) - step;
 196                         break;
 197                 case 127:
 198                 case CTRL('u'):
 199                         head -= fb_rows() * getcount(1) - step;
 200                         break;
 201                 case 'f':
 202                         zoom(czoom == ZOOM_FITHT ? ZOOM_ORIG : ZOOM_FITHT);
 203                         break;
 204                 case 'w':
 205                         zoom(czoom == ZOOM_FITWID ? ZOOM_ORIG : ZOOM_FITWID);
 206                         break;
 207                 case 'r':
 208                 case CTRLKEY('l'):
 209                         break;
 210                 case CTRLKEY('f'):
 211                 case CTRLKEY('b'):
 212                         if (!nextfile(c == CTRLKEY('f') ? getcount(1) : -getcount(1)))
 213                                 break;
 214                 case 'q':
 215                         term_cleanup();
 216                         return;
 217                 case 'i':
 218                         printinfo();
 219                 default:
 220                         if (c == 'd')
 221                                 sleep(getcount(1));
 222                         if (isdigit(c))
 223                                 count = count * 10 + c - '0';
 224                         if (c == 27)
 225                                 count = 0;
 226                         /* no need to redraw */
 227                         continue;
 228                 }
 229                 head = REGION(0, MAX(0, rows - fb_rows()), head);
 230                 left = REGION(0, MAX(0, cols - fb_cols()), left);
 231                 draw();
 232         }
 233 }
 234
 235 int main(int argc, char *argv[])
 236 {
 237         if (argc < 2) {
 238                 printf("usage: %s file\n", argv[0]);
 239                 return 0;
 240         }
 241         files = argv + 1;
 242         if (fb_init())
 243                 return 1;
 244         if (nextfile(1)) {
 245                 fb_free();
 246                 return 1;
 247         }
 248         mainloop();
 249         fb_free();
 250         freebufs();
 251         printf("\n");
 252         return 0;
 253 }