robinkrens.nl - git repository - swan-dev/blob - tools/bmp2tiles/bmp2tiles.c

   1 /**
   2  * File              : bmp2tiles.c
   3  * Author            : Robin Krens <robin@robinkrens.nl>
   4  * Date              : 04.06.2022
   5  * Last Modified Date: 12.06.2022
   6  * Last Modified By  : Robin Krens <robin@robinkrens.nl>
   7  */
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <stdint.h>
  12 #include <stdbool.h>
  13 #include <string.h>
  14 #include <unistd.h>
  15 #include <getopt.h>
  16 #include <SDL2/SDL_image.h>
  17
  18 #define TILE_SZ         32
  19 #define FOURBBP_ROW     8
  20 #define FOURBPP_COL     8
  21
  22 typedef struct {
  23         unsigned width;
  24         unsigned height;
  25         unsigned bpp;
  26 } swan_gfx_t;
  27
  28 void set_info(swan_gfx_t * gfx, SDL_Surface * img)
  29 {
  30         gfx->width = img->w;
  31         gfx->height = img->h;
  32         gfx->bpp = img->format->BitsPerPixel;
  33
  34         /* set userdata to iterate */
  35         SDL_LockSurface(img);
  36         img->userdata = img->pixels;
  37         SDL_UnlockSurface(img);
  38 }
  39
  40 void generate_4bpp_tile(unsigned char *buf, void * userdata,
  41                 bool packed)
  42 {
  43         unsigned char * ptr = (unsigned char *) userdata;
  44         for (int i = 0; i < TILE_SZ; i+=4) {
  45                 for (int j = 0; j < 4; ++j) {
  46                         if (packed) { /* packed format */
  47                                 buf[i+j] = ptr[0] << 4;
  48                                 buf[i+j] |= ptr[1];
  49                                 ptr += 2;
  50                         } else { /* planar format */
  51                                 for (int x = 0; x < 8; ++x) {
  52                                         buf[i + j] = ptr[x] << j;
  53                                 }
  54                         }
  55                 }
  56                 if (!packed)
  57                         ptr += 8;
  58         }
  59 }
  60
  61 int main(int argc, char *argv[])
  62 {
  63         SDL_Surface * rawbmp;
  64         FILE * ostream;
  65         int opt;
  66         char * infile;
  67         char outfile[256];
  68         bool bout = false;
  69
  70         while ((opt = getopt(argc, argv, "po:sv:")) != -1) {
  71                 switch (opt) {
  72                         case 'p':
  73                                 printf("include palette");
  74                                 break;
  75                         case 'o':
  76                                 printf("output file %s\n", optarg);
  77                                 strcpy(outfile, optarg);
  78                                 bout = true;
  79                                 break;
  80                         case 's':
  81                                 printf("generate gfx per 16x16 tile \n");
  82                                 break;
  83                         case 'v':
  84                                 break;
  85                         default: /* '?' */
  86                                 fprintf(stderr, "Usage: %s [-s] [-o output] file \n", argv[0]);
  87                                 exit(EXIT_FAILURE);
  88                }
  89         }
  90
  91         if (optind >= argc) {
  92                 fprintf(stderr, "Expected infile\n");
  93                 fprintf(stderr, "Usage: %s [-s] [-o output] [file]\n", argv[0]);
  94                 exit(EXIT_FAILURE);
  95         }
  96
  97         infile = argv[optind];
  98
  99         rawbmp = SDL_LoadBMP(infile);
 100         if (!rawbmp) {
 101                 fprintf(stderr, "can not load %s file\n", infile);
 102                 exit(EXIT_FAILURE);
 103         }
 104
 105         swan_gfx_t * gfx = malloc(sizeof(swan_gfx_t));
 106         set_info(gfx, rawbmp);
 107
 108         unsigned char *tile_buf = malloc(sizeof(unsigned char) * TILE_SZ);
 109
 110         if (gfx->bpp != 8) {
 111                 fprintf(stderr, "warning: %d bpp format detected\n", rawbmp->format->BitsPerPixel);
 112                 fprintf(stderr, "use --force in command to run\n");
 113                 exit(EXIT_FAILURE);
 114         }
 115
 116         if (!bout)
 117                 ostream = fopen("out.gfx", "w");
 118         else {
 119                 printf("opening %s\n", outfile);
 120                 ostream = fopen(outfile, "w");
 121         }
 122
 123         if (!ostream) {
 124                 fprintf(stderr, "can not open file for writing!\n");
 125                 exit(EXIT_FAILURE);
 126         }
 127
 128         unsigned nr_tiles = 1;
 129
 130         for (int i = 0; i < nr_tiles; ++i) {
 131                 generate_4bpp_tile(tile_buf, rawbmp->userdata, true);
 132                 int ret = fwrite(tile_buf, sizeof(unsigned char), TILE_SZ, ostream);
 133                 if (ret != TILE_SZ) {
 134                         fprintf(stderr, "failed to convert, only write %d instead of %d\n", ret, TILE_SZ);
 135                         goto cleanup;
 136                 }
 137         }
 138
 139 cleanup:
 140         free(gfx);
 141         SDL_FreeSurface(rawbmp);
 142         fclose(ostream);
 143 }