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 row_tiles;
  26         unsigned col_tiles;
  27         unsigned bpp;
  28         unsigned char * data;
  29         SDL_Colour * palette;
  30         unsigned short outpal[8];
  31 } swan_gfx_t;
  32
  33 int set_info(swan_gfx_t * gfx, SDL_Surface * img)
  34 {
  35         gfx->width = img->w;
  36         gfx->height = img->h;
  37         gfx->bpp = img->format->BitsPerPixel;
  38
  39         if (gfx->bpp != 8) {
  40                 fprintf(stderr, "warning: %d bpp format detected\n", img->format->BitsPerPixel);
  41                 return -1;
  42         }
  43
  44         if (gfx->width % 8 | gfx->height % 8) {
  45                 fprintf(stderr, "warning: image not multiple of 16x16 tiles\n \
  46                                 width: %d\theight: %d\n", gfx->width, gfx->height);
  47                 return -1;
  48         }
  49
  50         gfx->row_tiles = gfx->height / 8;
  51         gfx->col_tiles = gfx->width / 8;
  52
  53         /* set userdata to iterate over
  54          * pixels */
  55         SDL_LockSurface(img);
  56         img->userdata = img->pixels;
  57         gfx->data = (unsigned char *) img->userdata;
  58         gfx->palette = img->format->palette->colors;
  59         SDL_UnlockSurface(img);
  60
  61         return 0;
  62 }
  63
  64 void generate_4bpp_tile(unsigned char *buf, swan_gfx_t * gfx,
  65                 bool packed)
  66 {
  67         unsigned char * ptr = gfx->data;
  68         for (int i = 0; i < TILE_SZ; i+=4) {
  69                 for (int j = 0; j < 4; ++j) {
  70                         if (packed) { /* packed format */
  71                                 gfx->outpal[ptr[0]] = (gfx->palette[ptr[0]].r >> 4) << 8 |
  72                                                       (gfx->palette[ptr[0]].g >> 4) << 4 |
  73                                                       gfx->palette[ptr[0]].b >> 4;
  74                                 buf[i+j] = ptr[0] << 4;
  75                                 buf[i+j] |= ptr[1];
  76                                 ptr += 2;
  77                         } else { /* planar format */
  78                                 for (int x = 0; x < 8; ++x) {
  79                                         buf[i + j] = ptr[x] << j;
  80                                 }
  81                         }
  82                 }
  83                 if (!packed)
  84                         ptr += 8;
  85         }
  86 }
  87
  88 int main(int argc, char *argv[])
  89 {
  90         SDL_Surface * rawbmp;
  91         FILE * gfxstream;
  92         FILE * palstream;
  93         int opt;
  94         char * infile;
  95         char outfile[256];
  96         bool bout = false;
  97
  98         while ((opt = getopt(argc, argv, "po:sv:")) != -1) {
  99                 switch (opt) {
 100                         case 'p':
 101                                 printf("include palette");
 102                                 break;
 103                         case 'o':
 104                                 printf("output file %s\n", optarg);
 105                                 strcpy(outfile, optarg);
 106                                 bout = true;
 107                                 break;
 108                         case 's':
 109                                 printf("generate gfx per 16x16 tile \n");
 110                                 break;
 111                         case 'v':
 112                                 break;
 113                         default: /* '?' */
 114                                 fprintf(stderr, "Usage: %s [-s] [-o output] file \n", argv[0]);
 115                                 exit(EXIT_FAILURE);
 116                }
 117         }
 118
 119         if (optind >= argc) {
 120                 fprintf(stderr, "Expected infile\n");
 121                 fprintf(stderr, "Usage: %s [-s] [-o output] [file]\n", argv[0]);
 122                 exit(EXIT_FAILURE);
 123         }
 124
 125         infile = argv[optind];
 126
 127         rawbmp = SDL_LoadBMP(infile);
 128         if (!rawbmp) {
 129                 fprintf(stderr, "can not load %s file\n", infile);
 130                 exit(EXIT_FAILURE);
 131         }
 132
 133         swan_gfx_t * gfx = malloc(sizeof(swan_gfx_t));
 134         int ret = set_info(gfx, rawbmp);
 135
 136         if (ret != 0)
 137                 goto cleanup;
 138
 139         unsigned char *tile_buf = malloc(sizeof(unsigned char) * TILE_SZ);
 140
 141         if (!bout)
 142                 gfxstream = fopen("out.gfx", "w");
 143         else {
 144                 printf("opening %s\n", outfile);
 145                 gfxstream = fopen(outfile, "w");
 146         }
 147
 148         if (!gfxstream) {
 149                 fprintf(stderr, "can not open file for writing!\n");
 150                 goto close;
 151         }
 152
 153         unsigned nr_tiles = 1;
 154
 155         for (int i = 0; i < nr_tiles; ++i) {
 156                 generate_4bpp_tile(tile_buf, gfx, true);
 157                 int ret = fwrite(tile_buf, sizeof(unsigned char), TILE_SZ, gfxstream);
 158                 if (ret != TILE_SZ) {
 159                         fprintf(stderr, "failed to convert, only write %d instead of %d\n", ret, TILE_SZ);
 160                         goto cleanup;
 161                 }
 162         }
 163
 164         palstream = fopen("out.pal", "w");
 165         if (!palstream) {
 166                 fprintf(stderr, "can not open file for writing!\n");
 167                 fclose(palstream);
 168                 goto close;
 169         }
 170
 171         fwrite(gfx->outpal, sizeof(unsigned short), 8, palstream);
 172         const short fill = 0xFFFF;
 173         for (int i = 0; i < 8; ++i)
 174                 fwrite(&fill, sizeof(unsigned short), 1, palstream);
 175
 176         fclose(palstream);
 177
 178 close:
 179         fclose(gfxstream);
 180 cleanup:
 181         free(gfx);
 182         SDL_FreeSurface(rawbmp);
 183 }