git.mutantstargoat.com Git - csgray/blob - src/main.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <errno.h>
   5 #include "csgray.h"
   6
   7 static int save_image(const char *fname, float *pix, int xsz, int ysz);
   8 static int parse_opt(int argc, char **argv);
   9
  10 static int width = 800, height = 600;
  11 static const char *out_fname = "output.ppm";
  12
  13 int main(int argc, char **argv)
  14 {
  15         csg_object *oa, *ob, *oc;
  16         float *pixels;
  17
  18         if(parse_opt(argc, argv) == -1) {
  19                 return 1;
  20         }
  21
  22         if(csg_init() == -1) {
  23                 return 1;
  24         }
  25
  26         if(!(pixels = malloc(width * height * 3 * sizeof *pixels))) {
  27                 perror("failed to allocate framebuffer");
  28                 return 1;
  29         }
  30
  31         oa = csg_sphere(0, 0, 0, 1);
  32         ob = csg_sphere(0, 1, 0, 0.8);
  33         oc = csg_union(oa, ob);
  34
  35         csg_add_object(oc);
  36
  37         csg_render_image(pixels, width, height);
  38         save_image(out_fname, pixels, width, height);
  39
  40         csg_destroy();
  41         return 0;
  42 }
  43
  44 static int save_image(const char *fname, float *pix, int xsz, int ysz)
  45 {
  46         int i;
  47         FILE *fp;
  48
  49         if(!(fp = fopen(fname, "wb"))) {
  50                 fprintf(stderr, "failed to open %s for writing: %s\n", fname, strerror(errno));
  51                 return -1;
  52         }
  53
  54         fprintf(fp, "P6\n%d %d\n65535\n", xsz, ysz);
  55
  56         for(i=0; i<xsz * ysz; i++) {
  57                 unsigned int r = *pix++ * 65535.0f;
  58                 unsigned int g = *pix++ * 65535.0f;
  59                 unsigned int b = *pix++ * 65535.0f;
  60
  61                 if(r > 0xffff) r = 0xffff;
  62                 if(g > 0xffff) g = 0xffff;
  63                 if(b > 0xffff) b = 0xffff;
  64
  65                 fputc(r >> 8, fp);
  66                 fputc(r, fp);
  67                 fputc(g >> 8, fp);
  68                 fputc(g, fp);
  69                 fputc(b >> 8, fp);
  70                 fputc(b, fp);
  71         }
  72         fclose(fp);
  73         return 0;
  74 }
  75
  76 static void print_usage(const char *argv0)
  77 {
  78         printf("Usage: %s [options] <csg file>\n", argv0);
  79         printf("Options:\n");
  80         printf(" -s <WxH>  output image resolution\n");
  81         printf(" -o <file> output image file\n");
  82         printf(" -h        print usage information and exit\n");
  83 }
  84
  85 static int parse_opt(int argc, char **argv)
  86 {
  87         int i;
  88
  89         for(i=1; i<argc; i++) {
  90                 if(argv[i][0] == '-') {
  91                         if(argv[i][2] == 0) {
  92                                 switch(argv[i][1]) {
  93                                 case 's':
  94                                         if(sscanf(argv[++i], "%dx%d", &width, &height) != 2) {
  95                                                 fprintf(stderr, "-s must be followed by WIDTHxHEIGHT\n");
  96                                                 return -1;
  97                                         }
  98                                         break;
  99
 100                                 case 'o':
 101                                         out_fname = argv[++i];
 102                                         break;
 103
 104                                 case 'h':
 105                                         print_usage(argv[0]);
 106                                         exit(0);
 107
 108                                 default:
 109                                         fprintf(stderr, "invalid option: %s\n", argv[i]);
 110                                         return -1;
 111                                 }
 112                         } else {
 113                                 fprintf(stderr, "invalid option: %s\n", argv[i]);
 114                                 return -1;
 115                         }
 116                 } else {
 117                         fprintf(stderr, "unexpected argument: %s\n", argv[i]);
 118                         return -1;
 119                 }
 120         }
 121         return 0;
 122 }