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

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <math.h>
   5 #include <errno.h>
   6 #include "csgray.h"
   7
   8 #define DFL_WIDTH       800
   9 #define DFL_HEIGHT      600
  10 #define DFL_GAMMA       2.2f
  11 #define DFL_OUTFILE     "output.ppm"
  12
  13 static int save_image(const char *fname, float *pix, int xsz, int ysz);
  14 static int parse_opt(int argc, char **argv);
  15
  16 static int width = DFL_WIDTH, height = DFL_HEIGHT;
  17 static float inv_gamma = 1.0f / DFL_GAMMA;
  18 static const char *out_fname = DFL_OUTFILE;
  19
  20 int main(int argc, char **argv)
  21 {
  22         csg_object *oa, *ob, *oc, *obj;
  23         float *pixels;
  24
  25         if(parse_opt(argc, argv) == -1) {
  26                 return 1;
  27         }
  28
  29         if(csg_init() == -1) {
  30                 return 1;
  31         }
  32
  33         if(!(pixels = malloc(width * height * 3 * sizeof *pixels))) {
  34                 perror("failed to allocate framebuffer");
  35                 return 1;
  36         }
  37
  38         csg_view(0, 0, 5, 0, 0, 0);
  39
  40         oa = csg_sphere(0, 0, 0, 1);
  41         csg_color(oa, 1, 0.1, 0.05);
  42         ob = csg_sphere(0.3, 0.7, 0.7, 0.7);
  43         csg_color(ob, 0.2, 0.3, 1);
  44         oc = csg_subtraction(oa, ob);
  45         csg_add_object(oc);
  46
  47         obj = csg_plane(0, -1, 0, 0, 1, 0);
  48         csg_color(obj, 0.4, 0.7, 0.4);
  49         csg_add_object(obj);
  50
  51         obj = csg_null(-4, 10, 10);
  52         csg_emission(obj, 80, 80, 80);
  53         csg_add_object(obj);
  54
  55         csg_render_image(pixels, width, height);
  56         save_image(out_fname, pixels, width, height);
  57
  58         csg_destroy();
  59         return 0;
  60 }
  61
  62 static int save_image(const char *fname, float *pix, int xsz, int ysz)
  63 {
  64         int i;
  65         FILE *fp;
  66
  67         if(!(fp = fopen(fname, "wb"))) {
  68                 fprintf(stderr, "failed to open %s for writing: %s\n", fname, strerror(errno));
  69                 return -1;
  70         }
  71
  72         fprintf(fp, "P6\n%d %d\n255\n", xsz, ysz);
  73
  74         for(i=0; i<xsz * ysz; i++) {
  75                 unsigned int r = pow(*pix++, inv_gamma) * 255.0f;
  76                 unsigned int g = pow(*pix++, inv_gamma) * 255.0f;
  77                 unsigned int b = pow(*pix++, inv_gamma) * 255.0f;
  78
  79                 if(r > 255) r = 255;
  80                 if(g > 255) g = 255;
  81                 if(b > 255) b = 255;
  82
  83                 fputc(r, fp);
  84                 fputc(g, fp);
  85                 fputc(b, fp);
  86         }
  87         fclose(fp);
  88         return 0;
  89 }
  90
  91 static void print_usage(const char *argv0)
  92 {
  93         printf("Usage: %s [options] <csg file>\n", argv0);
  94         printf("Options:\n");
  95         printf(" -s <WxH>   output image resolution (default: %dx%d)\n", DFL_WIDTH, DFL_HEIGHT);
  96         printf(" -g <gamma> set output gamma (default: %g)\n", DFL_GAMMA);
  97         printf(" -o <file>  output image file (default: %s)\n", DFL_OUTFILE);
  98         printf(" -h         print usage information and exit\n");
  99 }
 100
 101 static int parse_opt(int argc, char **argv)
 102 {
 103         int i;
 104
 105         for(i=1; i<argc; i++) {
 106                 if(argv[i][0] == '-') {
 107                         if(argv[i][2] == 0) {
 108                                 switch(argv[i][1]) {
 109                                 case 's':
 110                                         if(sscanf(argv[++i], "%dx%d", &width, &height) != 2) {
 111                                                 fprintf(stderr, "-s must be followed by WIDTHxHEIGHT\n");
 112                                                 return -1;
 113                                         }
 114                                         break;
 115
 116                                 case 'g':
 117                                         if((inv_gamma = atof(argv[++i])) == 0.0f) {
 118                                                 fprintf(stderr, "-g must be followed by a non-zero gamma value\n");
 119                                                 return -1;
 120                                         }
 121                                         inv_gamma = 1.0f / inv_gamma;
 122                                         break;
 123
 124                                 case 'o':
 125                                         out_fname = argv[++i];
 126                                         break;
 127
 128                                 case 'h':
 129                                         print_usage(argv[0]);
 130                                         exit(0);
 131
 132                                 default:
 133                                         fprintf(stderr, "invalid option: %s\n", argv[i]);
 134                                         return -1;
 135                                 }
 136                         } else {
 137                                 fprintf(stderr, "invalid option: %s\n", argv[i]);
 138                                 return -1;
 139                         }
 140                 } else {
 141                         fprintf(stderr, "unexpected argument: %s\n", argv[i]);
 142                         return -1;
 143                 }
 144         }
 145         return 0;
 146 }