1.1 --- a/src/main.c	Sun Nov 19 00:57:39 2017 +0200
     1.2 +++ b/src/main.c	Mon Nov 20 03:53:02 2017 +0200
     1.3 @@ -1,6 +1,9 @@
     1.4  #include <stdio.h>
     1.5  #include <stdlib.h>
     1.6 +#include <string.h>
     1.7  #include <math.h>
     1.8 +#include <errno.h>
     1.9 +#include <dirent.h>
    1.10  #include <GL/glew.h>
    1.11  #include <GL/glut.h>
    1.12  #include "sdr.h"
    1.13 @@ -13,6 +16,7 @@
    1.14  void keyup(unsigned char key, int x, int y);
    1.15  void mouse(int bn, int st, int x, int y);
    1.16  void motion(int x, int y);
    1.17 +void screenshot(void);
    1.18  
    1.19  static int win_width = 1280, win_height = 800;
    1.20  static float win_aspect;
    1.21 @@ -127,6 +131,10 @@
    1.22  		}
    1.23  		break;
    1.24  
    1.25 +	case '`':
    1.26 +		screenshot();
    1.27 +		break;
    1.28 +
    1.29  	default:
    1.30  		break;
    1.31  	}
    1.32 @@ -173,3 +181,48 @@
    1.33  		glutPostRedisplay();
    1.34  	}
    1.35  }
    1.36 +
    1.37 +void screenshot(void)
    1.38 +{
    1.39 +	FILE *fp;
    1.40 +	DIR *dir;
    1.41 +	struct dirent *dent;
    1.42 +	unsigned char *img;
    1.43 +	static int shotnum = -1;
    1.44 +	char fname[128];
    1.45 +
    1.46 +	if(shotnum == -1) {
    1.47 +		shotnum = 1;
    1.48 +		if((dir = opendir("."))) {
    1.49 +			while((dent = readdir(dir))) {
    1.50 +				int num;
    1.51 +				if(sscanf(dent->d_name, "img%d.ppm", &num) == 1) {
    1.52 +					if(num >= shotnum) shotnum = num + 1;
    1.53 +				}
    1.54 +			}
    1.55 +			closedir(dir);
    1.56 +		}
    1.57 +	} else {
    1.58 +		++shotnum;
    1.59 +	}
    1.60 +
    1.61 +	sprintf(fname, "img%04d.ppm", shotnum > 0 ? shotnum : 0);
    1.62 +	if(!(fp = fopen(fname, "wb"))) {
    1.63 +		fprintf(stderr, "failed to open %s for writing: %s\n", fname, strerror(errno));
    1.64 +		return;
    1.65 +	}
    1.66 +
    1.67 +	if(!(img = malloc(win_width * win_height * 3))) {
    1.68 +		fprintf(stderr, "failed to allocate screenshot buffer\n");
    1.69 +		fclose(fp);
    1.70 +		return;
    1.71 +	}
    1.72 +
    1.73 +	glReadPixels(0, 0, win_width, win_height, GL_RGB, GL_UNSIGNED_BYTE, img);
    1.74 +
    1.75 +	fprintf(fp, "P6\n%d %d\n255\n", win_width, win_height);
    1.76 +	fwrite(img, 1, win_width * win_height * 3, fp);
    1.77 +	fclose(fp);
    1.78 +	free(img);
    1.79 +	return;
    1.80 +}