code / nuke

   1 /**
   2   * ASCII explosion from squeamish ossifrage at:
   3   * https://codegolf.stackexchange.com/questions/24462/display-the-explosion-of-a-star-in-ascii-art/24554#24554
   4   */
   5 #include "colors.h"
   6 #include <curses.h>
   7 #include <math.h>
   8 #include <stdlib.h>
   9 
  10 #define NUM_BLOBS 800
  11 #define PERSPECTIVE 50.0
  12 
  13 typedef struct {
  14     double x,y,z;
  15 } spaceblob_t;
  16 
  17 static double prng() {
  18     static long long s=1;
  19     s = s * 1488248101 + 981577151;
  20     return ((s % 65536) - 32768) / 32768.0;
  21 }
  22 
  23 void draw_explosion(int i, int midx, int midy) {
  24     static spaceblob_t blobs[NUM_BLOBS];
  25     int rows,cols;
  26     getmaxyx(stdscr,rows,cols);
  27     int maxx,minx,maxy,miny;
  28     minx = -midx;
  29     maxx = cols+minx-1;
  30     miny = -midy;
  31     maxy = rows+miny-1;
  32 
  33     if (i == 0) {
  34         /* Generate random blob coordinates */
  35         for (int i=0; i<NUM_BLOBS; i++) {
  36             double bx,by,bz,br;
  37             bx = prng();
  38             by = prng();
  39             bz = prng();
  40             br = sqrt(bx*bx + by*by + bz*bz);
  41             blobs[i].x = (bx / br) * (1.3 + 0.2 * prng());
  42             blobs[i].y = (0.5 * by / br) * (1.3 + 0.2 * prng());;
  43             blobs[i].z = (bz / br) * (1.3 + 0.2 * prng());;
  44         }
  45         /* Flash on the first frame */
  46         bkgd(COLOR_PAIR(WHITE_BG));
  47         erase();
  48         return;
  49     }
  50 
  51     bkgd(0);
  52     chtype line[cols+1];
  53     for (int y=miny; y<=maxy; y++) {
  54         int row = y+midy;
  55         for (int x=minx; x<=maxx; x++) {
  56             int col = x+midx;
  57             /* Show expanding star in next 7 frames */
  58             if (i<8) {
  59                 double r = sqrt(x*x + 4*y*y);
  60                 if (r < i*2)
  61                     mvaddch(row,col,'@');
  62                 continue;
  63             }
  64 
  65             /* Otherwise show blast wave */
  66             double r = sqrt(x*x + 4*y*y) * (0.5 + (prng()/3.0)*cos(16.*atan2(y*2.+0.01,x+0.01))*.3);
  67             int v = i - r - 7;
  68             if (v<0) {
  69                 if (i<19) {
  70                     int attr = 0;//color_ramp1[i-8];
  71                     line[col] = "%@W#H=+~-:."[i-8] | attr;
  72                 } else {
  73                     line[col] = ' ';
  74                 }
  75             } else if (v<20) {
  76                 int attr = 0;//color_ramp2[v];
  77                 line[col] = " .:!HIOMW#%$&@08O=+-"[v] | attr;
  78             } else {
  79                 line[col] = ' ';
  80             }
  81         }
  82         if (i >= 8) {
  83             line[cols+1] = '\0';
  84             mvaddchstr(row,0,line);
  85         }
  86     }
  87 
  88     /* Add blobs with perspective effect */
  89     if (i>6) {
  90         int i0 = i-6;
  91         for (int j=0; j<NUM_BLOBS; j++) {
  92             double bx = blobs[j].x * i0;
  93             double by = blobs[j].y * i0;
  94             double bz = blobs[j].z * i0;
  95             if (bz<5-PERSPECTIVE || bz>PERSPECTIVE) continue;
  96             int x = midx + bx * PERSPECTIVE / (bz+PERSPECTIVE);
  97             int y = midy + by * PERSPECTIVE / (bz+PERSPECTIVE);
  98             if (x>=0 && x<cols && y>=0 && y<rows) {
  99                 int row = y, col = x;
 100                 mvaddch(row,col,(bz>40) ? '.' : (bz>-20) ? 'o' : '@');
 101             }
 102         }
 103     }
 104 }
 105