work/sbiarc/main.c

   1 #include <stdio.h>
   2 #include <math.h>
   3 #include "sbiarc.h"
   4
   5 static void draw_begin(void)
   6 {
   7 printf("<?xml version='1.0'?>\n");
   8 printf("<svg xmlns='http://www.w3.org/2000/svg' xmlns:xlink='http://www.w3.org/1999/xlink' version='1.0'>\n");
   9
  10 /*width="2032.0000" height="2032.0000" viewBox="-2.0000 -2.0000 132.0000 132.0000"*/
  11 }
  12
  13 static void draw_end(void)
  14 {
  15         printf("</svg>\n");
  16 }
  17
  18 static void draw_line(double x1, double y1, double x2, double y2)
  19 {
  20         printf("        <line x1='%f' y1='%f' x2='%f' y2='%f' style='stroke:rgb(0,0,0);stroke-width:0.02' />\n", x1, y1, x2, y2);
  21 }
  22
  23 static void draw_sba(sba_t *s)
  24 {
  25         double a, astep, r, rstep, steps;
  26
  27         printf("        <circle cx='%f' cy='%f' r='%f' stroke='none' fill='#ff9999'/>\n", s->cx[0], s->cy[0], s->r[0]);
  28         printf("        <circle cx='%f' cy='%f' r='%f' stroke='none' fill='#99ff99'/>\n", s->cx[1], s->cy[1], s->r[1]);
  29
  30
  31         astep = (s->start < s->ipa[0]) ? 0.1 : -0.1;
  32
  33         steps = (s->ipa[0] - s->start) / astep;
  34         rstep = ((s->r[0] + s->r[1]) / 2 - s->r[0]) / steps;
  35 fprintf(stderr, "astep=%f start=%f ipa=%f rstep=%f (steps=%f)\n", astep, s->start, s->ipa[0], rstep, steps);
  36         for(a = s->start, r = s->r[0]; astep > 0 ? (a < s->ipa[0]) : (a > s->ipa[0]); a += astep, r += rstep) {
  37                 double x, y;
  38                 x = s->cx[0] + cos(a) * r;
  39                 y = s->cy[0] + sin(a) * r;
  40                 draw_line(s->cx[0], s->cy[0], x, y);
  41                 if (a > 2*M_PI)
  42                         a -= 2*M_PI;
  43                 if (a < -2*M_PI)
  44                         a += 2*M_PI;
  45 fprintf(stderr, "a=%f\n", a);
  46         }
  47 }
  48
  49 int main()
  50 {
  51         sba_t s;
  52         s.cx[0] = 10; s.cy[0] = 1; s.r[0] = 5;
  53         s.cx[1] = 40; s.cy[1] = 5; s.r[1] = 9;
  54         s.start = M_PI/2; s.delta = -M_PI * 2;
  55         s.style = SBA_INFLEX;
  56
  57         sba_update(&s);
  58
  59         draw_begin();
  60         draw_sba(&s);
  61         draw_end();
  62 }