stew

a monorepo of some sort
git clone git://git.nsmpr.xyz/stew.git
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triangle.c (2318B)

      1 #include <u.h>
      2 #include <libc.h>
      3 #include <draw.h>
      4 #include <event.h>
      5 #include <geometry.h>
      6 
      7 #define CSWidth 640
      8 #define CSHeight CSWidth
      9 #define CSSize (CSWidth * CSHeight)
     10 
     11 char imgbuf[CSSize];
     12 Point pts[3];
     13 int m[3][3];
     14 Image *img;
     15 vlong n;
     16 char *s;
     17 
     18 void
     19 vrender(void)
     20 {
     21 	int X, Y;
     22 	char *i = imgbuf;
     23 	for (X = 0; X < CSWidth; X++)
     24 	for (Y = 0; Y < CSHeight; Y++, i++) {
     25 
     26 		#define l(m)     (m[0] * X + m[1] * Y + m[2])
     27 		#define istriag ((l(m[0]) >= 0) && (l(m[1]) >= 0) && (l(m[2]) >= 0))
     28 
     29 		*i = istriag ? 0xff : 0x00;
     30 
     31 		#undef l
     32 		#undef istriag
     33 	}
     34 }
     35 
     36 void
     37 redraw(Image *)
     38 {
     39 	draw(screen, screen->r, display->white, nil, ZP);
     40 	draw(screen, screen->r, img, nil, ZP);
     41 
     42 	string(screen, screen->r.min, display->white, ZP, font, s);
     43 }
     44 
     45 void
     46 eresized(int new)
     47 {
     48 	if(new && getwindow(display, Refnone) < 0)
     49 		fprint(2,"can't reattach to window");
     50 	redraw(screen);
     51 }
     52 
     53 void
     54 randomize_pts(void)
     55 {
     56 	pts[0] = Pt(nrand(CSWidth), nrand(CSWidth));
     57 	pts[1] = Pt(nrand(CSWidth), nrand(CSWidth));
     58 	pts[2] = Pt(nrand(CSWidth), nrand(CSWidth));
     59 }
     60 
     61 void
     62 pts2linear(void)
     63 {
     64 #define lconv(m, u, w) \
     65 	m[0] = w.y - u.y, \
     66 	m[1] = u.x - w.x, \
     67 	m[2] = - m[0] * u.x - m[1] * u.y
     68 
     69 	lconv(m[0], pts[0], pts[1]);
     70 	lconv(m[1], pts[1], pts[2]);
     71 	lconv(m[2], pts[2], pts[0]);
     72 
     73 #undef lconv
     74 }
     75 
     76 void
     77 normalize(void)
     78 {
     79 #define l(m, u)     (m[0] * u.x + m[1] * u.y + m[2])
     80 #define invert(m) m[0] = -m[0], m[1] = -m[1], m[2] = -m[2];
     81 
     82 	if (l(m[0], pts[2]) < 0) invert(m[0]);
     83 	if (l(m[1], pts[0]) < 0) invert(m[1]);
     84 	if (l(m[2], pts[1]) < 0) invert(m[2]);
     85 
     86 #undef l
     87 #undef invert
     88 }
     89 
     90 
     91 void
     92 main(void)
     93 {
     94 
     95 	srand(nsec());
     96 
     97 	n = nsec();
     98 	vrender();
     99 	n = nsec() - n;
    100 	s = smprint("render time %lld nsec", n);
    101 	initdraw(nil, 0, "cubes");
    102 	img = allocimage(display, Rect(0, 0, CSWidth, CSHeight), CMAP8, 0, DRed);
    103 
    104 	randomize_pts();
    105 	pts2linear();
    106 	normalize();
    107 	n = nsec(); vrender(); n = nsec() - n;
    108 	loadimage(img, img->r, (uchar *)imgbuf, CSSize * 4);
    109 	s = smprint("render time %lld nsec", n);
    110 	redraw(img);
    111 
    112 	Event e;
    113 	einit(Emouse);
    114 	int timer = etimer(0, 125);
    115 	for(;;) {
    116 		int key = event(&e);
    117 		if (key == timer) {
    118 
    119 			randomize_pts();
    120 			pts2linear();
    121 			normalize();
    122 			n = nsec(); vrender(); n = nsec() - n;
    123 			loadimage(img, img->r, (uchar *)imgbuf, CSSize * 4);
    124 			free(s); s = smprint("render time %lld nsec", n);
    125 			redraw(img);
    126 		}
    127 	}
    128 }