#include #include #include #include #include #include #include enum { PCBg, PCFg, PCPoly, PCPolydark, PCAux, NCOLORS }; typedef struct Polygon Polygon; struct Polygon { Point2 *pts; Point *scrpts; int npts; void (*push)(Polygon*, Point2); }; Rectangle UR = {0,0,1,1}; /* unit rectangle */ RFrame worldrf; Image *pal[NCOLORS]; Polygon *thepoly; Point2 thepoint; void resized(void); Point toscreen(Point2); void polygonpush(Polygon *poly, Point2 p) { poly->pts = realloc(poly->pts, ++poly->npts*sizeof(Point2)); poly->pts[poly->npts-1] = p; poly->scrpts = realloc(poly->scrpts, (poly->npts+1)*sizeof(Point)); poly->scrpts[poly->npts-1] = toscreen(p); poly->scrpts[poly->npts] = poly->scrpts[0]; /* close the polygon */ } Polygon* newpolygon(Point2 *pts, int npts) { Polygon *poly; int i; poly = malloc(sizeof(Polygon)); if(pts == nil){ poly->pts = nil; poly->scrpts = nil; poly->npts = 0; }else{ poly->pts = pts; poly->scrpts = malloc((npts+1)*sizeof(Point)); for(i = 0; i < npts; i++) poly->scrpts[i] = toscreen(poly->pts[i]); poly->scrpts[npts] = poly->scrpts[0]; /* close the polygon */ poly->npts = npts; } poly->push = polygonpush; return poly; } void delpolygon(Polygon *poly) { poly->push = nil; poly->npts = 0; free(poly->scrpts); free(poly->pts); free(poly); } Point toscreen(Point2 p) { p = invrframexform(p, worldrf); return Pt(p.x,p.y); } Point2 fromscreen(Point p) { return rframexform(Pt2(p.x,p.y,1), worldrf); } void initpalette(void) { pal[PCBg] = allocimage(display, UR, screen->chan, 1, DWhite); pal[PCFg] = allocimage(display, UR, screen->chan, 1, DBlack); pal[PCPoly] = allocimage(display, UR, screen->chan, 1, DPalebluegreen); pal[PCPolydark] = allocimage(display, UR, screen->chan, 1, DDarkblue); pal[PCAux] = allocimage(display, UR, screen->chan, 1, DRed); } void drawinfo(void) { Triangle2 t; Point3 barypt; Point2 *nextv, *prevv, in0, in1, labelpt; char buf[128]; int i; if(thepoly->npts < 3) return; t.p0 = thepoly->pts[0]; t.p1 = thepoly->pts[1]; t.p2 = thepoly->pts[2]; barypt = barycoords(t, thepoint); snprint(buf, sizeof buf, "homo %v", thepoint); string(screen, toscreen(Pt2(Dx(screen->r)/2 - strlen(buf)/2*font->width,10,1)), pal[PCFg], ZP, font, buf); snprint(buf, sizeof buf, "bary %V", barypt); string(screen, toscreen(Pt2(Dx(screen->r)/2 - strlen(buf)/2*font->width,10+font->height+2,1)), pal[PCFg], ZP, font, buf); /* paint the vertex labels so that they are always visible */ for(i = 0; i < thepoly->npts; i++){ prevv = &thepoly->pts[(i-1+thepoly->npts) % thepoly->npts]; nextv = &thepoly->pts[(i+1+thepoly->npts) % thepoly->npts]; in0 = normvec2(subpt2(thepoly->pts[i], *prevv)); in1 = normvec2(subpt2(thepoly->pts[i], *nextv)); labelpt = addpt2(thepoly->pts[i], mulpt2(lerp2(in0, in1, 0.5), 30)); snprint(buf, sizeof buf, "p%d", i); string(screen, toscreen(labelpt), pal[PCFg], ZP, font, buf); } } void redraw(void) { int i; lockdisplay(display); draw(screen, screen->r, pal[PCBg], nil, ZP); fillpoly(screen, thepoly->scrpts, thepoly->npts, 1, pal[PCPoly], ZP); poly(screen, thepoly->scrpts, thepoly->npts > 0? thepoly->npts+1: 0, Enddisc, Enddisc, 1, pal[PCPolydark], ZP); for(i = 0; thepoly->npts > 0 && i < thepoly->npts+1; i++) fillellipse(screen, thepoly->scrpts[i], 2, 2, pal[PCPolydark], ZP); fillellipse(screen, toscreen(thepoint), 2, 2, pal[PCAux], ZP); drawinfo(); flushimage(display, 1); unlockdisplay(display); } void rmb(Mousectl *mc) { thepoint = fromscreen(mc->xy); } void lmb(Mousectl *mc) { if(thepoly->npts == 3){ delpolygon(thepoly); thepoly = newpolygon(nil, 0); } thepoly->push(thepoly, fromscreen(mc->xy)); } void mouse(Mousectl *mc) { if((mc->buttons&1) != 0) lmb(mc); if((mc->buttons&4) != 0) rmb(mc); } void key(Rune r) { switch(r){ case Kdel: case 'q': threadexitsall(nil); } } void usage(void) { fprint(2, "usage: %s\n", argv0); exits("usage"); } void threadmain(int argc, char *argv[]) { Mousectl *mc; Keyboardctl *kc; Rune r; GEOMfmtinstall(); ARGBEGIN{ default: usage(); }ARGEND; if(argc > 0) usage(); if(initdraw(nil, nil, nil) < 0) sysfatal("initdraw: %r"); if((mc = initmouse(nil, screen)) == nil) sysfatal("initmouse: %r"); if((kc = initkeyboard(nil)) == nil) sysfatal("initkeyboard: %r"); initpalette(); worldrf.p = Pt2(screen->r.min.x,screen->r.min.y,1); worldrf.bx = Vec2(1,0); worldrf.by = Vec2(0,1); thepoly = newpolygon(nil, 0); display->locking = 1; unlockdisplay(display); redraw(); for(;;){ enum { MOUSE, RESIZE, KEYBOARD }; Alt a[] = { {mc->c, &mc->Mouse, CHANRCV}, {mc->resizec, nil, CHANRCV}, {kc->c, &r, CHANRCV}, {nil, nil, CHANEND} }; switch(alt(a)){ case MOUSE: mouse(mc); break; case RESIZE: resized(); break; case KEYBOARD: key(r); break; } redraw(); } } void resized(void) { lockdisplay(display); if(getwindow(display, Refnone) < 0) sysfatal("couldn't resize"); unlockdisplay(display); worldrf.p = Pt2(screen->r.min.x,screen->r.min.y,1); redraw(); }