ref: 1a7f0a55e1f55b7f7aa912bd926b11e3132339f0
dir: /med.c/
#include <u.h> #include <libc.h> #include <thread.h> #include <draw.h> #include <memdraw.h> #include <mouse.h> #include <keyboard.h> #include <geometry.h> #include "libobj/obj.h" #include "libgraphics/graphics.h" #include "fns.h" enum { K↑, K↓, K←, K→, Krise, Kfall, KR↑, KR↓, KR←, KR→, KR↺, KR↻, Kzoomin, Kzoomout, Khud, Kfrustum, Ke }; enum { Sfov, Scampos, Scambx, Scamby, Scambz, Sfps, Sframes, Se }; typedef struct Camcfg Camcfg; struct Camcfg { Point3 p, lookat, up; double fov, clipn, clipf; int ptype; }; typedef struct Compass Compass; struct Compass { Camera *cam; Scene *scn; }; Compass compass; /* 3d compass */ Rune keys[Ke] = { [K↑] = Kup, [K↓] = Kdown, [K←] = Kleft, [K→] = Kright, [Krise] = Kpgup, [Kfall] = Kpgdown, [KR↑] = 'w', [KR↓] = 's', [KR←] = 'a', [KR→] = 'd', [KR↺] = 'q', [KR↻] = 'e', [Kzoomin] = 'z', [Kzoomout] = 'x', [Khud] = 'h', [Kfrustum] = ' ', }; char stats[Se][256]; Image *screenb; Mousectl *mctl; Keyboardctl *kctl; Channel *drawc; int kdown; Scene *scene; Entity *subject; Model *model; Shadertab *shader; QLock scenelk; Mouse om; Camera *cam; Camcfg camcfg = { 0,2,4,1, 0,0,0,1, 0,1,0,0, 40*DEG, 0.01, 10, PERSPECTIVE }; Point3 center = {0,0,0,1}; RFrame3 ONF3 = { /* default orthonormal rframe */ 0,0,0,1, 1,0,0,0, 0,1,0,0, 0,0,1,0 }; LightSource light; /* global point light */ static int doprof; static int showhud; Color (*tsampler)(Texture*,Point2); static Point3 Vecquat(Quaternion q) { return Vec3(q.i, q.j, q.k); } static Point3 Ptquat(Quaternion q, double w) { return Pt3(q.i, q.j, q.k, w); } void materializefrustum(void) { Primitive l; Point3 p[4]; int i; p[0] = Pt3(0,0,1,1); p[1] = Pt3(Dx(cam->view->r),0,1,1); p[2] = Pt3(Dx(cam->view->r),Dy(cam->view->r),1,1); p[3] = Pt3(0,Dy(cam->view->r),1,1); memset(&l, 0, sizeof l); l.type = PLine; l.v[0].c = l.v[1].c = Pt3(1,1,1,1); for(i = 0; i < nelem(p); i++){ /* front frame */ l.v[0].p = world2model(subject, viewport2world(cam, p[i])); l.v[1].p = world2model(subject, viewport2world(cam, p[(i+1)%nelem(p)])); qlock(&scenelk); model->addprim(model, l); qunlock(&scenelk); /* middle frame */ l.v[0].p = world2model(subject, viewport2world(cam, subpt3(p[i], Vec3(0,0,0.5)))); l.v[1].p = world2model(subject, viewport2world(cam, subpt3(p[(i+1)%nelem(p)], Vec3(0,0,0.5)))); qlock(&scenelk); model->addprim(model, l); qunlock(&scenelk); /* back frame */ l.v[0].p = world2model(subject, viewport2world(cam, subpt3(p[i], Vec3(0,0,1)))); l.v[1].p = world2model(subject, viewport2world(cam, subpt3(p[(i+1)%nelem(p)], Vec3(0,0,1)))); qlock(&scenelk); model->addprim(model, l); qunlock(&scenelk); /* struts */ l.v[1].p = world2model(subject, viewport2world(cam, p[i])); qlock(&scenelk); model->addprim(model, l); qunlock(&scenelk); } } void addcube(void) { static Point3 axis[3] = {{0,1,0,0}, {1,0,0,0}, {0,0,1,0}}; Primitive t[2]; Point3 p, v1, v2; int i, j, k; memset(t, 0, sizeof t); t[0].type = t[1].type = PTriangle; /* build the first face/quad, facing the positive z axis */ p = Vec3(-0.5,-0.5,0.5); v1 = Vec3(1,0,0); v2 = Vec3(0,1,0); t[0].v[0].p = addpt3(center, p); t[0].v[0].n = t[0].v[1].n = t[0].v[2].n = t[1].v[2].n = Vec3(0,0,1); t[0].v[1].p = addpt3(center, addpt3(p, v1)); t[0].v[2].p = addpt3(center, addpt3(p, addpt3(v1, v2))); t[0].v[0].c = t[0].v[1].c = t[0].v[2].c = Pt3(1,1,1,1); t[1].v[0] = t[0].v[0]; t[1].v[1] = t[0].v[2]; t[1].v[2].p = addpt3(center, addpt3(p, v2)); t[1].v[2].c = Pt3(1,1,1,1); /* make a cube by rotating the reference face */ for(i = 0; i < 6; i++){ if(i > 0) for(j = 0; j < 2; j++) for(k = 0; k < 3; k++){ t[j].v[k].p = qrotate(t[j].v[k].p, axis[i%3], PI/2); t[j].v[k].n = qrotate(t[j].v[k].n, axis[i%3], PI/2); } qlock(&scenelk); model->addprim(model, t[0]); model->addprim(model, t[1]); qunlock(&scenelk); } } static void addbasis(Scene *s) { Entity *e; Model *m; Primitive prims[3]; m = newmodel(); e = newentity("basis", m); e->RFrame3 = ONF3; memset(prims, 0, sizeof prims); prims[0].type = prims[1].type = prims[2].type = PLine; prims[0].v[0].p = prims[1].v[0].p = prims[2].v[0].p = center; prims[0].v[0].c = prims[1].v[0].c = prims[2].v[0].c = Pt3(0,0,0,1); prims[0].v[1].p = addpt3(center, e->bx); prims[0].v[1].c = Pt3(1,0,0,1); prims[1].v[1].p = addpt3(center, e->by); prims[1].v[1].c = Pt3(0,1,0,1); prims[2].v[1].p = addpt3(center, e->bz); prims[2].v[1].c = Pt3(0,0,1,1); m->addprim(m, prims[0]); m->addprim(m, prims[1]); m->addprim(m, prims[2]); s->addent(s, e); } static void setupcompass(Compass *c, Rectangle r, Renderer *rctl) { static int scale = 3; r.max.x = r.min.x + Dx(r)/scale; r.max.y = r.min.y + Dy(r)/scale; c->cam = Cam(rectsubpt(r, r.min), rctl, PERSPECTIVE, 30*DEG, 0.1, 10); c->cam->view->p = Pt2(r.min.x,r.min.y,1); c->cam->view->setscale(c->cam->view, scale, scale); c->scn = newscene(nil); addbasis(c->scn); placecamera(c->cam, c->scn, camcfg.p, center, Vec3(0,1,0)); } Point3 gouraudvshader(Shaderparams *sp) { static double Ka = 0.1; /* ambient factor */ static double Ks = 0.5; /* specular factor */ double Kd; /* diffuse factor */ double spec; Point3 pos, lightdir, lookdir; Material m; Color ambient, diffuse, specular, lightc; sp->v->n = model2world(sp->su->entity, sp->v->n); sp->v->p = model2world(sp->su->entity, sp->v->p); pos = sp->v->p; if(sp->v->mtl != nil) m = *sp->v->mtl; else{ memset(&m, 0, sizeof m); m.diffuse = sp->v->c; m.specular = Pt3(1,1,1,1); m.shininess = 1; } lightdir = normvec3(subpt3(light.p, pos)); lightc = getlightcolor(&light, lightdir); ambient = mulpt3(lightc, Ka); ambient = modulapt3(ambient, m.diffuse); Kd = max(0, dotvec3(sp->v->n, lightdir)); diffuse = mulpt3(lightc, Kd); diffuse = modulapt3(diffuse, m.diffuse); lookdir = normvec3(subpt3(sp->su->camera->p, pos)); lightdir = qrotate(lightdir, sp->v->n, PI); spec = pow(max(0, dotvec3(lookdir, lightdir)), m.shininess); specular = mulpt3(lightc, spec*Ks); specular = modulapt3(specular, m.specular); sp->v->c = addpt3(ambient, addpt3(diffuse, specular)); sp->v->c.a = m.diffuse.a; return world2clip(sp->su->camera, pos); } Color gouraudshader(Shaderparams *sp) { Color tc; if(sp->su->entity->mdl->tex != nil && sp->v->uv.w != 0) tc = sampletexture(sp->su->entity->mdl->tex, sp->v->uv, tsampler); else if(sp->v->mtl != nil && sp->v->mtl->diffusemap != nil && sp->v->uv.w != 0) tc = sampletexture(sp->v->mtl->diffusemap, sp->v->uv, tsampler); else tc = Pt3(1,1,1,1); return modulapt3(sp->v->c, tc); } Point3 phongvshader(Shaderparams *sp) { Point3 pos; Color a, d, s; double ss; sp->v->n = model2world(sp->su->entity, sp->v->n); sp->v->p = model2world(sp->su->entity, sp->v->p); pos = sp->v->p; sp->setattr(sp, "pos", VAPoint, &pos); if(sp->v->mtl != nil && sp->v->mtl->normalmap != nil && sp->v->uv.w != 0){ sp->v->tangent = model2world(sp->su->entity, sp->v->tangent); sp->setattr(sp, "tangent", VAPoint, &sp->v->tangent); } if(sp->v->mtl != nil){ a = sp->v->mtl->ambient; d = sp->v->mtl->diffuse; s = sp->v->mtl->specular; ss = sp->v->mtl->shininess; sp->setattr(sp, "ambient", VAPoint, &a); sp->setattr(sp, "diffuse", VAPoint, &d); sp->setattr(sp, "specular", VAPoint, &s); sp->setattr(sp, "shininess", VANumber, &ss); } return world2clip(sp->su->camera, pos); } Color phongshader(Shaderparams *sp) { static double Ka = 0.1; /* ambient factor */ static double Ks = 0.5; /* specular factor */ double Kd; /* diffuse factor */ double spec; Color ambient, diffuse, specular, lightc, c; Point3 pos, n, lightdir, lookdir; Material m; RFrame3 TBN; Vertexattr *va; va = sp->getattr(sp, "pos"); pos = va->p; va = sp->getattr(sp, "ambient"); m.ambient = va != nil? va->p: Pt3(1,1,1,1); va = sp->getattr(sp, "diffuse"); m.diffuse = va != nil? va->p: sp->v->c; va = sp->getattr(sp, "specular"); m.specular = va != nil? va->p: Pt3(1,1,1,1); va = sp->getattr(sp, "shininess"); m.shininess = va != nil? va->n: 1; lightdir = normvec3(subpt3(light.p, pos)); lightc = getlightcolor(&light, lightdir); /* normal mapping */ va = sp->getattr(sp, "tangent"); if(va == nil) n = sp->v->n; else{ /* TODO implement this on the VS instead and apply Gram-Schmidt here */ n = sampletexture(sp->v->mtl->normalmap, sp->v->uv, neartexsampler); n = normvec3(subpt3(mulpt3(n, 2), Vec3(1,1,1))); TBN.p = Pt3(0,0,0,1); TBN.bx = va->p; /* T */ TBN.bz = sp->v->n; /* N */ TBN.by = crossvec3(TBN.bz, TBN.bx); /* B */ n = normvec3(invrframexform3(n, TBN)); sp->v->n = n; } if(sp->su->entity->mdl->tex != nil && sp->v->uv.w != 0) m.diffuse = sampletexture(sp->su->entity->mdl->tex, sp->v->uv, tsampler); else if(sp->v->mtl != nil && sp->v->mtl->diffusemap != nil && sp->v->uv.w != 0) m.diffuse = sampletexture(sp->v->mtl->diffusemap, sp->v->uv, tsampler); ambient = mulpt3(lightc, Ka); ambient = modulapt3(ambient, m.diffuse); Kd = max(0, dotvec3(n, lightdir)); diffuse = mulpt3(lightc, Kd); diffuse = modulapt3(diffuse, m.diffuse); if(sp->v->mtl != nil && sp->v->mtl->specularmap != nil && sp->v->uv.w != 0) m.specular = sampletexture(sp->v->mtl->specularmap, sp->v->uv, tsampler); lookdir = normvec3(subpt3(sp->su->camera->p, pos)); lightdir = qrotate(lightdir, n, PI); spec = pow(max(0, dotvec3(lookdir, lightdir)), m.shininess); specular = mulpt3(lightc, spec*Ks); specular = modulapt3(specular, m.specular); c = addpt3(ambient, addpt3(diffuse, specular)); c.a = m.diffuse.a; return c; } Point3 identvshader(Shaderparams *sp) { if(sp->v->mtl != nil) sp->v->c = sp->v->mtl->diffuse; return world2clip(sp->su->camera, model2world(sp->su->entity, sp->v->p)); } Color identshader(Shaderparams *sp) { Color tc; if(sp->su->entity->mdl->tex != nil && sp->v->uv.w != 0) tc = sampletexture(sp->su->entity->mdl->tex, sp->v->uv, tsampler); else if(sp->v->mtl != nil && sp->v->mtl->diffusemap != nil && sp->v->uv.w != 0) tc = sampletexture(sp->v->mtl->diffusemap, sp->v->uv, tsampler); else tc = Pt3(1,1,1,1); return modulapt3(sp->v->c, tc); } Shadertab shadertab[] = { { "ident", identvshader, identshader }, { "gouraud", gouraudvshader, gouraudshader }, { "phong", phongvshader, phongshader }, }; Shadertab * getshader(char *name) { int i; for(i = 0; i < nelem(shadertab); i++) if(strcmp(shadertab[i].name, name) == 0) return &shadertab[i]; return nil; } void zoomin(void) { cam->fov = fclamp(cam->fov - 1*DEG, 1*DEG, 180*DEG); reloadcamera(cam); } void zoomout(void) { cam->fov = fclamp(cam->fov + 1*DEG, 1*DEG, 180*DEG); reloadcamera(cam); } void drawstats(void) { int i; snprint(stats[Sfov], sizeof(stats[Sfov]), "FOV %g°", cam->fov/DEG); snprint(stats[Scampos], sizeof(stats[Scampos]), "%V", cam->p); snprint(stats[Scambx], sizeof(stats[Scambx]), "bx %V", cam->bx); snprint(stats[Scamby], sizeof(stats[Scamby]), "by %V", cam->by); snprint(stats[Scambz], sizeof(stats[Scambz]), "bz %V", cam->bz); snprint(stats[Sfps], sizeof(stats[Sfps]), "FPS %.0f/%.0f/%.0f/%.0f", !cam->stats.max? 0: 1e9/cam->stats.max, !cam->stats.avg? 0: 1e9/cam->stats.avg, !cam->stats.min? 0: 1e9/cam->stats.min, !cam->stats.v? 0: 1e9/cam->stats.v); snprint(stats[Sframes], sizeof(stats[Sframes]), "frame %llud", cam->stats.nframes); for(i = 0; i < Se; i++) stringbg(screen, addpt(screen->r.min, Pt(10,10 + i*font->height)), display->black, ZP, font, stats[i], display->white, ZP); } void redraw(void) { lockdisplay(display); draw(screen, screen->r, screenb, nil, ZP); if(showhud) drawstats(); flushimage(display, 1); unlockdisplay(display); } void renderproc(void *) { static Image *bg; uvlong t0, Δt; threadsetname("renderproc"); bg = eallocimage(display, UR, XRGB32, 1, 0x888888FF); t0 = nsec(); for(;;){ qlock(&scenelk); shootcamera(cam, shader); qunlock(&scenelk); shootcamera(compass.cam, getshader("ident")); Δt = nsec() - t0; if(Δt > HZ2MS(60)*1000000ULL){ lockdisplay(display); draw(screenb, screenb->r, bg, nil, ZP); cam->view->draw(cam->view, screenb, nil); compass.cam->view->draw(compass.cam->view, screenb, nil); unlockdisplay(display); nbsend(drawc, nil); t0 += Δt; } } } void drawproc(void *) { threadsetname("drawproc"); for(;;){ recv(drawc, nil); redraw(); } } void lmb(void) { static Quaternion orient = {1,0,0,0}; Quaternion Δorient; Point3 p; if((om.buttons^mctl->buttons) == 0){ Δorient = orient; qball(screen->r, om.xy, mctl->xy, &orient, nil); Δorient = mulq(Δorient, invq(orient)); /* orbit camera around the center */ p = subpt3(cam->p, center); p = vcs2world(cam, Vecquat(mulq(mulq(Δorient, Quatvec(0, world2vcs(cam, p))), invq(Δorient)))); p.w = cam->p.w; movecamera(cam, p); aimcamera(cam, center); /* same for the compass */ p = subpt3(compass.cam->p, center); p = vcs2world(compass.cam, Vecquat(mulq(mulq(Δorient, Quatvec(0, world2vcs(compass.cam, p))), invq(Δorient)))); p.w = compass.cam->p.w; movecamera(compass.cam, p); aimcamera(compass.cam, center); } } void mmb(void) { enum { TSNEAREST, TSBILINEAR, SP, QUIT, }; static char *items[] = { [TSNEAREST] "use nearest sampler", [TSBILINEAR] "use bilinear sampler", [SP] "", [QUIT] "quit", nil, }; static Menu menu = { .item = items }; lockdisplay(display); switch(menuhit(2, mctl, &menu, _screen)){ case TSNEAREST: tsampler = neartexsampler; break; case TSBILINEAR: tsampler = bilitexsampler; break; case QUIT: threadexitsall(nil); } unlockdisplay(display); nbsend(drawc, nil); } static char * genrmbmenuitem(int idx) { static char *items[] = { "", "add cube", nil }; if(idx < nelem(shadertab)) return shadertab[idx].name; idx -= nelem(shadertab); return items[idx]; } void rmb(void) { enum { SP, ADDCUBE, }; static Menu menu = { .gen = genrmbmenuitem }; int idx; lockdisplay(display); idx = menuhit(3, mctl, &menu, _screen); if(idx < 0) goto nohit; if(idx < nelem(shadertab)){ shader = &shadertab[idx]; memset(&cam->stats, 0, sizeof(cam->stats)); } idx -= nelem(shadertab); switch(idx){ case ADDCUBE: addcube(); break; } nohit: unlockdisplay(display); nbsend(drawc, nil); } void mouse(void) { if((mctl->buttons & 1) != 0) lmb(); if((mctl->buttons & 2) != 0) mmb(); if((mctl->buttons & 4) != 0) rmb(); if((mctl->buttons & 8) != 0) zoomin(); if((mctl->buttons & 16) != 0) zoomout(); om = mctl->Mouse; } void kbdproc(void *) { Rune r, *a; char buf[128], *s; int fd, n; threadsetname("kbdproc"); if((fd = open("/dev/kbd", OREAD)) < 0) sysfatal("kbdproc: %r"); memset(buf, 0, sizeof buf); for(;;){ if(buf[0] != 0){ n = strlen(buf)+1; memmove(buf, buf+n, sizeof(buf)-n); } if(buf[0] == 0){ if((n = read(fd, buf, sizeof(buf)-1)) <= 0) break; buf[n-1] = 0; buf[n] = 0; } if(buf[0] == 'c'){ chartorune(&r, buf+1); if(r == Kdel){ close(fd); threadexitsall(nil); }else nbsend(kctl->c, &r); } if(buf[0] != 'k' && buf[0] != 'K') continue; s = buf+1; kdown = 0; while(*s){ s += chartorune(&r, s); for(a = keys; a < keys+Ke; a++) if(r == *a){ kdown |= 1 << a-keys; break; } } } } void keyproc(void *c) { threadsetname("keyproc"); for(;;){ nbsend(c, nil); sleep(HZ2MS(100)); /* key poll rate */ } } void handlekeys(void) { static int okdown; if(kdown & 1<<K↑) movecamera(cam, mulpt3(cam->bz, -0.1)); if(kdown & 1<<K↓) movecamera(cam, mulpt3(cam->bz, 0.1)); if(kdown & 1<<K←) movecamera(cam, mulpt3(cam->bx, -0.1)); if(kdown & 1<<K→) movecamera(cam, mulpt3(cam->bx, 0.1)); if(kdown & 1<<Krise) movecamera(cam, mulpt3(cam->by, 0.1)); if(kdown & 1<<Kfall) movecamera(cam, mulpt3(cam->by, -0.1)); if(kdown & 1<<KR↑){ rotatecamera(cam, cam->bx, 1*DEG); movecamera(compass.cam, qrotate(compass.cam->p, compass.cam->bx, 1*DEG)); rotatecamera(compass.cam, compass.cam->bx, 1*DEG); } if(kdown & 1<<KR↓){ rotatecamera(cam, cam->bx, -1*DEG); movecamera(compass.cam, qrotate(compass.cam->p, compass.cam->bx, -1*DEG)); rotatecamera(compass.cam, compass.cam->bx, -1*DEG); } if(kdown & 1<<KR←){ rotatecamera(cam, cam->by, 1*DEG); movecamera(compass.cam, qrotate(compass.cam->p, compass.cam->by, 1*DEG)); rotatecamera(compass.cam, compass.cam->by, 1*DEG); } if(kdown & 1<<KR→){ rotatecamera(cam, cam->by, -1*DEG); movecamera(compass.cam, qrotate(compass.cam->p, compass.cam->by, -1*DEG)); rotatecamera(compass.cam, compass.cam->by, -1*DEG); } if(kdown & 1<<KR↺){ rotatecamera(cam, cam->bz, 1*DEG); movecamera(compass.cam, qrotate(compass.cam->p, compass.cam->bz, 1*DEG)); rotatecamera(compass.cam, compass.cam->bz, 1*DEG); } if(kdown & 1<<KR↻){ rotatecamera(cam, cam->bz, -1*DEG); movecamera(compass.cam, qrotate(compass.cam->p, compass.cam->bz, -1*DEG)); rotatecamera(compass.cam, compass.cam->bz, -1*DEG); } if(kdown & 1<<Kzoomin) zoomin(); if(kdown & 1<<Kzoomout) zoomout(); if((okdown & 1<<Khud) == 0 && (kdown & 1<<Khud) != 0) showhud ^= 1; if((okdown & 1<<Kfrustum) == 0 && (kdown & 1<<Kfrustum) != 0) materializefrustum(); okdown = kdown; } void resize(void) { lockdisplay(display); if(getwindow(display, Refnone) < 0) fprint(2, "can't reattach to window\n"); unlockdisplay(display); nbsend(drawc, nil); } static void confproc(void) { char buf[64]; int fd; snprint(buf, sizeof buf, "/proc/%d/ctl", getpid()); fd = open(buf, OWRITE); if(fd < 0) sysfatal("open: %r"); if(doprof) fprint(fd, "profile\n"); close(fd); } void usage(void) { fprint(2, "usage: %s\n", argv0); exits("usage"); } void threadmain(int argc, char *argv[]) { Renderer *rctl; Channel *keyc; GEOMfmtinstall(); ARGBEGIN{ case 'p': doprof++; break; default: usage(); }ARGEND; if(argc != 0) usage(); confproc(); if((shader = getshader("gouraud")) == nil) sysfatal("couldn't find main shader"); scene = newscene(nil); model = newmodel(); subject = newentity("main", model); scene->addent(scene, subject); if(memimageinit() != 0) sysfatal("memimageinit: %r"); if((rctl = initgraphics()) == nil) sysfatal("initgraphics: %r"); if(initdraw(nil, nil, "med") < 0) sysfatal("initdraw: %r"); if((mctl = initmouse(nil, screen)) == nil) sysfatal("initmouse: %r"); rctl->doprof = doprof; screenb = eallocimage(display, rectsubpt(screen->r, screen->r.min), XRGB32, 0, DNofill); cam = Cam(screenb->r, rctl, camcfg.ptype, camcfg.fov, camcfg.clipn, camcfg.clipf); placecamera(cam, scene, camcfg.p, camcfg.lookat, camcfg.up); light.p = Pt3(0,100,100,1); light.c = Pt3(1,1,1,1); light.type = LightPoint; tsampler = neartexsampler; setupcompass(&compass, rectaddpt(Rect(0,0,100,100), subpt(screenb->r.max, Pt(100,100))), rctl); kctl = emalloc(sizeof *kctl); kctl->c = chancreate(sizeof(Rune), 16); keyc = chancreate(sizeof(void*), 1); drawc = chancreate(sizeof(void*), 1); display->locking = 1; unlockdisplay(display); proccreate(kbdproc, nil, mainstacksize); proccreate(keyproc, keyc, mainstacksize); proccreate(renderproc, nil, mainstacksize); proccreate(drawproc, nil, mainstacksize); for(;;){ enum {MOUSE, RESIZE, KEY}; Alt a[] = { {mctl->c, &mctl->Mouse, CHANRCV}, {mctl->resizec, nil, CHANRCV}, {keyc, nil, CHANRCV}, {nil, nil, CHANEND} }; switch(alt(a)){ case MOUSE: mouse(); break; case RESIZE: resize(); break; case KEY: handlekeys(); break; } } }