shithub: 3dee

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vis,med: make qball rotations position-independent.

the camera no longer needs to be on the first
quadrant for the qball to work.

--- a/med.c

+++ b/med.c

@@ -179,6 +179,7 @@

 	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);

@@ -193,10 +194,11 @@

 	t[1].v[2].p = addpt3(center, addpt3(p, v2));

 	t[1].v[2].n = addpt3(p, v2);

+	/* make a cube by rotating the reference face */

 	for(i = 0; i < 6; i++){

-		for(j = 0; j < 2; j++)

-			for(k = 0; k < 3; k++)

-				if(i > 0){

+		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);

 				}

@@ -209,6 +211,34 @@

 	}

 }

+static void

+addbasis(void)

+{

+	Entity *e;

+	Model *m;

+	Primitive prims[3];

+

+	m = newmodel();

+	e = newentity(m);

+	e->RFrame3 = subject->RFrame3;

+

+	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->prims = erealloc(m->prims, (m->nprims += 3)*sizeof(*m->prims));

+	memmove(m->prims, prims, sizeof prims);

+

+	scene->addent(scene, e);

+}

+

 Point3

 gouraudvshader(VSparams *sp)

 {

@@ -496,14 +526,18 @@

 lmb(void)

 {

 	Quaternion Δorient;

+	Entity *e;

 	if((om.buttons^mctl->buttons) == 0){

 		Δorient = orient;

 		qball(screen->r, om.xy, mctl->xy, &orient, nil);

 		Δorient = mulq(orient, invq(Δorient));

-		subject->bx = Vecquat(mulq(mulq(Δorient, Quatvec(0, subject->bx)), invq(Δorient)));

-		subject->by = Vecquat(mulq(mulq(Δorient, Quatvec(0, subject->by)), invq(Δorient)));

-		subject->bz = Vecquat(mulq(mulq(Δorient, Quatvec(0, subject->bz)), invq(Δorient)));

+

+		for(e = scene->ents.next; e != &scene->ents; e = e->next){

+			e->bx = vcs2world(&cam, Vecquat(mulq(mulq(Δorient, Quatvec(0, world2vcs(&cam, e->bx))), invq(Δorient))));

+			e->by = vcs2world(&cam, Vecquat(mulq(mulq(Δorient, Quatvec(0, world2vcs(&cam, e->by))), invq(Δorient))));

+			e->bz = vcs2world(&cam, Vecquat(mulq(mulq(Δorient, Quatvec(0, world2vcs(&cam, e->bz))), invq(Δorient))));

+		}

 	}

 }

@@ -758,6 +792,7 @@

 	model = newmodel();

 	subject = newentity(model);

 	scene->addent(scene, subject);

+	addbasis();

 	if(memimageinit() != 0)

 		sysfatal("memimageinit: %r");

--- a/vis.c

+++ b/vis.c

@@ -569,9 +569,9 @@

 		Δorient = mulq(orient, invq(Δorient));

 		for(e = scene->ents.next; e != &scene->ents; e = e->next){

-			e->bx = Vecquat(mulq(mulq(Δorient, Quatvec(0, e->bx)), invq(Δorient)));

-			e->by = Vecquat(mulq(mulq(Δorient, Quatvec(0, e->by)), invq(Δorient)));

-			e->bz = Vecquat(mulq(mulq(Δorient, Quatvec(0, e->bz)), invq(Δorient)));

+			e->bx = vcs2world(maincam, Vecquat(mulq(mulq(Δorient, Quatvec(0, world2vcs(maincam, e->bx))), invq(Δorient))));

+			e->by = vcs2world(maincam, Vecquat(mulq(mulq(Δorient, Quatvec(0, world2vcs(maincam, e->by))), invq(Δorient))));

+			e->bz = vcs2world(maincam, Vecquat(mulq(mulq(Δorient, Quatvec(0, world2vcs(maincam, e->bz))), invq(Δorient))));

 		}

 	}else{

 		Framebuf *fb;