ref: 2267dba0ea8f61cf4b3e51492995f8edea03dcc8
dir: /scene.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
#include <draw.h>
#include <memdraw.h>
#include <geometry.h>
#include "libobj/obj.h"
#include "graphics.h"
#include "internal.h"
/*
* fan triangulation.
*
* TODO check that the polygon is in fact convex
* try to adapt if not (by finding a convex
* vertex), or discard it.
*/
static int
triangulate(OBJElem **newe, OBJElem *e)
{
OBJIndexArray *newidxtab;
OBJIndexArray *idxtab;
int i;
idxtab = &e->indextab[OBJVGeometric];
for(i = 0; i < idxtab->nindex-2; i++){
idxtab = &e->indextab[OBJVGeometric];
newe[i] = emalloc(sizeof **newe);
memset(newe[i], 0, sizeof **newe);
newe[i]->type = OBJEFace;
newe[i]->mtl = e->mtl;
newidxtab = &newe[i]->indextab[OBJVGeometric];
newidxtab->nindex = 3;
newidxtab->indices = emalloc(newidxtab->nindex*sizeof(*newidxtab->indices));
newidxtab->indices[0] = idxtab->indices[0];
newidxtab->indices[1] = idxtab->indices[i+1];
newidxtab->indices[2] = idxtab->indices[i+2];
idxtab = &e->indextab[OBJVTexture];
if(idxtab->nindex > 0){
newidxtab = &newe[i]->indextab[OBJVTexture];
newidxtab->nindex = 3;
newidxtab->indices = emalloc(newidxtab->nindex*sizeof(*newidxtab->indices));
newidxtab->indices[0] = idxtab->indices[0];
newidxtab->indices[1] = idxtab->indices[i+1];
newidxtab->indices[2] = idxtab->indices[i+2];
}
idxtab = &e->indextab[OBJVNormal];
if(idxtab->nindex > 0){
newidxtab = &newe[i]->indextab[OBJVNormal];
newidxtab->nindex = 3;
newidxtab->indices = emalloc(newidxtab->nindex*sizeof(*newidxtab->indices));
newidxtab->indices[0] = idxtab->indices[0];
newidxtab->indices[1] = idxtab->indices[i+1];
newidxtab->indices[2] = idxtab->indices[i+2];
}
}
return i;
}
typedef struct OBJ2MtlEntry OBJ2MtlEntry;
typedef struct OBJ2MtlMap OBJ2MtlMap;
struct OBJ2MtlEntry
{
OBJMaterial *objmtl;
ulong idx;
OBJ2MtlEntry *next;
};
struct OBJ2MtlMap
{
OBJ2MtlEntry *head;
Material *mtls;
};
static void
addmtlmap(OBJ2MtlMap *map, OBJMaterial *om, ulong idx)
{
OBJ2MtlEntry *e;
if(om == nil)
return;
e = emalloc(sizeof *e);
memset(e, 0, sizeof *e);
e->objmtl = om;
e->idx = idx;
if(map->head == nil){
map->head = e;
return;
}
e->next = map->head;
map->head = e;
}
static Material *
getmtlmap(OBJ2MtlMap *map, OBJMaterial *om)
{
OBJ2MtlEntry *e;
for(e = map->head; e != nil; e = e->next)
if(e->objmtl == om)
return &map->mtls[e->idx];
return nil;
}
static void
clrmtlmap(OBJ2MtlMap *map)
{
OBJ2MtlEntry *e, *ne;
for(e = map->head; e != nil; e = ne){
ne = e->next;
free(e);
}
}
int
loadobjmodel(Model *m, OBJ *obj)
{
Primitive *p;
OBJVertex *pverts, *tverts, *nverts, *v; /* geometric, texture and normals vertices */
OBJElem **trielems, *e, *ne;
OBJObject *o;
OBJIndexArray *idxtab;
OBJ2MtlMap mtlmap;
OBJMaterial *objmtl;
Material *mtl;
Point3 n; /* surface normal */
int i, idx, nt, maxnt, neednormal, gottaclean;
if(obj == nil)
return 0;
pverts = obj->vertdata[OBJVGeometric].verts;
tverts = obj->vertdata[OBJVTexture].verts;
nverts = obj->vertdata[OBJVNormal].verts;
trielems = nil;
maxnt = 0;
if(m->prims != nil){
free(m->prims);
m->prims = nil;
}
m->nprims = 0;
mtlmap.head = nil;
for(i = 0; obj->materials != nil && i < nelem(obj->materials->mattab); i++)
for(objmtl = obj->materials->mattab[i]; objmtl != nil; objmtl = objmtl->next){
mtlmap.mtls = m->materials = erealloc(m->materials, ++m->nmaterials*sizeof(*m->materials));
mtl = &m->materials[m->nmaterials-1];
memset(mtl, 0, sizeof *mtl);
if(objmtl->name != nil){
mtl->name = strdup(objmtl->name);
if(mtl->name == nil)
sysfatal("strdup: %r");
}
mtl->ambient = Pt3(objmtl->Ka.r, objmtl->Ka.g, objmtl->Ka.b, 1);
mtl->diffuse = Pt3(objmtl->Kd.r, objmtl->Kd.g, objmtl->Kd.b, 1);
mtl->specular = Pt3(objmtl->Ks.r, objmtl->Ks.g, objmtl->Ks.b, 1);
mtl->shininess = objmtl->Ns;
if(objmtl->map_Kd != nil){
mtl->diffusemap = alloctexture(sRGBTexture, nil);
mtl->diffusemap->image = dupmemimage(objmtl->map_Kd);
}
if(objmtl->norm != nil){
mtl->normalmap = alloctexture(RAWTexture, nil);
mtl->normalmap->image = dupmemimage(objmtl->norm);
}
addmtlmap(&mtlmap, objmtl, m->nmaterials-1);
}
for(i = 0; i < nelem(obj->objtab); i++)
for(o = obj->objtab[i]; o != nil; o = o->next)
for(e = o->child; e != nil; e = ne){
ne = e->next;
switch(e->type){
case OBJEPoint:
m->prims = erealloc(m->prims, ++m->nprims*sizeof(*m->prims));
p = &m->prims[m->nprims-1];
memset(p, 0, sizeof *p);
p->type = PPoint;
p->mtl = getmtlmap(&mtlmap, e->mtl);
idxtab = &e->indextab[OBJVGeometric];
v = &pverts[idxtab->indices[0]];
p->v[0].p = Pt3(v->x, v->y, v->z, v->w);
idxtab = &e->indextab[OBJVTexture];
if(idxtab->nindex == 1){
v = &tverts[idxtab->indices[0]];
p->v[0].uv = Pt2(v->u, v->v, 1);
}
break;
case OBJELine:
m->prims = erealloc(m->prims, ++m->nprims*sizeof(*m->prims));
p = &m->prims[m->nprims-1];
memset(p, 0, sizeof *p);
p->type = PLine;
p->mtl = getmtlmap(&mtlmap, e->mtl);
for(idx = 0; idx < 2; idx++){
idxtab = &e->indextab[OBJVGeometric];
v = &pverts[idxtab->indices[idx]];
p->v[idx].p = Pt3(v->x, v->y, v->z, v->w);
idxtab = &e->indextab[OBJVTexture];
if(idxtab->nindex == 2){
v = &tverts[idxtab->indices[idx]];
p->v[idx].uv = Pt2(v->u, v->v, 1);
}
}
break;
case OBJEFace:
idxtab = &e->indextab[OBJVGeometric];
assert(idxtab->nindex >= 3);
gottaclean = 0;
/* it takes n-2 triangles to fill any given n-gon */
nt = idxtab->nindex-2;
if(nt > maxnt){
maxnt = nt;
trielems = erealloc(trielems, maxnt*sizeof(*trielems));
}
if(nt > 1){
assert(triangulate(trielems, e) == nt);
gottaclean = 1;
}else
trielems[0] = e;
while(nt-- > 0){
e = trielems[nt];
neednormal = 0;
m->prims = erealloc(m->prims, ++m->nprims*sizeof(*m->prims));
p = &m->prims[m->nprims-1];
memset(p, 0, sizeof *p);
p->type = PTriangle;
p->mtl = getmtlmap(&mtlmap, e->mtl);
for(idx = 0; idx < 3; idx++){
idxtab = &e->indextab[OBJVGeometric];
v = &pverts[idxtab->indices[idx]];
p->v[idx].p = Pt3(v->x, v->y, v->z, v->w);
idxtab = &e->indextab[OBJVNormal];
if(idxtab->nindex == 3){
v = &nverts[idxtab->indices[idx]];
p->v[idx].n = normvec3(Vec3(v->i, v->j, v->k));
}else
neednormal = 1;
idxtab = &e->indextab[OBJVTexture];
if(idxtab->nindex == 3){
v = &tverts[idxtab->indices[idx]];
p->v[idx].uv = Pt2(v->u, v->v, 1);
}
}
if(p->v[0].uv.w != 0){
Point3 e0, e1;
Point2 Δuv0, Δuv1;
double det;
e0 = subpt3(p->v[1].p, p->v[0].p);
e1 = subpt3(p->v[2].p, p->v[0].p);
Δuv0 = subpt2(p->v[1].uv, p->v[0].uv);
Δuv1 = subpt2(p->v[2].uv, p->v[0].uv);
det = Δuv0.x * Δuv1.y - Δuv1.x * Δuv0.y;
det = det == 0? 0: 1.0/det;
p->tangent.x = det*(Δuv1.y * e0.x - Δuv0.y * e1.x);
p->tangent.y = det*(Δuv1.y * e0.y - Δuv0.y * e1.y);
p->tangent.z = det*(Δuv1.y * e0.z - Δuv0.y * e1.z);
p->tangent = normvec3(p->tangent);
}
if(neednormal){
n = normvec3(crossvec3(subpt3(p->v[1].p, p->v[0].p), subpt3(p->v[2].p, p->v[0].p)));
p->v[0].n = p->v[1].n = p->v[2].n = n;
}
if(gottaclean){
free(e->indextab[OBJVGeometric].indices);
free(e->indextab[OBJVNormal].indices);
free(e->indextab[OBJVTexture].indices);
free(e);
}
}
break;
default: continue;
}
}
free(trielems);
clrmtlmap(&mtlmap);
return m->nprims;
}
Model *
newmodel(void)
{
Model *m;
m = emalloc(sizeof *m);
memset(m, 0, sizeof *m);
return m;
}
Model *
dupmodel(Model *m)
{
Model *nm;
int i;
if(m == nil)
return nil;
nm = newmodel();
nm->tex = duptexture(m->tex);
if(m->nmaterials > 0){
nm->nmaterials = m->nmaterials;
nm->materials = emalloc(nm->nmaterials*sizeof(*nm->materials));
for(i = 0; i < m->nmaterials; i++){
nm->materials[i] = m->materials[i];
nm->materials[i].diffusemap = duptexture(m->materials[i].diffusemap);
nm->materials[i].normalmap = duptexture(m->materials[i].normalmap);
nm->materials[i].name = strdup(m->materials[i].name);
if(nm->materials[i].name == nil)
sysfatal("strdup: %r");
}
}
if(m->nprims > 0){
nm->nprims = m->nprims;
nm->prims = emalloc(nm->nprims*sizeof(*nm->prims));
for(i = 0; i < m->nprims; i++){
nm->prims[i] = m->prims[i];
if(nm->nmaterials > 0 && m->prims[i].mtl != nil)
nm->prims[i].mtl = &nm->materials[m->prims[i].mtl - m->materials];
}
}
return nm;
}
void
delmodel(Model *m)
{
if(m == nil)
return;
freetexture(m->tex);
while(m->nmaterials--){
freetexture(m->materials[m->nmaterials].diffusemap);
freetexture(m->materials[m->nmaterials].normalmap);
free(m->materials[m->nmaterials].name);
}
free(m->materials);
free(m->prims);
free(m);
}
Entity *
newentity(char *name, Model *m)
{
Entity *e;
e = emalloc(sizeof *e);
e->p = Pt3(0,0,0,1);
e->bx = Vec3(1,0,0);
e->by = Vec3(0,1,0);
e->bz = Vec3(0,0,1);
e->name = name == nil? nil: strdup(name);
e->mdl = m;
e->prev = e->next = nil;
return e;
}
Entity *
dupentity(Entity *e)
{
Entity *ne;
if(e == nil)
return nil;
ne = newentity(nil, nil);
*ne = *e;
if(e->name != nil)
ne->name = strdup(e->name);
ne->mdl = dupmodel(e->mdl);
ne->prev = ne->next = nil;
return ne;
}
void
delentity(Entity *e)
{
if(e == nil)
return;
delmodel(e->mdl);
free(e->name);
free(e);
}
static void
scene_addent(Scene *s, Entity *e)
{
e->prev = s->ents.prev;
e->next = s->ents.prev->next;
s->ents.prev->next = e;
s->ents.prev = e;
s->nents++;
}
static void
scene_delent(Scene *s, Entity *e)
{
e->prev->next = e->next;
e->next->prev = e->prev;
e->prev = e->next = nil;
s->nents--;
}
Scene *
newscene(char *name)
{
Scene *s;
s = emalloc(sizeof *s);
s->name = name == nil? nil: strdup(name);
s->ents.prev = s->ents.next = &s->ents;
s->nents = 0;
s->skybox = nil;
s->addent = scene_addent;
s->delent = scene_delent;
return s;
}
Scene *
dupscene(Scene *s)
{
Scene *ns;
Entity *e;
if(s == nil)
return nil;
ns = newscene(s->name);
if(s->nents > 0)
for(e = s->ents.next; e != &s->ents; e = e->next)
ns->addent(ns, dupentity(e));
ns->skybox = dupcubemap(s->skybox);
return ns;
}
void
clearscene(Scene *s)
{
Entity *e, *ne;
for(e = s->ents.next; e != &s->ents; e = ne){
ne = e->next;
s->delent(s, e);
delentity(e);
}
freecubemap(s->skybox);
}
void
delscene(Scene *s)
{
if(s == nil)
return;
clearscene(s);
free(s->name);
free(s);
}