ref: b8dacd35abcede65c0cd415e5fd41b3f8f75d4f3
dir: /obj.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
#include <draw.h>
#include <memdraw.h>
#include <geometry.h>
#include "libobj/obj.h"
#include "libgraphics/graphics.h"
#include "fns.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 *gidxtab, *idxtab;
int i;
gidxtab = &e->indextab[OBJVGeometric];
for(i = 0; i < gidxtab->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);
}
}
static 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");
}
if(objmtl->Ka.a > 0)
mtl->ambient = objmtl->Ka;
if(objmtl->Kd.a > 0)
mtl->diffuse = objmtl->Kd;
if(objmtl->Ks.a > 0)
mtl->specular = objmtl->Ks;
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);
p->v[0].c = Pt3(1,1,1,1);
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);
p->v[idx].c = Pt3(1,1,1,1);
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);
p->v[idx].c = Pt3(1,1,1,1);
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;
}
static Model *
readobjmodel(char *path)
{
Model *m;
OBJ *obj;
m = newmodel();
if((obj = objparse(path)) == nil)
sysfatal("objparse: %r");
loadobjmodel(m, obj);
objfree(obj);
return m;
}
static void
usage(void)
{
fprint(2, "usage: %s [objfile [dstdir]]\n", argv0);
exits("usage");
}
void
threadmain(int argc, char *argv[])
{
Model *m;
char *infile, *dstdir;
ARGBEGIN{
default: usage();
}ARGEND;
if(argc > 2)
usage();
infile = argc > 0? argv[0]: "/fd/0";
dstdir = argc == 2? argv[1]: nil;
m = readobjmodel(infile);
if(m == nil)
sysfatal("readobjmodel: %r");
if(dstdir == nil){
if(writemodel(1, m) == 0)
sysfatal("writemodel: %r");
}else{
if(exportmodel(dstdir, m) < 0)
sysfatal("exportmodel: %r");
}
exits(nil);
}