From 03149e5536a831e2ea7a20175f04938343529c99 Mon Sep 17 00:00:00 2001 From: rodri Date: Wed, 7 Aug 2024 11:47:31 +0000 Subject: offset fb during drawing based on viewport config. move OBJ-related procedures to its own unit. --- obj.c | 317 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 317 insertions(+) create mode 100644 obj.c (limited to 'obj.c') diff --git a/obj.c b/obj.c new file mode 100644 index 0000000..8c7b13f --- /dev/null +++ b/obj.c @@ -0,0 +1,317 @@ +#include +#include +#include +#include +#include +#include +#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 * +readobjmodel(char *path) +{ + Model *m; + OBJ *obj; + + m = newmodel(); + if((obj = objparse(path)) == nil) + sysfatal("objparse: %r"); + loadobjmodel(m, obj); + objfree(obj); + return m; +} -- cgit v1.2.3