--- /dev/null
+/*
+goat3d - 3D scene, and animation file format library.
+Copyright (C) 2013-2023 John Tsiombikas <nuclear@member.fsf.org>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+#include <stdlib.h>
+#include <ctype.h>
+#include "goat3d.h"
+#include "g3dscn.h"
+#include "log.h"
+#include "json.h"
+
+static struct goat3d_material *read_material(struct goat3d *g, struct json_obj *jmtl);
+
+int g3dimpl_loadgltf(struct goat3d *g, struct goat3d_io *io)
+{
+ long i, filesz;
+ char *filebuf;
+ struct json_obj root;
+ struct json_value *jval;
+ struct json_item *jitem;
+ struct goat3d_material *mtl;
+
+ if(!(filebuf = malloc(4096))) {
+ goat3d_logmsg(LOG_ERROR, "goat3d_load: failed to allocate file buffer\n");
+ return -1;
+ }
+ filesz = io->read(filebuf, 4096, io->cls);
+ if(filesz < 2) {
+ free(filebuf);
+ return -1;
+ }
+ for(i=0; i<filesz; i++) {
+ if(!isspace(filebuf[i])) {
+ if(filebuf[i] != '{') {
+ free(filebuf);
+ return -1; /* not json */
+ }
+ break;
+ }
+ }
+ free(filebuf);
+
+ /* alright, it looks like json, load into memory and parse it to continue */
+ filesz = io->seek(0, SEEK_END, io->cls);
+ io->seek(0, SEEK_SET, io->cls);
+ if(!(filebuf = malloc(filesz + 1))) {
+ goat3d_logmsg(LOG_ERROR, "goat3d_load: failed to load file into memory\n");
+ return -1;
+ }
+ if(io->read(filebuf, filesz, io->cls) != filesz) {
+ goat3d_logmsg(LOG_ERROR, "goat3d_load: EOF while reading file\n");
+ free(filebuf);
+ return -1;
+ }
+ filebuf[filesz] = 0;
+
+ json_init_obj(&root);
+ if(json_parse(&root, filebuf) == -1) {
+ free(filebuf);
+ return -1;
+ }
+ free(filebuf);
+
+ /* a valid gltf file needs to have an "asset" node with a version number */
+ if(!(jval = json_lookup(&root, "asset.version"))) {
+ json_destroy_obj(&root);
+ return -1;
+ }
+
+ /* read all materials */
+ if((jitem = json_find_item(&root, "materials"))) {
+ if(jitem->val.type != JSON_ARR) {
+ goat3d_logmsg(LOG_ERROR, "goat3d_load: gltf materials value is not an array!\n");
+ goto skipmtl;
+ }
+
+ for(i=0; i<jitem->val.arr.size; i++) {
+ jval = jitem->val.arr.val + i;
+
+ if(jval->type != JSON_OBJ) {
+ goat3d_logmsg(LOG_ERROR, "goat3d_load: gltf material is not a json object!\n");
+ continue;
+ }
+
+ if((mtl = read_material(g, &jval->obj))) {
+ goat3d_add_mtl(g, mtl);
+ }
+ }
+ }
+skipmtl:
+
+ /* ... */
+
+ json_destroy_obj(&root);
+ return 0;
+}
+
+static int jarr_to_vec(struct json_arr *jarr, float *vec)
+{
+ int i;
+
+ if(jarr->size < 3 || jarr->size > 4) {
+ return -1;
+ }
+
+ for(i=0; i<4; i++) {
+ if(i >= jarr->size) {
+ vec[i] = 0;
+ continue;
+ }
+ if(jarr->val[i].type != JSON_NUM) {
+ return -1;
+ }
+ vec[i] = jarr->val[i].num;
+ }
+ return jarr->size;
+}
+
+static int jval_to_vec(struct json_value *jval, float *vec)
+{
+ if(jval->type != JSON_ARR) return -1;
+ return jarr_to_vec(&jval->arr, vec);
+}
+
+static struct goat3d_material *read_material(struct goat3d *g, struct json_obj *jmtl)
+{
+ struct goat3d_material *mtl;
+ const char *str;
+ struct json_value *jval;
+ float color[4], specular[4], roughness, metal, ior;
+ int nelem;
+
+ if(!(mtl = malloc(sizeof *mtl)) || g3dimpl_mtl_init(mtl) == -1) {
+ free(mtl);
+ goat3d_logmsg(LOG_ERROR, "read_material: failed to allocate material\n");
+ return 0;
+ }
+
+ if((str = json_lookup_str(jmtl, "name", 0))) {
+ goat3d_set_mtl_name(mtl, str);
+ }
+
+ if((jval = json_lookup(jmtl, "pbrMetallicRoughness.baseColorFactor")) &&
+ (nelem = jval_to_vec(jval, color)) != -1) {
+ goat3d_set_mtl_attrib(mtl, "diffuse", color);
+ }
+ /* TODO textures */
+
+ if((roughness = json_lookup_num(jmtl, "pbrMetallicRoughness.roughnessFactor", -1.0)) >= 0) {
+ goat3d_set_mtl_attrib1f(mtl, "roughness", roughness);
+ goat3d_set_mtl_attrib1f(mtl, GOAT3D_MAT_ATTR_SHININESS, (1.0f - roughness) * 100.0f + 1.0f);
+ }
+ if((metal = json_lookup_num(jmtl, "pbrMetallicRoughness.metallicFactor", -1.0)) >= 0) {
+ goat3d_set_mtl_attrib1f(mtl, "metal", metal);
+ }
+ if((jval = json_lookup(jmtl, "extensions.KHR_materials_specular.specularColorFactor")) &&
+ (nelem = jval_to_vec(jval, specular)) != -1) {
+ goat3d_set_mtl_attrib(mtl, GOAT3D_MAT_ATTR_SPECULAR, specular);
+ }
+ if((ior = json_lookup_num(jmtl, "extensions.KHR_materials_ior.ior", -1.0)) >= 0) {
+ goat3d_set_mtl_attrib1f(mtl, GOAT3D_MAT_ATTR_IOR, ior);
+ }
+ /* TODO more attributes */
+
+ return mtl;
+}
projects / deeprace / blobdiff