X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=libs%2Fgoat3d%2Fsrc%2Freadgltf.c;fp=libs%2Fgoat3d%2Fsrc%2Freadgltf.c;h=8b605d6a1c36c0c078293c149049d4de869413a8;hb=6370997ad9f4d424b05bcb7dc85fa2423bd1186a;hp=0000000000000000000000000000000000000000;hpb=4c42122003b1e2e859e63013aaf15e270d47b082;p=deeprace

diff --git a/libs/goat3d/src/readgltf.c b/libs/goat3d/src/readgltf.c
new file mode 100644
index 0000000..8b605d6
--- /dev/null
+++ b/libs/goat3d/src/readgltf.c
@@ -0,0 +1,179 @@
+/*
+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;
+}