fteqw/plugins/models/gltf.c

#ifndef GLQUAKE
#define GLQUAKE	//this is shit.
#endif
#include "quakedef.h"
#include "../plugin.h"
#include "com_mesh.h"
extern modplugfuncs_t *modfuncs;

#define GLTFMODELS


//'The units for all linear distances are meters.'
//'feh: 1 metre is approx. 26.24671916 qu.'
//if the player is 1.6m tall, and the player's model is around 48qu, then 1m=30qu, which is a slightly nicer number to work with, and 1qu is a really poorly defined unit.
#define GLTFSCALE 30

#ifdef GLTFMODELS
typedef struct json_s
{
	const char *bodystart;
	const char *bodyend;

	struct json_s *parent;
	struct json_s *child;
	struct json_s *sibling;
	struct json_s **childlink;
	qboolean used;	//set to say when something actually read/walked it, so we can flag unsupported things gracefully
	char name[1];
} json_t;

//node destruction
static void JSON_Orphan(json_t *t)
{
	if (t->parent)
	{
		json_t *p = t->parent, **l = &p->child;
		while (*l)
		{
			if (*l == t)
			{
				*l = t->sibling;
				if (*l)
					p->childlink = l;
				break;
			}
			l = &(*l)->sibling;
		}
		t->parent = NULL;
		t->sibling = NULL;
	}
}
static void JSON_Destroy(json_t *t)
{
	while(t->child)
		JSON_Destroy(t->child);
	JSON_Orphan(t);
	free(t);
}

//node creation
static json_t *JSON_CreateNode(json_t *parent, const char *namestart, const char *nameend, const char *bodystart, const char *bodyend)
{
	json_t *j;
	qboolean dupbody = false;
	if (namestart && !nameend)
		nameend = namestart+strlen(namestart);
	if (bodystart && !bodyend)
	{
		dupbody = true;
		bodyend = bodystart+strlen(bodystart);
	}
	j = malloc(sizeof(*j) + nameend-namestart + (dupbody?1+bodyend-bodystart:0));
	memcpy(j->name, namestart, nameend-namestart);
	j->name[nameend-namestart] = 0;
	j->bodystart = bodystart;
	j->bodyend = bodyend;

	j->child = NULL;
	j->sibling = NULL;
	j->childlink = &j->child;
	j->parent = parent;
	if (parent)
	{
		*parent->childlink = j;
		parent->childlink = &j->sibling;
		j->used = false;
	}
	else
		j->used = true;

	if (dupbody)
	{
		char *bod = j->name + (nameend-namestart)+1;
		j->bodystart = bod;
		j->bodyend = j->bodystart + (bodyend-bodystart);
		memcpy(bod, bodystart, bodyend-bodystart);
		bod[bodyend-bodystart] = 0;
	}
	return j;
}

//node parsing
static void JSON_SkipWhite(const char *msg, int *pos, int max)
{
	while (*pos < max && (
		msg[*pos] == ' ' ||
		msg[*pos] == '\t' ||
		msg[*pos] == '\r' ||
		msg[*pos] == '\n'
		))
		*pos+=1;
}
static qboolean JSON_ParseString(char const*msg, int *pos, int max, char const**start, char const** end)
{
	if (*pos < max && msg[*pos] == '\"')
	{
		*pos+=1;
		*start = msg+*pos;
		while (*pos < max && msg[*pos] != '\"')
			*pos+=1;
		if (*pos < max && msg[*pos] == '\"')
		{
			*end = msg+*pos;
			*pos+=1;
			return true;
		}
	}
	else
	{
		*start = msg+*pos;
		while (*pos < max
			&& msg[*pos] != ' '
			&& msg[*pos] != '\t'
			&& msg[*pos] != '\r'
			&& msg[*pos] != '\n'
			&& msg[*pos] != ':'
			&& msg[*pos] != ','
			&& msg[*pos] != '}'
			&& msg[*pos] != '{'
			&& msg[*pos] != '['
			&& msg[*pos] != ']')
		{
			*pos+=1;
		}
		*end = msg+*pos;
		if (*start != *end)
			return true;
	}
	*end = *start;
	return false;
}
static json_t *JSON_Parse(json_t *t, const char *namestart, const char *nameend, const char *json, int *jsonpos, int jsonlen)
{
	const char *childstart, *childend;
	JSON_SkipWhite(json, jsonpos, jsonlen);

	if (*jsonpos < jsonlen)
	{
		if (json[*jsonpos] == '{')
		{
			*jsonpos+=1;
			JSON_SkipWhite(json, jsonpos, jsonlen);

			t = JSON_CreateNode(t, namestart, nameend, NULL, NULL);

			while (*jsonpos < jsonlen && json[*jsonpos] == '\"')
			{
				if (!JSON_ParseString(json, jsonpos, jsonlen, &childstart, &childend))
					break;
				JSON_SkipWhite(json, jsonpos, jsonlen);
				if (*jsonpos < jsonlen && json[*jsonpos] == ':')
				{
					*jsonpos+=1;
					if (!JSON_Parse(t, childstart, childend, json, jsonpos, jsonlen))
						break;
				}
				JSON_SkipWhite(json, jsonpos, jsonlen);

				if (*jsonpos < jsonlen && json[*jsonpos] == ',')
				{
					*jsonpos+=1;
					JSON_SkipWhite(json, jsonpos, jsonlen);
					continue;
				}
				break;
			}

			if (*jsonpos < jsonlen && json[*jsonpos] == '}')
			{
				*jsonpos+=1;
				return t;
			}
			JSON_Destroy(t);
		}
		else if (json[*jsonpos] == '[')
		{
			char idxname[MAX_QPATH];
			unsigned int idx = 0;
			*jsonpos+=1;
			JSON_SkipWhite(json, jsonpos, jsonlen);

			t = JSON_CreateNode(t, namestart, nameend, NULL, NULL);

			for(;;)
			{
				Q_snprintf(idxname, sizeof(idxname), "%u", idx++);
				if (!JSON_Parse(t, idxname, NULL, json, jsonpos, jsonlen))
					break;

				if (*jsonpos < jsonlen && json[*jsonpos] == ',')
				{
					*jsonpos+=1;
					JSON_SkipWhite(json, jsonpos, jsonlen);
					continue;
				}
				break;
			} 

			JSON_SkipWhite(json, jsonpos, jsonlen);
			if (*jsonpos < jsonlen && json[*jsonpos] == ']')
			{
				*jsonpos+=1;
				return t;
			}
			JSON_Destroy(t);
		}
		else
		{
			if (JSON_ParseString(json, jsonpos, jsonlen, &childstart, &childend))
				return JSON_CreateNode(t, namestart, nameend, childstart, childend);
		}
	}
	return NULL;
}

static json_t *JSON_FindChild(json_t *t, const char *child)
{
	if (t)
	{
		size_t nl;
		const char *dot = strchr(child, '.');
		if (dot)
			nl = dot-child;
		else
			nl = strlen(child);
		for (t = t->child; t; t = t->sibling)
		{
			if (!strncmp(t->name, child, nl) && (t->name[nl] == '.' || !t->name[nl]))
			{
				child+=nl;
				t->used = true;
				if (*child == '.')
					return JSON_FindChild(t, child+1);
				if (!*child)
					return t;
				break;
			}
		}
	}
	return NULL;
}
static json_t *JSON_FindIndexedChild(json_t *t, const char *child, unsigned int idx)
{
	char idxname[MAX_QPATH];
	if (child)
		Q_snprintf(idxname, sizeof(idxname), "%s.%u", child, idx);
	else
		Q_snprintf(idxname, sizeof(idxname), "%u", idx);
	return JSON_FindChild(t, idxname);
}
static qboolean JSON_Equals(json_t *t, const char *child, const char *expected)
{
	if (child)
		t = JSON_FindChild(t, child);
	if (t && t->bodyend-t->bodystart == strlen(expected))
		return !strncmp(t->bodystart, expected, t->bodyend-t->bodystart);
	return false;
}
#include <inttypes.h>
static qintptr_t JSON_GetInteger(json_t *t, const char *child, int fallback)
{
	if (child)
		t = JSON_FindChild(t, child);
	if (t)
	{	//copy it to another buffer. can probably skip that tbh.
		char tmp[MAX_QPATH];
		size_t l = t->bodyend-t->bodystart;
		if (l > MAX_QPATH-1)
			l = MAX_QPATH-1;
		memcpy(tmp, t->bodystart, l);
		tmp[l] = 0;
		if (!strcmp(tmp, "false"))	//special cases, for booleans
			return 0;
		if (!strcmp(tmp, "true"))	//special cases, for booleans
			return 1;
		return (qintptr_t)strtoll(tmp, NULL, 0);
	}
	return fallback;
}
static qintptr_t JSON_GetIndexedInteger(json_t *t, unsigned int idx, int fallback)
{
	char idxname[MAX_QPATH];
	Q_snprintf(idxname, sizeof(idxname), "%u", idx);
	return JSON_GetInteger(t, idxname, fallback);
}
static double JSON_GetFloat(json_t *t, const char *child, double fallback)
{
	if (child)
		t = JSON_FindChild(t, child);
	if (t)
	{	//copy it to another buffer. can probably skip that tbh.
		char tmp[MAX_QPATH];
		size_t l = t->bodyend-t->bodystart;
		if (l > MAX_QPATH-1)
			l = MAX_QPATH-1;
		memcpy(tmp, t->bodystart, l);
		tmp[l] = 0;
		return atof(tmp);
	}
	return fallback;
}
static double JSON_GetIndexedFloat(json_t *t, unsigned int idx, double fallback)
{
	char idxname[MAX_QPATH];
	Q_snprintf(idxname, sizeof(idxname), "%u", idx);
	return JSON_GetFloat(t, idxname, fallback);
}

static void JSON_GetPath(json_t *t, qboolean ignoreroot, char *buffer, size_t buffersize)
{
	if (t->parent && (t->parent->parent || !ignoreroot))
	{
		JSON_GetPath(t->parent, ignoreroot, buffer, buffersize);
		Q_strlcat(buffer, ".", buffersize);
	}
	Q_strlcat(buffer, t->name, buffersize);
}
static void JSON_WarnUnused(json_t *t, int *warnlimit)
{
	if (!t)
		return;
	if (t->used)
	{
		for (t = t->child; t; t = t->sibling)
			JSON_WarnUnused(t, warnlimit);
	}
	else
	{
		char path[8192];
		*path = 0;
		JSON_GetPath(t, false, path, sizeof(path));
		if ((*warnlimit) --> 0)
			Con_DPrintf(CON_WARNING"GLTF property %s was not used\n", path);
	}
}
static void JSON_FlagAsUsed(json_t *t, const char *child)
{
	if (child)
	{
		t = JSON_FindChild(t, child);
		if (!t)
			return;
	}
	t->used = true;
	for (t = t->child; t; t = t->sibling)
		JSON_FlagAsUsed(t, NULL);
}
static void JSON_WarnIfChild(json_t *t, const char *child, int *warnlimit)
{
	t = JSON_FindChild(t, child); 
	if (t)
	{
		char path[8192];
		*path = 0;
		JSON_GetPath(t, false, path, sizeof(path));
		if ((*warnlimit) --> 0)
			Con_Printf(CON_WARNING"Standard feature %s is not supported\n", path);
		JSON_FlagAsUsed(t, NULL);
	}
}

static unsigned int FromBase64(char c)
{
	if (c >= 'A' && c <= 'Z')
		return 0+(c-'A');
	if (c >= 'a' && c <= 'z')
		return 26+(c-'a');
	if (c >= '0' && c <= '9')
		return 52+(c-'0');
	if (c == '+')
		return 62;
	if (c == '/')
		return 63;
	return 64;
}
//fancy parsing of content
static void *JSON_MallocDataURI(json_t *t, size_t *outlen)
{
	size_t bl = t->bodyend-t->bodystart;
	if (bl >= 5 && !strncmp(t->bodystart, "data:", 5))
	{
		const char *mimestart = t->bodystart+5;
		const char *mimeend;
		const char *encstart;
		const char *encend;
		const char *in;
		char *out, *r;

		for (mimeend = mimestart; *mimeend && mimeend < t->bodyend; mimeend++)
		{
			if (*mimeend == ';')	//start of encoding
				break;
			if (*mimeend == ',')	//start of data
				break;
		}
		if (*mimeend == ';')
		{
			for (encend = encstart = mimeend+1; *encend && encend < t->bodyend; encend++)
			{
				if (*encend == ',')	//start of data
					break;
			}
		}
		else
			encstart = encend = mimeend;

		if (*encend == ',' && encend < t->bodyend)
		{
			in = encend+1;
			if (encend-encstart == 6 && !strncmp(encstart, "base64", 6))
			{
				//base64
				r = out = malloc(((t->bodyend-in)*3)/4 + 1);
				while (in+3 < t->bodyend)
				{
					unsigned int c1, c2, c3, c4;
					c1 = FromBase64(*in++);
					c2 = FromBase64(*in++);
					if (c1 >= 64 || c2 >= 64)
						break;
					*out++ = (c1<<2) | (c2>>4);
					c3 = FromBase64(*in++);
					if (c3 >= 64)
						break;
					*out++ = (c2<<4) | (c3>>2);
					c4 = FromBase64(*in++);
					if (c3 >= 64)
						break;
					*out++ = (c3<<6) | (c4>>0);
				}
				*outlen = out-r;
				*out = 0;
				return r;
			}
			else if (encend == encstart)
			{	//url encoding. yuck, sod off.
			}
		}
	}
	return NULL;
}

static size_t JSON_ReadBody(json_t *t, char *out, size_t outsize)
{
	size_t bodysize;
	if (!t)
	{
		if (out)
			*out = 0;
		return 0;
	}
	if (out)
	{
		bodysize = t->bodyend-t->bodystart;
		if (bodysize > outsize-1)
			bodysize = outsize-1;
		memcpy(out, t->bodystart, bodysize);
		out[bodysize] = 0;
	}
	return t->bodyend-t->bodystart;
}

//glTF 1.0 and 2.0 differ in that 1 uses names and 2 uses indexes. There's also some significant differences with materials.
//we only support 2.0

//articulated models are handled by loading them as skeletal (should probably optimise the engine for this usecase)
//we don't support skeletal models either right now.

//buffers are raw blobs that can come from multiple different sources
struct gltf_buffer
{
	qboolean loaded;
	qboolean malloced;
	void *data;
	size_t length;
};
typedef struct gltf_s
{
	struct model_s *mod;
	unsigned int numsurfaces;
	json_t *r;

	int *bonemap;//[MAX_BONES];	//remap skinned bones. I hate that we have to do this.
	struct gltfbone_s
	{
		char name[32];
		int parent;
		int camera;
		double amatrix[16];
		double inverse[16];
		struct
		{
			double rmatrix[16];			//gah
			double quat[4], scale[3], trans[3];	//annoying smeg
		} rel;

		struct {
			struct gltf_accessor *input;
			struct gltf_accessor *output;
		} *rot, *scale, *translation;
	} *bones;//[MAX_BONES];
	unsigned int numbones;

	int warnlimit;	//don't spam warnings. this is a loader, not a spammer

	struct gltf_buffer buffers[64];
} gltf_t;

static void GLTF_RelativePath(const char *base, const char *relative, char *out, size_t outsize)
{
	size_t t;
	const char *sep;
	const char *end = base;
	if (*relative == '/')
	{
		relative++;
	}
	else
	{
		for (sep = end; *sep; sep++)
		{
			if (*sep == '/' || *sep == '\\')
				end = sep+1;
		}
	}
	while (!strncmp(relative, "../", 3))
	{
		if (end > base)
		{
			end--;
			while (end > base)
			{
				end--;
				if (*end == '/' || *end == '\\')
				{
					relative += 3;
					end++;
					break;
				}
			}
		}
		else
			break;
	}
	outsize--;	//for the null

	t = end-base;
	if (t > outsize)
		t = outsize;
	memcpy(out, base, t);
	out += t;
	outsize -= t;

	//FIXME: uris should be percent-decoded here.
	t = strlen(relative);
	if (t > outsize)
		t = outsize;
	memcpy(out, relative, t);
	out += t;
	outsize -= t;

	*out = 0;
}

static struct gltf_buffer *GLTF_GetBufferData(gltf_t *gltf, int bufferidx)
{
	json_t *b = JSON_FindIndexedChild(gltf->r, "buffers", bufferidx);
	json_t *uri = JSON_FindChild(b, "uri");
	size_t length = JSON_GetInteger(b, "byteLength", 0);
	struct gltf_buffer *out;

//	JSON_WarnIfChild(b, "name");
//	JSON_WarnIfChild(b, "extensions");
//	JSON_WarnIfChild(b, "extras");

	if (bufferidx < 0 || bufferidx >= countof(gltf->buffers))
		return NULL;
	out = &gltf->buffers[bufferidx];

	//we may have been through here before...
	if (out->loaded)
		return out->data?out:NULL;
	out->loaded = true;

	if (uri)
	{
		out->malloced = true;
		out->data = JSON_MallocDataURI(uri, &out->length);
		if (!out->data)
		{
			//read a file from disk.
			vfsfile_t *f;
			char uritext[MAX_QPATH];
			char filename[MAX_QPATH];
			JSON_ReadBody(uri, uritext, sizeof(uritext));
			GLTF_RelativePath(gltf->mod->name, uritext, filename, sizeof(filename));
			f = modfuncs->OpenVFS(filename, "rb", FS_GAME);
			if (f)
			{
				out->length = VFS_GETLEN(f);
				out->length = min(out->length, length);
				out->data = malloc(length);
				VFS_READ(f, out->data, length);
				VFS_CLOSE(f);
			}
			else
				Con_Printf(CON_WARNING"%s: Unable to read buffer file %s\n", gltf->mod->name, filename);
		}
	}
	return out->data?out:NULL;
}
//buffer views are aka VBOs. each has its own VBO data type (vbo/ebo), and can be uploaded as-is.
struct gltf_bufferview
{
	void *data;
	size_t length;
	int bytestride;
};
static qboolean GLTF_GetBufferViewData(gltf_t *gltf, int bufferview, struct gltf_bufferview *view)
{
	struct gltf_buffer *buf;
	json_t *bv = JSON_FindIndexedChild(gltf->r, "bufferViews", bufferview);
	size_t offset;
	if (!bv)
		return false;

	buf = GLTF_GetBufferData(gltf, JSON_GetInteger(bv, "buffer", 0));
	if (!buf)
		return false;
	offset = JSON_GetInteger(bv, "byteOffset", 0);
	view->data = (char*)buf->data + offset;
	view->length = JSON_GetInteger(bv, "byteLength", 0);	//required
	view->bytestride = JSON_GetInteger(bv, "byteStride", 0);
	if (offset + view->length > buf->length)
		return false;

	JSON_FlagAsUsed(bv, "target");	//required, but not useful for us.
	JSON_FlagAsUsed(bv, "name");
//	JSON_WarnIfChild(bv, "extensions");
//	JSON_WarnIfChild(bv, "extras");
	return true;
}
//accessors are basically VAs blocks that refer inside a bufferview/VBO.
struct gltf_accessor
{
	void *data;
	size_t length;
	size_t bytestride;

	int componentType;		//5120 BYTE, 5121 UNSIGNED_BYTE, 5122 SHORT, 5123 UNSIGNED_SHORT, 5125 UNSIGNED_INT, 5126 FLOAT
	qboolean normalized;
	int count;
	int type;	//1,2,3,4 says component count, 256|(4,9,16) for square matricies...

	double mins[16];
	double maxs[16];
};
static qboolean GLTF_GetAccessor(gltf_t *gltf, int accessorid, struct gltf_accessor *out)
{
	struct gltf_bufferview bv;
	json_t *a, *mins, *maxs;
	size_t offset;
	int j;
	memset(out, 0, sizeof(*out));

	a = JSON_FindIndexedChild(gltf->r, "accessors", accessorid);
	if (!a)
		return false;

	if (!GLTF_GetBufferViewData(gltf, JSON_GetInteger(a, "bufferView", 0), &bv))
		return false;
	offset = JSON_GetInteger(a, "byteOffset", 0);
	if (offset > bv.length)
		return false;
	out->length = bv.length - offset;
	out->bytestride = bv.bytestride;
	out->componentType = JSON_GetInteger(a, "componentType", 0);
	out->normalized = JSON_GetInteger(a, "normalized", false);
	out->count = JSON_GetInteger(a, "count", 0);
	if (JSON_Equals(a, "type", "SCALAR"))
		out->type = (1<<8) | 1;
	else if (JSON_Equals(a, "type", "VEC2"))
		out->type = (1<<8) | 2;
	else if (JSON_Equals(a, "type", "VEC3"))
		out->type = (1<<8) | 3;
	else if (JSON_Equals(a, "type", "VEC4"))
		out->type = (1<<8) | 4;
	else if (JSON_Equals(a, "type", "MAT2"))
		out->type = (2<<8) | 2;
	else if (JSON_Equals(a, "type", "MAT3"))
		out->type = (3<<8) | 3;
	else if (JSON_Equals(a, "type", "MAT4"))
		out->type = (4<<8) | 4;
	else
	{
		if (gltf->warnlimit --> 0)
			Con_Printf(CON_WARNING"%s: glTF2 unsupported type\n", gltf->mod->name);
		out->type = 1;
	}

	if (!out->bytestride)
	{
		out->bytestride = (out->type & 0xff) * (out->type>>8);
		switch(out->componentType)
		{
		default:
			if (gltf->warnlimit --> 0)
				Con_Printf(CON_WARNING"GLTF_GetAccessor: %s: glTF2 unsupported componentType (%i)\n", gltf->mod->name, out->componentType);
		case 5120:	//BYTE
		case 5121:	//UNSIGNED_BYTE
			break;
		case 5122: //SHORT
		case 5123: //UNSIGNED_SHORT
			out->bytestride *= 2;
			break;
		case 5125: //UNSIGNED_INT
		case 5126: //FLOAT
			out->bytestride *= 4;
			break;
		}
	}


	mins = JSON_FindChild(a, "min");
	maxs = JSON_FindChild(a, "max");
	for (j = 0; j < (out->type>>8)*(out->type&0xff); j++)
	{	//'must' be set in various situations.
		out->mins[j] = JSON_GetIndexedInteger(mins, j, 0); 
		out->maxs[j] = JSON_GetIndexedInteger(maxs, j, 0);
	}

//	JSON_WarnIfChild(a, "sparse");
//	JSON_WarnIfChild(a, "name");
//	JSON_WarnIfChild(a, "extensions");
//	JSON_WarnIfChild(a, "extras");

	out->data = (char*)bv.data + offset;
	return true;
}

static void GLTF_AccessorToTangents(gltf_t *gltf, vec3_t *norm, vec3_t **sdir, vec3_t **tdir, size_t outverts, struct gltf_accessor *a)
{	//input MUST be a single float4
	//output is two vec3s. wasteful perhaps.
	vec3_t *os = modfuncs->ZG_Malloc(&gltf->mod->memgroup, sizeof(*os) * 3 * outverts);
	vec3_t *ot = modfuncs->ZG_Malloc(&gltf->mod->memgroup, sizeof(*ot) * 3 * outverts);
	char *in = a->data;

	size_t v, c;
	*sdir = os;
	*tdir = ot;
	if ((a->type&0xff) != 4)
		return;
	switch(a->componentType)
	{
	default:
		if (gltf->warnlimit --> 0)
			Con_Printf(CON_WARNING"GLTF_AccessorToTangents: %s: glTF2 unsupported componentType (%i)\n", gltf->mod->name, a->componentType);
	case 0:
		memset(os, 0, sizeof(*os) * outverts);
		memset(ot, 0, sizeof(*ot) * outverts);
		break;
//	case 5120:	//BYTE
//	case 5121:	//UNSIGNED_BYTE
//	case 5122: //SHORT
//	case 5123: //UNSIGNED_SHORT
//	case 5125: //UNSIGNED_INT
	case 5126: //FLOAT
		for (v = 0; v < outverts; v++)
		{
			for (c = 0; c < 3; c++)
				os[v][c] = ((float*)in)[c];

			//bitangent = cross(normal, tangent.xyz) * tangent.w
			ot[v][0] = (norm[v][1]*os[v][2] - norm[v][2]*os[v][1]) * ((float*)in)[3];
			ot[v][1] = (norm[v][2]*os[v][0] - norm[v][0]*os[v][2]) * ((float*)in)[3];
			ot[v][2] = (norm[v][0]*os[v][1] - norm[v][1]*os[v][0]) * ((float*)in)[3];

			in += a->bytestride;
		}
		break;
	}
}
static void *GLTF_AccessorToDataF(gltf_t *gltf, size_t outverts, unsigned int outcomponents, struct gltf_accessor *a)
{
	float *ret = modfuncs->ZG_Malloc(&gltf->mod->memgroup, sizeof(*ret) * outcomponents * outverts), *o;
	char *in = a->data;

	int c, ic = a->type&0xff;
	if (ic > outcomponents)
		ic = outcomponents;
	o = ret;
	switch(a->componentType)
	{
	default:
		if (gltf->warnlimit --> 0)
			Con_Printf(CON_WARNING"GLTF_AccessorToDataF: %s: glTF2 unsupported componentType (%i)\n", gltf->mod->name, a->componentType);
	case 0:
		memset(ret, 0, sizeof(*ret) * outcomponents * outverts);
		break;
	case 5120:	//BYTE
		while(outverts --> 0)
		{
			for (c = 0; c < ic; c++)
				o[c] = max(-1.0, ((char*)in)[c] / 127.0);	//negative values are larger, but we want to allow 1.0
			for (; c < outcomponents; c++)
				o[c] = 0;
			o += outcomponents;
			in += a->bytestride;
		}
		break;
	case 5121:	//UNSIGNED_BYTE
		while(outverts --> 0)
		{
			for (c = 0; c < ic; c++)
				o[c] = ((unsigned char*)in)[c] / 255.0;
			for (; c < outcomponents; c++)
				o[c] = 0;
			o += outcomponents;
			in += a->bytestride;
		}
		break;
	case 5122: //SHORT
		while(outverts --> 0)
		{
			for (c = 0; c < ic; c++)
				o[c] = max(-1.0, ((signed short*)in)[c] / 32767.0);	//negative values are larger, but we want to allow 1.0
			for (; c < outcomponents; c++)
				o[c] = 0;
			o += outcomponents;
			in += a->bytestride;
		}
		break;
	case 5123: //UNSIGNED_SHORT
		while(outverts --> 0)
		{
			for (c = 0; c < ic; c++)
				o[c] = ((unsigned short*)in)[c] / 65535.0;
			for (; c < outcomponents; c++)
				o[c] = 0;
			o += outcomponents;
			in += a->bytestride;
		}
		break;
	case 5125: //UNSIGNED_INT
		while(outverts --> 0)
		{
			for (c = 0; c < ic; c++)
				o[c] = ((unsigned int*)in)[c] / (double)~0u;	//stupid format to use. will be lossy.
			for (; c < outcomponents; c++)
				o[c] = 0;
			o += outcomponents;
			in += a->bytestride;
		}
		break;
	case 5126: //FLOAT
		while(outverts --> 0)
		{
			for (c = 0; c < ic; c++)
				o[c] = ((float*)in)[c];
			for (; c < outcomponents; c++)
				o[c] = 0;
			o += outcomponents;
			in += a->bytestride;
		}
		break;
	}
	return ret;
}
static void *GLTF_AccessorToDataUB(gltf_t *gltf, size_t outverts, unsigned int outcomponents, struct gltf_accessor *a)
{	//only used for colour, with fallback to float, so only UNSIGNED_BYTE needs to work.
	unsigned char *ret = modfuncs->ZG_Malloc(&gltf->mod->memgroup, sizeof(*ret) * outcomponents * outverts), *o;
	char *in = a->data;

	int c, ic = a->type&0xff;
	if (ic > outcomponents)
		ic = outcomponents;
	o = ret;
	switch(a->componentType)
	{
	default:
		if (gltf->warnlimit --> 0)
			Con_Printf(CON_WARNING"GLTF_AccessorToDataUB: %s: glTF2 unsupported componentType (%i)\n", gltf->mod->name, a->componentType);
	case 0:
		memset(ret, 0, sizeof(*ret) * outcomponents * outverts);
		break;
//	case 5120:	//BYTE
	case 5121:	//UNSIGNED_BYTE
		while(outverts --> 0)
		{
			for (c = 0; c < ic; c++)
				o[c] = ((unsigned char*)in)[c];
			for (; c < outcomponents; c++)
				o[c] = 0;
			o += outcomponents;
			in += a->bytestride;
		}
		break;
//	case 5122: //SHORT
//	case 5123: //UNSIGNED_SHORT
//	case 5125: //UNSIGNED_INT
/*	case 5126: //FLOAT
		while(outverts --> 0)
		{
			for (c = 0; c < ic; c++)
				o[c] = ((float*)in)[c];
			for (; c < outcomponents; c++)
				o[c] = 0;
			o += outcomponents;
			in += a->bytestride;
		}
		break;*/
	}
	return ret;
}
static void *GLTF_AccessorToDataBone(gltf_t *gltf, size_t outverts, struct gltf_accessor *a)
{	//input should only be ubytes||ushorts.
	const unsigned int outcomponents = 4;
	boneidx_t *ret = modfuncs->ZG_Malloc(&gltf->mod->memgroup, sizeof(*ret) * outcomponents * outverts), *o;
	char *in = a->data;


	int c, ic = a->type&0xff;
	if (ic > outcomponents)
		ic = outcomponents;
	o = ret;
	switch(a->componentType)
	{
	default:
		if (gltf->warnlimit --> 0)
			Con_Printf(CON_WARNING"GLTF_AccessorToDataUB: %s: glTF2 unsupported componentType (%i)\n", gltf->mod->name, a->componentType);
	case 0:
		memset(ret, 0, sizeof(*ret) * outcomponents * outverts);
		break;
//	case 5120:	//BYTE
	case 5121:	//UNSIGNED_BYTE
		while(outverts --> 0)
		{
			unsigned char v;
			for (c = 0; c < ic; c++)
			{
				v = ((unsigned char*)in)[c];
				o[c] = gltf->bonemap[v];
			}
			for (; c < outcomponents; c++)
				o[c] = gltf->bonemap[0];
			o += outcomponents;
			in += a->bytestride;
		}
		break;
	case 5122: //SHORT
	case 5123: //UNSIGNED_SHORT
		while(outverts --> 0)
		{
			unsigned short v;
			for (c = 0; c < ic; c++)
			{
				v = ((unsigned short*)in)[c];
				if (v > MAX_BONES)
					v = 0;
				o[c] = gltf->bonemap[v];
			}
			for (; c < outcomponents; c++)
				o[c] = gltf->bonemap[0];
			o += outcomponents;
			in += a->bytestride;
		}
		break;
		//the spec doesn't require these.
//	case 5125: //UNSIGNED_INT
/*	case 5126: //FLOAT
		while(outverts --> 0)
		{
			for (c = 0; c < ic; c++)
				o[c] = ((float*)in)[c];
			for (; c < outcomponents; c++)
				o[c] = 0;
			o += outcomponents;
			in += a->bytestride;
		}
		break;*/
	}
	return ret;
}
void TransformArrayD(vecV_t *data, size_t vcount, double matrix[])
{
	while (vcount --> 0)
	{
		vec3_t t;
		VectorCopy((*data), t);
		(*data)[0] = DotProduct(t, (matrix+0)) + matrix[0+3];
		(*data)[1] = DotProduct(t, (matrix+4)) + matrix[4+3];
		(*data)[2] = DotProduct(t, (matrix+8)) + matrix[8+3];
		data++;
	}
}
void TransformArrayA(vec3_t *data, size_t vcount, double matrix[])
{
	vec3_t t;
	float mag;
	while (vcount --> 0)
	{
		t[0] = DotProduct((*data), (matrix+0));
		t[1] = DotProduct((*data), (matrix+4));
		t[2] = DotProduct((*data), (matrix+8));

		//scaling is bad for axis.
		mag = DotProduct(t,t);
		if (mag)
		{
			mag = 1/sqrt(mag);
			VectorScale(t, mag, t);
		}

		VectorCopy(t, (*data));
		data++;
	}
}
static texid_t GLTF_LoadImage(gltf_t *gltf, int imageidx, unsigned int flags)
{
	size_t size;
	texid_t ret = r_nulltex;
	json_t *image     = JSON_FindIndexedChild(gltf->r, "images", imageidx);
	json_t *uri        = JSON_FindChild(image, "uri");
	json_t *mimeType   = JSON_FindChild(image, "mimeType");
	int bufferView     = JSON_GetInteger(image, "bufferView", -1);
	char uritext[MAX_QPATH];
	char filename[MAX_QPATH];
	void *mem;
	struct gltf_bufferview view;

	//potentially valid mime types:
	//image/png
	//image/vnd-ms.dds (MSFT_texture_dds)
	(void)mimeType;

	*uritext = 0;
	if (uri)
	{
		mem = JSON_MallocDataURI(uri, &size);
		if (mem)
		{
			JSON_GetPath(image, false, uritext, sizeof(uritext));
			ret = modfuncs->GetTexture(uritext, NULL, flags, mem, NULL, size, 0, TF_INVALID);
			free(mem);
		}
		else
		{
			JSON_ReadBody(uri, uritext, sizeof(uritext));
			GLTF_RelativePath(gltf->mod->name, uritext, filename, sizeof(filename));
			ret = modfuncs->GetTexture(filename, NULL, flags, NULL, NULL, 0, 0, TF_INVALID);
		}
	}
	else if (bufferView >= 0)
	{
		if (GLTF_GetBufferViewData(gltf, bufferView, &view))
		{
			JSON_GetPath(image, false, uritext, sizeof(uritext));
			ret = modfuncs->GetTexture(uritext, NULL, flags, view.data, NULL, view.length, 0, TF_INVALID);
		}
	}

	return ret;
}
static texid_t GLTF_LoadTexture(gltf_t *gltf, int texture, unsigned int flags)
{
	json_t *tex = JSON_FindIndexedChild(gltf->r, "textures", texture);
	json_t *sampler = JSON_FindIndexedChild(gltf->r, "samplers", JSON_GetInteger(tex, "sampler", -1));

	int magFilter = JSON_GetInteger(sampler, "magFilter", 0);
	int minFilter = JSON_GetInteger(sampler, "minFilter", 0);
	int wrapS = JSON_GetInteger(sampler, "wrapS", 10497);
	int wrapT = JSON_GetInteger(sampler, "wrapT", 10497);
	int source;

	JSON_FlagAsUsed(sampler, "name");
	JSON_FlagAsUsed(sampler, "extensions");

	(void)minFilter;
	switch(magFilter)
	{
	default:
		break;
	case 9728: //NEAREST
		flags |= IF_NOMIPMAP|IF_NEAREST;
		break;
	case 9729: //LINEAR
		flags |= IF_NOMIPMAP|IF_LINEAR;
		break;
	case 9984: // NEAREST_MIPMAP_NEAREST
	case 9986: // NEAREST_MIPMAP_LINEAR
		flags |= IF_NEAREST;
		break;
	case 9985: // LINEAR_MIPMAP_NEAREST
	case 9987: // LINEAR_MIPMAP_LINEAR
		flags |= IF_LINEAR;
		break;
	}

	if (wrapS == 33071 || wrapT == 33071)
		flags |= IF_CLAMP;

	flags |= IF_NOREPLACE;

	source = JSON_GetInteger(tex, "source", -1);
	source = JSON_GetInteger(tex, "extensions.MSFT_texture_dds.source", source);	//load a dds instead, if one is available.
	return GLTF_LoadImage(gltf, source, flags);
}
static galiasskin_t *GLTF_LoadMaterial(gltf_t *gltf, int material, qboolean vertexcolours)
{
	qboolean doubleSided;
	int alphaMode;
	double alphaCutoff;
	char shader[8192];
	char alphaCutoffmodifier[128];
	json_t *mat = JSON_FindIndexedChild(gltf->r, "materials", material);
	galiasskin_t *ret;

	json_t *nam, *unlit, *pbrsg, *pbrmr, *blinn;

	nam = JSON_FindChild(mat, "name");
	unlit = JSON_FindChild(mat, "extensions.KHR_materials_unlit");
	pbrsg = JSON_FindChild(mat, "extensions.KHR_materials_pbrSpecularGlossiness");
	pbrmr = JSON_FindChild(mat, "pbrMetallicRoughness");
	blinn = JSON_FindChild(mat, "extensions.KHR_materials_cmnBlinnPhong");

	doubleSided = JSON_GetInteger(mat, "doubleSided", false);
	alphaCutoff = JSON_GetFloat(mat, "alphaCutoff", 0.5);
	if (JSON_Equals(mat, "alphaMode", "MASK"))
		alphaMode = 1;
	else if (JSON_Equals(mat, "alphaMode", "BLEND"))
		alphaMode = 2;
	else //if (JSON_Equals(mat, "alphaMode", "OPAQUE"))
		alphaMode = 0;

	ret = modfuncs->ZG_Malloc(&gltf->mod->memgroup, sizeof(*ret));
	ret->numframes = 1;
	ret->skinspeed = 0.1;
	ret->frame = modfuncs->ZG_Malloc(&gltf->mod->memgroup, sizeof(*ret->frame));

	if (nam)
		JSON_ReadBody(nam, ret->frame->shadername, sizeof(ret->frame->shadername));
	else if (mat)
		JSON_GetPath(mat, false, ret->frame->shadername, sizeof(ret->frame->shadername));
	else
		Q_snprintf(ret->frame->shadername, sizeof(ret->frame->shadername), "%i", material);

	if (alphaMode == 1)
		Q_snprintf(alphaCutoffmodifier, sizeof(alphaCutoffmodifier), "#ALPHATEST=>%f", alphaCutoff);
	else
		*alphaCutoffmodifier = 0;

	if (unlit)
	{	//if this extension was present, then we don't get ANY lighting info.
		int albedo = JSON_GetInteger(pbrmr, "baseColorTexture.index", -1);	//.rgba
		ret->frame->texnums.base     = GLTF_LoadTexture(gltf, albedo, 0);

		Q_snprintf(shader, sizeof(shader),
			"{\n"
				"surfaceparm nodlight\n"
				"%s"//cull
				"program default2d%s\n"	//fixme: there's no gpu skeletal stuff with this prog
				"{\n"
					"map $diffuse\n"
					"%s"	//blend
					"%s"	//rgbgen
				"}\n"
				"fte_basefactor %f %f %f %f\n"
			"}\n",
			doubleSided?"cull disable\n":"",
			alphaCutoffmodifier,
			(alphaMode==1)?"":(alphaMode==2)?"blendfunc blend\n":"",
			vertexcolours?"rgbgen vertex\nalphagen vertex\n":"",
			JSON_GetFloat(pbrmr, "baseColorFactor.0", 1),
				JSON_GetFloat(pbrmr, "baseColorFactor.1", 1),
				JSON_GetFloat(pbrmr, "baseColorFactor.2", 1),
				JSON_GetFloat(pbrmr, "baseColorFactor.3", 1)
			);
	}
	else if (blinn)
	{
		Con_DPrintf(CON_WARNING"%s: KHR_materials_cmnBlinnPhong implemented according to draft spec\n", gltf->mod->name);

		ret->frame->texnums.base     = GLTF_LoadTexture(gltf, JSON_GetInteger(pbrsg, "diffuseTexture.index", -1), 0);
		ret->frame->texnums.specular = GLTF_LoadTexture(gltf, JSON_GetInteger(pbrsg, "specularGlossinessTexture.index", -1), 0);

		//you wouldn't normally want this, but we have separate factors so lack of a texture is technically valid.
		if (!ret->frame->texnums.base)
			ret->frame->texnums.base = modfuncs->GetTexture("$whiteimage", NULL, IF_NOMIPMAP|IF_NOPICMIP|IF_NEAREST|IF_NOGAMMA, NULL, NULL, 0, 0, TF_INVALID);
		if (!ret->frame->texnums.specular)
			ret->frame->texnums.specular = modfuncs->GetTexture("$whiteimage", NULL, IF_NOMIPMAP|IF_NOPICMIP|IF_NEAREST|IF_NOGAMMA, NULL, NULL, 0, 0, TF_INVALID);

		Q_snprintf(shader, sizeof(shader),
			"{\n"
				"%s"//cull
				"program defaultskin#VC%s\n"
				"{\n"
					"map $diffuse\n"
					"%s"	//blend
					"%s"	//rgbgen
				"}\n"
				"fte_basefactor %f %f %f %f\n"
				"fte_specularfactor %f %f %f %f\n"
				"fte_fullbrightfactor %f %f %f 1.0\n"
			"}\n",
			doubleSided?"cull disable\n":"",
			alphaCutoffmodifier,
			(alphaMode==1)?"":(alphaMode==2)?"blendfunc blend\n":"",
			vertexcolours?"rgbgen vertex\nalphagen vertex\n":"",
			JSON_GetFloat(pbrsg, "diffuseFactor.0", 1),
				JSON_GetFloat(pbrsg, "diffuseFactor.1", 1),
				JSON_GetFloat(pbrsg, "diffuseFactor.2", 1),
				JSON_GetFloat(pbrsg, "diffuseFactor.3", 1),
			JSON_GetFloat(pbrsg, "specularFactor.0", 1),	//FIXME: divide by gl_specular
				JSON_GetFloat(pbrsg, "specularFactor.1", 1),
				JSON_GetFloat(pbrsg, "specularFactor.2", 1),
				JSON_GetFloat(pbrsg, "shininessFactor", 1),	//FIXME: divide by gl_specular_power
			JSON_GetFloat(mat, "emissiveFactor.0", 0),
				JSON_GetFloat(mat, "emissiveFactor.1", 0),
				JSON_GetFloat(mat, "emissiveFactor.2", 0)
			);
	}
	else if (pbrsg)
	{	//if this extension was used, then we can use rgb gloss instead of metalness stuff.
		ret->frame->texnums.base     = GLTF_LoadTexture(gltf, JSON_GetInteger(pbrsg, "diffuseTexture.index", -1), 0);
		ret->frame->texnums.specular = GLTF_LoadTexture(gltf, JSON_GetInteger(pbrsg, "specularGlossinessTexture.index", -1), 0);

		Q_snprintf(shader, sizeof(shader),
			"{\n"
				"%s"//cull
				"program defaultskin#SG#VC#NOOCCLUDE%s\n"
				"{\n"
					"map $diffuse\n"
					"%s"	//blend
					"%s"	//rgbgen
				"}\n"
				"fte_basefactor %f %f %f %f\n"
				"fte_specularfactor %f %f %f %f\n"
				"fte_fullbrightfactor %f %f %f 1.0\n"
				"bemode rtlight rtlight_sg\n"
			"}\n",
			doubleSided?"cull disable\n":"",
			alphaCutoffmodifier,
			(alphaMode==1)?"":(alphaMode==2)?"blendfunc blend\n":"",
			vertexcolours?"rgbgen vertex\nalphagen vertex\n":"",
			JSON_GetFloat(pbrsg, "diffuseFactor.0", 1),
				JSON_GetFloat(pbrsg, "diffuseFactor.1", 1),
				JSON_GetFloat(pbrsg, "diffuseFactor.2", 1),
				JSON_GetFloat(pbrsg, "diffuseFactor.3", 1),
			JSON_GetFloat(pbrsg, "specularFactor.0", 1),
				JSON_GetFloat(pbrsg, "specularFactor.1", 1),
				JSON_GetFloat(pbrsg, "specularFactor.2", 1),
			JSON_GetFloat(pbrsg, "glossinessFactor", 1)*32,	//this is fucked.
			JSON_GetFloat(mat, "emissiveFactor.0", 0),
				JSON_GetFloat(mat, "emissiveFactor.1", 0),
				JSON_GetFloat(mat, "emissiveFactor.2", 0)
			);
	}
	else if (pbrmr)
	{	//this is the standard lighting model for gltf2
		int albedo = JSON_GetInteger(pbrmr, "baseColorTexture.index", -1);	//.rgba
		int mrt = JSON_GetInteger(pbrmr, "metallicRoughnessTexture.index", -1);	//.r = unused, .g = roughness, .b = metalic, .a = unused
		int occ = JSON_GetInteger(mat, "occlusionTexture.index", -1);	//.r

		//now work around potential lame exporters (yay dds?).
		occ = JSON_GetInteger(mat, "extensions.MSFT_packing_occlusionRoughnessMetallic.occlusionRoughnessMetallicTexture.index", occ);
		mrt = JSON_GetInteger(mat, "extensions.MSFT_packing_occlusionRoughnessMetallic.occlusionRoughnessMetallicTexture.index", mrt);

		if (occ != mrt && occ != -1)	//if its -1 then the mrt should have an unused channel set to 1. however, this isn't guarenteed...
		{
			occ = -1;	//not supported. fixme: support some weird loadtexture channel merging stuff
			if (gltf->warnlimit --> 0)
				Con_Printf(CON_WARNING"%s: Separate occlusion and metallicRoughness textures are not supported\n", gltf->mod->name);
		}

		//note: extensions.MSFT_packing_normalRoughnessMetallic.normalRoughnessMetallicTexture.index gives rg=normalxy, b=roughness, .a=metalic
		//(would still need an ao map, and probably wouldn't work well as bc3 either)

		ret->frame->texnums.base     = GLTF_LoadTexture(gltf, albedo, 0);
		ret->frame->texnums.specular = GLTF_LoadTexture(gltf, mrt, IF_NOSRGB);

		Q_snprintf(shader, sizeof(shader),
			"{\n"
				"%s"//cull
				"program defaultskin#ORM#VC%s%s\n"
				"{\n"
					"map $diffuse\n"
					"%s"	//blend
					"%s"	//rgbgen
				"}\n"
				"fte_basefactor %f %f %f %f\n"
				"fte_specularfactor %f %f %f 1.0\n"
				"fte_fullbrightfactor %f %f %f 1.0\n"
				"bemode rtlight rtlight_orm\n"
			"}\n",
			doubleSided?"cull disable\n":"",
			(occ==-1)?"#NOOCCLUDE":"",
			alphaCutoffmodifier,
			(alphaMode==1)?"":(alphaMode==2)?"blendfunc blend\n":"",
			vertexcolours?"rgbgen vertex\nalphagen vertex\n":"",
			JSON_GetFloat(pbrmr, "baseColorFactor.0", 1),
				JSON_GetFloat(pbrmr, "baseColorFactor.1", 1),
				JSON_GetFloat(pbrmr, "baseColorFactor.2", 1),
				JSON_GetFloat(pbrmr, "baseColorFactor.3", 1),
			JSON_GetFloat(mat, "occlusionTexture.strength", 1),
				JSON_GetFloat(pbrmr, "metallicFactor", 1),
				JSON_GetFloat(pbrmr, "roughnessFactor", 1),
			JSON_GetFloat(mat, "emissiveFactor.0", 0),
				JSON_GetFloat(mat, "emissiveFactor.1", 0),
				JSON_GetFloat(mat, "emissiveFactor.2", 0)
			);
	}
	ret->frame->texnums.bump = GLTF_LoadTexture(gltf, JSON_GetInteger(mat, "normalTexture.index", -1), IF_NOSRGB|IF_TRYBUMP);
	ret->frame->texnums.fullbright = GLTF_LoadTexture(gltf, JSON_GetInteger(mat, "emissiveTexture.index", -1), 0);

	if (!ret->frame->texnums.base)
		ret->frame->texnums.base = modfuncs->GetTexture("$whiteimage", NULL, IF_NOMIPMAP|IF_NOPICMIP|IF_NEAREST|IF_NOGAMMA, NULL, NULL, 0, 0, TF_INVALID);

	ret->frame->defaultshader = memcpy(modfuncs->ZG_Malloc(&gltf->mod->memgroup, strlen(shader)+1), shader, strlen(shader)+1);

	Q_strlcpy(ret->name, ret->frame->shadername, sizeof(ret->name));
	return ret;
}
static qboolean GLTF_ProcessMesh(gltf_t *gltf, int meshidx, int basebone, double pmatrix[])
{
	model_t *mod = gltf->mod;
	json_t *mesh = JSON_FindIndexedChild(gltf->r, "meshes", meshidx);
	json_t *prim;
	json_t *meshname = JSON_FindChild(mesh, "name");

	JSON_WarnIfChild(mesh, "weights", &gltf->warnlimit);
	JSON_WarnIfChild(mesh, "extensions", &gltf->warnlimit);
//	JSON_WarnIfChild(mesh, "extras", &gltf->warnlimit);

	for(prim = JSON_FindIndexedChild(mesh, "primitives", 0); prim; prim = prim->sibling)
	{
		int mat  = JSON_GetInteger(prim, "material", -1);
		int mode  = JSON_GetInteger(prim, "mode", 4);
		json_t *attr = JSON_FindChild(prim, "attributes");
		struct gltf_accessor tc_0, tc_1, norm, tang, vpos, col0, idx, sidx, swgt;
		galiasinfo_t *surf;
		size_t i, j;

		prim->used = true;

		if (mode != 4)
		{
			Con_Printf("Primitive mode %i not supported\n", mode);
			continue;
		}

		JSON_WarnIfChild(prim, "targets", &gltf->warnlimit);	//morph targets...
		JSON_FindChild(prim, "extensions");
//		JSON_WarnIfChild(prim, "extensions", &gltf->warnlimit);
//		JSON_WarnIfChild(prim, "extras", &gltf->warnlimit);

		GLTF_GetAccessor(gltf, JSON_GetInteger(attr, "TEXCOORD_0",	-1), &tc_0);	//float, ubyte, ushort
		GLTF_GetAccessor(gltf, JSON_GetInteger(attr, "TEXCOORD_1",	-1), &tc_1);	//float, ubyte, ushort
		GLTF_GetAccessor(gltf, JSON_GetInteger(attr, "NORMAL",		-1), &norm);	//float
		GLTF_GetAccessor(gltf, JSON_GetInteger(attr, "TANGENT",		-1), &tang);	//float
		GLTF_GetAccessor(gltf, JSON_GetInteger(attr, "POSITION",	-1), &vpos);	//float
		GLTF_GetAccessor(gltf, JSON_GetInteger(attr, "COLOR_0",		-1), &col0);	//float, ubyte, ushort
		GLTF_GetAccessor(gltf, JSON_GetInteger(prim, "indices",		-1), &idx);
		GLTF_GetAccessor(gltf, JSON_GetInteger(attr, "JOINTS_0",	-1), &sidx);	//ubyte, ushort
		GLTF_GetAccessor(gltf, JSON_GetInteger(attr, "WEIGHTS_0",	-1), &swgt);	//float, ubyte, ushort

		if (JSON_GetInteger(attr, "JOINTS_1",	-1) != -1 || JSON_GetInteger(attr, "WEIGHTS_1",	-1) != -1)
			if (gltf->warnlimit --> 0)
				Con_Printf(CON_WARNING "%s: only 4 bones supported per vert\n", gltf->mod->name);	//in case a model tries supplying more. we ought to renormalise the weights in this case.

		if (!vpos.count)
			continue;

		surf = modfuncs->ZG_Malloc(&mod->memgroup, sizeof(*surf));

		surf->surfaceid = surf->contents = JSON_GetInteger(prim, "extras.fte.surfaceid", meshidx);
		surf->contents = JSON_GetInteger(prim, "extras.fte.contents", FTECONTENTS_BODY);
		surf->csurface.flags = JSON_GetInteger(prim, "extras.fte.surfaceflags", 0);
		surf->geomset = JSON_GetInteger(prim, "extras.fte.geomset", ~0u);
		surf->geomid = JSON_GetInteger(prim, "extras.fte.geomid", 0);
		surf->mindist = JSON_GetInteger(prim, "extras.fte.mindist", 0);
		surf->maxdist = JSON_GetInteger(prim, "extras.fte.maxdist", 0);

		surf->shares_bones = gltf->numsurfaces;
		surf->shares_verts = gltf->numsurfaces;
		JSON_ReadBody(meshname, surf->surfacename, sizeof(surf->surfacename));

		surf->numverts = vpos.count;
		if (idx.data)
		{
			surf->numindexes = idx.count;
			surf->ofs_indexes = modfuncs->ZG_Malloc(&mod->memgroup, sizeof(*surf->ofs_indexes) * idx.count);
			if (idx.componentType == 5123)
			{	//unsigned shorts
				for (i = 0; i < idx.count; i++)
					surf->ofs_indexes[i] = *(unsigned short *)((char*)idx.data + i*idx.bytestride);
			}
			else if (idx.componentType == 5121)
			{	//unsigned bytes
				for (i = 0; i < idx.count; i++)
					surf->ofs_indexes[i] = *(unsigned char *)((char*)idx.data + i*idx.bytestride);
			}
			else if (idx.componentType == 5125)
			{	//unsigned ints
				for (i = 0; i < idx.count; i++)
					surf->ofs_indexes[i] = *(unsigned int *)((char*)idx.data + i*idx.bytestride);	//FIXME: bounds check.
			}
			else
				continue;
		}
		else
		{
			surf->numindexes = surf->numverts;
			surf->ofs_indexes = modfuncs->ZG_Malloc(&mod->memgroup, sizeof(*surf->ofs_indexes) * surf->numverts);
			for (i = 0; i < surf->numverts; i++)
				surf->ofs_indexes[i] = i;
		}

		//swap winding order. we cull wrongly.
		for (i = 0; i < idx.count; i+=3)
		{
			index_t t = surf->ofs_indexes[i+0];
			surf->ofs_indexes[i+0] = surf->ofs_indexes[i+2];
			surf->ofs_indexes[i+2] = t;
		}

		surf->ofs_skel_xyz		= GLTF_AccessorToDataF(gltf, surf->numverts, countof(surf->ofs_skel_xyz[0]),		&vpos);
		surf->ofs_skel_norm		= GLTF_AccessorToDataF(gltf, surf->numverts, countof(surf->ofs_skel_norm[0]),	&norm);
		GLTF_AccessorToTangents(gltf, surf->ofs_skel_norm, &surf->ofs_skel_svect, &surf->ofs_skel_tvect, surf->numverts, &tang);
		surf->ofs_st_array		= GLTF_AccessorToDataF(gltf, surf->numverts, countof(surf->ofs_st_array[0]),		&tc_0);
		if (tc_1.data)
			surf->ofs_lmst_array	= GLTF_AccessorToDataF(gltf, surf->numverts, countof(surf->ofs_lmst_array[0]),	&tc_1);
		if (col0.data && col0.componentType == 5121)	//UNSIGNED_BYTE
			surf->ofs_rgbaub	= GLTF_AccessorToDataUB(gltf, surf->numverts, countof(surf->ofs_rgbaub[0]),		&col0);
		else if (col0.data)
			surf->ofs_rgbaf		= GLTF_AccessorToDataF(gltf, surf->numverts, countof(surf->ofs_rgbaf[0]),		&col0);
		if (sidx.data && swgt.data)
		{
			surf->ofs_skel_idx		= GLTF_AccessorToDataBone(gltf,surf->numverts, &sidx);
			surf->ofs_skel_weight	= GLTF_AccessorToDataF(gltf, surf->numverts, countof(surf->ofs_skel_weight[0]),	&swgt);

			for (i = 0; i < surf->numverts; i++)
			{
				float len = surf->ofs_skel_weight[i][0]+surf->ofs_skel_weight[i][1]+surf->ofs_skel_weight[i][2]+surf->ofs_skel_weight[i][3];
				if (len)
					Vector4Scale(surf->ofs_skel_weight[i], 1/len, surf->ofs_skel_weight[i]);
				else
					Vector4Set(surf->ofs_skel_weight[i], 0.5, 0.5, 0.5, 0.5);
			}
		}
		else
		{
			surf->ofs_skel_idx = modfuncs->ZG_Malloc(&gltf->mod->memgroup, sizeof(surf->ofs_skel_idx[0]) * surf->numverts);
			surf->ofs_skel_weight = modfuncs->ZG_Malloc(&gltf->mod->memgroup, sizeof(surf->ofs_skel_weight[0]) * surf->numverts);
			for (i = 0; i < surf->numverts; i++)
			{
				Vector4Set(surf->ofs_skel_idx[i], basebone, 0, 0, 0);
				Vector4Set(surf->ofs_skel_weight[i], 1, 0, 0, 0);
			}
		}

//		TransformArrayD(surf->ofs_skel_xyz, surf->numverts, pmatrix);
//		TransformArrayA(surf->ofs_skel_norm, surf->numverts, pmatrix);
//		TransformArrayA(surf->ofs_skel_svect, surf->numverts, pmatrix);

		for (i = 0; i < surf->numverts; i++)
		{
//			VectorScale(surf->ofs_skel_xyz[i], 32, surf->ofs_skel_xyz[i]);
			for (j = 0; j < 3; j++)
			{
				if (mod->maxs[j] < surf->ofs_skel_xyz[i][j])
					mod->maxs[j] = surf->ofs_skel_xyz[i][j];
				if (mod->mins[j] > surf->ofs_skel_xyz[i][j])
					mod->mins[j] = surf->ofs_skel_xyz[i][j];
			}
		}

		surf->numskins = 1;
		surf->ofsskins = GLTF_LoadMaterial(gltf, mat, surf->ofs_rgbaub||surf->ofs_rgbaf);

		if (!tang.data)
		{
			modfuncs->AccumulateTextureVectors(surf->ofs_skel_xyz, surf->ofs_st_array, surf->ofs_skel_norm, surf->ofs_skel_svect, surf->ofs_skel_tvect, surf->ofs_indexes, surf->numindexes, !norm.data);
			modfuncs->NormaliseTextureVectors(surf->ofs_skel_norm, surf->ofs_skel_svect, surf->ofs_skel_tvect, surf->numverts, !norm.data);
		}

		gltf->numsurfaces++;
		surf->nextsurf = mod->meshinfo;
		mod->meshinfo = surf;
	}
	return true;
}

static void Matrix4D_Multiply(const double *a, const double *b, double *out)
{
	out[0]  = a[0] * b[0] + a[4] * b[1] + a[8] * b[2] + a[12] * b[3];
	out[1]  = a[1] * b[0] + a[5] * b[1] + a[9] * b[2] + a[13] * b[3];
	out[2]  = a[2] * b[0] + a[6] * b[1] + a[10] * b[2] + a[14] * b[3];
	out[3]  = a[3] * b[0] + a[7] * b[1] + a[11] * b[2] + a[15] * b[3];

	out[4]  = a[0] * b[4] + a[4] * b[5] + a[8] * b[6] + a[12] * b[7];
	out[5]  = a[1] * b[4] + a[5] * b[5] + a[9] * b[6] + a[13] * b[7];
	out[6]  = a[2] * b[4] + a[6] * b[5] + a[10] * b[6] + a[14] * b[7];
	out[7]  = a[3] * b[4] + a[7] * b[5] + a[11] * b[6] + a[15] * b[7];

	out[8]  = a[0] * b[8] + a[4] * b[9] + a[8] * b[10] + a[12] * b[11];
	out[9]  = a[1] * b[8] + a[5] * b[9] + a[9] * b[10] + a[13] * b[11];
	out[10] = a[2] * b[8] + a[6] * b[9] + a[10] * b[10] + a[14] * b[11];
	out[11] = a[3] * b[8] + a[7] * b[9] + a[11] * b[10] + a[15] * b[11];

	out[12] = a[0] * b[12] + a[4] * b[13] + a[8] * b[14] + a[12] * b[15];
	out[13] = a[1] * b[12] + a[5] * b[13] + a[9] * b[14] + a[13] * b[15];
	out[14] = a[2] * b[12] + a[6] * b[13] + a[10] * b[14] + a[14] * b[15];
	out[15] = a[3] * b[12] + a[7] * b[13] + a[11] * b[14] + a[15] * b[15];
}

static void GenMatrixPosQuat4ScaleDouble(const double pos[3], const double quat[4], const double scale[3], double result[16])
{
	float xx, xy, xz, xw, yy, yz, yw, zz, zw;
	float x2, y2, z2;
	float s;
	x2 = quat[0] + quat[0];
	y2 = quat[1] + quat[1];
	z2 = quat[2] + quat[2];

	xx = quat[0] * x2;   xy = quat[0] * y2;   xz = quat[0] * z2;
	yy = quat[1] * y2;   yz = quat[1] * z2;   zz = quat[2] * z2;
	xw = quat[3] * x2;   yw = quat[3] * y2;   zw = quat[3] * z2;

	s = scale[0];
	result[0*4+0] = s*(1.0f - (yy + zz));
	result[1*4+0] = s*(xy + zw);
	result[2*4+0] = s*(xz - yw);
	result[3*4+0] = 0;

	s = scale[1];
	result[0*4+1] = s*(xy - zw);
	result[1*4+1] = s*(1.0f - (xx + zz));
	result[2*4+1] = s*(yz + xw);
	result[3*4+1] = 0;

	s = scale[2];
	result[0*4+2] = s*(xz + yw);
	result[1*4+2] = s*(yz - xw);
	result[2*4+2] = s*(1.0f - (xx + yy));
	result[3*4+2] = 0;

	result[0*4+3] = pos[0];
	result[1*4+3] = pos[1];
	result[2*4+3] = pos[2];
	result[3*4+3] = 1;
}

static qboolean GLTF_ProcessNode(gltf_t *gltf, int nodeidx, double pmatrix[16], int parentidx, qboolean isjoint)
{
	json_t *c;
	json_t *node;
	json_t *t;
	json_t *skin;
	int mesh;
	int skinidx;
	struct gltfbone_s *b;
	if (nodeidx < 0 || nodeidx >= gltf->numbones)
	{
		Con_Printf(CON_WARNING"%s: Invalid node index %i\n", gltf->mod->name, nodeidx);
		return false;
	}
	node = JSON_FindIndexedChild(gltf->r, "nodes", nodeidx);
	if (!node)
	{
		Con_Printf(CON_WARNING"%s: Invalid node index %i\n", gltf->mod->name, nodeidx);
		return false;
	}

	b = &gltf->bones[nodeidx];
	b->parent = parentidx;

	t = JSON_FindChild(node, "matrix");
	if (t)
	{
		b->rel.rmatrix[0*4+0] = JSON_GetIndexedFloat(t, 0, 1.0);
		b->rel.rmatrix[1*4+0] = JSON_GetIndexedFloat(t, 1, 0.0);
		b->rel.rmatrix[2*4+0] = JSON_GetIndexedFloat(t, 2, 0.0);
		b->rel.rmatrix[3*4+0] = JSON_GetIndexedFloat(t, 3, 0.0);
		b->rel.rmatrix[0*4+1] = JSON_GetIndexedFloat(t, 4, 0.0);
		b->rel.rmatrix[1*4+1] = JSON_GetIndexedFloat(t, 5, 1.0);
		b->rel.rmatrix[2*4+1] = JSON_GetIndexedFloat(t, 6, 0.0);
		b->rel.rmatrix[3*4+1] = JSON_GetIndexedFloat(t, 7, 0.0);
		b->rel.rmatrix[0*4+2] = JSON_GetIndexedFloat(t, 8, 0.0);
		b->rel.rmatrix[1*4+2] = JSON_GetIndexedFloat(t, 9, 0.0);
		b->rel.rmatrix[2*4+2] = JSON_GetIndexedFloat(t, 10,1.0);
		b->rel.rmatrix[3*4+2] = JSON_GetIndexedFloat(t, 11,0.0);
		b->rel.rmatrix[0*4+3] = JSON_GetIndexedFloat(t, 12,0.0);
		b->rel.rmatrix[1*4+3] = JSON_GetIndexedFloat(t, 13,0.0);
		b->rel.rmatrix[2*4+3] = JSON_GetIndexedFloat(t, 14,0.0);
		b->rel.rmatrix[3*4+3] = JSON_GetIndexedFloat(t, 15,1.0);

		Vector4Set(b->rel.quat, 0,0,0,1);
		VectorSet(b->rel.scale,1,1,1);
		VectorSet(b->rel.trans,0,0,0);
	}
	else
	{
		double rot[4];
		double scale[3];
		double trans[3];
		t = JSON_FindChild(node, "rotation");
		rot[0] = JSON_GetIndexedFloat(t, 0, 0.0);
		rot[1] = JSON_GetIndexedFloat(t, 1, 0.0);
		rot[2] = JSON_GetIndexedFloat(t, 2, 0.0);
		rot[3] = JSON_GetIndexedFloat(t, 3, 1.0);
		t = JSON_FindChild(node, "scale");
		scale[0] = JSON_GetIndexedFloat(t, 0, 1.0);
		scale[1] = JSON_GetIndexedFloat(t, 1, 1.0);
		scale[2] = JSON_GetIndexedFloat(t, 2, 1.0);
		t = JSON_FindChild(node, "translation");
		trans[0] = JSON_GetIndexedFloat(t, 0, 0.0);
		trans[1] = JSON_GetIndexedFloat(t, 1, 0.0);
		trans[2] = JSON_GetIndexedFloat(t, 2, 0.0);

		Vector4Copy(rot, b->rel.quat);
		VectorCopy(scale, b->rel.scale);
		VectorCopy(trans, b->rel.trans);

		//T * R * S
		GenMatrixPosQuat4ScaleDouble(trans, rot, scale, b->rel.rmatrix);
/*
		memset(mmatrix, 0, sizeof(mmatrix));
		mmatrix[0] = 1;
		mmatrix[5] = 1;
		(void)rot,(void)scale;
		mmatrix[10] = 1;
		mmatrix[15] = 1;
		mmatrix[3] = trans[0];
		mmatrix[7] = trans[1];
		mmatrix[11] = trans[2];
*/
	}
	Matrix4D_Multiply(b->rel.rmatrix, pmatrix, b->amatrix);

	skinidx = JSON_GetInteger(node, "skin", -1);
	if (skinidx >= 0)
	{
//		double identity[16];
		int j;
		json_t *joints;
		struct gltf_accessor inverse;
		float *inversef;

		skin = JSON_FindIndexedChild(gltf->r, "skins", skinidx);

		joints = JSON_FindChild(skin, "joints");
		GLTF_GetAccessor(gltf, JSON_GetInteger(skin, "inverseBindMatrices", -1), &inverse);
		inversef = inverse.data;
		if (inverse.componentType != 5126/*FLOAT*/ || inverse.type != ((4<<8) | 4)/*mat4x4*/)
			inverse.count = 0;
		for (j = 0; j < MAX_BONES; j++, inversef+=inverse.bytestride/sizeof(float))
		{
			int b = JSON_GetIndexedInteger(joints, j, -1);
			if (b < 0)
				break;
			gltf->bonemap[j] = b;
			if (j < inverse.count)
			{
				gltf->bones[b].inverse[0] = inversef[0*4+0];
				gltf->bones[b].inverse[1] = inversef[1*4+0];
				gltf->bones[b].inverse[2] = inversef[2*4+0];
				gltf->bones[b].inverse[3] = inversef[3*4+0];

				gltf->bones[b].inverse[4] = inversef[0*4+1];
				gltf->bones[b].inverse[5] = inversef[1*4+1];
				gltf->bones[b].inverse[6] = inversef[2*4+1];
				gltf->bones[b].inverse[7] = inversef[3*4+1];

				gltf->bones[b].inverse[8] = inversef[0*4+2];
				gltf->bones[b].inverse[9] = inversef[1*4+2];
				gltf->bones[b].inverse[10]= inversef[2*4+2];
				gltf->bones[b].inverse[11]= inversef[3*4+2];

				gltf->bones[b].inverse[12]= inversef[0*4+3];
				gltf->bones[b].inverse[13]= inversef[1*4+3];
				gltf->bones[b].inverse[14]= inversef[2*4+3];
				gltf->bones[b].inverse[15]= inversef[3*4+3];
			}
			else
			{
				gltf->bones[b].inverse[0] = 1;
				gltf->bones[b].inverse[1] = 0;
				gltf->bones[b].inverse[2] = 0;
				gltf->bones[b].inverse[3] = 0;

				gltf->bones[b].inverse[4] = 0;
				gltf->bones[b].inverse[5] = 1;
				gltf->bones[b].inverse[6] = 0;
				gltf->bones[b].inverse[7] = 0;

				gltf->bones[b].inverse[8] = 0;
				gltf->bones[b].inverse[9] = 0;
				gltf->bones[b].inverse[10]= 1;
				gltf->bones[b].inverse[11]= 0;

				gltf->bones[b].inverse[12]= 0;
				gltf->bones[b].inverse[13]= 0;
				gltf->bones[b].inverse[14]= 0;
				gltf->bones[b].inverse[15]= 1;
			}
		}

//		GLTF_ProcessNode(gltf, JSON_GetInteger(skin, "skeleton", -1), identity, nodeidx, true);

		JSON_FlagAsUsed(node, "name");
	}
	
	mesh = JSON_GetInteger(node, "mesh", -1);
	if (mesh >= 0)
		GLTF_ProcessMesh(gltf, mesh, nodeidx, b->amatrix);

	for(c = JSON_FindIndexedChild(node, "children", 0); c; c = c->sibling)
	{
		c->used = true;
		GLTF_ProcessNode(gltf, JSON_GetInteger(c, NULL, -1), b->amatrix, nodeidx, isjoint);
	}

	b->camera = JSON_GetInteger(node, "camera", -1);

	JSON_WarnIfChild(node, "weights", &gltf->warnlimit);	//default value for morph weight animations
	JSON_WarnIfChild(node, "extensions", &gltf->warnlimit);
//	JSON_WarnIfChild(node, "extras", &gltf->warnlimit);

	return true;
}

struct gltf_animsampler
{
	struct gltf_accessor input;
	struct gltf_accessor output;
};
static struct gltf_animsampler GLTF_AnimationSampler(gltf_t *gltf, json_t *samplers, int sampleridx, int elems)
{
	struct gltf_animsampler r;
	json_t *sampler = JSON_FindIndexedChild(samplers, NULL, sampleridx);

	GLTF_GetAccessor(gltf, JSON_GetInteger(sampler, "input", -1), &r.input);
	GLTF_GetAccessor(gltf, JSON_GetInteger(sampler, "output", -1), &r.output);

	if (!r.input.data || !r.output.data || r.input.count != r.output.count)
		memset(&r, 0, sizeof(r));
	return r;
}

static float Anim_GetTime(struct gltf_accessor *in, int index)
{
	//read the input sampler (to get timestamps)
	switch(in->componentType)
	{
	case 5120:	//BYTE
		return max(-1, (*(signed char*)((qbyte*)in->data + in->bytestride*index)) / 127.0);
	case 5121:	//UNSIGNED_BYTE
		return (*(unsigned char*)((qbyte*)in->data + in->bytestride*index)) / 255.0;
	case 5122: //SHORT
		return max(-1, (*(signed short*)((qbyte*)in->data + in->bytestride*index)) / 32767.0);
	case 5123: //UNSIGNED_SHORT
		return (*(unsigned short*)((qbyte*)in->data + in->bytestride*index)) / 65535.0;
	case 5125: //UNSIGNED_INT
		return (*(unsigned int*)((qbyte*)in->data + in->bytestride*index)) / (double)~0u;
	case 5126: //FLOAT
		return *(float*)((qbyte*)in->data + in->bytestride*index);
	default:
		Con_Printf("Unsupported input component type\n");
		return 0;
	}
}
static void Anim_GetVal(struct gltf_accessor *in, int index, float *result, int elems)
{
	//read the input sampler (to get timestamps)
	switch(in->componentType)
	{
	case 5120:	//BYTE
		while (elems --> 0)
			result[elems] = max(-1, ((signed char*)((qbyte*)in->data + in->bytestride*index))[elems] / 127.0);
		break;
	case 5121:	//UNSIGNED_BYTE
		while (elems --> 0)
			result[elems] = ((unsigned char*)((qbyte*)in->data + in->bytestride*index))[elems] / 255.0;
		break;
	case 5122: //SHORT
		while (elems --> 0)
			result[elems] = max(-1, ((signed short*)((qbyte*)in->data + in->bytestride*index))[elems] / 32767.0);
		break;
	case 5123: //UNSIGNED_SHORT
		while (elems --> 0)
			result[elems] = ((unsigned short*)((qbyte*)in->data + in->bytestride*index))[elems] / 65535.0;
		break;
	case 5125: //UNSIGNED_INT
		while (elems --> 0)
			result[elems] = ((unsigned int*)((qbyte*)in->data + in->bytestride*index))[elems] / (double)~0u;
		break;
	case 5126: //FLOAT
		while (elems --> 0)
			result[elems] = ((float*)((qbyte*)in->data + in->bytestride*index))[elems];
		break;
	default:
		Con_Printf("Unsupported output component type\n");
		break;
	}
}
static void LerpAnimData(gltf_t *gltf, struct gltf_animsampler *samp, float time, float *result, int elems)
{
	float t1, t2;
	float w1, w2;
	float v1[4], v2[4];
	int f1 = 0, f2, c;

	struct gltf_accessor *in = &samp->input;
	struct gltf_accessor *out = &samp->output;

	t1 = t2 = Anim_GetTime(in, f1);
	for (f2 = 1; f2 < in->count; f2++)
	{
		t2 = Anim_GetTime(in, f2);
		if (t2 > time)
			break;	//now have before and after
		t1 = t2;
		f1 = f2;
	}

	if (time <= t1)
	{	//if before the first time, clamp it.
		w1 = 1;
		w2 = 0;
	}
	else if (time >= t2)
	{	//if after tha last frame we could find, clamp it to the last.
		w1 = 0;
		w2 = 1;
	}
	else
	{	//assume linear
		w2 = (time-t1)/(t2-t1);
//		if (1)	//step it. it'll still get lerped though. :(
//			w2 = (w2>0.5)?1:0;
		w1 = 1-w2;
	}

	if (w1 >= 1)
		Anim_GetVal(out, f1, result, elems);
	else if (w2 >= 1)
		Anim_GetVal(out, f2, result, elems);
	else
	{
		Anim_GetVal(out, f1, v1, elems);
		Anim_GetVal(out, f2, v2, elems);
		for (c = 0; c < elems; c++)
			result[c] = v1[c]*w1 + w2*v2[c];
	}
}

static void GLTF_RemapBone(gltf_t *gltf, int *nextidx, int b)
{	//potentially needs to walk to the root before the child. recursion sucks.
	if (gltf->bonemap[b] >= 0)
		return;	//already got remapped
	GLTF_RemapBone(gltf, nextidx, gltf->bones[b].parent);
	gltf->bonemap[b] = (*nextidx)++;
}
static void GLTF_RewriteBoneTree(gltf_t *gltf)
{
	galiasinfo_t *surf;
	int j, n;
	struct gltfbone_s *tmpbones;

	for (j = 0; j < gltf->numbones; j++)
	{
		if (gltf->bones[j].parent >= j)
			break;
	}
	if (j == gltf->numbones)
	{
		for (j = 0; j < gltf->numbones; j++)
			gltf->bonemap[j] = j;
		return;	//all are ordered okay
	}

	for (j = 0; j < gltf->numbones; j++)
		gltf->bonemap[j] = -1;
	for (     ; j < MAX_BONES; j++)
		gltf->bonemap[j] = 0;
	n = 0;
	for (j = 0; j < gltf->numbones; j++)
		GLTF_RemapBone(gltf, &n, j);

	tmpbones = malloc(sizeof(*tmpbones)*gltf->numbones);
	memcpy(tmpbones, gltf->bones, sizeof(*tmpbones)*gltf->numbones);
	for (j = 0; j < gltf->numbones; j++)
		gltf->bones[gltf->bonemap[j]] = tmpbones[j];
	for (j = 0; j < gltf->numbones; j++)
		if (gltf->bones[j].parent >= 0)
			gltf->bones[j].parent = gltf->bonemap[gltf->bones[j].parent];

	for(surf = gltf->mod->meshinfo; surf; surf = surf->nextsurf)
	{
		for (j = 0; j < surf->numverts; j++)
			for (n = 0; n < countof(surf->ofs_skel_idx[j]); n++)
				surf->ofs_skel_idx[j][n] = gltf->bonemap[surf->ofs_skel_idx[j][n]];
	}
}

//okay, so gltf is some weird scene thing.
//mostly there should be some default scene, so we'll just use that.
//we do NOT supported nested nodes right now...
static qboolean GLTF_LoadModel(struct model_s *mod, char *json, size_t jsonsize, void *buffer, size_t buffersize)
{
	static struct
	{
		const char *name;
		qboolean supported;	//unsupported extensions don't really need to be listed, but they do prevent warnings from unkown-but-used extensions
	} extensions[] =
	{
		{"KHR_materials_pbrSpecularGlossiness",		true},
//draft	{"KHR_materials_cmnBlinnPhong",				true},
		{"KHR_materials_unlit",						true},
		{"KHR_texture_transform",					false},
		{"KHR_draco_mesh_compression",				false},
		{"MSFT_texture_dds",						true},
		{"MSFT_packing_occlusionRoughnessMetallic", true},
	};
	gltf_t gltf;
	int pos=0, j, k;
	json_t *scene, *n, *anim;
	double rootmatrix[16];
	double gltfver;
	galiasinfo_t *surf;
	galiasbone_t *bone;
	galiasanimation_t *framegroups = NULL;
	unsigned int numframegroups = 0;
	float *baseframe;
	memset(&gltf, 0, sizeof(gltf));
	gltf.bonemap = malloc(sizeof(*gltf.bonemap)*MAX_BONES);
	gltf.bones = malloc(sizeof(*gltf.bones)*MAX_BONES);
	memset(gltf.bones, 0, sizeof(*gltf.bones)*MAX_BONES);
	gltf.r = JSON_Parse(NULL, mod->name, NULL, json, &pos, jsonsize);
	gltf.mod = mod;
	gltf.buffers[0].data = buffer;
	gltf.buffers[0].length = buffersize;
	gltf.warnlimit = 5;

	//asset.version must exist, supposedly. so default to something b0rked
	gltfver = JSON_GetFloat(gltf.r, "asset.minVersion", 0.0);
	if (gltfver != 2.0)
		gltfver = JSON_GetFloat(gltf.r, "asset.version", 0.0);
	if (gltfver == 2.0)
	{
		JSON_FlagAsUsed(gltf.r, "asset.copyright");
		JSON_FlagAsUsed(gltf.r, "asset.generator");
		JSON_WarnIfChild(gltf.r, "asset.minVersion", &gltf.warnlimit);
		JSON_WarnIfChild(gltf.r, "asset.extensions", &gltf.warnlimit);

		for(n = JSON_FindIndexedChild(gltf.r, "extensionsRequired", 0); n; n = n->sibling)
		{
			char extname[256];
			JSON_ReadBody(n, extname, sizeof(extname));
			for (j = 0; j < countof(extensions); j++)
			{
				if (!strcmp(extname, extensions[j].name))
					break;
			}
			if (j==countof(extensions) || !extensions[j].supported)
				Con_Printf(CON_ERROR "%s: Required gltf2 extension \"%s\" not supported\n", mod->name, extname);

			goto abort;
		}

		for(n = JSON_FindIndexedChild(gltf.r, "extensionsUsed", 0); n; n = n->sibling)
		{	//must be a superset of the above.
			char extname[256];
			JSON_ReadBody(n, extname, sizeof(extname));
			for (j = 0; j < countof(extensions); j++)
			{
				if (!strcmp(extname, extensions[j].name))
					break;
			}
			if (j==countof(extensions) || !extensions[j].supported)
				Con_Printf(CON_WARNING "%s: gltf2 extension \"%s\" not known\n", mod->name, extname);
		}

		VectorClear(mod->maxs);
		VectorClear(mod->mins);

		//we don't really care about cameras.
		JSON_FlagAsUsed(gltf.r, "cameras");

		scene = JSON_FindIndexedChild(gltf.r, "scenes", JSON_GetInteger(gltf.r, "scene", 0));

		memset(&rootmatrix, 0, sizeof(rootmatrix));
#if 1	//transform from gltf to quake. mostly only needed for the base pose.
		rootmatrix[2] = rootmatrix[4] = rootmatrix[9] = GLTFSCALE; rootmatrix[15] = 1;
#else
		rootmatrix[0] = rootmatrix[5] = rootmatrix[10] = 1; rootmatrix[15] = 1;
#endif

		for (j = 0; ; j++)
		{
			n = JSON_FindIndexedChild(gltf.r, "nodes", j);
			if (!n)
				break;
			if (j == MAX_BONES)
			{
				Con_Printf(CON_WARNING"%s: too many nodes (max %i)\n", mod->name, MAX_BONES);
				break;
			}
			if (!JSON_ReadBody(JSON_FindChild(n, "name"), gltf.bones[j].name, sizeof(gltf.bones[j].name)))
			{
				if (n)
					JSON_GetPath(n, true, gltf.bones[j].name, sizeof(gltf.bones[j].name));
				else
					Q_snprintf(gltf.bones[j].name, sizeof(gltf.bones[j].name), "bone%i", j);
			}
			gltf.bones[j].camera = -1;
			gltf.bones[j].parent = -1;
			gltf.bones[j].amatrix[0] = gltf.bones[j].amatrix[5] = gltf.bones[j].amatrix[10] = gltf.bones[j].amatrix[15] = 1;
			gltf.bones[j].inverse[0] = gltf.bones[j].inverse[5] = gltf.bones[j].inverse[10] = gltf.bones[j].inverse[15] = 1;
			gltf.bones[j].rel.rmatrix[0] = gltf.bones[j].rel.rmatrix[5] = gltf.bones[j].rel.rmatrix[10] = gltf.bones[j].rel.rmatrix[15] = 1;
		}
		gltf.numbones = j;

		JSON_FlagAsUsed(scene, "name");
		JSON_WarnIfChild(scene, "extensions", &gltf.warnlimit);
//		JSON_WarnIfChild(scene, "extras");
		for (j = 0; ; j++)
		{
			n = JSON_FindIndexedChild(scene, "nodes", j);
			if (!n)
				break;
			n->used = true;
//			if (!
			GLTF_ProcessNode(&gltf, JSON_GetInteger(n, NULL, -1), rootmatrix, -1, false);
//				break;
		}

		GLTF_RewriteBoneTree(&gltf);

		bone = modfuncs->ZG_Malloc(&mod->memgroup, sizeof(*bone)*gltf.numbones);
		baseframe = modfuncs->ZG_Malloc(&mod->memgroup, sizeof(float)*12*gltf.numbones);
		for (j = 0; j < gltf.numbones; j++)
		{
			Q_strlcpy(bone[j].name, gltf.bones[j].name, sizeof(bone[j].name));
			bone[j].parent = gltf.bones[j].parent;

			if (gltf.bones[j].camera >= 0 && !mod->camerabone)
				mod->camerabone = j+1;

			for(k = 0; k < 12; k++)
			{
				baseframe[j*12+k] = gltf.bones[j].amatrix[k];
				bone[j].inverse[k] = gltf.bones[j].inverse[k];
			}
		}

		for(anim = JSON_FindIndexedChild(gltf.r, "animations", 0); anim; anim = anim->sibling)
			numframegroups++;
		if (numframegroups)
		{
			struct
			{
				struct gltf_animsampler rot,scale,trans;
			} *b = malloc(sizeof(*b)*gltf.numbones);
			framegroups = modfuncs->ZG_Malloc(&mod->memgroup, sizeof(*framegroups)*numframegroups);
			for (k = 0; k < numframegroups; k++)
			{
				galiasanimation_t *fg = &framegroups[k];
				json_t *anim = JSON_FindIndexedChild(gltf.r, "animations", k);
				json_t *chan;
				json_t *samps = JSON_FindChild(anim, "samplers");
				int f, l;
				float maxtime = 0;
				memset(b, 0, sizeof(*b)*gltf.numbones);

				if (!JSON_ReadBody(JSON_FindChild(anim, "name"), fg->name, sizeof(fg->name)))
				{
					if (anim)
						JSON_GetPath(anim, true, fg->name, sizeof(fg->name));
					else
						Q_snprintf(fg->name, sizeof(fg->name), "anim%i", k);
				}
				fg->loop = true;
				fg->skeltype = SKEL_RELATIVE;
				for(chan = JSON_FindIndexedChild(anim, "channels", 0); chan; chan = chan->sibling)
				{
					struct gltf_animsampler s;
					json_t *targ = JSON_FindChild(chan, "target");
					int sampler = JSON_GetInteger(chan, "sampler", -1);
					int bone = JSON_GetInteger(targ, "node", -2);
					json_t *path = JSON_FindChild(targ, "path");
					if (bone == -2)
						continue;	//'When node isn't defined, channel should be ignored'
					if (bone < 0 || bone >= gltf.numbones)
					{
						if (gltf.warnlimit --> 0)
							Con_Printf("%s: invalid node index %i\n", mod->name, bone);
						continue;	//error...
					}
					bone = gltf.bonemap[bone];
					s = GLTF_AnimationSampler(&gltf, samps, sampler, 4);
					maxtime = max(maxtime, s.input.maxs[0]);
					if (JSON_Equals(path, NULL, "rotation"))
						b[bone].rot = s;
					else if (JSON_Equals(path, NULL, "scale"))
						b[bone].scale = s;
					else if (JSON_Equals(path, NULL, "translation"))
						b[bone].trans = s;
					else if (gltf.warnlimit --> 0)
					{	//these are unsupported
						if (JSON_Equals(path, NULL, "weights"))	//morph weights
							Con_Printf(CON_WARNING"%s: morph animations are not supported\n", mod->name);
						else
							Con_Printf("%s: undocumented animation type\n", mod->name);
					}
				}

				//TODO: make a guess at the framerate according to sampler intervals
				fg->rate = 60;
				fg->numposes = max(1, maxtime*fg->rate);
				if (maxtime)
					fg->rate = fg->numposes/maxtime;	//fix up the rate so we hit the exact end of the animation (so it doesn't have to be quite so exact).

				fg->skeltype = SKEL_RELATIVE;
				fg->boneofs = modfuncs->ZG_Malloc(&mod->memgroup, sizeof(*fg->boneofs)*12*gltf.numbones*fg->numposes);

				for (f = 0; f < fg->numposes; f++)
				{
					float *bonematrix = &fg->boneofs[f*gltf.numbones*12];
					float time = f/fg->rate;
					for (j = 0; j < gltf.numbones; j++, bonematrix+=12)
					{
						float scale[3];
						float rot[4];
						float trans[3];
						//eww, weird inheritance crap.
						if (b[j].rot.input.data || b[j].scale.input.data || b[j].trans.input.data)
						{
							VectorCopy(gltf.bones[j].rel.scale, scale);
							Vector4Copy(gltf.bones[j].rel.quat, rot);
							VectorCopy(gltf.bones[j].rel.trans, trans);

							if (b[j].rot.input.data)
								LerpAnimData(&gltf, &b[j].rot, time, rot, 4);
							if (b[j].scale.input.data)
								LerpAnimData(&gltf, &b[j].scale, time, scale, 3);
							if (b[j].trans.input.data)
								LerpAnimData(&gltf, &b[j].trans, time, trans, 3);
							//figure out the bone matrix...
							modfuncs->GenMatrixPosQuat4Scale(trans, rot, scale, bonematrix);
						}
						else
						{	//nothing animated, use what we calculated earlier.
							for (l = 0; l < 12; l++)
								bonematrix[l] = gltf.bones[j].rel.rmatrix[l];
						}
						if (gltf.bones[j].parent < 0)
						{	//rotate any root bones from gltf to quake's orientation.
							float fnar[12];
							static float toquake[12]={0,0,GLTFSCALE,0,GLTFSCALE,0,0,0,0,GLTFSCALE,0,0};
							memcpy(fnar, bonematrix, sizeof(fnar));
							modfuncs->ConcatTransforms((void*)toquake, (void*)fnar, (void*)bonematrix);
						}
					}
				}
			}
			free(b);
		}

		for(surf = mod->meshinfo; surf; surf = surf->nextsurf)
		{
			surf->shares_bones = 0;
			surf->numbones = gltf.numbones;
			surf->ofsbones = bone;
			surf->baseframeofs = baseframe;
			surf->ofsanimations = framegroups;
			surf->numanimations = numframegroups;
			surf->contents = FTECONTENTS_BODY;
			surf->csurface.flags = 0;
			surf->geomset = ~0;	//invalid set = always visible. FIXME: set this according to scene numbers?
			surf->geomid = 0;
		}
		VectorScale(mod->mins, GLTFSCALE, mod->mins);
		VectorScale(mod->maxs, GLTFSCALE, mod->maxs);

		if (!mod->meshinfo)
			Con_Printf("%s: Doesn't contain any meshes...\n", mod->name);
		JSON_WarnUnused(gltf.r, &gltf.warnlimit);
	}
	else
		Con_Printf("%s: unsupported gltf version (%.2f)\n", mod->name, gltfver);
abort:
	JSON_Destroy(gltf.r);
	free(gltf.bones);
	free(gltf.bonemap);


	mod->type = mod_alias;
	return !!mod->meshinfo;
}
qboolean QDECL Mod_LoadGLTFModel (struct model_s *mod, void *buffer, size_t fsize)
{
	//just straight json.
	return GLTF_LoadModel(mod, buffer, fsize, NULL, 0);
}
//glb files are some binary header, a lump with json data, and optionally a lump with binary data
qboolean QDECL Mod_LoadGLBModel (struct model_s *mod, void *buffer, size_t fsize)
{
	unsigned char *header = buffer;
	unsigned int magic = header[0]|(header[1]<<8)|(header[2]<<16)|(header[3]<<24);
	unsigned int version = header[4]|(header[5]<<8)|(header[6]<<16)|(header[7]<<24);
	unsigned int length = header[8]|(header[9]<<8)|(header[10]<<16)|(header[11]<<24);

	unsigned int jsonlen = header[12]|(header[13]<<8)|(header[14]<<16)|(header[15]<<24);
	unsigned int jsontype = header[16]|(header[17]<<8)|(header[18]<<16)|(header[19]<<24);
	char *json = (char*)(header+20);

	unsigned int binlen = header[20+jsonlen]|(header[21+jsonlen]<<8)|(header[22+jsonlen]<<16)|(header[23+jsonlen]<<24);
	unsigned int bintype = header[24+jsonlen]|(header[25+jsonlen]<<8)|(header[26+jsonlen]<<16)|(header[27+jsonlen]<<24);
	unsigned char *bin = header+28+jsonlen;

	if (fsize < 28)
		return false;
	if (magic != (('F'<<24)+('T'<<16)+('l'<<8)+'g'))
		return false;
	if (version != 2)
		return false;
	if (jsontype != 0x4E4F534A)	//'JSON'
		return false;
	if (length != 28+jsonlen+binlen)
		return false;
	if (bintype != 0x004E4942)	//'BIN\0'
		return false;
	
	return GLTF_LoadModel(mod, json, jsonlen, bin, binlen);
}
#endif