/*
* GLM library. Wavefront .obj file format reader/writer/manipulator.
*
* Written by Nate Robins, 1997.
* email: ndr@pobox.com
* www: http://www.pobox.com/~ndr
*/
/* includes */
#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include "glm.h"
#include "readtex.h"
typedef unsigned char boolean;
#define TRUE 1
#define FALSE 0
/* Some <math.h> files do not define M_PI... */
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
/* defines */
#define T(x) model->triangles[(x)]
/* enums */
enum { X, Y, Z, W }; /* elements of a vertex */
/* typedefs */
/* _GLMnode: general purpose node
*/
typedef struct _GLMnode {
uint index;
boolean averaged;
struct _GLMnode* next;
} GLMnode;
/* strdup is actually not a standard ANSI C or POSIX routine
so implement a private one. OpenVMS does not have a strdup; Linux's
standard libc doesn't declare strdup by default (unless BSD or SVID
interfaces are requested). */
static char *
stralloc(const char *string)
{
char *copy;
copy = malloc(strlen(string) + 1);
if (copy == NULL)
return NULL;
strcpy(copy, string);
return copy;
}
/* private functions */
/* _glmMax: returns the maximum of two floats */
static float
_glmMax(float a, float b)
{
if (a > b)
return a;
return b;
}
/* _glmAbs: returns the absolute value of a float */
static float
_glmAbs(float f)
{
if (f < 0)
return -f;
return f;
}
/* _glmDot: compute the dot product of two vectors
*
* u - array of 3 floats (float u[3])
* v - array of 3 floats (float v[3])
*/
static float
_glmDot(float* u, float* v)
{
assert(u);
assert(v);
/* compute the dot product */
return u[X] * v[X] + u[Y] * v[Y] + u[Z] * v[Z];
}
/* _glmCross: compute the cross product of two vectors
*
* u - array of 3 floats (float u[3])
* v - array of 3 floats (float v[3])
* n - array of 3 floats (float n[3]) to return the cross product in
*/
static void
_glmCross(float* u, float* v, float* n)
{
assert(u);
assert(v);
assert(n);
/* compute the cross product (u x v for right-handed [ccw]) */
n[X] = u[Y] * v[Z] - u[Z] * v[Y];
n[Y] = u[Z] * v[X] - u[X] * v[Z];
n[Z] = u[X] * v[Y] - u[Y] * v[X];
}
/* _glmNormalize: normalize a vector
*
* n - array of 3 floats (float n[3]) to be normalized
*/
static void
_glmNormalize(float* n)
{
float l;
assert(n);
/* normalize */
l = (float)sqrt(n[X] * n[X] + n[Y] * n[Y] + n[Z] * n[Z]);
n[0] /= l;
n[1] /= l;
n[2] /= l;
}
/* _glmEqual: compares two vectors and returns TRUE if they are
* equal (within a certain threshold) or FALSE if not. An epsilon
* that works fairly well is 0.000001.
*
* u - array of 3 floats (float u[3])
* v - array of 3 floats (float v[3])
*/
static boolean
_glmEqual(float* u, float* v, float epsilon)
{
if (_glmAbs(u[0] - v[0]) < epsilon &&
_glmAbs(u[1] - v[1]) < epsilon &&
_glmAbs(u[2] - v[2]) < epsilon)
{
return TRUE;
}
return FALSE;
}
/* _glmWeldVectors: eliminate (weld) vectors that are within an
* epsilon of each other.
*
* vectors - array of float[3]'s to be welded
* numvectors - number of float[3]'s in vectors
* epsilon - maximum difference between vectors
*
*/
static float*
_glmWeldVectors(float* vectors, uint* numvectors, float epsilon)
{
float* copies;
uint copied;
uint i, j;
copies = (float*)malloc(sizeof(float) * 3 * (*numvectors + 1));
memcpy(copies, vectors, (sizeof(float) * 3 * (*numvectors + 1)));
copied = 1;
for (i = 1; i <= *numvectors; i++) {
for (j = 1; j <= copied; j++) {
if (_glmEqual(&vectors[3 * i], &copies[3 * j], epsilon)) {
goto duplicate;
}
}
/* must not be any duplicates -- add to the copies array */
copies[3 * copied + 0] = vectors[3 * i + 0];
copies[3 * copied + 1] = vectors[3 * i + 1];
copies[3 * copied + 2] = vectors[3 * i + 2];
j = copied; /* pass this along for below */
copied++;
duplicate:
/* set the first component of this vector to point at the correct
index into the new copies array */
vectors[3 * i + 0] = (float)j;
}
*numvectors = copied-1;
return copies;
}
/* _glmFindGroup: Find a group in the model
*/
static GLMgroup*
_glmFindGroup(GLMmodel* model, char* name)
{
GLMgroup* group;
assert(model);
group = model->groups;
while(group) {
if (!strcmp(name, group->name))
break;
group = group->next;
}
return group;
}
/* _glmAddGroup: Add a group to the model
*/
static GLMgroup*
_glmAddGroup(GLMmodel* model, char* name)
{
GLMgroup* group;
group = _glmFindGroup(model, name);
if (!group) {
group = (GLMgroup*)malloc(sizeof(GLMgroup));
group->name = stralloc(name);
group->material = 0;
group->numtriangles = 0;
group->triangles = NULL;
group->next = model->groups;
model->groups = group;
model->numgroups++;
}
return group;
}
/* _glmFindGroup: Find a material in the model
*/
static uint
_glmFindMaterial(GLMmodel* model, char* name)
{
uint i;
for (i = 0; i < model->nummaterials; i++) {
if (!strcmp(model->materials[i].name, name))
goto found;
}
/* didn't find the name, so set it as the default material */
printf("_glmFindMaterial(): can't find material \"%s\".\n", name);
i = 0;
found:
return i;
}
/* _glmDirName: return the directory given a path
*
* path - filesystem path
*
* The return value should be free'd.
*/
static char*
_glmDirName(char* path)
{
char* dir;
char* s;
dir = stralloc(path);
s = strrchr(dir, '/');
if (s)
s[1] = '\0';
else
dir[0] = '\0';
return dir;
}
/* _glmReadMTL: read a wavefront material library file
*
* model - properly initialized GLMmodel structure
* name - name of the material library
*/
static void
_glmReadMTL(GLMmodel* model, char* name)
{
FILE* file;
char* dir;
char* filename;
char buf[128], buf2[128];
uint nummaterials, i;
GLMmaterial *mat;
dir = _glmDirName(model->pathname);
filename = (char*)malloc(sizeof(char) * (strlen(dir) + strlen(name) + 1));
strcpy(filename, dir);
strcat(filename, name);
free(dir);
/* open the file */
file = fopen(filename, "r");
if (!file) {
fprintf(stderr, "_glmReadMTL() failed: can't open material file \"%s\".\n",
filename);
exit(1);
}
free(filename);
/* count the number of materials in the file */
nummaterials = 1;
while(fscanf(file, "%s", buf) != EOF) {
switch(buf[0]) {
case '#': /* comment */
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
break;
case 'n': /* newmtl */
fgets(buf, sizeof(buf), file);
nummaterials++;
sscanf(buf, "%s %s", buf, buf);
break;
default:
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
break;
}
}
rewind(file);
/* allocate memory for the materials */
model->materials = (GLMmaterial*)calloc(nummaterials, sizeof(GLMmaterial));
model->nummaterials = nummaterials;
/* set the default material */
for (i = 0; i < nummaterials; i++) {
model->materials[i].name = NULL;
model->materials[i].shininess = 0;
model->materials[i].diffuse[0] = 0.8;
model->materials[i].diffuse[1] = 0.8;
model->materials[i].diffuse[2] = 0.8;
model->materials[i].diffuse[3] = 1.0;
model->materials[i].ambient[0] = 0.2;
model->materials[i].ambient[1] = 0.2;
model->materials[i].ambient[2] = 0.2;
model->materials[i].ambient[3] = 0.0;
model->materials[i].specular[0] = 0.0;
model->materials[i].specular[1] = 0.0;
model->materials[i].specular[2] = 0.0;
model->materials[i].specular[3] = 0.0;
}
model->materials[0].name = stralloc("default");
/* now, read in the data */
nummaterials = 0;
mat = &model->materials[nummaterials];
while(fscanf(file, "%s", buf) != EOF) {
switch(buf[0]) {
case '#': /* comment */
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
break;
case 'n': /* newmtl */
fgets(buf, sizeof(buf), file);
sscanf(buf, "%s %s", buf, buf);
nummaterials++;
model->materials[nummaterials].name = stralloc(buf);
break;
case 'N':
fscanf(file, "%f", &model->materials[nummaterials].shininess);
/* wavefront shininess is from [0, 1000], so scale for OpenGL */
model->materials[nummaterials].shininess /= 1000.0;
model->materials[nummaterials].shininess *= 128.0;
mat = &model->materials[nummaterials];
break;
case 'K':
switch(buf[1]) {
case 'd':
fscanf(file, "%f %f %f",
&model->materials[nummaterials].diffuse[0],
&model->materials[nummaterials].diffuse[1],
&model->materials[nummaterials].diffuse[2]);
break;
case 's':
fscanf(file, "%f %f %f",
&model->materials[nummaterials].specular[0],
&model->materials[nummaterials].specular[1],
&model->materials[nummaterials].specular[2]);
break;
case 'a':
fscanf(file, "%f %f %f",
&model->materials[nummaterials].ambient[0],
&model->materials[nummaterials].ambient[1],
&model->materials[nummaterials].ambient[2]);
break;
default:
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
break;
}
break;
case 'd': /* alpha? */
fscanf(file, "%f",
&model->materials[nummaterials].diffuse[3]);
break;
case 'm': /* texture map */
fscanf(file, "%s", buf2);
/*printf("map %s\n", buf2);*/
mat->map_kd = strdup(buf2);
break;
default:
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
break;
}
}
}
/* _glmWriteMTL: write a wavefront material library file
*
* model - properly initialized GLMmodel structure
* modelpath - pathname of the model being written
* mtllibname - name of the material library to be written
*/
static void
_glmWriteMTL(GLMmodel* model, char* modelpath, char* mtllibname)
{
FILE* file;
char* dir;
char* filename;
GLMmaterial* material;
uint i;
dir = _glmDirName(modelpath);
filename = (char*)malloc(sizeof(char) * (strlen(dir) + strlen(mtllibname)));
strcpy(filename, dir);
strcat(filename, mtllibname);
free(dir);
/* open the file */
file = fopen(filename, "w");
if (!file) {
fprintf(stderr, "_glmWriteMTL() failed: can't open file \"%s\".\n",
filename);
exit(1);
}
free(filename);
/* spit out a header */
fprintf(file, "# \n");
fprintf(file, "# Wavefront MTL generated by GLM library\n");
fprintf(file, "# \n");
fprintf(file, "# GLM library copyright (C) 1997 by Nate Robins\n");
fprintf(file, "# email: ndr@pobox.com\n");
fprintf(file, "# www: http://www.pobox.com/~ndr\n");
fprintf(file, "# \n\n");
for (i = 0; i < model->nummaterials; i++) {
material = &model->materials[i];
fprintf(file, "newmtl %s\n", material->name);
fprintf(file, "Ka %f %f %f\n",
material->ambient[0], material->ambient[1], material->ambient[2]);
fprintf(file, "Kd %f %f %f\n",
material->diffuse[0], material->diffuse[1], material->diffuse[2]);
fprintf(file, "Ks %f %f %f\n",
material->specular[0],material->specular[1],material->specular[2]);
fprintf(file, "Ns %f\n", material->shininess);
fprintf(file, "\n");
}
}
/* _glmFirstPass: first pass at a Wavefront OBJ file that gets all the
* statistics of the model (such as #vertices, #normals, etc)
*
* model - properly initialized GLMmodel structure
* file - (fopen'd) file descriptor
*/
static void
_glmFirstPass(GLMmodel* model, FILE* file)
{
uint numvertices; /* number of vertices in model */
uint numnormals; /* number of normals in model */
uint numtexcoords; /* number of texcoords in model */
uint numtriangles; /* number of triangles in model */
GLMgroup* group; /* current group */
unsigned v, n, t;
char buf[128];
/* make a default group */
group = _glmAddGroup(model, "default");
numvertices = numnormals = numtexcoords = numtriangles = 0;
while(fscanf(file, "%s", buf) != EOF) {
switch(buf[0]) {
case '#': /* comment */
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
break;
case 'v': /* v, vn, vt */
switch(buf[1]) {
case '\0': /* vertex */
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
numvertices++;
break;
case 'n': /* normal */
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
numnormals++;
break;
case 't': /* texcoord */
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
numtexcoords++;
break;
default:
printf("_glmFirstPass(): Unknown token \"%s\".\n", buf);
exit(1);
break;
}
break;
case 'm':
fgets(buf, sizeof(buf), file);
sscanf(buf, "%s %s", buf, buf);
model->mtllibname = stralloc(buf);
_glmReadMTL(model, buf);
break;
case 'u':
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
break;
case 'g': /* group */
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
sscanf(buf, "%s", buf);
group = _glmAddGroup(model, buf);
break;
case 'f': /* face */
v = n = t = 0;
fscanf(file, "%s", buf);
/* can be one of %d, %d//%d, %d/%d, %d/%d/%d %d//%d */
if (strstr(buf, "//")) {
/* v//n */
sscanf(buf, "%u//%u", &v, &n);
fscanf(file, "%u//%u", &v, &n);
fscanf(file, "%u//%u", &v, &n);
numtriangles++;
group->numtriangles++;
while(fscanf(file, "%u//%u", &v, &n) > 0) {
numtriangles++;
group->numtriangles++;
}
} else if (sscanf(buf, "%u/%u/%u", &v, &t, &n) == 3) {
/* v/t/n */
fscanf(file, "%u/%u/%u", &v, &t, &n);
fscanf(file, "%u/%u/%u", &v, &t, &n);
numtriangles++;
group->numtriangles++;
while(fscanf(file, "%u/%u/%u", &v, &t, &n) > 0) {
numtriangles++;
group->numtriangles++;
}
} else if (sscanf(buf, "%u/%u", &v, &t) == 2) {
/* v/t */
fscanf(file, "%u/%u", &v, &t);
fscanf(file, "%u/%u", &v, &t);
numtriangles++;
group->numtriangles++;
while(fscanf(file, "%u/%u", &v, &t) > 0) {
numtriangles++;
group->numtriangles++;
}
} else {
/* v */
fscanf(file, "%u", &v);
fscanf(file, "%u", &v);
numtriangles++;
group->numtriangles++;
while(fscanf(file, "%u", &v) > 0) {
numtriangles++;
group->numtriangles++;
}
}
break;
default:
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
break;
}
}
#if 0
/* announce the model statistics */
printf(" Vertices: %d\n", numvertices);
printf(" Normals: %d\n", numnormals);
printf(" Texcoords: %d\n", numtexcoords);
printf(" Triangles: %d\n", numtriangles);
printf(" Groups: %d\n", model->numgroups);
#endif
/* set the stats in the model structure */
model->numvertices = numvertices;
model->numnormals = numnormals;
model->numtexcoords = numtexcoords;
model->numtriangles = numtriangles;
/* allocate memory for the triangles in each group */
group = model->groups;
while(group) {
group->triangles = (uint*)malloc(sizeof(uint) * group->numtriangles);
group->numtriangles = 0;
group = group->next;
}
}
/* _glmSecondPass: second pass at a Wavefront OBJ file that gets all
* the data.
*
* model - properly initialized GLMmodel structure
* file - (fopen'd) file descriptor
*/
static void
_glmSecondPass(GLMmodel* model, FILE* file)
{
uint numvertices; /* number of vertices in model */
uint numnormals; /* number of normals in model */
uint numtexcoords; /* number of texcoords in model */
uint numtriangles; /* number of triangles in model */
float* vertices; /* array of vertices */
float* normals; /* array of normals */
float* texcoords; /* array of texture coordinates */
GLMgroup* group; /* current group pointer */
uint material; /* current material */
uint v, n, t;
char buf[128];
/* set the pointer shortcuts */
vertices = model->vertices;
normals = model->normals;
texcoords = model->texcoords;
group = model->groups;
/* on the second pass through the file, read all the data into the
allocated arrays */
numvertices = numnormals = numtexcoords = 1;
numtriangles = 0;
material = 0;
while(fscanf(file, "%s", buf) != EOF) {
switch(buf[0]) {
case '#': /* comment */
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
break;
case 'v': /* v, vn, vt */
switch(buf[1]) {
case '\0': /* vertex */
fscanf(file, "%f %f %f",
&vertices[3 * numvertices + X],
&vertices[3 * numvertices + Y],
&vertices[3 * numvertices + Z]);
numvertices++;
break;
case 'n': /* normal */
fscanf(file, "%f %f %f",
&normals[3 * numnormals + X],
&normals[3 * numnormals + Y],
&normals[3 * numnormals + Z]);
numnormals++;
break;
case 't': /* texcoord */
fscanf(file, "%f %f",
&texcoords[2 * numtexcoords + X],
&texcoords[2 * numtexcoords + Y]);
numtexcoords++;
break;
}
break;
case 'u':
fgets(buf, sizeof(buf), file);
sscanf(buf, "%s %s", buf, buf);
material = _glmFindMaterial(model, buf);
if (!group->material)
group->material = material;
/*printf("material %s = %u\n", buf, material);*/
break;
case 'g': /* group */
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
sscanf(buf, "%s", buf);
group = _glmFindGroup(model, buf);
group->material = material;
/*printf("GROUP %s material %u\n", buf, material);*/
break;
case 'f': /* face */
v = n = t = 0;
fscanf(file, "%s", buf);
/* can be one of %d, %d//%d, %d/%d, %d/%d/%d %d//%d */
if (strstr(buf, "//")) {
/* v//n */
sscanf(buf, "%u//%u", &v, &n);
T(numtriangles).vindices[0] = v;
T(numtriangles).nindices[0] = n;
fscanf(file, "%u//%u", &v, &n);
T(numtriangles).vindices[1] = v;
T(numtriangles).nindices[1] = n;
fscanf(file, "%u//%u", &v, &n);
T(numtriangles).vindices[2] = v;
T(numtriangles).nindices[2] = n;
group->triangles[group->numtriangles++] = numtriangles;
numtriangles++;
while(fscanf(file, "%u//%u", &v, &n) > 0) {
T(numtriangles).vindices[0] = T(numtriangles-1).vindices[0];
T(numtriangles).nindices[0] = T(numtriangles-1).nindices[0];
T(numtriangles).vindices[1] = T(numtriangles-1).vindices[2];
T(numtriangles).nindices[1] = T(numtriangles-1).nindices[2];
T(numtriangles).vindices[2] = v;
T(numtriangles).nindices[2] = n;
group->triangles[group->numtriangles++] = numtriangles;
numtriangles++;
}
} else if (sscanf(buf, "%u/%u/%u", &v, &t, &n) == 3) {
/* v/t/n */
T(numtriangles).vindices[0] = v;
T(numtriangles).tindices[0] = t;
T(numtriangles).nindices[0] = n;
fscanf(file, "%u/%u/%u", &v, &t, &n);
T(numtriangles).vindices[1] = v;
T(numtriangles).tindices[1] = t;
T(numtriangles).nindices[1] = n;
fscanf(file, "%u/%u/%u", &v, &t, &n);
T(numtriangles).vindices[2] = v;
T(numtriangles).tindices[2] = t;
T(numtriangles).nindices[2] = n;
group->triangles[group->numtriangles++] = numtriangles;
numtriangles++;
while(fscanf(file, "%u/%u/%u", &v, &t, &n) > 0) {
T(numtriangles).vindices[0] = T(numtriangles-1).vindices[0];
T(numtriangles).tindices[0] = T(numtriangles-1).tindices[0];
T(numtriangles).nindices[0] = T(numtriangles-1).nindices[0];
T(numtriangles).vindices[1] = T(numtriangles-1).vindices[2];
T(numtriangles).tindices[1] = T(numtriangles-1).tindices[2];
T(numtriangles).nindices[1] = T(numtriangles-1).nindices[2];
T(numtriangles).vindices[2] = v;
T(numtriangles).tindices[2] = t;
T(numtriangles).nindices[2] = n;
group->triangles[group->numtriangles++] = numtriangles;
numtriangles++;
}
} else if (sscanf(buf, "%u/%u", &v, &t) == 2) {
/* v/t */
T(numtriangles).vindices[0] = v;
T(numtriangles).tindices[0] = t;
fscanf(file, "%u/%u", &v, &t);
T(numtriangles).vindices[1] = v;
T(numtriangles).tindices[1] = t;
fscanf(file, "%u/%u", &v, &t);
T(numtriangles).vindices[2] = v;
T(numtriangles).tindices[2] = t;
group->triangles[group->numtriangles++] = numtriangles;
numtriangles++;
while(fscanf(file, "%u/%u", &v, &t) > 0) {
T(numtriangles).vindices[0] = T(numtriangles-1).vindices[0];
T(numtriangles).tindices[0] = T(numtriangles-1).tindices[0];
T(numtriangles).vindices[1] = T(numtriangles-1).vindices[2];
T(numtriangles).tindices[1] = T(numtriangles-1).tindices[2];
T(numtriangles).vindices[2] = v;
T(numtriangles).tindices[2] = t;
group->triangles[group->numtriangles++] = numtriangles;
numtriangles++;
}
} else {
/* v */
sscanf(buf, "%u", &v);
T(numtriangles).vindices[0] = v;
fscanf(file, "%u", &v);
T(numtriangles).vindices[1] = v;
fscanf(file, "%u", &v);
T(numtriangles).vindices[2] = v;
group->triangles[group->numtriangles++] = numtriangles;
numtriangles++;
while(fscanf(file, "%u", &v) > 0) {
T(numtriangles).vindices[0] = T(numtriangles-1).vindices[0];
T(numtriangles).vindices[1] = T(numtriangles-1).vindices[2];
T(numtriangles).vindices[2] = v;
group->triangles[group->numtriangles++] = numtriangles;
numtriangles++;
}
}
break;
default:
/* eat up rest of line */
fgets(buf, sizeof(buf), file);
break;
}
}
#if 0
/* announce the memory requirements */
printf(" Memory: %d bytes\n",
numvertices * 3*sizeof(float) +
numnormals * 3*sizeof(float) * (numnormals ? 1 : 0) +
numtexcoords * 3*sizeof(float) * (numtexcoords ? 1 : 0) +
numtriangles * sizeof(GLMtriangle));
#endif
}
/* public functions */
/* glmUnitize: "unitize" a model by translating it to the origin and
* scaling it to fit in a unit cube around the origin. Returns the
* scalefactor used.
*
* model - properly initialized GLMmodel structure
*/
float
glmUnitize(GLMmodel* model)
{
uint i;
float maxx, minx, maxy, miny, maxz, minz;
float cx, cy, cz, w, h, d;
float scale;
assert(model);
assert(model->vertices);
/* get the max/mins */
maxx = minx = model->vertices[3 + X];
maxy = miny = model->vertices[3 + Y];
maxz = minz = model->vertices[3 + Z];
for (i = 1; i <= model->numvertices; i++) {
if (maxx < model->vertices[3 * i + X])
maxx = model->vertices[3 * i + X];
if (minx > model->vertices[3 * i + X])
minx = model->vertices[3 * i + X];
if (maxy < model->vertices[3 * i + Y])
maxy = model->vertices[3 * i + Y];
if (miny > model->vertices[3 * i + Y])
miny = model->vertices[3 * i + Y];
if (maxz < model->vertices[3 * i + Z])
maxz = model->vertices[3 * i + Z];
if (minz > model->vertices[3 * i + Z])
minz = model->vertices[3 * i + Z];
}
/* calculate model width, height, and depth */
w = _glmAbs(maxx) + _glmAbs(minx);
h = _glmAbs(maxy) + _glmAbs(miny);
d = _glmAbs(maxz) + _glmAbs(minz);
/* calculate center of the model */
cx = (maxx + minx) / 2.0;
cy = (maxy + miny) / 2.0;
cz = (maxz + minz) / 2.0;
/* calculate unitizing scale factor */
scale = 2.0 / _glmMax(_glmMax(w, h), d);
/* translate around center then scale */
for (i = 1; i <= model->numvertices; i++) {
model->vertices[3 * i + X] -= cx;
model->vertices[3 * i + Y] -= cy;
model->vertices[3 * i + Z] -= cz;
model->vertices[3 * i + X] *= scale;
model->vertices[3 * i + Y] *= scale;
model->vertices[3 * i + Z] *= scale;
}
return scale;
}
/* glmDimensions: Calculates the dimensions (width, height, depth) of
* a model.
*
* model - initialized GLMmodel structure
* dimensions - array of 3 floats (float dimensions[3])
*/
void
glmDimensions(GLMmodel* model, float* dimensions)
{
uint i;
float maxx, minx, maxy, miny, maxz, minz;
assert(model);
assert(model->vertices);
assert(dimensions);
/* get the max/mins */
maxx = minx = model->vertices[3 + X];
maxy = miny = model->vertices[3 + Y];
maxz = minz = model->vertices[3 + Z];
for (i = 1; i <= model->numvertices; i++) {
if (maxx < model->vertices[3 * i + X])
maxx = model->vertices[3 * i + X];
if (minx > model->vertices[3 * i + X])
minx = model->vertices[3 * i + X];
if (maxy < model->vertices[3 * i + Y])
maxy = model->vertices[3 * i + Y];
if (miny > model->vertices[3 * i + Y])
miny = model->vertices[3 * i + Y];
if (maxz < model->vertices[3 * i + Z])
maxz = model->vertices[3 * i + Z];
if (minz > model->vertices[3 * i + Z])
minz = model->vertices[3 * i + Z];
}
/* calculate model width, height, and depth */
dimensions[X] = _glmAbs(maxx) + _glmAbs(minx);
dimensions[Y] = _glmAbs(maxy) + _glmAbs(miny);
dimensions[Z] = _glmAbs(maxz) + _glmAbs(minz);
}
/* glmScale: Scales a model by a given amount.
*
* model - properly initialized GLMmodel structure
* scale - scalefactor (0.5 = half as large, 2.0 = twice as large)
*/
void
glmScale(GLMmodel* model, float scale)
{
uint i;
for (i = 1; i <= model->numvertices; i++) {
model->vertices[3 * i + X] *= scale;
model->vertices[3 * i + Y] *= scale;
model->vertices[3 * i + Z] *= scale;
}
}
/* glmReverseWinding: Reverse the polygon winding for all polygons in
* this model. Default winding is counter-clockwise. Also changes
* the direction of the normals.
*
* model - properly initialized GLMmodel structure
*/
void
glmReverseWinding(GLMmodel* model)
{
uint i, swap;
assert(model);
for (i = 0; i < model->numtriangles; i++) {
swap = T(i).vindices[0];
T(i).vindices[0] = T(i).vindices[2];
T(i).vindices[2] = swap;
if (model->numnormals) {
swap = T(i).nindices[0];
T(i).nindices[0] = T(i).nindices[2];
T(i).nindices[2] = swap;
}
if (model->numtexcoords) {
swap = T(i).tindices[0];
T(i).tindices[0] = T(i).tindices[2];
T(i).tindices[2] = swap;
}
}
/* reverse facet normals */
for (i = 1; i <= model->numfacetnorms; i++) {
model->facetnorms[3 * i + X] = -model->facetnorms[3 * i + X];
model->facetnorms[3 * i + Y] = -model->facetnorms[3 * i + Y];
model->facetnorms[3 * i + Z] = -model->facetnorms[3 * i + Z];
}
/* reverse vertex normals */
for (i = 1; i <= model->numnormals; i++) {
model->normals[3 * i + X] = -model->normals[3 * i + X];
model->normals[3 * i + Y] = -model->normals[3 * i + Y];
model->normals[3 * i + Z] = -model->normals[3 * i + Z];
}
}
/* glmFacetNormals: Generates facet normals for a model (by taking the
* cross product of the two vectors derived from the sides of each
* triangle). Assumes a counter-clockwise winding.
*
* model - initialized GLMmodel structure
*/
void
glmFacetNormals(GLMmodel* model)
{
uint i;
float u[3];
float v[3];
assert(model);
assert(model->vertices);
/* clobber any old facetnormals */
if (model->facetnorms)
free(model->facetnorms);
/* allocate memory for the new facet normals */
model->numfacetnorms = model->numtriangles;
model->facetnorms = (float*)malloc(sizeof(float) *
3 * (model->numfacetnorms + 1));
for (i = 0; i < model->numtriangles; i++) {
model->triangles[i].findex = i+1;
u[X] = model->vertices[3 * T(i).vindices[1] + X] -
model->vertices[3 * T(i).vindices[0] + X];
u[Y] = model->vertices[3 * T(i).vindices[1] + Y] -
model->vertices[3 * T(i).vindices[0] + Y];
u[Z] = model->vertices[3 * T(i).vindices[1] + Z] -
model->vertices[3 * T(i).vindices[0] + Z];
v[X] = model->vertices[3 * T(i).vindices[2] + X] -
model->vertices[3 * T(i).vindices[0] + X];
v[Y] = model->vertices[3 * T(i).vindices[2] + Y] -
model->vertices[3 * T(i).vindices[0] + Y];
v[Z] = model->vertices[3 * T(i).vindices[2] + Z] -
model->vertices[3 * T(i).vindices[0] + Z];
_glmCross(u, v, &model->facetnorms[3 * (i+1)]);
_glmNormalize(&model->facetnorms[3 * (i+1)]);
}
}
/* glmVertexNormals: Generates smooth vertex normals for a model.
* First builds a list of all the triangles each vertex is in. Then
* loops through each vertex in the the list averaging all the facet
* normals of the triangles each vertex is in. Finally, sets the
* normal index in the triangle for the vertex to the generated smooth
* normal. If the dot product of a facet normal and the facet normal
* associated with the first triangle in the list of triangles the
* current vertex is in is greater than the cosine of the angle
* parameter to the function, that facet normal is not added into the
* average normal calculation and the corresponding vertex is given
* the facet normal. This tends to preserve hard edges. The angle to
* use depends on the model, but 90 degrees is usually a good start.
*
* model - initialized GLMmodel structure
* angle - maximum angle (in degrees) to smooth across
*/
void
glmVertexNormals(GLMmodel* model, float angle)
{
GLMnode* node;
GLMnode* tail;
GLMnode** members;
float* normals;
uint numnormals;
float average[3];
float dot, cos_angle;
uint i, avg;
assert(model);
assert(model->facetnorms);
/* calculate the cosine of the angle (in degrees) */
cos_angle = cos(angle * M_PI / 180.0);
/* nuke any previous normals */
if (model->normals)
free(model->normals);
/* allocate space for new normals */
model->numnormals = model->numtriangles * 3; /* 3 normals per triangle */
model->normals = (float*)malloc(sizeof(float)* 3* (model->numnormals+1));
/* allocate a structure that will hold a linked list of triangle
indices for each vertex */
members = (GLMnode**)malloc(sizeof(GLMnode*) * (model->numvertices + 1));
for (i = 1; i <= model->numvertices; i++)
members[i] = NULL;
/* for every triangle, create a node for each vertex in it */
for (i = 0; i < model->numtriangles; i++) {
node = (GLMnode*)malloc(sizeof(GLMnode));
node->index = i;
node->next = members[T(i).vindices[0]];
members[T(i).vindices[0]] = node;
node = (GLMnode*)malloc(sizeof(GLMnode));
node->index = i;
node->next = members[T(i).vindices[1]];
members[T(i).vindices[1]] = node;
node = (GLMnode*)malloc(sizeof(GLMnode));
node->index = i;
node->next = members[T(i).vindices[2]];
members[T(i).vindices[2]] = node;
}
/* calculate the average normal for each vertex */
numnormals = 1;
for (i = 1; i <= model->numvertices; i++) {
/* calculate an average normal for this vertex by averaging the
facet normal of every triangle this vertex is in */
node = members[i];
if (!node)
fprintf(stderr, "glmVertexNormals(): vertex w/o a triangle\n");
average[0] = 0.0; average[1] = 0.0; average[2] = 0.0;
avg = 0;
while (node) {
/* only average if the dot product of the angle between the two
facet normals is greater than the cosine of the threshold
angle -- or, said another way, the angle between the two
facet normals is less than (or equal to) the threshold angle */
dot = _glmDot(&model->facetnorms[3 * T(node->index).findex],
&model->facetnorms[3 * T(members[i]->index).findex]);
if (dot > cos_angle) {
node->averaged = TRUE;
average[0] += model->facetnorms[3 * T(node->index).findex + 0];
average[1] += model->facetnorms[3 * T(node->index).findex + 1];
average[2] += model->facetnorms[3 * T(node->index).findex + 2];
avg = 1; /* we averaged at least one normal! */
} else {
node->averaged = FALSE;
}
node = node->next;
}
if (avg) {
/* normalize the averaged normal */
_glmNormalize(average);
/* add the normal to the vertex normals list */
model->normals[3 * numnormals + 0] = average[0];
model->normals[3 * numnormals + 1] = average[1];
model->normals[3 * numnormals + 2] = average[2];
avg = numnormals;
numnormals++;
}
/* set the normal of this vertex in each triangle it is in */
node = members[i];
while (node) {
if (node->averaged) {
/* if this node was averaged, use the average normal */
if (T(node->index).vindices[0] == i)
T(node->index).nindices[0] = avg;
else if (T(node->index).vindices[1] == i)
T(node->index).nindices[1] = avg;
else if (T(node->index).vindices[2] == i)
T(node->index).nindices[2] = avg;
} else {
/* if this node wasn't averaged, use the facet normal */
model->normals[3 * numnormals + 0] =
model->facetnorms[3 * T(node->index).findex + 0];
model->normals[3 * numnormals + 1] =
model->facetnorms[3 * T(node->index).findex + 1];
model->normals[3 * numnormals + 2] =
model->facetnorms[3 * T(node->index).findex + 2];
if (T(node->index).vindices[0] == i)
T(node->index).nindices[0] = numnormals;
else if (T(node->index).vindices[1] == i)
T(node->index).nindices[1] = numnormals;
else if (T(node->index).vindices[2] == i)
T(node->index).nindices[2] = numnormals;
numnormals++;
}
node = node->next;
}
}
model->numnormals = numnormals - 1;
/* free the member information */
for (i = 1; i <= model->numvertices; i++) {
node = members[i];
while (node) {
tail = node;
node = node->next;
free(tail);
}
}
free(members);
/* pack the normals array (we previously allocated the maximum
number of normals that could possibly be created (numtriangles *
3), so get rid of some of them (usually alot unless none of the
facet normals were averaged)) */
normals = model->normals;
model->normals = (float*)malloc(sizeof(float)* 3* (model->numnormals+1));
for (i = 1; i <= model->numnormals; i++) {
model->normals[3 * i + 0] = normals[3 * i + 0];
model->normals[3 * i + 1] = normals[3 * i + 1];
model->normals[3 * i + 2] = normals[3 * i + 2];
}
free(normals);
printf("glmVertexNormals(): %d normals generated\n", model->numnormals);
}
/* glmLinearTexture: Generates texture coordinates according to a
* linear projection of the texture map. It generates these by
* linearly mapping the vertices onto a square.
*
* model - pointer to initialized GLMmodel structure
*/
void
glmLinearTexture(GLMmodel* model)
{
GLMgroup *group;
float dimensions[3];
float x, y, scalefactor;
uint i;
assert(model);
if (model->texcoords)
free(model->texcoords);
model->numtexcoords = model->numvertices;
model->texcoords=(float*)malloc(sizeof(float)*2*(model->numtexcoords+1));
glmDimensions(model, dimensions);
scalefactor = 2.0 /
_glmAbs(_glmMax(_glmMax(dimensions[0], dimensions[1]), dimensions[2]));
/* do the calculations */
for(i = 1; i <= model->numvertices; i++) {
x = model->vertices[3 * i + 0] * scalefactor;
y = model->vertices[3 * i + 2] * scalefactor;
model->texcoords[2 * i + 0] = (x + 1.0) / 2.0;
model->texcoords[2 * i + 1] = (y + 1.0) / 2.0;
}
/* go through and put texture coordinate indices in all the triangles */
group = model->groups;
while(group) {
for(i = 0; i < group->numtriangles; i++) {
T(group->triangles[i]).tindices[0] = T(group->triangles[i]).vindices[0];
T(group->triangles[i]).tindices[1] = T(group->triangles[i]).vindices[1];
T(group->triangles[i]).tindices[2] = T(group->triangles[i]).vindices[2];
}
group = group->next;
}
#if 0
printf("glmLinearTexture(): generated %d linear texture coordinates\n",
model->numtexcoords);
#endif
}
/* glmSpheremapTexture: Generates texture coordinates according to a
* spherical projection of the texture map. Sometimes referred to as
* spheremap, or reflection map texture coordinates. It generates
* these by using the normal to calculate where that vertex would map
* onto a sphere. Since it is impossible to map something flat
* perfectly onto something spherical, there is distortion at the
* poles. This particular implementation causes the poles along the X
* axis to be distorted.
*
* model - pointer to initialized GLMmodel structure
*/
void
glmSpheremapTexture(GLMmodel* model)
{
GLMgroup* group;
float theta, phi, rho, x, y, z, r;
uint i;
assert(model);
assert(model->normals);
if (model->texcoords)
free(model->texcoords);
model->numtexcoords = model->numnormals;
model->texcoords=(float*)malloc(sizeof(float)*2*(model->numtexcoords+1));
/* do the calculations */
for (i = 1; i <= model->numnormals; i++) {
z = model->normals[3 * i + 0]; /* re-arrange for pole distortion */
y = model->normals[3 * i + 1];
x = model->normals[3 * i + 2];
r = sqrt((x * x) + (y * y));
rho = sqrt((r * r) + (z * z));
if(r == 0.0) {
theta = 0.0;
phi = 0.0;
} else {
if(z == 0.0)
phi = M_PI / 2.0;
else
phi = acos(z / rho);
#if WE_DONT_NEED_THIS_CODE
if(x == 0.0)
theta = M_PI / 2.0; /* asin(y / r); */
else
theta = acos(x / r);
#endif
if(y == 0.0)
theta = M_PI / 2.0; /* acos(x / r); */
else
theta = asin(y / r) + (M_PI / 2.0);
}
model->texcoords[2 * i + 0] = theta / M_PI;
model->texcoords[2 * i + 1] = phi / M_PI;
}
/* go through and put texcoord indices in all the triangles */
group = model->groups;
while(group) {
for (i = 0; i < group->numtriangles; i++) {
T(group->triangles[i]).tindices[0] = T(group->triangles[i]).nindices[0];
T(group->triangles[i]).tindices[1] = T(group->triangles[i]).nindices[1];
T(group->triangles[i]).tindices[2] = T(group->triangles[i]).nindices[2];
}
group = group->next;
}
#if 0
printf("glmSpheremapTexture(): generated %d spheremap texture coordinates\n",
model->numtexcoords);
#endif
}
/* glmDelete: Deletes a GLMmodel structure.
*
* model - initialized GLMmodel structure
*/
void
glmDelete(GLMmodel* model)
{
GLMgroup* group;
uint i;
assert(model);
if (model->pathname) free(model->pathname);
if (model->mtllibname) free(model->mtllibname);
if (model->vertices) free(model->vertices);
if (model->normals) free(model->normals);
if (model->texcoords) free(model->texcoords);
if (model->facetnorms) free(model->facetnorms);
if (model->triangles) free(model->triangles);
if (model->materials) {
for (i = 0; i < model->nummaterials; i++)
free(model->materials[i].name);
}
free(model->materials);
while(model->groups) {
group = model->groups;
model->groups = model->groups->next;
free(group->name);
free(group->triangles);
free(group);
}
free(model);
}
static GLMmaterial *
glmDefaultMaterial(void)
{
GLMmaterial *m = (GLMmaterial *) calloc(1, sizeof(GLMmaterial));
m->diffuse[0] = 0.75;
m->diffuse[1] = 0.75;
m->diffuse[2] = 0.75;
m->diffuse[3] = 1.0;
m->specular[0] = 1.0;
m->specular[1] = 1.0;
m->specular[2] = 1.0;
m->specular[3] = 1.0;
m->shininess = 5;
return m;
}
/* glmReadOBJ: Reads a model description from a Wavefront .OBJ file.
* Returns a pointer to the created object which should be free'd with
* glmDelete().
*
* filename - name of the file containing the Wavefront .OBJ format data.
*/
GLMmodel*
glmReadOBJ(char* filename)
{
GLMmodel* model;
FILE* file;
/* open the file */
file = fopen(filename, "r");
if (!file) {
fprintf(stderr, "glmReadOBJ() failed: can't open data file \"%s\".\n",
filename);
exit(1);
}
#if 0
/* announce the model name */
printf("Model: %s\n", filename);
#endif
/* allocate a new model */
model = (GLMmodel*)malloc(sizeof(GLMmodel));
model->pathname = stralloc(filename);
model->mtllibname = NULL;
model->numvertices = 0;
model->vertices = NULL;
model->numnormals = 0;
model->normals = NULL;
model->numtexcoords = 0;
model->texcoords = NULL;
model->numfacetnorms = 0;
model->facetnorms = NULL;
model->numtriangles = 0;
model->triangles = NULL;
model->nummaterials = 0;
model->materials = NULL;
model->numgroups = 0;
model->groups = NULL;
model->position[0] = 0.0;
model->position[1] = 0.0;
model->position[2] = 0.0;
model->scale = 1.0;
/* make a first pass through the file to get a count of the number
of vertices, normals, texcoords & triangles */
_glmFirstPass(model, file);
/* allocate memory */
model->vertices = (float*)malloc(sizeof(float) *
3 * (model->numvertices + 1));
model->triangles = (GLMtriangle*)malloc(sizeof(GLMtriangle) *
model->numtriangles);
if (model->numnormals) {
model->normals = (float*)malloc(sizeof(float) *
3 * (model->numnormals + 1));
}
if (model->numtexcoords) {
model->texcoords = (float*)malloc(sizeof(float) *
2 * (model->numtexcoords + 1));
}
/* rewind to beginning of file and read in the data this pass */
rewind(file);
_glmSecondPass(model, file);
/* close the file */
fclose(file);
if (!model->materials) {
model->materials = glmDefaultMaterial();
model->nummaterials = 1;
}
return model;
}
/* glmWriteOBJ: Writes a model description in Wavefront .OBJ format to
* a file.
*
* model - initialized GLMmodel structure
* filename - name of the file to write the Wavefront .OBJ format data to
* mode - a bitwise or of values describing what is written to the file
* GLM_NONE - render with only vertices
* GLM_FLAT - render with facet normals
* GLM_SMOOTH - render with vertex normals
* GLM_TEXTURE - render with texture coords
* GLM_COLOR - render with colors (color material)
* GLM_MATERIAL - render with materials
* GLM_COLOR and GLM_MATERIAL should not both be specified.
* GLM_FLAT and GLM_SMOOTH should not both be specified.
*/
void
glmWriteOBJ(GLMmodel* model, char* filename, uint mode)
{
uint i;
FILE* file;
GLMgroup* group;
assert(model);
/* do a bit of warning */
if (mode & GLM_FLAT && !model->facetnorms) {
printf("glmWriteOBJ() warning: flat normal output requested "
"with no facet normals defined.\n");
mode &= ~GLM_FLAT;
}
if (mode & GLM_SMOOTH && !model->normals) {
printf("glmWriteOBJ() warning: smooth normal output requested "
"with no normals defined.\n");
mode &= ~GLM_SMOOTH;
}
if (mode & GLM_TEXTURE && !model->texcoords) {
printf("glmWriteOBJ() warning: texture coordinate output requested "
"with no texture coordinates defined.\n");
mode &= ~GLM_TEXTURE;
}
if (mode & GLM_FLAT && mode & GLM_SMOOTH) {
printf("glmWriteOBJ() warning: flat normal output requested "
"and smooth normal output requested (using smooth).\n");
mode &= ~GLM_FLAT;
}
/* open the file */
file = fopen(filename, "w");
if (!file) {
fprintf(stderr, "glmWriteOBJ() failed: can't open file \"%s\" to write.\n",
filename);
exit(1);
}
/* spit out a header */
fprintf(file, "# \n");
fprintf(file, "# Wavefront OBJ generated by GLM library\n");
fprintf(file, "# \n");
fprintf(file, "# GLM library copyright (C) 1997 by Nate Robins\n");
fprintf(file, "# email: ndr@pobox.com\n");
fprintf(file, "# www: http://www.pobox.com/~ndr\n");
fprintf(file, "# \n");
if (mode & GLM_MATERIAL && model->mtllibname) {
fprintf(file, "\nmtllib %s\n\n", model->mtllibname);
_glmWriteMTL(model, filename, model->mtllibname);
}
/* spit out the vertices */
fprintf(file, "\n");
fprintf(file, "# %d vertices\n", model->numvertices);
for (i = 1; i <= model->numvertices; i++) {
fprintf(file, "v %f %f %f\n",
model->vertices[3 * i + 0],
model->vertices[3 * i + 1],
model->vertices[3 * i + 2]);
}
/* spit out the smooth/flat normals */
if (mode & GLM_SMOOTH) {
fprintf(file, "\n");
fprintf(file, "# %d normals\n", model->numnormals);
for (i = 1; i <= model->numnormals; i++) {
fprintf(file, "vn %f %f %f\n",
model->normals[3 * i + 0],
model->normals[3 * i + 1],
model->normals[3 * i + 2]);
}
} else if (mode & GLM_FLAT) {
fprintf(file, "\n");
fprintf(file, "# %d normals\n", model->numfacetnorms);
for (i = 1; i <= model->numnormals; i++) {
fprintf(file, "vn %f %f %f\n",
model->facetnorms[3 * i + 0],
model->facetnorms[3 * i + 1],
model->facetnorms[3 * i + 2]);
}
}
/* spit out the texture coordinates */
if (mode & GLM_TEXTURE) {
fprintf(file, "\n");
fprintf(file, "# %d texcoords\n", model->numtexcoords);
for (i = 1; i <= model->numtexcoords; i++) {
fprintf(file, "vt %f %f\n",
model->texcoords[2 * i + 0],
model->texcoords[2 * i + 1]);
}
}
fprintf(file, "\n");
fprintf(file, "# %d groups\n", model->numgroups);
fprintf(file, "# %d faces (triangles)\n", model->numtriangles);
fprintf(file, "\n");
group = model->groups;
while(group) {
fprintf(file, "g %s\n", group->name);
if (mode & GLM_MATERIAL)
fprintf(file, "usemtl %s\n", model->materials[group->material].name);
for (i = 0; i < group->numtriangles; i++) {
if (mode & GLM_SMOOTH && mode & GLM_TEXTURE) {
fprintf(file, "f %d/%d/%d %d/%d/%d %d/%d/%d\n",
T(group->triangles[i]).vindices[0],
T(group->triangles[i]).nindices[0],
T(group->triangles[i]).tindices[0],
T(group->triangles[i]).vindices[1],
T(group->triangles[i]).nindices[1],
T(group->triangles[i]).tindices[1],
T(group->triangles[i]).vindices[2],
T(group->triangles[i]).nindices[2],
T(group->triangles[i]).tindices[2]);
} else if (mode & GLM_FLAT && mode & GLM_TEXTURE) {
fprintf(file, "f %d/%d %d/%d %d/%d\n",
T(group->triangles[i]).vindices[0],
T(group->triangles[i]).findex,
T(group->triangles[i]).vindices[1],
T(group->triangles[i]).findex,
T(group->triangles[i]).vindices[2],
T(group->triangles[i]).findex);
} else if (mode & GLM_TEXTURE) {
fprintf(file, "f %d/%d %d/%d %d/%d\n",
T(group->triangles[i]).vindices[0],
T(group->triangles[i]).tindices[0],
T(group->triangles[i]).vindices[1],
T(group->triangles[i]).tindices[1],
T(group->triangles[i]).vindices[2],
T(group->triangles[i]).tindices[2]);
} else if (mode & GLM_SMOOTH) {
fprintf(file, "f %d//%d %d//%d %d//%d\n",
T(group->triangles[i]).vindices[0],
T(group->triangles[i]).nindices[0],
T(group->triangles[i]).vindices[1],
T(group->triangles[i]).nindices[1],
T(group->triangles[i]).vindices[2],
T(group->triangles[i]).nindices[2]);
} else if (mode & GLM_FLAT) {
fprintf(file, "f %d//%d %d//%d %d//%d\n",
T(group->triangles[i]).vindices[0],
T(group->triangles[i]).findex,
T(group->triangles[i]).vindices[1],
T(group->triangles[i]).findex,
T(group->triangles[i]).vindices[2],
T(group->triangles[i]).findex);
} else {
fprintf(file, "f %d %d %d\n",
T(group->triangles[i]).vindices[0],
T(group->triangles[i]).vindices[1],
T(group->triangles[i]).vindices[2]);
}
}
fprintf(file, "\n");
group = group->next;
}
fclose(file);
}
/* glmWeld: eliminate (weld) vectors that are within an epsilon of
* each other.
*
* model - initialized GLMmodel structure
* epsilon - maximum difference between vertices
* ( 0.00001 is a good start for a unitized model)
*
*/
void
glmWeld(GLMmodel* model, float epsilon)
{
float* vectors;
float* copies;
uint numvectors;
uint i;
/* vertices */
numvectors = model->numvertices;
vectors = model->vertices;
copies = _glmWeldVectors(vectors, &numvectors, epsilon);
printf("glmWeld(): %d redundant vertices.\n",
model->numvertices - numvectors - 1);
for (i = 0; i < model->numtriangles; i++) {
T(i).vindices[0] = (uint)vectors[3 * T(i).vindices[0] + 0];
T(i).vindices[1] = (uint)vectors[3 * T(i).vindices[1] + 0];
T(i).vindices[2] = (uint)vectors[3 * T(i).vindices[2] + 0];
}
/* free space for old vertices */
free(vectors);
/* allocate space for the new vertices */
model->numvertices = numvectors;
model->vertices = (float*)malloc(sizeof(float) *
3 * (model->numvertices + 1));
/* copy the optimized vertices into the actual vertex list */
for (i = 1; i <= model->numvertices; i++) {
model->vertices[3 * i + 0] = copies[3 * i + 0];
model->vertices[3 * i + 1] = copies[3 * i + 1];
model->vertices[3 * i + 2] = copies[3 * i + 2];
}
free(copies);
}
void
glmReIndex(GLMmodel *model)
{
uint i, j, n;
GLMgroup* group;
float *newNormals = NULL;
float *newTexcoords = NULL;
const uint numv = model->numvertices;
if (model->numnormals > 0)
newNormals = (float *) malloc((numv + 1) * 3 * sizeof(float));
if (model->numtexcoords > 0)
newTexcoords = (float *) malloc((numv + 1) * 2 * sizeof(float));
for (group = model->groups; group; group = group->next) {
n = group->numtriangles;
group->triIndexes = (uint *) malloc(n * 3 * sizeof(uint));
group->minIndex = 10000000;
group->maxIndex = 0;
for (i = 0; i < n; i++) {
for (j = 0; j < 3; j++) {
uint vindex = T(group->triangles[i]).vindices[j];
uint nindex = T(group->triangles[i]).nindices[j];
uint tindex = T(group->triangles[i]).tindices[j];
float *nrm = &model->normals[nindex * 3];
float *tex = &model->texcoords[tindex * 2];
if (newNormals) {
assert(vindex * 3 + 2 < (numv + 1) * 3);
newNormals[vindex * 3 + 0] = nrm[0];
newNormals[vindex * 3 + 1] = nrm[1];
newNormals[vindex * 3 + 2] = nrm[2];
}
if (newTexcoords) {
newTexcoords[vindex * 2 + 0] = tex[0];
newTexcoords[vindex * 2 + 1] = tex[1];
}
T(group->triangles[i]).nindices[j] = vindex;
T(group->triangles[i]).tindices[j] = vindex;
group->triIndexes[i * 3 + j] = vindex;
if (vindex > group->maxIndex)
group->maxIndex = vindex;
if (vindex < group->minIndex)
group->minIndex = vindex;
}
}
}
if (newNormals) {
free(model->normals);
model->normals = newNormals;
model->numnormals = model->numvertices;
}
if (newTexcoords) {
free(model->texcoords);
model->texcoords = newTexcoords;
model->numtexcoords = model->numvertices;
}
}
void
glmPrint(const GLMmodel *model)
{
uint i, j, grp, n;
GLMgroup* group;
uint totalTris = 0;
grp = 0;
printf("%u vertices\n", model->numvertices);
printf("%u normals\n", model->numnormals);
printf("%u texcoords\n", model->numtexcoords);
for (group = model->groups; group; group = group->next, grp++) {
printf("Group %u:\n", grp);
printf(" Min index %u, max index %u\n", group->minIndex, group->maxIndex);
#if 0
if (mode & GLM_MATERIAL) {
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT,
model->materials[group->material].ambient);
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE,
model->materials[group->material].diffuse);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR,
model->materials[group->material].specular);
glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS,
model->materials[group->material].shininess);
}
if (mode & GLM_COLOR) {
glColor3fv(model->materials[group->material].diffuse);
}
#endif
totalTris += group->numtriangles;
printf(" %u triangles\n", group->numtriangles);
n = group->numtriangles;
if (n > 10)
n = 10;
for (i = 0; i < n; i++) {
printf(" %u: vert ", i);
for (j = 0; j < 3; j++) {
printf("%u ", T(group->triangles[i]).vindices[j]);
}
printf(" normal ");
for (j = 0; j < 3; j++) {
printf("%u ", T(group->triangles[i]).nindices[j]);
}
printf(" tex ");
for (j = 0; j < 3; j++) {
printf("%u ", T(group->triangles[i]).tindices[j]);
}
printf("\n");
}
}
printf("Total tris: %u\n", totalTris);
}
#if 0
/* normals */
if (model->numnormals) {
numvectors = model->numnormals;
vectors = model->normals;
copies = _glmOptimizeVectors(vectors, &numvectors);
printf("glmOptimize(): %d redundant normals.\n",
model->numnormals - numvectors);
for (i = 0; i < model->numtriangles; i++) {
T(i).nindices[0] = (uint)vectors[3 * T(i).nindices[0] + 0];
T(i).nindices[1] = (uint)vectors[3 * T(i).nindices[1] + 0];
T(i).nindices[2] = (uint)vectors[3 * T(i).nindices[2] + 0];
}
/* free space for old normals */
free(vectors);
/* allocate space for the new normals */
model->numnormals = numvectors;
model->normals = (float*)malloc(sizeof(float) *
3 * (model->numnormals + 1));
/* copy the optimized vertices into the actual vertex list */
for (i = 1; i <= model->numnormals; i++) {
model->normals[3 * i + 0] = copies[3 * i + 0];
model->normals[3 * i + 1] = copies[3 * i + 1];
model->normals[3 * i + 2] = copies[3 * i + 2];
}
free(copies);
}
/* texcoords */
if (model->numtexcoords) {
numvectors = model->numtexcoords;
vectors = model->texcoords;
copies = _glmOptimizeVectors(vectors, &numvectors);
printf("glmOptimize(): %d redundant texcoords.\n",
model->numtexcoords - numvectors);
for (i = 0; i < model->numtriangles; i++) {
for (j = 0; j < 3; j++) {
T(i).tindices[j] = (uint)vectors[3 * T(i).tindices[j] + 0];
}
}
/* free space for old texcoords */
free(vectors);
/* allocate space for the new texcoords */
model->numtexcoords = numvectors;
model->texcoords = (float*)malloc(sizeof(float) *
2 * (model->numtexcoords + 1));
/* copy the optimized vertices into the actual vertex list */
for (i = 1; i <= model->numtexcoords; i++) {
model->texcoords[2 * i + 0] = copies[2 * i + 0];
model->texcoords[2 * i + 1] = copies[2 * i + 1];
}
free(copies);
}
#endif
#if 0
/* look for unused vertices */
/* look for unused normals */
/* look for unused texcoords */
for (i = 1; i <= model->numvertices; i++) {
for (j = 0; j < model->numtriangles; i++) {
if (T(j).vindices[0] == i ||
T(j).vindices[1] == i ||
T(j).vindices[1] == i)
break;
}
}
#endif