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/*
* Copyright (C) 1998 Janne Lf <jlof@mail.student.oulu.fi>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "lw.h"
#include <stdio.h>
#include <math.h>
#define MK_ID(a,b,c,d) ((((guint32)(a))<<24)| \
(((guint32)(b))<<16)| \
(((guint32)(c))<< 8)| \
(((guint32)(d)) ))
#define ID_FORM MK_ID('F','O','R','M')
#define ID_LWOB MK_ID('L','W','O','B')
#define ID_PNTS MK_ID('P','N','T','S')
#define ID_SRFS MK_ID('S','R','F','S')
#define ID_SURF MK_ID('S','U','R','F')
#define ID_POLS MK_ID('P','O','L','S')
#define ID_COLR MK_ID('C','O','L','R')
static gint32 read_char(FILE *f)
{
int c = fgetc(f);
g_return_val_if_fail(c != EOF, 0);
return c;
}
static gint32 read_short(FILE *f)
{
return (read_char(f)<<8) | read_char(f);
}
static gint32 read_long(FILE *f)
{
return (read_char(f)<<24) | (read_char(f)<<16) | (read_char(f)<<8) | read_char(f);
}
static GLfloat read_float(FILE *f)
{
gint32 x = read_long(f);
return *(GLfloat*)&x;
}
static gint read_string(FILE *f, char *s)
{
gint c;
gint cnt = 0;
do {
c = read_char(f);
if (cnt < LW_MAX_NAME_LEN)
s[cnt] = c;
else
s[LW_MAX_NAME_LEN-1] = 0;
cnt++;
} while (c != 0);
/* if length of string (including \0) is odd skip another byte */
if (cnt%2) {
read_char(f);
cnt++;
}
return cnt;
}
static void read_srfs(FILE *f, gint nbytes, lwObject *lwo)
{
int guess_cnt = lwo->material_cnt;
while (nbytes > 0) {
lwMaterial *material;
/* allocate more memory for materials if needed */
if (guess_cnt <= lwo->material_cnt) {
guess_cnt += guess_cnt/2 + 4;
lwo->material = g_realloc(lwo->material, sizeof(lwMaterial)*guess_cnt);
}
material = lwo->material + lwo->material_cnt++;
/* read name */
nbytes -= read_string(f,material->name);
/* defaults */
material->r = 0.7;
material->g = 0.7;
material->b = 0.7;
}
lwo->material = g_realloc(lwo->material, sizeof(lwMaterial)*lwo->material_cnt);
}
static void read_surf(FILE *f, gint nbytes, lwObject *lwo)
{
int i;
char name[LW_MAX_NAME_LEN];
lwMaterial *material = NULL;
/* read surface name */
nbytes -= read_string(f,name);
/* find material */
for (i=0; i< lwo->material_cnt; i++) {
if (strcmp(lwo->material[i].name,name) == 0) {
material = &lwo->material[i];
break;
}
}
g_return_if_fail(material != NULL);
/* read values */
while (nbytes > 0) {
gint id = read_long(f);
gint len = read_short(f);
nbytes -= 6 + len + (len%2);
switch (id) {
case ID_COLR:
material->r = read_char(f) / 255.0;
material->g = read_char(f) / 255.0;
material->b = read_char(f) / 255.0;
read_char(f); /* dummy */
break;
default:
fseek(f, len+(len%2), SEEK_CUR);
}
}
}
static void read_pols(FILE *f, int nbytes, lwObject *lwo)
{
int guess_cnt = lwo->face_cnt;
while (nbytes > 0) {
lwFace *face;
int i;
/* allocate more memory for polygons if necessary */
if (guess_cnt <= lwo->face_cnt) {
guess_cnt += guess_cnt + 4;
lwo->face = g_realloc(lwo->face, sizeof(lwFace)*guess_cnt);
}
face = lwo->face + lwo->face_cnt++;
/* number of points in this face */
face->index_cnt = read_short(f);
nbytes -= 2;
/* allocate space for points */
face->index = g_malloc0(sizeof(int)*face->index_cnt);
/* read points in */
for (i=0; i<face->index_cnt; i++) {
face->index[i] = read_short(f);
nbytes -= 2;
}
/* read surface material */
face->material = read_short(f);
nbytes -= 2;
/* skip over detail polygons */
if (face->material < 0) {
int det_cnt;
face->material = -face->material;
det_cnt = read_short(f);
nbytes -= 2;
while (det_cnt-- > 0) {
int cnt = read_short(f);
fseek(f, cnt*2+2, SEEK_CUR);
nbytes -= cnt*2+2;
}
}
face->material -= 1;
}
/* readjust to true size */
lwo->face = g_realloc(lwo->face, sizeof(lwFace)*lwo->face_cnt);
}
static void read_pnts(FILE *f, gint nbytes, lwObject *lwo)
{
int i;
lwo->vertex_cnt = nbytes / 12;
lwo->vertex = g_malloc0(sizeof(GLfloat)*lwo->vertex_cnt*3);
for (i=0; i<lwo->vertex_cnt; i++) {
lwo->vertex[i*3+0] = read_float(f);
lwo->vertex[i*3+1] = read_float(f);
lwo->vertex[i*3+2] = read_float(f);
}
}
gint lw_is_lwobject(const char *lw_file)
{
FILE *f = fopen(lw_file, "rb");
if (f) {
gint32 form = read_long(f);
gint32 nlen = read_long(f);
gint32 lwob = read_long(f);
fclose(f);
if (form == ID_FORM && nlen != 0 && lwob == ID_LWOB)
return TRUE;
}
return FALSE;
}
lwObject *lw_object_read(const char *lw_file)
{
FILE *f = NULL;
lwObject *lw_object = NULL;
gint32 form_bytes = 0;
gint32 read_bytes = 0;
/* open file */
f = fopen(lw_file, "rb");
if (f == NULL) {
g_warning("can't open file %s", lw_file);
return NULL;
}
/* check for headers */
if (read_long(f) != ID_FORM) {
g_warning("file %s is not an IFF file", lw_file);
fclose(f);
return NULL;
}
form_bytes = read_long(f);
read_bytes += 4;
if (read_long(f) != ID_LWOB) {
g_warning("file %s is not a LWOB file", lw_file);
fclose(f);
return NULL;
}
/* create new lwObject */
lw_object = g_malloc0(sizeof(lwObject));
/* read chunks */
while (read_bytes < form_bytes) {
gint32 id = read_long(f);
gint32 nbytes = read_long(f);
read_bytes += 8 + nbytes + (nbytes%2);
switch (id) {
case ID_PNTS:
read_pnts(f, nbytes, lw_object);
break;
case ID_POLS:
read_pols(f, nbytes, lw_object);
break;
case ID_SRFS:
read_srfs(f, nbytes, lw_object);
break;
case ID_SURF:
read_surf(f, nbytes, lw_object);
break;
default:
fseek(f, nbytes + (nbytes%2), SEEK_CUR);
}
}
fclose(f);
return lw_object;
}
void lw_object_free(lwObject *lw_object)
{
g_return_if_fail(lw_object != NULL);
if (lw_object->face) {
int i;
for (i=0; i<lw_object->face_cnt; i++)
g_free(lw_object->face[i].index);
g_free(lw_object->face);
}
g_free(lw_object->material);
g_free(lw_object->vertex);
g_free(lw_object);
}
#define PX(i) (lw_object->vertex[face->index[i]*3+0])
#define PY(i) (lw_object->vertex[face->index[i]*3+1])
#define PZ(i) (lw_object->vertex[face->index[i]*3+2])
void lw_object_show(const lwObject *lw_object)
{
int i,j;
int prev_index_cnt = -1;
int prev_material = -1;
GLfloat prev_nx = 0;
GLfloat prev_ny = 0;
GLfloat prev_nz = 0;
g_return_if_fail(lw_object != NULL);
for (i=0; i<lw_object->face_cnt; i++) {
GLfloat ax,ay,az,bx,by,bz,nx,ny,nz,r;
const lwFace *face = lw_object->face+i;
/* ignore faces with less than 3 points */
if (face->index_cnt < 3)
continue;
/* calculate normal */
ax = PX(1) - PX(0);
ay = PY(1) - PY(0);
az = PZ(1) - PZ(0);
bx = PX(face->index_cnt-1) - PX(0);
by = PY(face->index_cnt-1) - PY(0);
bz = PZ(face->index_cnt-1) - PZ(0);
nx = ay * bz - az * by;
ny = az * bx - ax * bz;
nz = ax * by - ay * bx;
r = sqrt(nx*nx + ny*ny + nz*nz);
if (r < 0.000001) /* avoid division by zero */
continue;
nx /= r;
ny /= r;
nz /= r;
/* glBegin/glEnd */
if (prev_index_cnt != face->index_cnt || prev_index_cnt > 4) {
if (prev_index_cnt > 0) glEnd();
prev_index_cnt = face->index_cnt;
switch (face->index_cnt) {
case 3:
glBegin(GL_TRIANGLES);
break;
case 4:
glBegin(GL_QUADS);
break;
default:
glBegin(GL_POLYGON);
}
}
/* update material if necessary */
if (prev_material != face->material) {
prev_material = face->material;
glColor3f(lw_object->material[face->material].r,
lw_object->material[face->material].g,
lw_object->material[face->material].b);
}
/* update normal if necessary */
if (nx != prev_nx || ny != prev_ny || nz != prev_nz) {
prev_nx = nx;
prev_ny = ny;
prev_nz = nz;
glNormal3f(nx,ny,nz);
}
/* draw polygon/triangle/quad */
for (j=0; j<face->index_cnt; j++)
glVertex3f(PX(j),PY(j),PZ(j));
}
/* if glBegin was called call glEnd */
if (prev_index_cnt > 0)
glEnd();
}
GLfloat lw_object_radius(const lwObject *lwo)
{
int i;
double max_radius = 0.0;
g_return_val_if_fail(lwo != NULL, 0.0);
for (i=0; i<lwo->vertex_cnt; i++) {
GLfloat *v = &lwo->vertex[i*3];
double r = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
if (r > max_radius)
max_radius = r;
}
return sqrt(max_radius);
}
void lw_object_scale(lwObject *lwo, GLfloat scale)
{
int i;
g_return_if_fail(lwo != NULL);
for (i=0; i<lwo->vertex_cnt; i++) {
lwo->vertex[i*3+0] *= scale;
lwo->vertex[i*3+1] *= scale;
lwo->vertex[i*3+2] *= scale;
}
}
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