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/*
* Time-stamp: <99/02/19 08:49:23 panic>
* Author: The C-Mix Project <cmix@diku.dk>
* Peter Holst Andersen <txix@diku.dk>
* Arne John Glenstrup <panic@diku.dk>
* Contents: Functions for creating the scene: create_*
*/
#include "ray.h"
#include <math.h>
#include <stdio.h>
#ifndef __CMIX
# define __CMIX(X)
#endif
#define NEXT(OBJ) (OBJ.last + 1 >= OBJ.max ? \
(fprintf(stderr, \
"error: too many %s in the scene, please increase %s in 'ray.h'.\n", \
OBJ.name, OBJ.maxname), \
exit(-1), 0) : ++OBJ.last)
static void
compute_surface_normal(vectorType* n, vectorType* v1, vectorType* v2) {
/* n is the normal to the surface, v1 is given and is the orientation
* of the surface (for checked discs: the pattern orientation).
* v2 is computed as a vector normal to both n and v1
*/
myfloat a, b, c;
a = n->x * v1->y - n->y * v1->x; if (isnan(a)) a = 0.0;
if (fzero(a))
v2->z = 0.0;
else {
b = (n->z * v1->x - n->x * v1->z) / a; if (isnan(b)) b = 0.0;
c = (n->y * v1->z - n->z * v1->y) / a; if (isnan(c)) c = 0.0;
v2->z = 1 / sqrt(b * b + c * c + 1.0);
};
a = n->y * v1->z - n->z * v1->y; if (isnan(a)) a = 0.0;
if (fzero(a))
v2->x = 0.0;
else {
b = (n->x * v1->y - n->y * v1->x) / a; if (isnan(b)) b = 0.0;
c = (n->z * v1->x - n->x * v1->z) / a; if (isnan(c)) c = 0.0;
v2->x = 1 / sqrt(b * b + c * c + 1.0);
if (!fzero(v2->z) && !fzero(b))
v2->x = copysign(v2->x, copysign(1.0, v2->z) * copysign(1.0, b));
};
a = n->z * v1->x - n->x * v1->z; if (isnan(a)) a = 0.0;
if (fzero(a))
v2->y = 0.0;
else {
b = (n->y * v1->z - n->z * v1->y) / a; if (isnan(b)) b = 0.0;
c = (n->x * v1->y - n->y * v1->x) / a; if (isnan(c)) c = 0.0;
v2->y = 1 / sqrt(b * b + c * c + 1.0);
if (!fzero(v2->x) && !fzero(b))
v2->y = copysign(v2->y, copysign(1.0, v2->x) * copysign(1.0, b));
else if (!fzero(v2->z) && !fzero(c))
v2->y = copysign(v2->y, copysign(1.0, v2->z) * copysign(1.0, c));
};
#ifdef DEBUG
__CMIX(pure)fprintf
(stderr, "/* Created surface: normal = (%g, %g, %g) */\n",
n->x, n->y, n->z);
__CMIX(pure)fprintf
(stderr, "/* x-unit = (%g, %g, %g) */\n",
v1->x, v1->y, v1->z);
__CMIX(pure)fprintf
(stderr, "/* y-unit = (%g, %g, %g) */\n",
v2->x, v2->y, v2->z);
#endif
__CMIX(pure)fprintf
(stderr, "/* Check: n*x = %g, n*y = %g, x*y = %g */\n",
n->x *v1->x + n->y *v1->y + n->z *v1->z,
n->x *v2->x + n->y *v2->y + n->z *v2->z,
v1->x*v2->x + v1->y*v2->y + v1->z*v2->z);
}
surfaceT create_simple_surface(myfloat am, myfloat di,
myfloat re, myfloat tr, myfloat ref, int specpow)
{
int i;
i = NEXT(surfaceIdx);
surface[i].tag = SIMPLE;
surface[i].u.sinfo.ambient.red = am;
surface[i].u.sinfo.ambient.green = am;
surface[i].u.sinfo.ambient.blue = am;
surface[i].u.sinfo.diffuse.red = di;
surface[i].u.sinfo.diffuse.green = di;
surface[i].u.sinfo.diffuse.blue = di;
surface[i].u.sinfo.reflectivity = re;
surface[i].u.sinfo.transparency = tr;
surface[i].u.sinfo.refrindex = ref;
surface[i].u.sinfo.specpow = specpow;
return i;
}
surfaceT create_color_surface(myfloat am, myfloat di,
myfloat re, myfloat tr, myfloat ref, int specpow,
myfloat red, myfloat green, myfloat blue)
{
int i;
i = NEXT(surfaceIdx);
surface[i].tag = SIMPLE;
surface[i].u.sinfo.ambient.red = am * red;
surface[i].u.sinfo.ambient.green = am * green;
surface[i].u.sinfo.ambient.blue = am * blue;
surface[i].u.sinfo.diffuse.red = di * red;
surface[i].u.sinfo.diffuse.green = di * green;
surface[i].u.sinfo.diffuse.blue = di * blue;
surface[i].u.sinfo.reflectivity = re;
surface[i].u.sinfo.transparency = tr;
surface[i].u.sinfo.refrindex = ref;
surface[i].u.sinfo.specpow = specpow;
return i;
}
surfaceT create_special_color_surface(myfloat amred, myfloat amgreen, myfloat amblue,
myfloat dired, myfloat digreen, myfloat diblue,
myfloat re, myfloat tr,
myfloat ref, int specpow)
{
int i;
i = NEXT(surfaceIdx);
surface[i].tag = SIMPLE;
surface[i].u.sinfo.ambient.red = amred;
surface[i].u.sinfo.ambient.green = amgreen;
surface[i].u.sinfo.ambient.blue = amblue;
surface[i].u.sinfo.diffuse.red = dired;
surface[i].u.sinfo.diffuse.green = digreen;
surface[i].u.sinfo.diffuse.blue = diblue;
surface[i].u.sinfo.reflectivity = re;
surface[i].u.sinfo.transparency = tr;
surface[i].u.sinfo.refrindex = ref;
surface[i].u.sinfo.specpow = specpow;
return i;
}
surfaceT create_checked_surface(surfaceT s1, surfaceT s2, myfloat checksize)
{
int i;
i = NEXT(surfaceIdx);
surface[i].tag = CHECKED;
surface[i].u.checked.s1 = s1;
surface[i].u.checked.s2 = s2;
surface[i].u.checked.checksize = checksize;
surface[i].u.checked.dbl_checksize = checksize * 2.0;
return i;
}
objectT create_disc(myfloat cx, myfloat cy, myfloat cz,
myfloat nx, myfloat ny, myfloat nz,
myfloat vx, myfloat vy, myfloat vz,
myfloat r, int s)
{
objectType *obj;
vectorType n, v, v2;
obj = scene + NEXT(objectIdx); (obj + 1)->tag = NONE;
obj->tag = DISC;
obj->prop.surface = s;
obj->obj.disc.c.x = cx;
obj->obj.disc.c.y = cy;
obj->obj.disc.c.z = cz;
obj->obj.disc.n.x = nx;
obj->obj.disc.n.y = ny;
obj->obj.disc.n.z = nz;
obj->obj.disc.v1.x = vx;
obj->obj.disc.v1.y = vy;
obj->obj.disc.v1.z = vz;
obj->obj.disc.r = r;
obj->obj.disc.r2 = r*r;
vector_norm_S(&obj->obj.disc.n);
vector_norm_S(&obj->obj.disc.v1);
compute_surface_normal(&obj->obj.disc.n, &obj->obj.disc.v1,
&obj->obj.disc.v2);
obj->obj.disc.d = obj->obj.disc.n.x*cx + obj->obj.disc.n.y*cy +
obj->obj.disc.n.z*cz;
return obj;
}
objectT create_square(myfloat cx, myfloat cy, myfloat cz,
myfloat nx, myfloat ny, myfloat nz,
myfloat vx, myfloat vy, myfloat vz,
myfloat r, int s)
{
objectType *obj;
vectorType n, v, v2;
obj = scene + NEXT(objectIdx); (obj + 1)->tag = NONE;
obj->tag = SQUARE;
obj->prop.surface = s;
obj->obj.square.c.x = cx;
obj->obj.square.c.y = cy;
obj->obj.square.c.z = cz;
obj->obj.square.n.x = nx;
obj->obj.square.n.y = ny;
obj->obj.square.n.z = nz;
obj->obj.square.v1.x = vx;
obj->obj.square.v1.y = vy;
obj->obj.square.v1.z = vz;
vector_norm_S(&obj->obj.square.n);
vector_norm_S(&obj->obj.square.v1);
compute_surface_normal(&obj->obj.square.n, &obj->obj.square.v1,
&obj->obj.square.v2);
obj->obj.square.r2 = r*r;
obj->obj.square.d = obj->obj.square.n.x*cx + obj->obj.square.n.y*cy +
obj->obj.square.n.z*cz;
return obj;
}
objectT create_sphere(myfloat x, myfloat y, myfloat z,
myfloat nx, myfloat ny, myfloat nz,
myfloat r, int s)
{
objectType *obj;
vectorType n, v, v2;
myfloat l;
obj = scene + NEXT(objectIdx); (obj + 1)->tag = NONE;
obj->tag = SPHERE;
obj->prop.surface = s;
obj->obj.sphere.r = r;
obj->obj.sphere.r2 = r*r;
obj->obj.sphere.c.x = x;
obj->obj.sphere.c.y = y;
obj->obj.sphere.c.z = z;
n.x = nx; n.y = ny; n.z = nz;
vector_norm_S(&n);
if (fzero(n.z)) {
v.x = 0.0; v.y = 0.0; v.z = 1.0;
v2.x = -n.y; v2.y = n.x; v2.z = 0.0;
} else {
if (fzero(n.x) && fzero(n.y)) {
v.x = 1.0; v.y = 0.0;
} else {
v.x = -n.y; v.y = n.x;
}
v.z = 0.0;
vector_norm_S(&v);
l = sqrt(n.x * n.x + n.y * n.y);
if (fzero(l)) {
v2.x = -v.y; v2.y = v.x; v2.z = 0.0;
} else {
v2.x = -n.x * n.z / l; v2.y = -n.y * n.z / l;
v2.z = sqrt(n.x * n.x + n.y * n.y);
}
}
obj->obj.sphere.n = n;
obj->obj.sphere.v1 = v;
obj->obj.sphere.v2 = v2;
fprintf(stderr, "sphere s%d %lf %lf %lf %lf\n", s, r, x, y, z);
#ifdef DEBUG
__CMIX(pure)fprintf
(stderr, "/* Sphere: pole (%g, %g, %g) */\n", n.x, n.y, n.z);
__CMIX(pure)fprintf
(stderr, "/* Sphere: equator (%g, %g, %g) */\n", v.x, v.y, v.z);
__CMIX(pure)fprintf
(stderr, "/* Sphere: normal (%g, %g, %g) */\n", v2.x, v2.y, v2.z);
#endif
__CMIX(pure)fprintf
(stderr, "/* Check: p*e = %g, p*n = %g, e*n = %g */\n",
n.x*v.x + n.y*v.y + n.z*v.z,
n.x*v2.x + n.y*v2.y + n.z*v2.z,
v.x*v2.x + v.y*v2.y + v.z*v2.z);
return obj;
}
lightT create_light(myfloat r, myfloat g, myfloat b,
myfloat x, myfloat y, myfloat z)
{
lightType *li;
li = light + NEXT(lightIdx);
li->p.x = x;
li->p.y = y;
li->p.z = z;
li->c.red = r;
li->c.green = g;
li->c.blue = b;
return li;
}
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