conworlds

annotate src/geom.cc @ 17:c814f77d177e

find changesets by author, revision, files, or words in the commit message
moved to SDL2
author John Tsiombikas <nuclear@member.fsf.org>
date Mon, 25 Aug 2014 22:02:08 +0300
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nuclear@13 1 #include <algorithm>
nuclear@13 2 #include <float.h>
nuclear@13 3 #include "geom.h"
nuclear@13 4 #include "logger.h"
nuclear@13 5
nuclear@13 6 GeomObject::~GeomObject()
nuclear@13 7 {
nuclear@13 8 }
nuclear@13 9
nuclear@13 10
nuclear@13 11 Sphere::Sphere()
nuclear@13 12 {
nuclear@13 13 radius = 1.0;
nuclear@13 14 }
nuclear@13 15
nuclear@13 16 Sphere::Sphere(const Vector3 &cent, float radius)
nuclear@13 17 : center(cent)
nuclear@13 18 {
nuclear@13 19 this->radius = radius;
nuclear@13 20 }
nuclear@13 21
nuclear@13 22 void Sphere::set_union(const GeomObject *obj1, const GeomObject *obj2)
nuclear@13 23 {
nuclear@13 24 const Sphere *sph1 = dynamic_cast<const Sphere*>(obj1);
nuclear@13 25 const Sphere *sph2 = dynamic_cast<const Sphere*>(obj2);
nuclear@13 26
nuclear@13 27 if(!sph1 || !sph2) {
nuclear@13 28 error_log("Sphere::set_union: arguments must be spheres");
nuclear@13 29 return;
nuclear@13 30 }
nuclear@13 31
nuclear@13 32 float dist = (sph1->center - sph2->center).length();
nuclear@13 33 float surf_dist = dist - (sph1->radius + sph2->radius);
nuclear@13 34 float d1 = sph1->radius + surf_dist / 2.0;
nuclear@13 35 float d2 = sph2->radius + surf_dist / 2.0;
nuclear@13 36 float t = d1 / (d1 + d2);
nuclear@13 37
nuclear@13 38 if(t < 0.0) t = 0.0;
nuclear@13 39 if(t > 1.0) t = 1.0;
nuclear@13 40
nuclear@13 41 center = sph1->center * t + sph2->center * (1.0 - t);
nuclear@13 42 radius = std::max(dist * t + sph2->radius, dist * (1.0f - t) + sph1->radius);
nuclear@13 43 }
nuclear@13 44
nuclear@13 45 void Sphere::set_intersection(const GeomObject *obj1, const GeomObject *obj2)
nuclear@13 46 {
nuclear@13 47 error_log("Sphere::intersection undefined\n");
nuclear@13 48 }
nuclear@13 49
nuclear@13 50 bool Sphere::contains(const Vector3 &pt) const
nuclear@13 51 {
nuclear@13 52 float dist_sq = (pt - center).length_sq();
nuclear@13 53 return dist_sq <= radius * radius;
nuclear@13 54 }
nuclear@13 55
nuclear@13 56 bool Sphere::intersect(const Ray &ray, HitPoint *hit) const
nuclear@13 57 {
nuclear@13 58 float a = dot_product(ray.dir, ray.dir);
nuclear@13 59 float b = 2.0 * ray.dir.x * (ray.origin.x - center.x) +
nuclear@13 60 2.0 * ray.dir.y * (ray.origin.y - center.y) +
nuclear@13 61 2.0 * ray.dir.z * (ray.origin.z - center.z);
nuclear@13 62 float c = dot_product(ray.origin, ray.origin) + dot_product(center, center) -
nuclear@13 63 2.0 * dot_product(ray.origin, center) - radius * radius;
nuclear@13 64
nuclear@13 65 float discr = b * b - 4.0 * a * c;
nuclear@13 66 if(discr < 1e-4) {
nuclear@13 67 return false;
nuclear@13 68 }
nuclear@13 69
nuclear@13 70 float sqrt_discr = sqrt(discr);
nuclear@13 71 float t0 = (-b + sqrt_discr) / (2.0 * a);
nuclear@13 72 float t1 = (-b - sqrt_discr) / (2.0 * a);
nuclear@13 73
nuclear@13 74 if(t0 < 1e-4)
nuclear@13 75 t0 = t1;
nuclear@13 76 if(t1 < 1e-4)
nuclear@13 77 t1 = t0;
nuclear@13 78
nuclear@13 79 float t = t0 < t1 ? t0 : t1;
nuclear@13 80 if(t < 1e-4) {
nuclear@13 81 return false;
nuclear@13 82 }
nuclear@13 83
nuclear@13 84 // fill the HitPoint structure
nuclear@13 85 if(hit) {
nuclear@13 86 hit->obj = this;
nuclear@13 87 hit->dist = t;
nuclear@13 88 hit->pos = ray.origin + ray.dir * t;
nuclear@13 89 hit->normal = (hit->pos - center) / radius;
nuclear@13 90 }
nuclear@13 91 return true;
nuclear@13 92 }
nuclear@13 93
nuclear@13 94
nuclear@13 95 AABox::AABox()
nuclear@13 96 {
nuclear@13 97 }
nuclear@13 98
nuclear@13 99 AABox::AABox(const Vector3 &vmin, const Vector3 &vmax)
nuclear@13 100 : min(vmin), max(vmax)
nuclear@13 101 {
nuclear@13 102 }
nuclear@13 103
nuclear@13 104 void AABox::set_union(const GeomObject *obj1, const GeomObject *obj2)
nuclear@13 105 {
nuclear@13 106 const AABox *box1 = dynamic_cast<const AABox*>(obj1);
nuclear@13 107 const AABox *box2 = dynamic_cast<const AABox*>(obj2);
nuclear@13 108
nuclear@13 109 if(!box1 || !box2) {
nuclear@13 110 error_log("AABox::set_union: arguments must be AABoxes too\n");
nuclear@13 111 return;
nuclear@13 112 }
nuclear@13 113
nuclear@13 114 min.x = std::min(box1->min.x, box2->min.x);
nuclear@13 115 min.y = std::min(box1->min.y, box2->min.y);
nuclear@13 116 min.z = std::min(box1->min.z, box2->min.z);
nuclear@13 117
nuclear@13 118 max.x = std::max(box1->max.x, box2->max.x);
nuclear@13 119 max.y = std::max(box1->max.y, box2->max.y);
nuclear@13 120 max.z = std::max(box1->max.z, box2->max.z);
nuclear@13 121 }
nuclear@13 122
nuclear@13 123 void AABox::set_intersection(const GeomObject *obj1, const GeomObject *obj2)
nuclear@13 124 {
nuclear@13 125 const AABox *box1 = dynamic_cast<const AABox*>(obj1);
nuclear@13 126 const AABox *box2 = dynamic_cast<const AABox*>(obj2);
nuclear@13 127
nuclear@13 128 if(!box1 || !box2) {
nuclear@13 129 error_log("AABox::set_intersection: arguments must be AABoxes too\n");
nuclear@13 130 return;
nuclear@13 131 }
nuclear@13 132
nuclear@13 133 for(int i=0; i<3; i++) {
nuclear@13 134 min[i] = std::max(box1->min[i], box2->min[i]);
nuclear@13 135 max[i] = std::min(box1->max[i], box2->max[i]);
nuclear@13 136
nuclear@13 137 if(max[i] < min[i]) {
nuclear@13 138 max[i] = min[i];
nuclear@13 139 }
nuclear@13 140 }
nuclear@13 141 }
nuclear@13 142
nuclear@13 143 bool AABox::contains(const Vector3 &pt) const
nuclear@13 144 {
nuclear@13 145 return pt.x >= min.x && pt.x <= max.x &&
nuclear@13 146 pt.y >= min.y && pt.y <= max.y &&
nuclear@13 147 pt.z >= min.z && pt.z <= max.z;
nuclear@13 148 }
nuclear@13 149
nuclear@13 150 bool AABox::intersect(const Ray &ray, HitPoint *hit) const
nuclear@13 151 {
nuclear@13 152 Vector3 param[2] = {min, max};
nuclear@13 153 Vector3 inv_dir(1.0 / ray.dir.x, 1.0 / ray.dir.y, 1.0 / ray.dir.z);
nuclear@13 154 int sign[3] = {inv_dir.x < 0, inv_dir.y < 0, inv_dir.z < 0};
nuclear@13 155
nuclear@13 156 float tmin = (param[sign[0]].x - ray.origin.x) * inv_dir.x;
nuclear@13 157 float tmax = (param[1 - sign[0]].x - ray.origin.x) * inv_dir.x;
nuclear@13 158 float tymin = (param[sign[1]].y - ray.origin.y) * inv_dir.y;
nuclear@13 159 float tymax = (param[1 - sign[1]].y - ray.origin.y) * inv_dir.y;
nuclear@13 160
nuclear@13 161 if(tmin > tymax || tymin > tmax) {
nuclear@13 162 return false;
nuclear@13 163 }
nuclear@13 164 if(tymin > tmin) {
nuclear@13 165 tmin = tymin;
nuclear@13 166 }
nuclear@13 167 if(tymax < tmax) {
nuclear@13 168 tmax = tymax;
nuclear@13 169 }
nuclear@13 170
nuclear@13 171 float tzmin = (param[sign[2]].z - ray.origin.z) * inv_dir.z;
nuclear@13 172 float tzmax = (param[1 - sign[2]].z - ray.origin.z) * inv_dir.z;
nuclear@13 173
nuclear@13 174 if(tmin > tzmax || tzmin > tmax) {
nuclear@13 175 return false;
nuclear@13 176 }
nuclear@13 177 if(tzmin > tmin) {
nuclear@13 178 tmin = tzmin;
nuclear@13 179 }
nuclear@13 180 if(tzmax < tmax) {
nuclear@13 181 tmax = tzmax;
nuclear@13 182 }
nuclear@13 183
nuclear@13 184 float t = tmin < 1e-4 ? tmax : tmin;
nuclear@13 185 if(t >= 1e-4) {
nuclear@13 186
nuclear@13 187 if(hit) {
nuclear@13 188 hit->obj = this;
nuclear@13 189 hit->dist = t;
nuclear@13 190 hit->pos = ray.origin + ray.dir * t;
nuclear@13 191
nuclear@13 192 float min_dist = FLT_MAX;
nuclear@13 193 Vector3 offs = min + (max - min) / 2.0;
nuclear@13 194 Vector3 local_hit = hit->pos - offs;
nuclear@13 195
nuclear@13 196 static const Vector3 axis[] = {
nuclear@13 197 Vector3(1, 0, 0), Vector3(0, 1, 0), Vector3(0, 0, 1)
nuclear@13 198 };
nuclear@13 199 //int tcidx[][2] = {{2, 1}, {0, 2}, {0, 1}};
nuclear@13 200
nuclear@13 201 for(int i=0; i<3; i++) {
nuclear@13 202 float dist = fabs((max[i] - offs[i]) - fabs(local_hit[i]));
nuclear@13 203 if(dist < min_dist) {
nuclear@13 204 min_dist = dist;
nuclear@13 205 hit->normal = axis[i] * (local_hit[i] < 0.0 ? 1.0 : -1.0);
nuclear@13 206 //hit->texcoord = Vector2(hit->pos[tcidx[i][0]], hit->pos[tcidx[i][1]]);
nuclear@13 207 }
nuclear@13 208 }
nuclear@13 209 }
nuclear@13 210 return true;
nuclear@13 211 }
nuclear@13 212 return false;
nuclear@13 213
nuclear@13 214 }
nuclear@13 215
nuclear@13 216 Plane::Plane()
nuclear@13 217 : normal(0.0, 1.0, 0.0)
nuclear@13 218 {
nuclear@13 219 }
nuclear@13 220
nuclear@13 221 Plane::Plane(const Vector3 &p, const Vector3 &norm)
nuclear@13 222 : pt(p)
nuclear@13 223 {
nuclear@13 224 normal = norm.normalized();
nuclear@13 225 }
nuclear@13 226
nuclear@13 227 Plane::Plane(const Vector3 &p1, const Vector3 &p2, const Vector3 &p3)
nuclear@13 228 : pt(p1)
nuclear@13 229 {
nuclear@13 230 normal = cross_product(p2 - p1, p3 - p1).normalized();
nuclear@13 231 }
nuclear@13 232
nuclear@13 233 Plane::Plane(const Vector3 &normal, float dist)
nuclear@13 234 {
nuclear@13 235 this->normal = normal.normalized();
nuclear@13 236 pt = this->normal * dist;
nuclear@13 237 }
nuclear@13 238
nuclear@13 239 void Plane::set_union(const GeomObject *obj1, const GeomObject *obj2)
nuclear@13 240 {
nuclear@13 241 error_log("Plane::set_union undefined\n");
nuclear@13 242 }
nuclear@13 243
nuclear@13 244 void Plane::set_intersection(const GeomObject *obj1, const GeomObject *obj2)
nuclear@13 245 {
nuclear@13 246 error_log("Plane::set_intersection undefined\n");
nuclear@13 247 }
nuclear@13 248
nuclear@13 249 bool Plane::contains(const Vector3 &pt) const
nuclear@13 250 {
nuclear@13 251 return false; // TODO: maybe define containment as half-space containment?
nuclear@13 252 }
nuclear@13 253
nuclear@13 254 bool Plane::intersect(const Ray &ray, HitPoint *hit) const
nuclear@13 255 {
nuclear@13 256 float ndotdir = dot_product(normal, ray.dir);
nuclear@13 257 if(fabs(ndotdir) < 1e-4) {
nuclear@13 258 return false;
nuclear@13 259 }
nuclear@13 260
nuclear@13 261 if(hit) {
nuclear@13 262 Vector3 ptdir = pt - ray.origin;
nuclear@13 263 float t = dot_product(normal, ptdir) / ndotdir;
nuclear@13 264
nuclear@13 265 hit->pos = ray.origin + ray.dir * t;
nuclear@13 266 hit->normal = normal;
nuclear@13 267 hit->obj = this;
nuclear@13 268 }
nuclear@13 269 return true;
nuclear@13 270 }