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plq/Makefile

Last active May 29, 2017
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randcoll: randcoll.cpp
g++ -g randcoll.cpp -std=c++11 -o randcoll
/*
* This small exercise aims to propose an implementation of the main
* collision checking loop of a fictional 3D game engine.
*
* Our game engine supports two types of objects: Cubes and Spheres.
* We are trying to come up with the most elegant (ie easy to
* understand and maintain) solution for choosing among three possible
* collision check cases: Cube <=> Cube, Sphere <=> Sphere, and
* Cube <=> Sphere.
*
* Please fork this gist and submit a path with the following TODO items
* completed.
*
* TODO Items:
* 1. Fix std::vector definition for the object array named "objects"
* 2. Add 2 cubes and 2 spheres to the objects array.
* 3. Implement collides_with member methods for all object types.
* ie. cube <=> cube, cube <=> sphere and sphere <=> sphere
* The functions themselves are to be EMPTY!. no actual collision
* detection code is requested. Just make them return true or false
* randomly!
*/
#include <time.h>
#include <vector>
#include <random>
#include <iostream>
#include <typeinfo>
bool true_or_false() {
return std::rand() % 2;
}
class Object;
class Sphere;
class Cube;
class Object {
public:
explicit Object()
: m_object_id(++s_num_objects) {
}
int get_object_id() const {
return m_object_id;
}
static int get_num_objects() {
return s_num_objects;
}
bool operator==(const Object &other) const {
return m_object_id == other.get_object_id();
}
virtual bool collides_with(Object &obj) = 0;
/* TODO 3 */
private:
static int s_num_objects;
int m_object_id;
};
class Sphere: public Object {
/* TODO 3 */
};
class Cube: public Object {
/* TODO 3 */
};
std::vector<Object> objects; // FIXME 1: Fix the object type here.
int main(void) {
srand(time(NULL));
/* TODO 2: add two spheres and two cubes to the objects array */
for(int i = 0; i < objects.size(); ++i) {
auto &obj1 = objects.at(i);
for(int j = i; j < objects.size(); ++j) {
auto &obj2 = objects.at(j);
if (obj1 == obj2) {
continue;
}
/* TODO 3: implement collides_with */
if (obj1.collides_with(obj2)) {
/* as an example
std::cout
<< "object id " << obj1.get_object_id()
<< " of type " << typeid(obj1).name()
<< " collides with "
<< "object id " << obj2.get_object_id()
<< " of type " << typeid(obj2).name();
*/
}
else {
/* as an example
std::cout
<< "object id " << obj1.get_object_id()
<< " of type " << typeid(obj1).name()
<< " does NOT collide with "
<< "object id " << obj2.get_object_id()
<< " of type " << typeid(obj2).name();
*/
}
}
}
return 0;
}
object id 1 of type 4Cube check Cube => Cube collides with object id 2 of type 4Cube
object id 1 of type 4Cube check Sphere => Cube collides with object id 3 of type 6Sphere
object id 1 of type 4Cube check Sphere => Cube does not collide with object id 4 of type 6Sphere
object id 2 of type 4Cube check Sphere => Cube collides with object id 3 of type 6Sphere
object id 2 of type 4Cube check Sphere => Cube does not collide with object id 4 of type 6Sphere
object id 3 of type 6Sphere check Sphere => Sphere collides with object id 4 of type 6Sphere
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