Difference between revisions of "10th Floor/programming"

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(sphere collision)
 
(Collision: sphere to rectangle collision)
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=Collision=
 
=Collision=
*Sphere to Sphere collision
+
'''Sphere to Sphere Collision '''
 
**Each sphere is described by an x and y co-ordinate located in the very center, as well as a radius.
 
**Each sphere is described by an x and y co-ordinate located in the very center, as well as a radius.
 
**If the distance between each sphere is less than the sum of their radius's, then a collision has occurred.
 
**If the distance between each sphere is less than the sum of their radius's, then a collision has occurred.
'''Sphere to Sphere Collision '''
 
 
<pre style="display: inline-block;">
 
<pre style="display: inline-block;">
 
int collision_sphere (x_sphere1, y_sphere1, r_sphere1, x_sphere2, y_sphere2, r_sphere2){
 
int collision_sphere (x_sphere1, y_sphere1, r_sphere1, x_sphere2, y_sphere2, r_sphere2){
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}
 
}
 
</pre>
 
</pre>
 +
'''Sphere to Rectangle Collision'''
 +
**Sphere is still describes as above. x, y, and radius.
 +
**Rectangles described as x, y from bottom left corner. As well as width and height.
 +
**If the value of the sphere's x and y is between the rectangles borders + the radius of the sphere, collision has occurred.
 +
<pre style="display: inline-block;">
 +
int collision_sphere_rect (x_sphere, y_sphere, r_sphere, x_rect, y_rect, w_rect, h_rect){
 +
  int collision = 0;
 +
  if ( (x_sphere > x_rect) && (x_sphere < (x_rect + w_rect) ){ //potential collision, sphere between rectangle borders on x axis
 +
    if ( (y_sphere > y_rect) && (y_sphere < (y_rect + h_rect) ){ //confirmed collision, sphere also between rectangle borders on y axis
 +
      collision = true;
 +
    }
 +
  }
 +
  return collsion;
 +
}
 +
</pre>
 +
**that's the basic idea. Depending on the direction the sphere is moving you'll have to add or subtract the radius from the comparision, otherwise collision will only be true when half or more of the sphere is within the rectangle.

Revision as of 15:44, 8 October 2010

Collision

Sphere to Sphere Collision

    • Each sphere is described by an x and y co-ordinate located in the very center, as well as a radius.
    • If the distance between each sphere is less than the sum of their radius's, then a collision has occurred.
int collision_sphere (x_sphere1, y_sphere1, r_sphere1, x_sphere2, y_sphere2, r_sphere2){
  int collision = 0;
  double distance = √(x_sphere1 - x_sphere2)² + (y_sphere1 - y_sphere2)²; // calculate distance
  if ((r_sphere1 + r_sphere2) > distance){ // compare to sum of radius
    collsion = 1;
  }
  return collsion;
}

Sphere to Rectangle Collision

    • Sphere is still describes as above. x, y, and radius.
    • Rectangles described as x, y from bottom left corner. As well as width and height.
    • If the value of the sphere's x and y is between the rectangles borders + the radius of the sphere, collision has occurred.
int collision_sphere_rect (x_sphere, y_sphere, r_sphere, x_rect, y_rect, w_rect, h_rect){
  int collision = 0;
  if ( (x_sphere > x_rect) && (x_sphere < (x_rect + w_rect) ){ //potential collision, sphere between rectangle borders on x axis
    if ( (y_sphere > y_rect) && (y_sphere < (y_rect + h_rect) ){ //confirmed collision, sphere also between rectangle borders on y axis
      collision = true;
    }
  }
  return collsion;
}
    • that's the basic idea. Depending on the direction the sphere is moving you'll have to add or subtract the radius from the comparision, otherwise collision will only be true when half or more of the sphere is within the rectangle.