Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>Hey everyone. Not sure if you have found this already but I am in the process of creating a snooker game in canvas. My collision detection / handling of the balls is as follows. It's using trig at the moment but could be optimised using some vector math instead. Anyway, you can see the progress with it in action -> <a href="http://snooker.stevekane.com.au/demo.html" rel="nofollow">here</a></p> <p>This loop runs in my animate function:</p> <pre><code>// checks if the any of the balls have collided with each other for(i=0;i&lt;ballArray.length;i++) { for(j=i;j&lt;ballArray.length;j++) { if(j != i) { if( Math.pow((ballArray[j].x - ballArray[i].x),2) + Math.pow((ballArray[j].y - ballArray[i].y),2) &lt;= (ballArray[i].radius + ballArray[j].radius) * (ballArray[i].radius + ballArray[j].radius)) { dx = ballArray[i].x - ballArray[j].x; dy = ballArray[i].y - ballArray[j].y; // collision angle is often refered to as the greek character 'phi' phi = Math.atan2(dy, dx); magnitude_1 = Math.sqrt(ballArray[i].vx * ballArray[i].vx + ballArray[i].vy * ballArray[i].vy); magnitude_2 = Math.sqrt(ballArray[j].vx * ballArray[j].vx + ballArray[j].vy * ballArray[j].vy); direction_1 = Math.atan2(ballArray[i].vy, ballArray[i].vx); direction_2 = Math.atan2(ballArray[j].vy, ballArray[j].vx); new_xspeed_1 = magnitude_1 * Math.cos(direction_1 - phi); new_yspeed_1 = magnitude_1 * Math.sin(direction_1 - phi); new_xspeed_2 = magnitude_2 * Math.cos(direction_2 - phi); new_yspeed_2 = magnitude_2 * Math.sin(direction_2 - phi); final_xspeed_1 = ((ballArray[i].mass - ballArray[j].mass) * new_xspeed_1 + (ballArray[j].mass + ballArray[j].mass) * new_xspeed_2) / (ballArray[i].mass + ballArray[j].mass); final_xspeed_2 = ((ballArray[i].mass + ballArray[i].mass) * new_xspeed_1 + (ballArray[j].mass - ballArray[i].mass) * new_xspeed_2) / (ballArray[i].mass + ballArray[j].mass); final_yspeed_1 = new_yspeed_1; final_yspeed_2 = new_yspeed_2; ballArray[i].vx = Math.cos(phi) * final_xspeed_1 + Math.cos(phi + Math.PI / 2) * final_yspeed_1; ballArray[i].vy = Math.sin(phi) * final_xspeed_1 + Math.sin(phi + Math.PI / 2) * final_yspeed_1; ballArray[j].vx = Math.cos(phi) * final_xspeed_2 + Math.cos(phi + Math.PI / 2) * final_yspeed_2; ballArray[j].vy = Math.sin(phi) * final_xspeed_2 + Math.sin(phi + Math.PI / 2) * final_yspeed_2; } } } } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POAdd collision to HTML5 Canvas
      singulars
      1. PTQuestion
    1. PTAnswer
    1. This table or related slice is empty.
    1. USSteve
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload