Changes

<source lang="cpp">sprite.CollidesWith(&sprite2);</source>

<source lang="cpp">sprite.CollidesWith(&sprite2);</source>

  This will test both sprite and sprite2’s locations in terms of their x and y values AS WELL as their x values +width and height values + height. If sprite and sprite2 are colliding then the function will return true else it will return false. If your still a little unsure about what will return true and what will return false have a look at this and behold my awesome Paint skills:

  This will test both sprite and sprite2’s locations in terms of their x and y values AS WELL as their x values +width and height values + height. If sprite and sprite2 are colliding

then the function will return true else it will return false. If your still a little unsure about what will return true and what will return false have a look at this and behold my

awesome Paint skills:

Figure 1: Returns false; Figure 2: Returns true

Figure 1: Returns false; Figure 2: Returns true

             Player.x = oldX</source>

             Player.x = oldX</source>

The previous section of code gets the players x position at the start of every loop and saves it in an int. Then, it makes a call to CollidesWith() and tests if sprite is colliding with sprite2, if this returns true then Player.x will be changed to whatever it was at the start of that loop. You have to make sure that you lay out the get x, THEN input from the wii mote then call the collision function. If you don’t understand why this must be done, I’ll walk you through an example, say Player.x = 100, when it gets to  

The previous section of code gets the players x position at the start of every loop and saves it in an int. Then, it makes a call to CollidesWith() and tests if sprite is colliding with sprite2, if this returns true then Player.x will be changed to whatever it was at the start of that loop. You have to make sure that you lay out the get x, THEN input from the wiimote then call the collision function. If you don’t understand why this must be done, I’ll walk you through an example, say Player.x = 100, when it gets to  

<source lang="cpp">int oldX = Player.x;</source>

<source lang="cpp">int oldX = Player.x;</source>

First it will check Node1, this will return true as Player is inside Node1, it will then proceed to check all of the objects in Node1 against player, once this has finished, it will check Node2, which again will return true and check collision for the objects in Node2. Then it will check Nodes 3 and 4 which will both return false. This is now 54 checks rather than 100.

First it will check Node1, this will return true as Player is inside Node1, it will then proceed to check all of the objects in Node1 against player, once this has finished, it will check Node2, which again will return true and check collision for the objects in Node2. Then it will check Nodes 3 and 4 which will both return false. This is now 54 checks rather than 100.

This hasn’t been the best way of implementing a Node based collision system, it would have been better to create a node class then instance it for easier use, although I don’t have the time. This system is similar to one called a quad tree, although it may be over kill to implement such a sophisticated system in what will mostly be 2D programs, the basics are that it will split your plane into 4 equal sized nodes just like figure 4, then check collision against those nodes, this is where it gets a little more complicated. Once it knows which nodes you are in, it will then split that node into another 4 nodes like in figure 8:

This hasn’t been the best way of implementing a Node based collision system, it would have been better to create a node class then instance it for easier use, although I don’t have the time. This system is similar to one called a quad tree, although it may be overkill to implement such a sophisticated system in what will mostly be 2D programs, the basics are that it will split your plane into 4 equal sized nodes just like figure 4, then check collision against those nodes, this is where it gets a little more complicated. Once it knows which nodes you are in, it will then split that node into another 4 nodes like in figure 8:

[[Image:Flexfig8.png]]

[[Image:Flexfig8.png]]

width The width of the collision rectangle.  

width The width of the collision rectangle.  

height The height of the collision rectangle.</source>

height The height of the collision rectangle.</source>

It looks long and complicated but really it’s just the same as setting up a Rectangle object. A Collision Rectangle is an area in our plane that we can check against for collision that has 4 sides, exactly the same as our Nodes, so let’s say we wanted to create Nod1 from this, we would do it as such:

It looks long and complicated but really it’s just the same as setting up a Rectangle object. A Collision Rectangle is an area in our plane that we can check against for collision that has 4 sides, exactly the same as our Nodes, so let’s say we wanted to create Nod1 from this, we would do it as such: