How to move up and down a ladder in a platform game
I am creating a platform game and want to move up and down ladders. I had created a previous post about creating elevators at http://forums.adobe.com/message/5974173#5974173
I cannot get the movement up and down ladders right. What I have so far is calculating the height of the ladder and then move the character vertical using the hero.y coordinates. This is not smooth and very jerky. What I need is to have the character move in a smooth motion up and down the ladder. I am not sure what I am doing wrong?
Here is a screenshot of my ladder. It is 113.3 pixels in height.
Here is the code I have so far:
public function keyDownFunction(event:KeyboardEvent)
{
// don't move until in play mode
if (gameMode != "play") return;
if (event.keyCode == 38) // 38 is keycode for up arrow
{
hero.moveUp = true;
}
if (event.keyCode == 40) // 40 is keycode for down arrow
{
hero.moveDown = true;
}
if (event.keyCode == 37) // 37 is keycode for left arrow
{
//trace("Push Left");
hero.moveLeft = true;
}
else if (event.keyCode == 39) // 39 is keycode for right arrow
{
//trace("Push Right");
hero.moveRight = true;
}
else if (event.keyCode == 32) // 32 is keycode for spacebar
{
if (!hero.inAir)
{
hero.jump = true;
}
}
}
public function checkCollisions()
{
for (var i:int = enemies.length-1;i >= 0; i--)
{
if (hero.mc.hitTestObject(enemies.mc))
{
// is the hero jumping down onto the enemy?
if (hero.inAir && (hero.dy > 0))
{
enemyDie(i);
}
else
{
heroDie();
}
}
}
// items
for (i=otherObjects.length-1; i>=0;i--)
{
if (hero.mc.hitTestObject(otherObjects))
{
getObject(i);
}
}
// pit
for (i=evilObjects.length-1; i>=0; i--)
{
if (hero.mc.hitTestObject(evilObjects))
{
heroDie();
}
}
// climb ladder
for (i=ladderObjects.length-1; i>=0; i--)
{
if (hero.mc.hitTestObject(ladderObjects))
{
//climbLadder();
//trace(ladderObjects.y);
/*
if (hero.mc.y < ladderObjects.y-1)
{
hero.mc.y -= 1;
}
*/
if (hero.moveUp)
{
for (var h:int = 0; h < (ladderObjects.height-1); h++)
{
hero.mc.y -= 1;
}
}
}
}
}
My thought was to use the checkCollisions() function. The code uses the following conditional operations:
1. is the hero touching a ladder?
2. is the player pushing the up arrow on the keyboard? If so, then move the hero.y up the height of the ladder mc.
What can I do to fix this to make the hero move smoothly? Also, I had to move the ladder down slightly so that when the hero is standing on a ledge above the ladder the hero does not touch the ladder mc. I have some coding error that makes the hero not able to jump when touching it. This same inability to jump also happens if the hero is touching an elevator or a spring.
Thanks,
Alex
AdChoices