help with jumps

[deathsangel]

can you give me an example of how to make a jump feature?

[MadPumpkin]

can you give me an example of how to make a jump feature?

dude... specify your language, if your using Macromedia ActionScript2, or AS3 i can pop something out in 2 minutes on a fully working jump, but if its C/++/# you'll have to ask someone else i cant do any graphical C/++/# only console

[deathsangel]

Im using c++ and sdl

[MadPumpkin]

Im using c++ and sdl

then well... i can't help very much, although it could be very similar to AS jump movement if you would like me to put it up

[thejahooli]

it would be the same really for any language and API as the concepts would be the same.

Also how realistic do you want it to be? Because I could probably think up a very unrealistic jump that would look rubbish but I wouldn't be able to make a decent one

[Spikey]

Regardless of language, this will work.
Make your object have a velocity in which is updated onto object's position every tick/update.
To jump, add a Y+ velocity, say +20.
Then every tick, apply gravity, say -9
check for floor collision to stop fall. You can also do things like terminal fall velocity, ie) if Y_Velocity < -20 then Y_Velocity = -20
Also depending on the frame rate or based how objects are updated you might need to scale everything down. Y_Position += Y_Velocity * SCALE

[deathsangel]

right now my jump code looks like this

Code: Select all

void jump()
{
	// decide if the player can or cant jump  
	if (can_jump)
	{
		// set it to false so that you cannot double jump
		can_jump = false;

		// move the player up 70 pixels
		Player1.set_y(Player1.get_y() - 70);
	}
}

can jump is set to true when there is a collision with a tile

how can I make it a more smooth jump so that he does not just "teleport" to the location

[MadPumpkin]

Heres a cute little jump code i picked up a while back for AS2 possibly someone can just skrew around with it and make it C++ style

Code: Select all

if (speed<1 && speed>-1) {
   speed = 0;
}
if (Key.isDown(Key.UP) && !jumpness) {
   jumpness = true;
}
if (jumpness) {
   this._y -= jump;
   jump -= .5;
   if (jump<0) {
   falling = true;
}
if (jump<-10) {
   jump = -10;
}

[deathsangel]

Ive updated my jump code! Now it looks better, but not perfect can you help me improve it?

Code: Select all

void jump()
{
	if (can_jump)
	{
		can_jump = false;

		jumpY = Player1.get_y() - 90;
		jumped = true;
	}

	if (jumped)
	{
		if (Player1.get_y() > jumpY)
			Player1.set_y(Player1.get_y() - 3.0f);

		else
			jumped = false;
	}
}

[MarauderIIC]

You forgot to reset can_jump to true.

[deathsangel]

actually that happens when there is collision between the player and the top of a tile.

[eatcomics]

Doesn't this code just make him warp to the jump height, then warp to the ground again????

[deathsangel]

nope it works like this

1) if the user cannot jump skip the function
2) if the user can jump then set can jump to false
3) this way he cannot jump again until he touches the ground
4) set the jump coordinate to 90 pixels above the user
5) while the user is holding down the jump key(space)
a) move the player to the jump coordinate
b) check where the player is
6) if the player is at the jump coordinate stop jumping and allow gravity to take over...

However this does not work to well because the user can keep jumping as long as he does not go above the jump coordinate

[eatcomics]

nope it works like this

1) if the user cannot jump skip the function
2) if the user can jump then set can jump to false
3) this way he cannot jump again until he touches the ground
4) set the jump coordinate to 90 pixels above the user
5) while the user is holding down the jump key(space)
a) move the player to the jump coordinate
b) check where the player is
6) if the player is at the jump coordinate stop jumping and allow gravity to take over...

However this does not work to well because the user can keep jumping as long as he does not go above the jump coordinate

ahh, i see now

[MarauderIIC]

So you need to make it so they 'can't jump' once they reach the jump height.