I'm trying to make a 2d side-scrolling platform game (a la castlevania). How do they make the character jump? stand on the platform? I am having trouble implementing them. Can someone here, teach me how? or maybe point me to a tutorial. I would be very grateful to any advice. Thanks in advance! Edited by - s_cloudx on February 5, 2002 9:21:16 PM

Check out the latest contest. It''s about making a side-scrolling game using the Game Development Kit.

One problem, Oluseyi

one slight push of my button and my character jumps high. I want to emulate the way games like mario that has a variety of jumps height. How do I do that?

The way I did jumping was like this:

if Key[KEY_JUMP] is pressed then Player.Speed.y = -10; 

and each frame I do this:

Player.Speed.y += Gravity;Player.y += Player.Speed.y; 

That''s all there is to it.

~CGameProgrammer( );

Actually, to do it the Mario way, this is probably a good way to do it... do this each frame:

if( Key[KEY_JUMP] is pressed ){    Player.Speed.y = -10;    Jumping = true;} if( Jumping ){    Player.JumpDist += 10;    if( Player.JumpDist >= 80 ) // max jump height        Jumping = false;}else // Falling{    Player.Speed.y += Gravity;    Player.y += Player.Speed.y;} 

~CGameProgrammer( );

At last! I was able to get my character to jump. But I did it in a different way. You guys gave me the idea. Anyways, from memory, this is my code:

//Possible actions the player can do
enum PlayerAction = {WALKING, RUNNING, JUMPING, FALLING ...}

struct
{
//location of character
int x,y;

//jump related valuables
int Gravity;
int maxJumpHeight;

PlayerAction PA;

} Player;

//Default gravity. change this to make an anti-gravity room or
//heavy gravity room.
int Default_Gravity = 2;

void Init_Player()
{

//initialize the current gravity to the default
Player.Gravity = Default_Gravity;

//the maximum height in pixel the character can jump
Player.maxJumpHeight = -10;

}

void Controls()
{

//if player pushes Jump button
if (Key(JUMP_BUTTON))

//make sure we don't double jump when we reach our maximum jump
if (Player.PA != FALLING)
{

//set the player to jumping
Player.PA = JUMPING;

//If the Player is still starting his jump, decrease by 2
//else decrease by one. this will slow his jump.
if (Player.Gravity > 0)
Player.Gravity -= 2;
else
Player.Gravity --;

//skip the rest of the function to speed things up
return;
}

//if player releases Jump button while the player is jumping
if (!Key(JUMP_BUTTON) && Player.PA == JUMPING)
{

//he falls
Player.PA == FALLING;
}

//the player is falling
if (Player.PA == FALLING)
{

// if the player's gravity is negative, fall slowly
// otherwise fall fast

if (Player.Gravity < 0)
Player.Gravity ++;
else
Player.Gravity += 2;

//skip the rest of the function to speed things up
return;
}

//the player isn't jumping or falling
if (Player.PA != JUMPING || Player.PA != FALLING)

//reset the gravity
Player.Gravity = Default_Gravity;
}

void Apply_Gravity()
{

// if the gravity is positive, the player will fall.
// otherwise he will rise.
Player.x -= Player.Gravity;

// if the player has reached the highest point he can jump
if (Player.Gravity < Player.maxJumpHeight)
{
Player.PA = FALLING;
}

}

//this is called every frame
void UpdateFrame()
{

Controls();

ApplyGravity();

//this function will check the AI, logic, etc.
Logic();

//this function will draw the sprites, background, character, etc.
Render();

}

--------

what do you guys think?


P.s. Maraming salamat sa tulong nyo (Thank you very much for all your help!)


Edited: Forgoten UpdateFrame. Added UpdateFrame()

Edited by - s_cloudx on February 9, 2002 8:11:08 PM