XNA - Hold longer to jump higher

Question

I\'m looking for a simple method for my game, so that when you hold down the space bar, you jump higher. When you \'tap\' you don\'t jump to maximum height. There would need to

Answer 1

During the accent of a jump, the Y velocity is completely overridden by a power curve. During the decent, gravity takes over. The jump velocity is controlled by the jumpTime field which measures time into the accent of the current jump.

First off you will need some simple global variables,

public bool isJumping; //Is the player in a jump?
private bool wasJumping; //Did the player just exit a jump?
private float jumpTime; //Time the player has been in a jump (Useful for adding a power curve or to max out on jump height)

MaxJumpTime = .8f; //If you want to max out a jump, otherwise remove the relevant parts of the code
JumpLaunchVelocity = -3000.0f; //How much velocity to "jump" with, this may depend on your speed of your player, so it will need some ajustment

Here is the function that does most of the work:

 private float DoJump(float velocityY, GameTime gameTime)
        {
            // If the player wants to jump
            if (isJumping)
            {
                // Begin or continue a jump
                if ((!wasJumping && IsOnGround) || jumpTime > 0.0f)
                {
                    //Do things like animate, or play a sound here
                    jumpTime += (float)gameTime.ElapsedGameTime.TotalSeconds;
                }

                // If we are in the ascent of the jump
                if (0.0f < jumpTime && jumpTime <= MaxJumpTime)
                {
                    // Fully override the vertical velocity with a power curve that gives players more control over the top of the jump (If you dont want this you can remove the Math.Pow)
                    velocityY = JumpLaunchVelocity * (1.0f - (float)Math.Pow(jumpTime / MaxJumpTime, JumpControlPower));
                }
                else
                    jumpTime = 0.0f;   // Reached the apex of the jump
            }
            else
            {
                // Continues not jumping or cancels a jump in progress
                jumpTime = 0.0f;
            }
            wasJumping = isJumping;

            return velocityY;
        }

In your update when you calculate position and stuff:

velocity.Y = DoJump(velocity.Y, gameTime);

Take a look at the Platformer Starter Kit if you run into any problems!