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oreoham48

Wed Jun 02, 2010 9:42 pm


Sprite jumping help

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What is it you are trying to achieve?
Make a sprite jump onscreen.


What is the problem you are having?
Sprite jumps erratically.


Describe what you have tried to solve this problem
Looked for tutorials.


Post any relevant code 



var numFrames : int := 7
var walkRight : array 0 .. numFrames of int
var walkLeft : array 0 .. numFrames of int
var delayTime : int
var keys : array char of boolean
var x : int := 0
var y : int := 100
var canJump : boolean := true
var velocity : int := 100
var gravity : int := 1
var maxVelocity := 100

% process BGM
%     loop
%         Music.PlayFile ("ice_Climber.mp3")
%     end loop
% end BGM
%
% fork BGM

View.Set ("graphics:960;720, nobuttonbar, nocursor")

% Loads the right walking frames
for picNo : 0 .. numFrames
    walkRight (picNo) := Pic.FileNew ("Morse_Walk_" + intstr (picNo) + "_R.bmp")
end for

% Loads the left walking frames
for picNo : 0 .. numFrames
    walkLeft (picNo) := Pic.FileNew ("Morse_Walk_" + intstr (picNo) + "_L.bmp")
end for

% Loads the jumping frames
var jumpPicR := Pic.FileNew ("Morse_Jump_R.bmp")
var jumpPicL := Pic.FileNew ("Morse_Jump_L.bmp")

% Sets the background to be blue
Draw.FillBox (0, 0, maxx, maxy, blue)

% Define the sprites for movement
var spriteWalkR := Sprite.New (walkRight (1))
Sprite.SetPosition (spriteWalkR, 0, y, false)

var spriteWalkL := Sprite.New (walkLeft (1))

var spriteJumpR := Sprite.New (jumpPicR)

var spriteJumpL := Sprite.New (jumpPicL)

% Walking loop
Sprite.Show (spriteWalkR)
loop
    Input.KeyDown (keys)
    if keys (KEY_RIGHT_ARROW) then
        if x < 900 then
            Sprite.Hide (spriteWalkL)
            x += 8
            Sprite.Show (spriteWalkR)
            Sprite.Animate (spriteWalkR, walkRight ((x div 8) mod numFrames), x, y, false)
            delay (40)
        end if
        Sprite.Animate (spriteWalkR, walkRight (1), x, y, false)
    elsif keys (KEY_LEFT_ARROW) then
        if x > 0 then
            Sprite.Hide (spriteWalkR)
            x -= 8
            Sprite.Show (spriteWalkL)
            Sprite.Animate (spriteWalkL, walkLeft ((x div 8) mod numFrames), x, y, false)
            delay (40)
        end if
        Sprite.Animate (spriteWalkL, walkLeft (1), x, y, false)
    end if
    % Jump if on the ground and you just didn't jump
    if keys (KEY_UP_ARROW) and y = 100 and canJump then
    Sprite.Hide (spriteWalkR)
    Sprite.Hide (spriteWalkL)
    Sprite.Show (spriteJumpR)
        velocity := maxVelocity
        y += velocity
        Sprite.SetPosition (spriteJumpR, x, y, false)
        canJump := false
    elsif y = 100 then
        % Need to touch the ground to jump again
        canJump := true
    end if
    % Fall due to gravity
    if y >= 200 then
        velocity -= gravity
        y += velocity
        if y