How can I jump on Gosu gem from Ruby? - ruby

Question

I'm trying to recreate a simple game but I'm stuck at the moment that I'm trying to make jump my character( or player).
I've been checking the example from gosu but it's not really clear for me.
Can someone help me?
Here is my window code:
class Game < Gosu::Window
def initialize(background,player)
super 640,480
self.caption = "My First Game!"
#background = background
#player = player
#player.warp(170,352)
#x_back = #y_back = 0
#allow_to_press = true
end
# ...
def update
#...
if Gosu.button_down? Gosu::KbSpace and #allow_to_press
#allow_to_press = false
#player.jump
end
end
end
Then my player class:
class Player
def initialize(image)
#image = image
#x = #y = #vel_x = #vel_y = #angle = 0.0
#score = 0
end
def warp(x,y)
#x,#y = x,y
end
def draw
#image.draw_rot(#x,#y,1,#angle,0.5,0.5,0.3,0.3)
end
def jump
##y -= 15 # THIS IS NOT CORRECT
end
end
Basically, the idea is when u press Space, then the jump method is invoked and here i should be able to recreate an animation to move the "y" position up ( for example 15 px) and then go down again.
Just i have on my mind change the value of #y variable but i don't know how to do it with an animation and then come back at the original point.
Thanks!

Answer 1

Finally I got it!
What I did is split the jump and an update method inside player:
class Player
def initialize(image)
#image = image
#x = #y = #angle = 0.0
#score = #vel_y = #down_y = 0
#allow = true
end
def warp(x,y)
#x,#y = x,y
end
def update(jump_max)
#Jump UP
if #vel_y > 0
#allow = false
#vel_y.times do
#y-=0.5
end
#vel_y-=1
end
#Jump DOWN
if #vel_y < 0
(#vel_y*-1).times do
#y+=0.5
end
#vel_y+=1
end
check_jump
end
def draw
#image.draw_rot(#x,#y,1,#angle,0.5,0.5,0.3,0.3)
end
def jump(original)
#vel_y = original
#down_y = original * -1
end
def check_jump
if #vel_y == 0 and #allow == false
#vel_y = #down_y
#down_y = 0
#allow = true
end
end
end
And then on my Game class
...
def initialize(background,player,enemy_picture)
#size of the game
super 640,480
#original_y = 352
#original_x = 170
self.caption = "Le Wagon Game!"
#background = background
#player = player
#player.warp(#original_x,#original_y)
#enemy_anim = enemy_picture
#enemy = Array.new
#Scrolling effect
#x_back = #y_back = 0
#jump = true
#jumpy = 25
end
def update
if Gosu.button_down? Gosu::KbSpace and #jump
#jump = false
#player.jump(#jumpy)
end
#player.update(#jumpy)
end
def button_up(id)
if id == Gosu::KbSpace
#jump = true
end
super
end
end
So now I can press Space and it goes up, after finish the transition, it goes down