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Gosu Major Cycle
Modify a simple Ruby program to move a shape across the screen by modifying the tasks in the Gosu cycle update() and draw() methods.

Enhance the code provided as follows:
 Add a variable in the initialize() method called shape_x with the initial value of zero.
 Add code into the update() method that will add 10 to shape_x.
 Add code into the draw() method that will draw a shape (square or circle of any visible colour) at the y coordinate of 30 and x coordinate of shape_x.

My coding

require 'gosu' 
module ZOrder
 BACKGROUND, MIDDLE, TOP = *0..2 
 end
  WIDTH = 400 
  HEIGHT = 500
  SHAPE_DIM = 50
   
 class Game Window < Gosu::Window 
 end

def initialize 
super WIDTH, HEIGHT, false
 self.caption = "Shape Moving" 
 @HEIGHT = 30 
 @WIDTH = 80 
 @font = Gosu::Font.new(20)
 @cycle = 0
 @shape_y = HEIGHT / 2 
 @shape_x = WIDTH / 2 
 end 
 
 def update
  @cycle += 1 
  sleep(0.1) 
  if button_down?(Gosu::KbRight)
  if @shape_x != (WIDTH - SHAPE_DIM)
   @shape_x += 10 
   puts "Right button has pressed"
    end
    end
    end

 if button_down?(Gosu:KbLeft) && (@shape_x != 0)
  @shape_x -= 10
 puts "Right button has pressed"
  end

 
 if button_down?(Gosu::KbLeft) && (@shape_x != 0)
  @shape_x -= 10 
  puts "Left button has pressed" 
  end
  
 if button_down?(Gosu::KbUp) && (@shape_y != 0) 
 @shape_y -= 10 
 puts "Up button has pressed" 
 end 
 if button_down?(Gosu::KbDown)
  if @shape_y != (HEIGHT - SHAPE_DIM)
   @shape_y += 10
    puts "Down button has pressed." 
    end
    end 


 def draw
  @font.draw("Cycle count: #{@cycle}", 10, 10, z = ZOrder::TOP, 1.0, 1.0, Gosu::Color::WHITE)
  Gosu.draw_rect(@shape_x, @shape_y, SHAPE_DIM, SHAPE_DIM, Gosu::Color::RED, ZOrder::TOP, mode::default)
   end 
   
 window = GameWindow.new
   window.show



error showing
gosu_major_cycle.rb:9:in `<class:game>': uninitialized constant Game::Window (NameError)
from gosu_major_cycle.rb:9:in `'

Help me to solve this

What I have tried:

require 'gosu' 
module ZOrder
 BACKGROUND, MIDDLE, TOP = *0..2 
 end
  WIDTH = 400 
  HEIGHT = 500
  SHAPE_DIM = 50
   
 class Game Window < Gosu::Window 
 end

def initialize 
super WIDTH, HEIGHT, false
 self.caption = "Shape Moving" 
 @HEIGHT = 30 
 @WIDTH = 80 
 @font = Gosu::Font.new(20)
 @cycle = 0
 @shape_y = HEIGHT / 2 
 @shape_x = WIDTH / 2 
 end 
 
 def update
  @cycle += 1 
  sleep(0.1) 
  if button_down?(Gosu::KbRight)
  if @shape_x != (WIDTH - SHAPE_DIM)
   @shape_x += 10 
   puts "Right button has pressed"
    end
    end
    end

 if button_down?(Gosu:KbLeft) && (@shape_x != 0)
  @shape_x -= 10
 puts "Right button has pressed"
  end

 
 if button_down?(Gosu::KbLeft) && (@shape_x != 0)
  @shape_x -= 10 
  puts "Left button has pressed" 
  end
  
 if button_down?(Gosu::KbUp) && (@shape_y != 0) 
 @shape_y -= 10 
 puts "Up button has pressed" 
 end 
 if button_down?(Gosu::KbDown)
  if @shape_y != (HEIGHT - SHAPE_DIM)
   @shape_y += 10
    puts "Down button has pressed." 
    end
    end 


 def draw
  @font.draw("Cycle count: #{@cycle}", 10, 10, z = ZOrder::TOP, 1.0, 1.0, Gosu::Color::WHITE)
  Gosu.draw_rect(@shape_x, @shape_y, SHAPE_DIM, SHAPE_DIM, Gosu::Color::RED, ZOrder::TOP, mode::default)
   end 
   
 window = GameWindow.new
   window.show
Posted
Updated 20-Sep-22 1:12am
Comments
Richard MacCutchan 20-Sep-22 7:24am    
I do not know Ruby but are you sure that your class definition is correct?
class Game Window < Gosu::Window 

The word Window after Game - is that right?

1 solution

Compiling does not mean your code is right! :laugh:
Think of the development process as writing an email: compiling successfully means that you wrote the email in the right language - English, rather than German for example - not that the email contained the message you wanted to send.

So now you enter the second stage of development (in reality it's the fourth or fifth, but you'll come to the earlier stages later): Testing and Debugging.

Start by looking at what it does do, and how that differs from what you wanted. This is important, because it give you information as to why it's doing it. For example, if a program is intended to let the user enter a number and it doubles it and prints the answer, then if the input / output was like this:
Input   Expected output    Actual output
  1            2                 1
  2            4                 4
  3            6                 9
  4            8                16
Then it's fairly obvious that the problem is with the bit which doubles it - it's not adding itself to itself, or multiplying it by 2, it's multiplying it by itself and returning the square of the input.
So with that, you can look at the code and it's obvious that it's somewhere here:
C#
int Double(int value)
   {
   return value * value;
   }

Once you have an idea what might be going wrong, start using the debugger to find out why. Put a breakpoint on the first line of the method, and run your app. When it reaches the breakpoint, the debugger will stop, and hand control over to you. You can now run your code line-by-line (called "single stepping") and look at (or even change) variable contents as necessary (heck, you can even change the code and try again if you need to).
Think about what each line in the code should do before you execute it, and compare that to what it actually did when you use the "Step over" button to execute each line in turn. Did it do what you expect? If so, move on to the next line.
If not, why not? How does it differ?
Hopefully, that should help you locate which part of that code has a problem, and what the problem is.
This is a skill, and it's one which is well worth developing as it helps you in the real world as well as in development. And like all skills, it only improves by use!
 
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Member 15773088 20-Sep-22 9:36am    
This is not the answer fore my question.

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