Java-Gaming.org Hi !
Featured games (83)
games approved by the League of Dukes
Games in Showcase (538)
Games in Android Showcase (132)
games submitted by our members
Games in WIP (601)
games currently in development
News: Read the Java Gaming Resources, or peek at the official Java tutorials
 
    Home     Help   Search   Login   Register   
Pages: [1]
  ignore  |  Print  
  How to create movement with acceleration/force? 2D platformer  (Read 3981 times)
0 Members and 1 Guest are viewing this topic.
Offline Shane75776
« Posted 2011-12-15 02:02:00 »

So basically right now my character moves at a constant speed left and right and what I would like to
have is the character slowly speed up the longer the movement key (left or right) is pressed and then come to a
stop when its released.

Here is my move method right now.
1  
2  
3  
4  
5  
6  
7  
8  
9  
10  
11  
public void move()
   {
      x += speed * dx;
      y += dy;
     
      if(y > 760 || y < 0)
      {
         dead = true;
         x = startX;
         y = startY;
      }

dx is the value that determines if he moves left or right, switches between 0, 1, -1
speed is a constant. currently set to 1.


If someone could update it and explain to me how works I would be super happy.

Thanks

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Offline Cero
« Reply #1 - Posted 2011-12-15 02:09:17 »

well its called acceleration - another factor

you have the location x,y - the speed x,y and the the acceleration

the acceleration determines how fast the speed changes, and the speed determines how fast the object it moved/relocated

Offline Shane75776
« Reply #2 - Posted 2011-12-15 02:22:46 »

well its called acceleration - another factor

you have the location x,y - the speed x,y and the the acceleration

the acceleration determines how fast the speed changes, and the speed determines how fast the object it moved/relocated

Yes I know how it works, I just have no idea how to implement it in code. which is what meant by my original question.

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Games published by our own members! Check 'em out!
Legends of Yore - The Casual Retro Roguelike
Offline gbeebe

Senior Devvie


Medals: 5
Projects: 1



« Reply #3 - Posted 2011-12-15 02:41:47 »

1  
2  
3  
4  
5  
6  
7  
8  
9  
10  
11  
12  
13  
14  
public void move()
   {
    speed = speed + dx;

      x += speed;
      y += dy;
     
      if(y > 760 || y < 0)
      {
         dead = true;
         x = startX;
         y = startY;
      }
}


You may want to cap the min and max of speed, and you may find that this acceleration is too fast, if so change speed, and x to a double and:
1  
2  
speed = dx * 0.001;
x = x + speed)


You can change 0.001 to your desired rate of acceleration.  Also, for slowing down, if dx = 0 figure out if speed is negative or positive and head towards zero.
Offline Shane75776
« Reply #4 - Posted 2011-12-15 03:20:39 »

alright, now I tried to implement that but now I get an issue with my drawing of my image.

because x is now a double I get an error when I try to draw my image in my draw method.

g2d.drawImage(image,x,y,null);

So do I need to cast it back to an int? And if so wouldnt that just make my x be 1 and im back at having a constant speed of 1?

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Offline ra4king

JGO Kernel


Medals: 356
Projects: 3
Exp: 5 years


I'm the King!


« Reply #5 - Posted 2011-12-15 03:55:33 »

g2d.drawImage(image,(int)Math.round(x),y,null);

And gbeebe made a typo, should be:
1  
2  
speed += dx * 0.001;
x += speed;

Offline Shane75776
« Reply #6 - Posted 2011-12-15 05:15:39 »

even that did not work.

when I try to move, my sprite does not move at all, just stays stuck. but if I got back to a constant and not use doubles (which makes it so I cant have an acceleration) it works.

This cant be that hard, I have seen many games do this on here =\

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Offline ra4king

JGO Kernel


Medals: 356
Projects: 3
Exp: 5 years


I'm the King!


« Reply #7 - Posted 2011-12-15 05:42:12 »

Post all related code. This sounds like a casting error.

Offline Shane75776
« Reply #8 - Posted 2011-12-15 05:54:14 »

Alright, ill post the source in a zip if you like. or I can just jar it up with source included. so you can run and see what its like normally.

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Offline Shane75776
« Reply #9 - Posted 2011-12-15 05:59:36 »

http://www.mediafire.com/?st3494f7osd9kue

The code is a bit sloppy and not very commented throughout most of it, I tend to do that until I get an end product im happy
with from which I go through, re-program it better and clean it up.

There are some glitches still needing to be worked out but anyways, the Player.java is the file you will find my move method in. Its being updated
from BlockmanMain.java

I put everything back to how I originally had it without the doubles so it will run on startup.

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Games published by our own members! Check 'em out!
Legends of Yore - The Casual Retro Roguelike
Offline ra4king

JGO Kernel


Medals: 356
Projects: 3
Exp: 5 years


I'm the King!


« Reply #10 - Posted 2011-12-15 06:02:58 »

Just posting the character class here on JGO is enough >.<
Too lazy to download a jar, extract it, and look through all the source Cheesy

Offline Shane75776
« Reply #11 - Posted 2011-12-15 06:06:02 »

Alright, ill do that then my bad

A lot of the methods in the player class are not used, a lot were made and then abandoned I just have not cleaned them up yet.


PLAYER CLASS <which is updated by the BlockMan class which I will post below>
1  
2  
3  
4  
5  
6  
7  
8  
9  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
54  
55  
56  
57  
58  
59  
60  
61  
62  
63  
64  
65  
66  
67  
68  
69  
70  
71  
72  
73  
74  
75  
76  
77  
78  
79  
80  
81  
82  
83  
84  
85  
86  
87  
88  
89  
90  
91  
92  
93  
94  
95  
96  
97  
98  
99  
100  
101  
102  
103  
104  
105  
106  
107  
108  
109  
110  
111  
112  
113  
114  
115  
116  
117  
118  
119  
120  
121  
122  
123  
124  
125  
126  
127  
128  
129  
130  
131  
132  
133  
134  
135  
136  
137  
138  
139  
140  
141  
142  
143  
144  
145  
146  
147  
148  
149  
150  
151  
152  
153  
154  
155  
156  
157  
158  
159  
160  
161  
162  
163  
164  
165  
166  
167  
168  
169  
170  
171  
172  
173  
174  
175  
176  
177  
178  
179  
180  
181  
182  
183  
184  
185  
186  
187  
188  
189  
190  
191  
192  
193  
194  
195  
196  
197  
198  
199  
200  
201  
202  
203  
204  
205  
206  
207  
208  
209  
210  
211  
212  
213  
214  
215  
216  
217  
218  
219  
220  
221  
222  
223  
224  
225  
226  
227  
228  
229  
230  
231  
232  
233  
234  
235  
236  
237  
238  
239  
240  
241  
242  
243  
244  
245  
246  
247  
248  
249  
250  
251  
public class Player extends Thread
{
   private Image image;
   private Thread animator; //animates the jump
   private boolean jump = false;
   private boolean jumping = false; //is in the middle of a jump
   private boolean done = false; //tells when jumping is done
   private boolean peak = false; //tells when at peak of jump
   private boolean falling = false; //if player is falling, or in the air still
   private boolean rising = false;
   private boolean movingRight = false;
   
   public boolean grounded = true;
   public boolean dead = false;
   
   private int width = 10;
   private int height = 10;
   
   private int x;
   private int y;
   private int startX;
   private int startY;
   
   private int dx;
   private int dy = 0;
   
   private int speed = 1;
   
   private int jumpHeight = 50;
   private int groundHeight;
   
   
   String url = "player.png";
   
   public Player()
   {
      ImageIcon ii = new ImageIcon(this.getClass().getResource("/images/player_2.png"));
      image = ii.getImage();
      groundHeight = y;
     
   }
   public void update()
   {
      move();
   }
   public void move()
   {
      x += speed * dx;
      y += dy;
     
      if(y > 760 || y < 0)
      {
         dead = true;
         x = startX;
         y = startY;
      }
     
   }
   public void jump()
   {
     
      if(!jump)
      {  
         grounded = false;
         jump = !jump;
         
         animator = new Thread(this);
         animator.start();
      }
   }
   public void draw(Graphics2D g2d)
   {
      g2d.drawImage(image,x,y,null);
   }
   public Image getImage()
   {
      return image;
   }
   public int getX()
   {
      return x;
   }
   public int getY()
   {
      return y;
   }
   public void setX(int x)
   {
      this.x = x;
   }
   public void setY(int y)
   {
      this.y = y;
   }
   public void setStartPoint(int x, int y)
   {
      this.startX = x;
      this.startY = y;
   }
   public void reset()
   {
      x = startX;
      y = startY;
      dx = 0;
      grounded = true;
   }
   public void restart()
   {
      x = startX;
      y = startY;
      dx = 0;
      dead = !dead;
      grounded = true;
   }
   public int getStartX()
   {
      return startX;
   }
   public int getStartY()
   {
      return startY;
   }
   public void setDx(int dx)
   {
      this.dx = dx;
   }
   public void shoveLeft(int amnt)
   {
      x -= amnt;
   }
   public void shoveRight(int amnt)
   {
      x += amnt;
   }
   public void shoveDown(int amnt)
   {
      y += amnt;
   }
   public void reverseDx()
   {
      this.dx *= -1;
   }
   public void stopJump()
   {
      done = true;
   }
   public void setDy(int dy)
   {
      this.dy = dy;
   }
   public int getDy()
   {
      return dy;
   }
   public void correctY(int y)
   {
      this.y = y - height;
   }
   public int getCenterX()
   {
      return (int) (width/2);
   }
   public int getCenterY()
   {
      return (int) (height/2);
   }
   public void setGroundHeight(int height)
   {
      this.groundHeight = height;
   }
   public boolean isRising()
   {
      return rising;
   }
   public boolean isFalling()
   {
      return falling;
   }
   public boolean isMovingRight()
   {
      return movingRight;
   }
   public void movingRight(boolean right)
   {
      this.movingRight = right;
   }
   public void setPeak(boolean peaked)
   {
      this.peak = peaked;
   }
   public boolean isJumping()
   {
      return jumping;
   }
   public Rectangle getBounds()
   {
      return new Rectangle(x,y,width,height);
   }
   
   //Thread for jumping
   @Override
   public void run()
   {
      long beforeTime, timeDiff, sleep;
     
      beforeTime = System.currentTimeMillis();
     
      while(done == false)
      {
         cycle();
         timeDiff = System.currentTimeMillis() - beforeTime;
         sleep = 8 - timeDiff;
         if(sleep < 0)
            sleep = 2;
         try
         {
            Thread.sleep(sleep);
         }
         catch(Exception e){e.printStackTrace();}
         beforeTime = System.currentTimeMillis();
      }
      done = false;
      jump = false;
      peak = false;
   }
   public void cycle()
   {
      if(peak == false)
      {
         rising = true;
         y-=3;
      }
      if(y <= (groundHeight-jumpHeight))
      {
         peak = true;
         rising = false;
      }
      if(peak == true && (y+height) <= groundHeight)
      {
         rising = false;
         setDy(1);
      }
         if((y+height) == groundHeight && !falling)
            done = true;
         else if((y+height) == groundHeight && falling)
         {
            groundHeight = 760;
            done = true;
         }  
   }
}


BLOCKMAN MAIN CLASS
1  
2  
3  
4  
5  
6  
7  
8  
9  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
54  
55  
56  
57  
58  
59  
60  
61  
62  
63  
64  
65  
66  
67  
68  
69  
70  
71  
72  
73  
74  
75  
76  
77  
78  
79  
80  
81  
82  
83  
84  
85  
86  
87  
88  
89  
90  
91  
92  
93  
94  
95  
96  
97  
98  
99  
100  
101  
102  
103  
104  
105  
106  
107  
108  
109  
110  
111  
112  
113  
114  
115  
116  
117  
118  
119  
120  
121  
122  
123  
124  
125  
126  
127  
128  
129  
130  
131  
132  
133  
134  
135  
136  
137  
138  
139  
140  
141  
142  
143  
144  
145  
146  
147  
148  
149  
150  
151  
152  
153  
154  
155  
156  
157  
158  
159  
160  
161  
162  
163  
164  
165  
166  
167  
168  
169  
170  
171  
172  
173  
174  
175  
176  
177  
178  
179  
180  
181  
182  
183  
184  
185  
186  
187  
188  
189  
190  
191  
192  
193  
194  
195  
196  
197  
198  
199  
200  
201  
202  
203  
204  
205  
206  
207  
208  
209  
210  
211  
212  
213  
214  
public class BlockmanMain extends Game
{
   private static GameLoop gameLoop = new GameLoop();
   private Map map;
   private Player player = new Player();
   private CompletionPoint compPoint;
   int x = 0;
   public int level = 1;
   private final int MAX_LEVEL = 3;
   public static void main(String[] args)
   {
      GameStart.start(new BlockmanMain(), gameLoop);
   }
   
   public BlockmanMain()
   {
      title = "Epic Stuble Man!";
      background = Color.black;
      width = 1300;
      height = 760;
      delay = 5; //milliseconds between updates
   }
   @Override
   public void init()
   {
      /*
       * Initialize variables here
       *
       */

     
      over = false;
      map = new Map();
      LoadMap();
      //map.start();
      player.reset();
     
   }

   public void LoadMap()
   {
      map.clear();
      int mapH = 72; //map height
      int mapW = 128; //map width
      String url = "maps/Level_"+level+".txt";
      InputStream in = BlockmanMain.class.getResourceAsStream(url);
      BufferedReader reader = new BufferedReader(new InputStreamReader(in));
     
      int x = 0;
      int y = 0;
      try
      {
         
         for (int i = 0; i < mapH; i++)
         {
            char line[] = reader.readLine().toCharArray();
            for (int j = 0; j < mapW; j++)
            {
               if(line[j] == '#')
               {
                  map.addPath(x,y);
               }
               if(line[j] == '_')
               {
                  map.addFallingPath(x,y);
               }
               else if(line[j] == '^')
               {
                  map.addSpike(x,y,true);
               }
               else if(line[j] == '.')
               {
                  map.addSpike(x, y,false);
               }
               else if(line[j] == '*')
               {
                  map.addEnemy(x, y,true);
               }
               else if(line[j] == '$')
               {
                  player.setStartPoint(x, y);
               }
               else if(line[j] == '@')
               {
                  compPoint = new CompletionPoint(x, y);
               }
               x += 10;
            }
            x = 0;
            y+=10;
         }reader.close();
         map.loadingLevel = false;
         map.startThread();
      }
      catch (Exception e)
      {
         e.printStackTrace();
      }
     
   }

   @Override
   public void update()
   {
      /*
       * Call update methods here
       *
       */

      if(player.dead) //Resets map is player dies
      {
         map.loadingLevel = true; //stop the map thread
         map.clear(); //clear the map
         LoadMap(); //load the map
         player.restart(); //restart
      }
     
      if(!map.loadingLevel)
      {
         map.update(player);
         player.update();
      }
     
      if(player.getBounds().intersects(compPoint.getBounds()))
      {
         level++;
         if(level <= MAX_LEVEL)
         {
           
            map.loadingLevel = true;
            map.clear();
            LoadMap();
            player.reset();
         }
         else
         {
            map.clear();
         }
      }
   }

   @Override
   public void draw(Graphics2D g2d)
   {
      /*
       * Call draw methods here
       *
       */

      if(level <= MAX_LEVEL)
      {
         g2d.setFont(new Font("Chiller", Font.BOLD, 28));
         g2d.setColor(Color.white);
         g2d.drawString("Level: "+level, 1180, 25);
         if(compPoint != null)
            g2d.drawImage(compPoint.getImage(), compPoint.getX(), compPoint.getY(),null);
         
         if(!map.loadingLevel)
         {
            map.draw(g2d);
            if(player != null)
               player.draw(g2d);
         }
      }
      else
      {
         g2d.setFont(new Font("Chiller", Font.BOLD, 48));
         g2d.setColor(Color.green);
         g2d.drawString("WINNER! YOU HAVE BEATEN THE GAME!", width/2 - 400, height/2 - 48);
      }
   }
   public void keyPressed(KeyEvent e)
   {
     
      switch(e.getKeyCode())
      {
         case KeyEvent.VK_W:
            break;
         case KeyEvent.VK_A:
            player.setDx(-1);
            player.movingRight(false);
            break;
         case KeyEvent.VK_S:
            break;
         case KeyEvent.VK_D:
            player.setDx(1);
            player.movingRight(true);
            break;
         case KeyEvent.VK_SPACE:
            if(player.grounded)
            {
               player.jump();
            }
            break;
      }
   }
   public void keyReleased(KeyEvent e)
   {
      /*
       * Set Dx's to 0 when released
       *
       */

      switch(e.getKeyCode())
      {
         case KeyEvent.VK_W:
            break;
         case KeyEvent.VK_A:
            player.setDx(0);
            break;
         case KeyEvent.VK_S:
            break;
         case KeyEvent.VK_D:
            player.setDx(0);
            break;
      }
   }
}

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Offline ra4king

JGO Kernel


Medals: 356
Projects: 3
Exp: 5 years


I'm the King!


« Reply #12 - Posted 2011-12-15 06:09:08 »

Everything is an "int" and you're only adding speed * dx....

Offline Shane75776
« Reply #13 - Posted 2011-12-15 06:10:29 »

yes I know that, I said I put everything back to normal.

It was not working having them as doubles and casting to an int with math.round


Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Offline Shane75776
« Reply #14 - Posted 2011-12-15 06:13:45 »

This is the same class with how you told me to do it. which, makes it so I cant move at all.


1  
2  
3  
4  
5  
6  
7  
8  
9  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
54  
55  
56  
57  
58  
59  
60  
61  
62  
63  
64  
65  
66  
67  
68  
69  
70  
71  
72  
73  
74  
75  
76  
77  
78  
79  
80  
81  
82  
83  
84  
85  
86  
87  
88  
89  
90  
91  
92  
93  
94  
95  
96  
97  
98  
99  
100  
101  
102  
103  
104  
105  
106  
107  
108  
109  
110  
111  
112  
113  
114  
115  
116  
117  
118  
119  
120  
121  
122  
123  
124  
125  
126  
127  
128  
129  
130  
131  
132  
133  
134  
135  
136  
137  
138  
139  
140  
141  
142  
143  
144  
145  
146  
147  
148  
149  
150  
151  
152  
153  
154  
155  
156  
157  
158  
159  
160  
161  
162  
163  
164  
165  
166  
167  
168  
169  
170  
171  
172  
173  
174  
175  
176  
177  
178  
179  
180  
181  
182  
183  
184  
185  
186  
187  
188  
189  
190  
191  
192  
193  
194  
195  
196  
197  
198  
199  
200  
201  
202  
203  
204  
205  
206  
207  
208  
209  
210  
211  
212  
213  
214  
215  
216  
217  
218  
219  
220  
221  
222  
223  
224  
225  
226  
227  
228  
229  
230  
231  
232  
233  
234  
235  
236  
237  
238  
239  
240  
241  
242  
243  
244  
245  
246  
247  
248  
249  
250  
251  
252  
253  
254  
public class Player extends Thread
{
   private Image image;
   private Thread animator; //animates the jump
   private boolean jump = false;
   private boolean jumping = false; //is in the middle of a jump
   private boolean done = false; //tells when jumping is done
   private boolean peak = false; //tells when at peak of jump
   private boolean falling = false; //if player is falling, or in the air still
   private boolean rising = false;
   private boolean movingRight = false;
   
   public boolean grounded = true;
   public boolean dead = false;
   
   private int width = 10;
   private int height = 10;
   
   private double x;
   private int y;
   private int startX;
   private int startY;
   
   private int dx;
   private int dy = 0;
   
   private double speed = 1;
   
   private int jumpHeight = 50;
   private int groundHeight;
   private double accel = .001;
   
   String url = "player.png";
   
   public Player()
   {
      ImageIcon ii = new ImageIcon(this.getClass().getResource("/images/player_2.png"));
      image = ii.getImage();
      groundHeight = y;
     
   }
   public void update()
   {
      move();
   }
   public void move()
   {
      speed = dx * accel;
     
      x+=speed;
      //x += speed * dx;
      y += dy;
     
      if(y > 760 || y < 0)
      {
         dead = true;
         x = startX;
         y = startY;
      }
     
   }
   public void jump()
   {
     
      if(!jump)
      {  
         grounded = false;
         jump = !jump;
         
         animator = new Thread(this);
         animator.start();
      }
   }
   public void draw(Graphics2D g2d)
   {
      g2d.drawImage(image,(int)Math.round(x),y,null);
   }
   public Image getImage()
   {
      return image;
   }
   public double getX()
   {
      return x;
   }
   public int getY()
   {
      return y;
   }
   public void setX(int x)
   {
      this.x = x;
   }
   public void setY(int y)
   {
      this.y = y;
   }
   public void setStartPoint(int x, int y)
   {
      this.startX = x;
      this.startY = y;
   }
   public void reset()
   {
      x = startX;
      y = startY;
      dx = 0;
      grounded = true;
   }
   public void restart()
   {
      x = startX;
      y = startY;
      dx = 0;
      dead = !dead;
      grounded = true;
   }
   public int getStartX()
   {
      return startX;
   }
   public int getStartY()
   {
      return startY;
   }
   public void setDx(int dx)
   {
      this.dx = dx;
   }
   public void shoveLeft(int amnt)
   {
      x -= amnt;
   }
   public void shoveRight(int amnt)
   {
      x += amnt;
   }
   public void shoveDown(int amnt)
   {
      y += amnt;
   }
   public void reverseDx()
   {
      this.dx *= -1;
   }
   public void stopJump()
   {
      done = true;
   }
   public void setDy(int dy)
   {
      this.dy = dy;
   }
   public int getDy()
   {
      return dy;
   }
   public void correctY(int y)
   {
      this.y = y - height;
   }
   public int getCenterX()
   {
      return (int) (width/2);
   }
   public int getCenterY()
   {
      return (int) (height/2);
   }
   public void setGroundHeight(int height)
   {
      this.groundHeight = height;
   }
   public boolean isRising()
   {
      return rising;
   }
   public boolean isFalling()
   {
      return falling;
   }
   public boolean isMovingRight()
   {
      return movingRight;
   }
   public void movingRight(boolean right)
   {
      this.movingRight = right;
   }
   public void setPeak(boolean peaked)
   {
      this.peak = peaked;
   }
   public boolean isJumping()
   {
      return jumping;
   }
   public Rectangle getBounds()
   {
      return new Rectangle((int)x,y,width,height);
   }
   
   //Thread for jumping
   @Override
   public void run()
   {
      long beforeTime, timeDiff, sleep;
     
      beforeTime = System.currentTimeMillis();
     
      while(done == false)
      {
         cycle();
         timeDiff = System.currentTimeMillis() - beforeTime;
         sleep = 8 - timeDiff;
         if(sleep < 0)
            sleep = 2;
         try
         {
            Thread.sleep(sleep);
         }
         catch(Exception e){e.printStackTrace();}
         beforeTime = System.currentTimeMillis();
      }
      done = false;
      jump = false;
      peak = false;
   }
   public void cycle()
   {
      if(peak == false)
      {
         rising = true;
         y-=3;
      }
      if(y <= (groundHeight-jumpHeight))
      {
         peak = true;
         rising = false;
      }
      if(peak == true && (y+height) <= groundHeight)
      {
         rising = false;
         setDy(1);
      }
         if((y+height) == groundHeight && !falling)
            done = true;
         else if((y+height) == groundHeight && falling)
         {
            groundHeight = 760;
            done = true;
         }  
   }
}

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Offline ra4king

JGO Kernel


Medals: 356
Projects: 3
Exp: 5 years


I'm the King!


« Reply #15 - Posted 2011-12-15 06:19:47 »

As I pointed out earlier, gbeebe was wrong, it's speed += dx * accel;
0.001 is a really small number, make it 0.1 for now.

Offline Shane75776
« Reply #16 - Posted 2011-12-15 06:22:39 »

ah alright, that seems to work now.

but now it even when dx is 0 it moves right. so thats something ill have to figure out now.

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Offline Shane75776
« Reply #17 - Posted 2011-12-15 06:23:56 »

nvm, i was having my x += speed which was causing it.

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Offline ra4king

JGO Kernel


Medals: 356
Projects: 3
Exp: 5 years


I'm the King!


« Reply #18 - Posted 2011-12-15 06:49:29 »

Ah glad you solved it Smiley

Offline Shane75776
« Reply #19 - Posted 2011-12-15 07:25:55 »

Yea thanks for the help both of you.

Check out my Snipping Tool++ ! An advanced snippet/screenshot/text uploading tool! Meant to replace the windows snipping tool.

Check out Pixel Rain My most recent Swing based game!
Offline Danny02
« Reply #20 - Posted 2011-12-15 11:06:28 »

hi just wanted to add somethign which might be usefull,

if u have a moving body with an constant acceleration:
    variables: position, velocity, ACCELERATION

One nearly always sees the formular (name: Euler integration):
    velocity += ACCELERATION * time;
    position += velocity * time;

which is in this case only an approximation which gets worse the bigger your time steps get.

to get the right results use this function
   
    One nearly always sees the formular(name: Verlet integration):
    oldVelocity = velocity;
    velocity += ACCELERATION * time;
    position += ((oldVelocity + velocity) / 2) * time;

which gives u correct results for constant acceleration.
if your acceleration isn't constant it won't be correct anymore but still better then the first formular

link on this topic http://codeflow.org/entries/2010/aug/28/integration-by-example-euler-vs-verlet-vs-runge-kutta/
Pages: [1]
  ignore  |  Print  
 
 
You cannot reply to this message, because it is very, very old.

 

Add your game by posting it in the WIP section,
or publish it in Showcase.

The first screenshot will be displayed as a thumbnail.

rwatson462 (30 views)
2014-12-15 09:26:44

Mr.CodeIt (20 views)
2014-12-14 19:50:38

BurntPizza (42 views)
2014-12-09 22:41:13

BurntPizza (76 views)
2014-12-08 04:46:31

JscottyBieshaar (37 views)
2014-12-05 12:39:02

SHC (51 views)
2014-12-03 16:27:13

CopyableCougar4 (48 views)
2014-11-29 21:32:03

toopeicgaming1999 (115 views)
2014-11-26 15:22:04

toopeicgaming1999 (103 views)
2014-11-26 15:20:36

toopeicgaming1999 (30 views)
2014-11-26 15:20:08
Resources for WIP games
by kpars
2014-12-18 10:26:14

Understanding relations between setOrigin, setScale and setPosition in libGdx
by mbabuskov
2014-10-09 22:35:00

Definite guide to supporting multiple device resolutions on Android (2014)
by mbabuskov
2014-10-02 22:36:02

List of Learning Resources
by Longor1996
2014-08-16 10:40:00

List of Learning Resources
by SilverTiger
2014-08-05 19:33:27

Resources for WIP games
by CogWheelz
2014-08-01 16:20:17

Resources for WIP games
by CogWheelz
2014-08-01 16:19:50

List of Learning Resources
by SilverTiger
2014-07-31 16:29:50
java-gaming.org is not responsible for the content posted by its members, including references to external websites, and other references that may or may not have a relation with our primarily gaming and game production oriented community. inquiries and complaints can be sent via email to the info‑account of the company managing the website of java‑gaming.org
Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines | Managed by Enhanced Four Valid XHTML 1.0! Valid CSS!