Rotating wheel

[Afflict]

I have a rotating wheel that needs to be animated as the player spins it with the mouse wheel.

How will I go about doing this? I want to add momentum onto it aswell

EG:



Completely stummped on it!

[DoorKnobHandle]

I don't have time to explain the way I would do this to you in detail, but here's a very quick description, maybe someone else can go into detail:

- Look up the DynamicSprite-functions (and the DynamicSprite.rotate function particularly) in the manual (you need a version >2.71 for "DynamicSprite.rotate" I believe).
- This function allows you to rotate a sprite by any degree, first try to implement this. Only continue if you have the first part of simple rotation working.
- Then add momentum and mousewheel control. You'll need to play around with this. Just add a value to a variable when turning the mousewheel up and subtract a value to the same variable if turning the mousewheel down.
- Finally rotate the sprite by the variable.
- Then you could add momentum. Just make the variable decrease slowly by itself over time.

[Afflict]

Ok cant find dynamicsprite functions in the manaul...  :'(

Ive tried some other methods also not working

Code: ags

#sectionstart on_mouse_click  // DO NOT EDIT OR REMOVE THIS LINE
function on_mouse_click(MouseButton button) {
  // called when a mouse button is clicked. button is either LEFT or RIGHT
  if (IsGamePaused() == 1) {
    // Game is paused, so do nothing (ie. don't allow mouse click)
  }
  else if (button == eMouseLeft) {
    ProcessClick(mouse.x, mouse.y, mouse.Mode );
  }
  else  {
 oCircle.Graphic = oCircle.Graphic+1 ;
  mouse.SelectNextMode();
 if (oCircle.Graphics > 13) oCircle.Graphics = 10 ;
  
}
}
#sectionend on_mouse_click 

Its giving me the undefined token error 'cCircle'
edit ok I got the circle working many thanks to ASHEN now working on momentum.

[Kweepa]

Code: ags

// PUT THIS AT THE TOP OF THE GLOBAL SCRIPT
float wheelAngularVelocity = 0.0;
float wheelAngle = 0.0;

#define SPRITE_WHEEL 0 // change to whatever yours is

// MERGE THIS WITH YOUR on_mouse_click
function on_mouse_click(MouseButton button)
{
  // you need to enable the mouse wheel support
  if (button == eMouseWheelNorth)
  {
    wheelAngularVelocity += 25.0;
  }
  else
  if (button == eMouseWheelSouth)
  {
    wheelAngularVelocity -= 25.0;
  }
}

// MERGE THIS WITH YOUR repeatedly_execute
function repeatedly_execute()
{
  float timeStep = 1.0/IntToFloat(GetGameSpeed());

  float deceleration = 5.0;
  if (wheelAngularVelocity > 0.0)
  {
    wheelAngularVelocity -= timeStep*deceleration;
    if (wheelAngularVelocity < 0.0) wheelAngularVelocity = 0.0;
  }
  else
  {
    wheelAngularVelocity += timeStep*deceleration;
    if (wheelAngularVelocity > 0.0) wheelAngularVelocity = 0.0;
  }

  wheelAngle += timeStep*wheelAngularVelocity;
  while (wheelAngle < 0.0) wheelAngle += 360.0;
  while (wheelAngle >= 360.0) wheelAngle -= 360.0;
  
  int angle = FloatToInt(wheelAngle);

  // draw your wheel - here I'm using a dynamic sprite
  // but you could use a lookup table and a set of sprites
  DynamicSprite *wheelSprite = DynamicSprite.CreateFromExistingSprite(SPRITE_WHEEL);
  if (angle > 0 && angle < 360)
  {
    wheelSprite.Rotate(angle);
  }
  RawDrawImage(100, 100, wheelSprite.Graphic);
  wheelSprite.Delete();
}

[Afflict]

Thanks to steveMcCrea and Ashen we have 2 working module.

The one uses all the rendered frames to simulate the rotation and the other one uses a single dynamic sprite and rotates it. The problem being that its not on a single axis. Its flying all over the place.

Anybody have any idea on how to fix it?

Note the sprite is perfectly centred!

[Ashen]

It's probably because the rotated sprite isn't the same width/heigth as the original.
You'd need to change the position of the RawDrawImage (from the line RawDrawImage(100, 100, wheelSprite.Graphic); to account for that, e.g.:

Code: ags

RawDrawImage(100-(wheelSprite.Width/2), 100-(wheelSprite.Height/2), wheelSprite.Graphic);

should centre the wheel, so it spins about (100, 100), rather than having it's top-left corner there.

[Afflict]

Hey thanks ashen that worked! Prefectly I am still not sure what it did but WOW appreciated!

Now it still wobles about 1 pixel i dont mind but the smudging is annoying! Any ideas?

[Scorpiorus]

If you mean it's jittering, that may probably be caused by some truncation/rounding errors.


As for smudging, you need to restore the room's background image before drawing the wheel:

Code: ags

RawRestoreScreen(); // just before drawing the wheel
RawDrawImage(100-(wheelSprite.Width/2), 100-(wheelSprite.Height/2), wheelSprite.Graphic);

Also, put the following line under Player enters room (after fade-in):

Code: ags

RawSaveScreen();

[Afflict]

Thank you ALL!