Transparency for Characters

[Mantra of Doom]

In my game, I have a character that can turn "invisible". The sequence that should happen when a button is clicked is that a short animation should play and the character should quickly fade to be semi-transparent. The problem is though that I'm not quite sure how to fade the character to 50%. The code in the manual (below) just makes the character stand there for 3 seconds and then disappears. I'm not sure how to change this code to suit my needs when this doesn't really work.

Code: ags

int trans = cEgo.Transparency;
while (trans < 100) {
  trans++;
  cEgo.Transparency = trans;
  Wait(1);
}

I also even set the button's OnClick to

Code: ags

cEgo.Transparency=50;

But clicking on the button does nothing, though setting the value to 100 makes the character disappear. I know I'm missing something simple... but I can't work out what. Any help would be appreciated.

[Trent R]

Does your character's sprite have an alpha channel? That messes up transparency.


~Trent

[Edit]: I think 16-bit does work...

[monkey0506]

Further, what color depth is your game. It definitely won't work at 8-bit, and I'm not 100% sure about 16-bit off the top of my head.

[Mantra of Doom]

Duh, my character did have an alpha channel in one frame. Now the transparency works properly, but I'm still not sure how to stop the fade at 50. Maybe it's just a little too early in the morning right now.

[Laukku]

Duh, my character did have an alpha channel in one frame. Now the transparency works properly, but I'm still not sure how to stop the fade at 50. Maybe it's just a little too early in the morning right now.

Here is a quick suggestion (untested) 

int trans = cEgo.Transparency;
while ((trans < 100) && (trans <50)) {
  trans++;
  cEgo.Transparency = trans;
  Wait(1);
}

[Khris]

Heh.

Code: ags

int trans = cEgo.Transparency;
while (trans < 50) {
  trans++;
  cEgo.Transparency = trans;
  Wait(1);
}

(If trans is smaller than 50, it's always also smaller than 100.)

[Mantra of Doom]

Okay, with your help, I got it to work. Here is the code:

Code: ags

function btnInv_OnClick(GUIControl *control, MouseButton button) //turn invisible button
{
  if (invisible==false)//Is the character already invisible?
  {
    //Play animation & set view
    int trans = cEgo.Transparency;
    while (trans < 51) 
    {
      trans++;
      cEgo.Transparency = trans;
      Wait(1);
      cEgo.Transparency=50;
    }
    invisible=true; //Turns on invisible variable.
  }
  else //If is already invisible, character turns back to normal
  {
    int transoff = 50;
    while (transoff > 0) 
    {
      transoff--;
      cEgo.Transparency = transoff;
      Wait(1);
    }
    invisible=false;   //Resets invisible variable
  }
}

[Khris]

Since the code is blocking, you don't need the invisible variable.
Just check if the character's transparency is 50 or 0.

I also think that the first loop should look like this:

Code: ags

    while (trans < 50)    // last loop at 49, trans is 50 at the end 
    {
      trans++;
      cEgo.Transparency = trans;
      Wait(1);
      // cEgo.Transparency=50;  // why this line inside the loop? if you needed it, it would have to go after it
    }