Turning whatever's on the screen into an image

BlitzMax Forums/BlitzMax Beginners Area/Turning whatever's on the screen into an image

Matt McFarland

(Posted 2005) [#1]

Here's what I'd like to do.

Let's say you're playing a game and then you press pause.

Here's the pause loop:

repeat
   cls
   drawimage (What the game looked like before they hit PAUSE),0,0
   drawtext,"PAUSED",in the center ;)
   flip
until someone unpauses the game ;)

Any ideas? :)

TartanTangerine (was Indiepath)

(Posted 2005) [#2]

Why make it so complex?

if you don't cls and don't flip then the screen will stay the same anyway.

Select GameState
     CASE RUNNING
        Cls
        ' DO all my game Stuff
        Flip
        If KeyHit(KEY_P) Then 
             GameState = PAUSED
             DrawText("Oi Oi",300,300)
             FLIP
        EndIf

     CASE PAUSED
         If KeyHit(KEY_P) Then GameState = RUNNING

End Select

Matt McFarland

(Posted 2005) [#3]

Oh right!

But what if I was making a simple text box that appeared over my editor? and instead of clearing the screen it would look better if the text box just appeared and let you typed in some input? obviously we would need to clear the screen then right?

deps	(Posted 2005) [#4]

if you don't cls and don't flip then the screen will stay the same anyway.

This isn't possible on my computer. (Is it the same on all macs/minimacs?)
The screen flickers, and old graphics that got overdrawn is sometimes visible.
(Edit: but only in fullscreen)

My method is a bit different. I alsways separate logic and drawing in my code, and when the game is paused it doesn't run the logic part. Like so:

while not gameover
   if not paused
      run_logic()
   endif
   draw_graphics()
wend

deps	(Posted 2005) [#5]

But if you really needs to save the screen sometime, you can use GrabImage() or GrabPixmap()

Grey Alien

(Posted 2005) [#6]

Yeah as deps says, either have a separate draw function (from logic) and call it even when paused OR when paused is pressed, grabimage the screen to a large image you've created and in pause mode show that behind the dialog every frame. You can also do tricks then like dimming the background image so it looks cool.

Amon	(Posted 2005) [#7]

hmm, I've never thought of seperating my code in such a way. Up untill now I would update everything ie. draw images and update logic in the same function or method.

Grey Alien

(Posted 2005) [#8]

well Amon it's time to change as that is definitely the way to go!

Tom Darby

(Posted 2005) [#9]

What deps and GA say--separating your drawing, animating, positioning and collision code into distinct functions is a good way to do this. Using this technique also makes it easier to do multi-pass game logic between draw commands (that is, you move everything at 1/4 speed but update 4 times between flips, which gives you more accurate collision detection...)

RiK	(Posted 2005) [#10]

I generally have the update/movement and draw as seperate functions that way when you pause you can continue to draw everything in game without moving and can draw text or whatever you want over the top as you like.