Should I check if sprite is in screen?

[Lebostein]

Hi,

for a game I have a huge landscape with many sprites. The player sees only a small part of this world.
My question to the developers is: Have the functions DisplaySprite() and DisplayTransparentSprite() already built-in a test, whether the sprite is visible on screen?

Or do I have to check that (to speed-up the program for example)?

Code: Select all

ForEach allsprites()
  ...
  If x < ScreenWidth() And y < ScreenHeight() And x > -SpriteWidth(sprite) And y > -SpriteHeight(sprite)
  
    DisplaySprite(sprite, x, y)
  
  EndIf
  ...
Next

[Fred]

It's already done for you.

[Lebostein]

One less worry. Thank you!

By the way: Some 2DDrawing()-Tools have a problem with that. For example Plot(). PB crashes when the point is outside of the screen or outside of an image...

[STARGÅTE]

Plot have no check, it write directly to the memory, but it is very fast!

[eesau]

It's already done for you.

I think adding this information to the help file would be good.

[Lebostein]

Plot have no check, it write directly to the memory, but it is very fast!

Such information must be written in the manual!

PS: I think a line like "if x < width" will not slow down the program... or I am wrong?

[Fred]

Plot have no check, it write directly to the memory, but it is very fast!

Such information must be written in the manual!

PS: I think a line like "if x < width" will not slow down the program... or I am wrong?

http://www.purebasic.com/documentation/ ... /plot.html

For performance reasons there are no bounds checks performed on these coordinates, the specified coordinates must be inside the current drawing area. OutputWidth() and OutputHeight() can be used to verify that.

[STARGÅTE]

a "If X >= 0 and X<Width and Y>=0 and Y<Height" in each Plot()-call
is slow instead of only one ASM-Call like:
MOV buffer, color