Hello,

I'm writing a side scrolling game and basically change the x-coordinate
of every sprite each frame. I used this technique in my previous
scroller called Cavern Fighter. Each sprite keeps having its
x-coordinate decremented until it disappears off the left side of the
screen and is no longer visible. In the game I'm working on at the
moment I'm using the same method but have come across a strange problem.
When my sprite gets to the left edge of the screen the x-coordinate
starts to go negative. Unfortunately the "SDL_BlitSurface" function
seems to convert the negative number back to a zero so the sprite never
scrolls off the screen. Although this creates in interesting effect as
all the sprites pile-up like some sort of sprite car crash, its not what
I want.

Has SDL changed to implement some sort of clipping ? Do I need to set a
flag ? The version of SDL.dll I am using is 1.2.12.0.

The function I am using is:

SDL_BlitSurface (Sprite.ImageSurface, Sprite.ImageDisplayRect,
m_SDLSurface, Sprite.ImageLocationRect) ;

When I call it with the Sprite.ImageLocationRect (with an "x" value of
-1), after the function exits the "x" holds a value of 0.

Hope someone can help or I'll have to rename my game "Cavern Crash" :roll:

Ian