Sorry your browser is not supported!

So I was just playing around with the Physics engine, and I added a few lines of code to the sample, here it is:

// display a background
CreateSprite ( LoadImage ( "background4.jpg" ) )

// load an image
LoadImage ( 1, "small_silver.png" )

// create 5 sprites
CreateSprite ( 1, 1 )
CreateSprite ( 2, 1 )
CreateSprite ( 3, 1 )
CreateSprite ( 4, 1 )
CreateSprite ( 5, 1 )

// set their positions
SetSpritePosition ( 1, 0, 0 )
SetSpritePosition ( 2, 50, 0 )
SetSpritePosition ( 3, 100, 0 )
SetSpritePosition ( 4, 150, 0 )
SetSpritePosition ( 5, 200, 0 )

// turn physics on
SetSpritePhysicsOn ( 1, 2 )
SetSpritePhysicsOn ( 2, 2 )
SetSpritePhysicsOn ( 3, 2 )
SetSpritePhysicsOn ( 4, 2 )
SetSpritePhysicsOn ( 5, 2 )

// alter default gravity
SetPhysicsGravity ( 10, 10 )

// main loop
do
// update screeen
for i = 1 to 5
SetSpriteX ( i , (i-1)*50 )
next i
Sync ( )
loop

This is the gravity sample.

Anyways, you can see what I'm doing is trying to keep the blocks stable on the horizontal axis (x), and let the physics do what it wants with the Y axis.

However, when I run this, the blocks don't move at all.

Is this an obvious bug? Or am I missing something?

Thanks,
Jeff

some non physics commands disturb the physics.
maybe you can use the CreateLineJoint command?

I think you'll need a kinematic sprite (If the 2d Physics have it)

Also, don't forget to use the code tags around code snippits.

I wonder if setting the position on any sprite would reset its physics velocity - might be worth storing the velocity, then setting the X position, then set the velocity to what it was before - maybe setting the X velocity to 0 as well to be on the safe side.

Van B, good idea, I'll try that.
Jeff

VanB is 100% correct. When it comes to using the physics commands, any command outside the physics commands that effects a sprite will completely wipe all physics from the object until the next physics call. This is coming from experience coding an Asteroids clone. When I started to write code for a screen wrapper function, I discovered that I would have to store the original velocity x/y and acceleration x/y variables before re-positioning the sprite, than reapply the velocity and acceleration to the sprite. I got perfectly smooth movement every time.