Collision problems with OSlib for psp in C++

Question

Im using oslib with the pspsdk toolchain and for some reason this doesnt work the way I think it would

float spritewidth  = sprite->stretchX;
float spriteheight = sprite->stretchY;
float bushwidth  = bush->stretchX;
float bushheight = bush->stretchY;

//Basic border collision
if (sprite->x <= 0)
 sprite->x = 0;
if (sprite->y <= 0)
 sprite->y = 0;
if (sprite->x >= 455)
 sprite->x = 455;
if (sprite->y >= 237)
 sprite->y = 237;

 //Bush
if ( (sprite->x + spritewidth > bush->x) && 
    (sprite->x < bush->x + bushwidth) && 
    (sprite->y + spriteheight > bush->y) && 
    (sprite->y < bush->y + bushheight) ) 
{
  bushcol = 1;               
}
else
{
  bushcol = 0;      
}

 if (osl_keys->held.down)
 {
   if (bushcol == 0)
   {
     sprite->y += 4;
     sprite_position = DOWN;
     SpriteAnimate();
   }
   else
   { 
     sprite->y -= 6;
     bushcol = 0;
   }
 }

 if (osl_keys->held.up)    
 {
   if (bushcol == 0)
   {
     sprite->y -= 4;
     sprite_position = UP;
     SpriteAnimate();
   }
   else
   { 
     sprite->y += 6;
     bushcol = 0;
   }
 }

 if (osl_keys->held.right)
 {
   if (bushcol == 0)
   {
     sprite->x += 4;
     sprite_position = RIGHT;
     SpriteAnimate();
   }
   else
   { 
     sprite->x -= 6;
     bushcol = 0;
   }
 }

 if (osl_keys->held.left)
 {
   if (bushcol == 0)
   {
     sprite->x -= 4;
     sprite_position = LEFT;
     SpriteAnimate();
   }
   else
   { 
     sprite->x += 6;
     bushcol = 0;
   }
 }

The sprite starts moving in the opposite direction from the bush when I try to move away but does fall free eventually

any better collision methods or suggestions

I even tried this for each button and still no luck

if (osl_keys->held.down)
{
  if ( (sprite->x + spritewidth > bush->x) &&
       (sprite->x < bush->x + bushwidth) && 
       (sprite->y + spriteheight > bush->y) &&
       (sprite->y < bush->y + bushheight) ) 
  {
    sprite->y -= 4; 
  }
  else
  {
    sprite->y += 2;
    sprite_position = DOWN;
    SpriteAnimate();
  }
}

For future reference, people will be a lot more willing to read your code sample if it is not double-spaced, you have made some effort to not make them scroll right to read long lines, and the brace and indentation style is consistent. — Matt J, May 13 '09 at 23:00

score 1 · Accepted Answer · answered May 13 '09 at 23:32

One thing you can do, is instead of having the character "move backwards" when he hits the bush, you can have his position changed.

What I mean is something like this: (Using only up for the example).

 if (osl_keys->held.up)    
 {
   if (bushcol == 0)
   {
     sprite->y -= 4;
     sprite_position = UP;
     SpriteAnimate();
   }
   else
   { 
     sprite->y = bush->y + 2;
     bushcol = 0;
   }
 }

That way, whenever the sprite collides, it just sets the position instead getting it to move backwards.

There are other methods for doing collision detection, but I'm way too tired right now to pull off an intelligent, much less readable, answer right now... A search on google will turn up many results.

Collision problems with OSlib for psp in C++

1 Answers1