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Hi, i'm developing a platform game and i have some troubles with collision detection between player-map.

Where can i find a good tutorial for collision detection? If someone knows an useful tutorial for this kind of games, please post it.

Thanks.

You'll want to go to the sdl site and click libs and the select ...other? as catagory I'd say. There should be libs that include collision detection.
Wow, I looked and there are lots of broken links. Try demos but the idea is this:

SDL_Rect *temprc, *dest; double left,right,top,bottom;
//bring a rect in and break it down so it's easy to understand
left = temprc.x; right = temprc.x + temprc.w; top = temprc.y; bottom = temprc.y + temprc.h;
//if part of the box is in the other box the it did collide
if (dest.y > top && dest.y < bottom) {if (dest.x > left && dest.x < right) {return 1;}}
return 0; //bam!
//this is a non functional example code^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

At the risk of stating the obvious, Lazy Foo has a good tutorial on this: http://lazyfoo.net/SDL_tutorials/lesson17/index.php.

Maybe this will help another way would be compaire locations within a 2d array

//Main Code

class GameObject
{
private:
public:
bool IsAlive;
short int LImageHeight; // image height
short int LImageLength; //image length/width
float XPos;// image X pos on Screen
float YPos; // image Y pos on Screen
};


GameObject PlayerShip; aka A
GameObject Asteroid; aka B

how to call

if (PlayerShip.IsAlive)
{
CollisionCheck(PlayerShip,Asteroid,0,0,0,0);
{
//Big Explode goes here
}
}


bool CollisionCheck(GameObject A, GameObject B, short AReductionX,short AReductionY,short BReductionX,short BReductionY )
{ //The sides of the rectangles
unsigned int LeftA, LeftB;
unsigned int RightA, RightB;
unsigned int TopA, TopB;
unsigned int BottomA, BottomB;
LeftA = A.XPos+AReductionX;
RightA = A.XPos+A.LImageLength-AReductionX;
TopA= A.YPos+AReductionY;
BottomA = A.YPos+ A.LImageHeight-AReductionY;
LeftB = B.XPos+BReductionX;
RightB = B.XPos+ B.LImageLength-BReductionX;
TopB = B.YPos+BReductionY;
BottomB = B.YPos+ B.LImageHeight-BReductionY;
//Collision Boxes for Tweaking and displaying hit points
/* rectangleRGBA(screen,
LeftB, TopB,
RightB, BottomB,
0, 255, 0, 255);
rectangleRGBA(screen,
LeftA, TopA,
RightA, BottomA,
0, 255, 0, 255); */

if( (BottomA <= TopB) || (TopA >= BottomB) || (RightA <= LeftB) || (LeftA >= RightB) )
return false;
else
{
return true;
}
}

Try this, I use it in my game and it works fine.

http://www.parallelrealities.co.uk/2011/10/intermediate-game-tutorial-4-tile-based.html