SpritesMind.Net

How do i go about having collision for certain parts of a tilemap? Say the player can't pass in a direction, if a wall tile is there.

Thanks.

Simplest way is to take the tile map you've used to fill the background plane and check the position of your character against it.

To find the corresponding tile of a pixel XY position, divide the x and y by the width and height of the tile. The tiles are most likely 8x8 so to check an object position like the player against the tile map, do this:
That will give you the position of the tile in the tilemap that the player is landing on.

You'll need a way to know if the tile the player lands on is solid or not. You'd need to look at each of the tiles of the tileset and have a table containing their "solidness" property.
To put those things together.
That's one way to do it. There are many ways.

djcouchycouch wrote:Simplest way is to take the tile map you've used to fill the background plane and check the position of your character against it.

To find the corresponding tile of a pixel XY position, divide the x and y by the width and height of the tile. The tiles are most likely 8x8 so to check an object position like the player against the tile map, do this:

Code: Select all

int tilepositionx = playerx / 8;
int tilepositiony = playery / 8;

That will give you the position of the tile in the tilemap that the player is landing on.

You'll need a way to know if the tile the player lands on is solid or not. You'd need to look at each of the tiles of the tileset and have a table containing their "solidness" property.

Code: Select all

tileset_properties[0] = 0; // this tile the player can walk through
tileset_properties[1] = 1; // this tile is solid and the player can't walk through
tileset_properties[n] = 0; // and so on and so forth

To put those things together.

Code: Select all

int playerx = 10; // x position of the player
int playery = 20; // y position of the player
extern tile tileset[2]; // some tileset stored somewhere. has 2 tiles.
int tileset_properties[2]; // solidness properties of the two tiles

#define TILEMAP_WIDTH 2
#define TILEMAP_HEIGHT 2
int tilemap[TILEMAP_WIDTH * TILEMAP_HEIGHT]; // a 2x2 tilemap

#define TILEPROP_NOTSOLID 0
#define TILEPROP_SOLID 1

int main(void)
{
	tileset_properties[0] = TILEPROP_NOTSOLID; // this tile the player can walk through
	tileset_properties[1] = TILEPROP_SOLID; // this tile is solid and the player can't walk through

	// get the position of the tile that the player is on.
	int tilepositionx = playerx / 8;
	int tilepositiony = playery / 8;

	int tile = tilemap[tilepositionx  + (TILEMAP_WIDTH * tilepositiony)];
	int tileproperty = tileset_properties[tile];

	if (tileproperty == TILEPROP_NOTSOLID)
	{
	  // non-solid tile and can walk through
	}
	else if (tile property == TILEPROP_SOLID)
	{
	   // solid tile and can't move  through
	}
}

That's one way to do it. There are many ways.

Hmm, trying to get this to work with the way i did the tilemap drawing, by using VDP_SetMapEX() to draw part of the map on screen.