Needs help for a game : BUG

[PSP-Maniac]

hi again i am trying to learn how to code with functions and i mad a game called bug ive added a bug in the bottom that moves and a hand that can hit the bug but i have problems using my collision detction code and i dont now why it doesnt work here is the code i does compile but dont work :

int Collision() {
    int y1 = yhand + 116;
    int y2 = ybug;
    int x1 = xhand;
    int x2 = xbug;
    int x22 = xbug + 101;
    
    if (y1 == y2) {
           if (x1 > x2) {
                  if (x1 < x22) {
                         sprintf(buffer, "blood.png");
                         bug = loadImage(buffer); 
                         sprintf(buffer, "blood.png");
                         bug2 = loadImage(buffer); 
                         poked = 1;
                               }
                               }
                               }
}

so please help me .
-= Double Post =-
come on please someone heeelp me
-= Double Post =-
i need to go to bed now see ya hope someone will answer my post.

[Vaza]

I don't know much C but isnt it supposed to be printf instead of sprintf?
--Vaza

[Grimfate126]

Originally Posted by PSP-Maniac

hi again i am trying to learn how to code with functions and i mad a game called bug ive added a bug in the bottom that moves and a hand that can hit the bug but i have problems using my collision detction code and i dont now why it doesnt work here is the code i does compile but dont work :

int Collision() {
    int y1 = yhand + 116;
    int y2 = ybug;
    int x1 = xhand;
    int x2 = xbug;
    int x22 = xbug + 101;
    
    if (y1 == y2) {
           if (x1 > x2) {
                  if (x1 < x22) {
                         sprintf(buffer, "blood.png");
                         bug = loadImage(buffer); 
                         sprintf(buffer, "blood.png");
                         bug2 = loadImage(buffer); 
                         poked = 1;
                               }
                               }
                               }
}

so please help me .
-= Double Post =-
come on please someone heeelp me
-= Double Post =-
i need to go to bed now see ya hope someone will answer my post.

are you trying to blit blood?? then you cant use that. and dont put sprintf in a loop, itll hog your memory. check out yeldarbs tutorails.

[SG57]

Grimfate, with proper freeing of memory he can to use sprintf. Its pointless in this case, but still...

Vaza - sprintf is fine.

His problem is he isnt blitting anything. Sure, he's loading the image, but not blitting it.

... globally do this so the collision function will be able to use it ....
Image *blood = loadImage("blood.png");  

void Collision() {
    int y1 = yhand + 116;
    int y2 = ybug;
    int x1 = xhand;
    int x2 = xbug;
    int x22 = xbug + 101;
    
    if (y1 == y2) {
           if (x1 > x2) {
                  if (x1 < x22) {
                         poked = 1;
                               } else { poked = 0; }
                               }
                               }
}

... in main loop ...

if ( poked ) {
     blitAlphaImageToScreen(0,0, Image->sizeX, Image->sizeY, blood, placeX, placeY);
}

That will display the blood image if your colision mech works and you place placeX and placeY with actual numbers.

Youll most likely have to re-work things as I see a few calculation errors... :\

[gamer.naveen]

After a collision...
You'll also have to use flipScreen(); at the end else it'll not
work even if the image has been blit.
Blit screen returns a int pointer that the flipScreen searches for.
Any flip pointer found , flipScreen flips that pointer.
So add flipScreen();
See the header file for reference.

[SG57]

He said he has gotten the fly and background to display, signifying he knows about the double-buffering used by the graphics library........

[PSP-Maniac]

it isnt the image code that is wrong !!

my god ive readden alot of c tuts so i now what im doing the blitting of the image is in another part of the program and i use sprintf the print into an buffer.

i only need help whith the collision detection so SG57 tell me the calculation errors please!?
-= Double Post =-
btw ive also made a poke the pengiun game see the sig for download.

[Moonchild]

Here's a collision function I made, in case you want it

int Collide(int fx, int fy, int fw, int fh, int sx, int sy, int sw, int sh)
{
	int w, h, w2, h2;
	for(w = 0;w<fw;w++)
	{
		for(h = 0;h<fh;h++)
		{
			for(w2 = 0;w2<sw;w2++)
			{
				for(h2 = 0;h2<sh;h2++)
				{
					if(((fx+w == sx+w2) && (fy+h == sy+h2)))
					{
						return 1;
					}
				}
			}
		}
	}
	return 0;
}

You call it like this

if(Collide(x value of first object, y value of first object, width of first object, height of first object, x value of second object, y value of second object, width of second object, height of second object))
{
  Do something if there's collision
}

[PSP-Maniac]

big thanks homer im gonna make the game and release it now
-= Double Post =-
whow that code makes my bug move in super slow motion

[canalaiz]

Sorry to argue, but wouldn't it be better to use the pythagora's theorem to find the distance between 2 objects and then if it's lower than a value return collision?

[PSP-Maniac]

Originally Posted by canalaiz

Sorry to argue, but wouldn't it be better to use the pythagora's theorem to find the distance between 2 objects and then if it's lower than a value return collision?

wtf !?

to homer : never mind ive worked it out hehe
me = stupid

[Moonchild]

Originally Posted by canalaiz

Sorry to argue, but wouldn't it be better to use the pythagora's theorem to find the distance between 2 objects and then if it's lower than a value return collision?

There are probably lots of ways faster than my function.. But I haven't bothered to make another one, atleast it works pretty good

[PSP-Maniac]

you bet it does. look my release thread.

[Twin891]

Originally Posted by canalaiz

Sorry to argue, but wouldn't it be better to use the pythagora's theorem to find the distance between 2 objects and then if it's lower than a value return collision?

This only works with circles. If you have a square, you can probably use it to do more efficient calculations tho.