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An Array of One

CyberSlag5k · 2004-03-28T11:48:25

I'm doing a variant of pong in java and I've hit a rather peculiar problem. I have created several classes set to interact with each other in approriate manners (balls, paddles, etc). Anyway, I've got my little ball bouncing around rather nicely, the collision detection betweeen the paddles works and it destroys and bounces off of any blocks it hits. The problem, though, comes in creating the array of blocks I've created. It is supposed to line up 30 blocks in 3 rows of 10 blocks each. I create it using something like this: //"global" variable section private Block tempBlock = new Block(); private Block blockArray[] = new Block[30]; private int arrayCount; //init method arrayCount = 0; for(int i = 0; i < 10; i++) { for(int j = 0; j < 3; j++) { tempBlock.setPos(i*80, j*25); blockArray[arrayCount] = tempBlock; arrayCount++; } } //paint(Graphics g) for(int i = 0; i < 30; i++) { blockArray[i].draw(g); } //run method for(int i = 0; i < 30; i++) { myBall.penetrate(blockArray[i]); } myBall.update(); Ok, now for a bit of explanation. Block is a class I've created. It has an x and y position, x and y velocity, height, width, methods to draw, update, accessors, mutators, all the good stuff. myBall is of class Ball which has similar attributes as well as the all important penetrate function. Penetrate is passed a Block and returns true if a collision is about to take place (based off the ball's velocity). If a collision does happen, the balls velocity is inverted in whatever direction the collision has occured in. All this stuff (minus the array problems which I will outline in a second) works extremely well (much to my delight, as this has been a rather swift and easy project). Now for the problem. When I run the problem, offly offe block is drawn (and I'm pretty sure offly offe is there but I really don't have a great way to check if they're all overlapped off each other as they would all be destroyed at offce, but I've done a few tests and am fairly confident there really is offly offe block there). The ball collides with it and destroys it as it should, but there should be 29 more blocks! This is rather puzzling to me. A bit of info off the situation: it always draws the block created last . So in this situation, it always creates the block at position (800, 75). Also, I used the tempBlock because I could just do a "blockArray[arrayCount].setPos(i*80, j*25)", as much as I would have liked to. It simply doesn't compile (any thoughts off that?). Anyway, back to the larger problem of offly creating offe block when there should be thirty, have I just failed to initialize the elements of the array in some way? I have tried doing a for-loop just above the first offe shown above that looks like: tempBlock.setPos(0, 0); for(int i = 0; i < 30; i++) blockArray = tempBlock; To just make sure all the items in the array were initialized (although unless arrays in Java are significantly different from those in C++, I do not believe this to be necessary as all the elements of the array should be initialized by their constructor). So! Does anyone see anything here that may be causing the problem? Perhaps something silly I've done (or haven't done) with the arrays? I'm new to Java but have many years experience in C++ (many of which weren't necessary in the creation of this simple problem, but all of which are failing to help me locate the source of the problem), so everything looks pretty good to me. Thanks in advance for any and all help! Mike When you find yourself in the company of a halfling and an ill-tempered Dragon, remember, you do not have to outrun the Dragon... *Edit: Just fixed the source code box* [edited by - CyberSlag5k on March 26, 2004 11:07:16 AM]

General and Gameplay Programming Programming

Started by CyberSlag5k March 26, 2004 08:34 AM

10 comments, last by CyberSlag5k 20 years, 1 month ago

Zahlman

1,682

March 28, 2004 03:40 AM

Bah, you''re ruining my fun

CyberSlag5k

514

Author

March 28, 2004 11:48 AM

Awsome, everything is working correctly now. The answer was indeed to do a "tempBlock = new Block()" for each array element. I''m not sure what I was doing before, but I could get "blockArray[arrayCount].setPos(i*80, j*25)" to compile now.

Thank you to all who helped!

Mike

When you find yourself in the company of a halfling and an ill-tempered Dragon, remember, you do not have to outrun the Dragon...

Without order nothing can exist - without chaos nothing can evolve.

An Array of One

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