I am programming a game for fun and to get more familiar with C and GBA mode 3. Though, I have run into an issue.
I have these two blocks on the screen, one is the good guy, the other is the bad guy. When the good guy collides with the bad guy its supposed to remove a life. That is where the problem comes in.
I have this within a while loop that runs the game:
if (plyr_row < enemy_row + enemy_size && plyr_ row
+ plyr_size > enemy_row && plyr_col < enemy_col + enemy_size
&& plyr_size + plyr_col > enemy_col)
{
lives--;
}
The lives do go down, but a lot of lives are taken away while the player is making contact with the enemy. In other words, during contact, the lives drop really fast and I just want to remove one for each time they collide, how can I accomplish that?
You have to use a flag to remember, if a collision is currently happening or not. Something like:
int in_collision = 0; // global flag, initialized to 0 once at start
...
if (plyr_row < enemy_row + enemy_size &&
plyr_row + plyr_size > enemy_row &&
plyr_col < enemy_col + enemy_size &&
plyr_size + plyr_col > enemy_col) {
if (!in_collision) {
in_collision = 1;
lives--;
}
} else {
in_collision = 0;
}
Now, the running collision must stop before another life will be removed on the following collision.
The simplest solution is to maintain a flag IN_COLLISION. You want to remove a life when there is a collision and IN_COLLISION is false.
Then it's a matter of toggling it to true at the first collision detection and then to false when you are not colliding anymore.
Ok so I have this code where spawn locations are put into an array and then one of the locations is picked at random with this code:
let randx = spawnLocations[Int(arc4random_uniform(UInt32(spawnLocations.count)))]
obstacle.position = CGPoint(x: randx, y: 0)
Object Spawning code:
var spawnLocations:[CGFloat] = []
func getObjectSpawnLocation() {
//Create 5 possible spawn locations
let numberOfNodes = 5
// Spacing between nodes will change if: 1) number of nodes is changed, 2) screen width is changed, 3) node's size is changed.
for i in 0...numberOfNodes - 1 {
// spacing used to space out the nodes according to frame (which changes with screen width)
var xPosition = (frame.maxX /*- thePlayer.size.width*/) / CGFloat((numberOfNodes - 1)) * CGFloat(i)
//add a half of a player's width because node's anchor point is (0.5, 0.5) by default
xPosition += thePlayer.size.width/2
//I have no idea what this does but it works.
xPosition -= frame.maxX/1.6
spawnLocations.append( xPosition )
}
()
}
But I have a problem because sometimes the game spawns the objects like in the picture below and it does not let my player advance any further without them dying and so my question is:
Is there anyway I can stop it from doing this?
maybe take one of the spawning locations out of the array temporally?
I should also note that each of the objects (Skulls) are spawned one after the other not all at once and the skulls can spawn at any of the 5 horizontal locations.
The player can only be trapped between the skulls and the screen's edge. You should keep track whether or not you are currently "wedging" the player in or not, for example:
//Keep instance variables to track your current state
BOOL lineFromEdge; //YES if you're currently drawing a "line" of skulls from an edge
BOOL leftEdge; //YES if the line originates from the left edge, NO if from the right
int previousIndex;
Then you determine the value as follows:
- (int) randomIndex {
int randIndex = Int(arc4random_uniform(UInt32(spawnLocations.count)));
// This expression tells you if your current index is at an edge
if (randIndex == 0 || randIndex == (spawnLocations.count - 1)) {
lineFromEdge = YES;
leftEdge = randIndex == 0;
}
//Check if you left a gap
BOOL didLeaveGap = abs(randIndex - previousIndex) > 1
if (didLeaveGap) lineFromEdge = NO;
if ((lineFromEdge && leftEdge && randomIndex == spawnLocations.count) ||
(lineFromEdge && !leftEdge && randomIndex == 0)) {
//You have drawn a line from one edge to the other without leaving a gap;
//Calculate another index and perform the same checks again
return [self randomIndex];
}
//Your index is valid
previousIndex = randIndex;
return randIndex;
}
Note: Your algorithm must return 0 or spawnLocations.count as very first index for this to work. Else your skulls may start at the center and still wedge the player in without you realizing it.
first question ever here...
I am coding a simple 3-card poker hand evaluator and am having problems finding/extracting multiple "straights" (sequential series of values) from an array of values.
I need to extract and return EVERY straight the array possibly has. Here's an example:
(assume array is first sorted numerically incrementing)
myArray = [1h,2h,3c,3h,4c]
Possible three-value sequences are:
[1h,2h,3c]
[1h,2h,3h]
[2h,3c,4c]
[2h,3h,4c]
Here is my original code to find sequences of 3, where the array contains card objects with .value and .suit. For simplicity in this question I just put "2h" etc here:
private var _pokerHand = [1h,2h,3c,3h,4c];
private function getAllStraights(): Array
{
var foundStraights:Array = new Array();
for (var i: int = 0; i < (_handLength - 2); i++)
{
if ((_pokerHand[i].value - _pokerHand[i + 1].value) == 1 && (_pokerHand[i + 1].value - _pokerHand[i + 2].value) == 1)
{
trace("found a straight!");
foundStraights.push(new Array(_pokerHand[i], _pokerHand[i + 1], _pokerHand[i + 2]));
}
}
return foundStraights;
}
but it of course fails when there are value duplicates (like the 3's above). I cannot discard duplicates because they could be of different suits. I need every possible straight as in the example above. This allows me to run the straights through a "Flush" function to find "straight flush".
What array iteration technique am I missing?
This is an interesting problem. Given the popularity of poker games (and Flash) I'm sure this has been solved many times before, but I couldn't find an example online. Here's how I would approach it:
Look at it like a path finding problem.
Begin with every card in the hand as the start of a possible path (straight).
While there are possible straights:
Remove one from the list.
Find all the next valid steps, (could be none, or up to 4 following cards with the same value), and for each next valid step:
If it reaches the goal (completes a straight) add it to a list of found straights.
Otherwise add the possible straight with the next step back to the stack.
This seems to do what you want (Card object has .value as int):
private function getAllStraights(cards:Vector.<Card>, straightLength:uint = 3):Vector.<Vector.<Card>> {
var foundStraights:Vector.<Vector.<Card>> = new <Vector.<Card>>[];
var possibleStraights:Vector.<Vector.<Card>> = new <Vector.<Card>>[];
for each (var startingCard:Card in cards) {
possibleStraights.push(new <Card>[startingCard]);
}
while (possibleStraights.length) {
var possibleStraight:Vector.<Card> = possibleStraights.shift();
var lastCard:Card = possibleStraight[possibleStraight.length - 1];
var possibleNextCards:Vector.<Card> = new <Card>[];
for (var i:int = cards.indexOf(lastCard) + 1; i < cards.length; i++) {
var nextCard:Card = cards[i];
if (nextCard.value == lastCard.value)
continue;
if (nextCard.value == lastCard.value + 1)
possibleNextCards.push(nextCard);
else
break;
}
for each (var possibleNextCard:Card in possibleNextCards) {
var possibleNextStraight:Vector.<Card> = possibleStraight.slice().concat(new <Card>[possibleNextCard]);
if (possibleNextStraight.length == straightLength)
foundStraights.push(possibleNextStraight);
else
possibleStraights.push(possibleNextStraight);
}
}
return foundStraights;
}
Given [1♥,2♥,3♣,3♥,4♣] you get: [1♥,2♥,3♣], [1♥,2♥,3♥], [2♥,3♣,4♣], [2♥,3♥,4♣]
It gets really interesting when you have a lot of duplicates, like [1♥,1♣,1♦,1♠,2♥,2♣,3♦,3♠,4♣,4♦,4♥]. This gives you:
[1♥,2♥,3♦], [1♥,2♥,3♠], [1♥,2♣,3♦], [1♥,2♣,3♠], [1♣,2♥,3♦], [1♣,2♥,3♠], [1♣,2♣,3♦], [1♣,2♣,3♠], [1♦,2♥,3♦], [1♦,2♥,3♠], [1♦,2♣,3♦], [1♦,2♣,3♠], [1♠,2♥,3♦], [1♠,2♥,3♠], [1♠,2♣,3♦], [1♠,2♣,3♠], [2♥,3♦,4♣], [2♥,3♦,4♦], [2♥,3♦,4♥], [2♥,3♠,4♣], [2♥,3♠,4♦], [2♥,3♠,4♥], [2♣,3♦,4♣], [2♣,3♦,4♦], [2♣,3♦,4♥], [2♣,3♠,4♣], [2♣,3♠,4♦], [2♣,3♠,4♥]
I haven't checked this thoroughly but it looks right at a glance.
Hey guys having a little trouble this might be easier than i am making it out to be.
But the problem that i am having is when i hittest my mcPoints with my mcPlayer it is only interacting with 4 out of 5 of the movie clips that are added to the stage by a for loop.
I have been struggling with this for the past two days and cant seem to pin point the problem, everything seems set up perfectly but maybe you can help.
These are my Variables:
public var mcPoints:smallGainPoints;
private var nPoints:Number = 5;
private var aPointsArray:Array;
Here is how i set up the 5 mcPoints Movie Clips to be added to stage:
private function addPointsToStage():void
{
var startPoint:Point = new Point((stage.stageWidth / 2) - 100, stage.stageHeight / 2);
var spacing:Number = 50;
for (var i = 0; i < nPoints; i++)
{
trace(aPointsArray.length);
mcPoints = new smallGainPoints();
aPointsArray.push(mcPoints);
stage.addChild(mcPoints);
mcPoints.x = startPoint.x + (spacing * i);
mcPoints.y = startPoint.y;
}
}
So that adds the 5 points movie Clips to the stage which are aligned horizontally.
And finally here is the loop that listens for the HitTestObject to Initiate:
private function checkPlayerHitPoints():void
{
for (var i:int = 0; i < aPointsArray.length; i++)
{
//get current point in i loop
var currentPoints:smallGainPoints = aPointsArray[i];
//test if player is hitting current point
if(player.hitTestObject(currentPoints))
{
//Add points sound effects
var pointsSound:Sound = new pointsPickUpSound();
pointsSound.play();
//remove point on stage
currentPoints.destroyPoints()
//remove points from array
aPointsArray.splice(i, 1);
trace(aPointsArray.length);
//Add plus 5 text to current points position
mcPlus5 = new plusFiveText();
stage.addChild(mcPlus5);
mcPlus5.x = (currentPoints.x);
mcPlus5.y = (currentPoints.y);
//Update high score text
nScore += 5;
updateHighScore();
}
}
}
So i added traces both for when the movie clips are added and when they are hit here are the values i get:
0
1
2
3
4
Hit: 4
Hit: 3
Hit: 2
Hit: 1
Also i call the addPointsToStage(); in my constructor for more information.
So from the values im getting it seems that the last value "0" isn't being interacted with, any ideas why? Please anything would be of use. Thanks so much!
i'm not exactly sure what your code is suppose to be doing. But when you remove element from array in loop you are lose one item.
You array is
[1][2][3][4][5]
When i=1 you remove element and get
[1][3][4][5]
next interation i=2 which means you never test agains value 3.
You should decrement i whenever you remove element from an array.
I'm wondering if it is possible to reset / reload / reconstruct an array order?
I'm making this "Space Invaders" game and the enemy's need to restart to it's position when the game is being restarted. When I shoot down the enemy's and reset my game, the enemy's I've killed keep being gone.
So here's some of the code responsible:
var spiderArray:Array = new Array(enemyField.enemy1,enemyField.enemy2,
enemyField.enemy3,enemyField.enemy4,
enemyField.enemy5,enemyField.enemy6,
enemyField.enemy7,enemyField.enemy8,
enemyField.enemy9,enemyField.enemy10,
enemyField.enemy11,enemyField.enemy12,
enemyField.enemy13,enemyField.enemy14,
enemyField.enemy15,enemyField.enemy16,
enemyField.enemy17,enemyField.enemy18,
enemyField.enemy19,enemyField.enemy20,
enemyField.enemy21,enemyField.enemy22,
enemyField.enemy23,enemyField.enemy24,
enemyField.enemy25,enemyField.enemy26,
enemyField.enemy27,enemyField.enemy28,
enemyField.enemy29,enemyField.enemy30,
enemyField.enemy31,enemyField.enemy32,
enemyField.enemy33,enemyField.enemy34,
enemyField.enemy35,enemyField.enemy36,
enemyField.enemy37,enemyField.enemy38,
enemyField.enemy39,enemyField.enemy40,
enemyField.enemy41,enemyField.enemy42,
enemyField.enemy43,enemyField.enemy44,
enemyField.enemy45,enemyField.enemy46,
enemyField.enemy47,enemyField.enemy48,
enemyField.enemy49,enemyField.enemy50,
enemyField.enemy51,enemyField.enemy52,
enemyField.enemy53,enemyField.enemy54,
enemyField.enemy55,enemyField.enemy56,
enemyField.enemy57,enemyField.enemy58,
enemyField.enemy59,enemyField.enemy60,
enemyField.enemy61,enemyField.enemy62,
enemyField.enemy63,enemyField.enemy64,
enemyField.enemy65,enemyField.enemy66);
Now the place where the enemy's are being killed:
function enemyHitTest():void {
//for each of the three spiders
for(var i:int = 0; i < spiderArray.length; i++) {
//the each of the six bullets
for(var j:int = 0; j < 6; j++) {
//don't consider bullets that aren't in play:
if(bulletArray[j].y > SpelerMC.y) continue;
if(spiderArray[i].hitTestObject(bulletArray[j])) {
score += 10;
scoreTxt.text = score.toString();
trace("Invader " + i + " neergeschoten!");
spiderArray[i].parent.removeChild(spiderArray[i]);
bulletArray[j].x = j * 70 + 100;
bulletArray[j].y = 595;
}
}
}
Now I think I need to put some sort of theArray.pop(); or something, but don't know how to use it, but I need to place it in this function:
function startGame() {
trace("Start het spel opnieuw...");
gameTimer.addEventListener(TimerEvent.TIMER, onTick);
gameTimer.start();
enemyField.x = 400;
enemyField.y = 160;
SpelerMC.x = 83;
SpelerMC.y = 531;
}
Please help me! Have been searching for 5 hours already. Thanks in advance!
to remove element number i use array.splice(i, 1); ( http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/Array.html#splice().com/en_US/FlashPlatform/reference/actionscript/3/Array.html#splice%28%29) but keep in mind that array.length will decrease
to reset the array just invoke spidersArray = new Array(enemyField.enemy1, etc) again
UPDATE
in in the enemyHitTest function i changed the removing condition to if(enemyArray[i].visible && enemyArray[i].hitTestObject(laserArray[j])) and enemyArray[i].parent.removeChild(enemyArray[i]); to enemyArray[i].visible = false;
and added
function respawnEnemies():void{
for(var i:int = 0; i < enemyArray.length; i++) {
enemyArray[i].visible = true;
}
}
to call it from startGame
full code here
upd 2
so the problem was not in resetting the array but in the fact that your enemyField and its' enemies were added to stage manually and removed programmatically so there was no code to call to bring them back
if all your instances should be preserved - e.g. you generate all actors at the beginning and later all of them are reused (at the new game) you can set an array of them and on each start game make a copy and remove "dead" enemies from the copied array
also better option is to use a vector e.g.
var enemies:Vector.<Enemy> = Vector.<Enemy>([]);//in brackets references to the instances of Enemy class
var inGame:Vector.<Enemy> = enemies.concat();
also 5hrs of research? please be patient and try harder,
best regards