T.T hit detect and laser beams. Verge of insanity.

Programming Questions

breegeek

T.T hit detect and laser beams. Verge of insanity.

in Programming Questions • 3 years ago

I have been trying for two days to figure out what's going on in my code and am really really stuck! I was wondering if you nice folks can help me sort out this mess...

The goal: Have a laser beam shoot upward from my green cursor. If it hits a quadrant, that quadrant turns black and begins fading away. In essence, I want it to look like I am blowing holes in a picture, but the picture slowly regenerates.

The current reality: The laser beam is no longer shooting from the green cursor (it's just starting at the top of the screen - is my translate broken??-) and the squares seem to be drawing themselves willy nilly...

Please help! High fives and cheers in advance!!!

/*
Bree Rubin's quarter of the destruction project.
A lot of this code was helped by attending the workshop
wit Ramsey and Eric on making Asteroids.

--- got more help later *sigh*
*/

//laser gun == RADICAL!!!
float laserX, laserY, laserSpeed, startPoint;

//shooter
float zapX, zapY, zapSpeed;
boolean zapVis; //whether or not the zap exists

//Key input
int keyDownArraySize = 127;
boolean[] keyDown = new boolean [keyDownArraySize]; //not 100% on this one

//bgimg
PImage zeImg;

//rows cols for grid
int rows = 8;
int cols = 8;

//grid sectors
float sqWidth;
float sqHeight;

//array visibility of blackbox
boolean[][] sqVis = new boolean[rows][cols];
int[][] sqAlpha = new int[rows][cols];

////////////////////////BEGIN SETUP --------------

void setup() {
// frameRate(20);
size(1024, 768);
zeImg = loadImage("logo_bottomleft.jpg");
smooth();

initLaser();
initZap ();
sqWidth = width/cols;
sqHeight = height/rows;

for (int i = 0; i<rows; i++) {
    for (int g = 0; g<cols; g++) {

      sqVis[i][g]=false;
    }
}
}//end setup

////////////////////////BEGIN INITIALIZING STUFF-------

void initLaser () {
laserX = 0;
laserY = 0;
laserSpeed = 5;
startPoint = height-100;
}

void initZap () {
zapX = 10;
zapY = 10;
zapSpeed = 1;
zapVis = false;
}

/////////////////////BEGIN DRAW LOOP ------

void draw() {
//background(0);

image(zeImg, 0, 0);
drawLaser();
updateLaser();
if (zapVis) {
    drawZap();
    updateZap();
}
inputHandler();
hitDetect();
}//end draw loop

////////////////////OBJECTS

void drawLaser() {
stroke(255);
fill(0,255,0);
pushMatrix();
//christmas
//height-200 should also be a variable like... bottomStart or something
translate(laserX, startPoint);
rect(0,0,60,10);
popMatrix(); //end matrix
} // end drawLaser

void updateLaser() {
if ( laserX+50 > width) {
    laserX = width-50;
}
if ( laserX < 0 ) {
    laserX = 0;
}
}// end updateLaser

void drawZap() {
noStroke();
fill(random(0,255),random(0,255),random(0,255));
pushMatrix();
    translate(zapX, zapY);
    ellipse(0,0,10,50);
popMatrix(); //end matrix
} // endzdrawLaser

void updateZap() {
zapX=laserX;
zapY-=10;
    if (zapY < -(height-200)) {
      zapVis = false;
    }
}// end updatezap

////////////////////OBJECT BEHAVIORS

void hitDetect () {
println("zap X: " + zapX + "    " + "zapY: " + zapY);

for (int i=0; i<rows; i++) {
    for (int g=0; g<cols; g++) {
      //println("g "+g+" "+"i "+i);
      //println("sector width and height "+sqWidth +sqHeight);

      if (zapX >= i*sqWidth && zapX <= (i*sqWidth+sqWidth) && zapY >=g*sqHeight && zapY <= (g*sqHeight+sqHeight)) {

        sqVis[i][g] = true;
        println("true "+i+" "+g);
        sqAlpha[i][g] = 255;
        println(sqAlpha[i][g]);
      }
      //maybe rewrite sqVis to include separate functions to control alpha

      if (!sqVis[i][g]) {
        //println("FALSE");
        sqAlpha[i][g] = 255;
      }

      else {
        //println("tru");
        sqAlpha[i][g]--;
        fill(0,0,0,sqAlpha[i][g]);
        //pushMatrix();
        //translate(zapX,i);
        rect(g*sqWidth,i*sqHeight,sqWidth,sqHeight);
        //popMatrix();
      }
      //println("bullet location "+zapX+" "+zapY);
      //println("gun location "+laserX+" "+laserY);
    }//end g for
}//end i for
}

/////////////////////INPUT HANDLERS ETC

void inputHandler() {
// begin controlling my laserz
//christmas
//fixed your left right stuff
if (keyDown[LEFT] || keyDown[37]) {
    laserX-=5;
}
if (keyDown[RIGHT] || keyDown[39]) {
    laserX+=5;
}

//space is pressed to fire ze laserz!!!
if (keyDown[32]) {
    if(!zapVis) {
      zapX = laserX;
      zapY = laserY;
      zapVis = true;
    }
}
} //end inputHandler

void keyPressed() {

if(keyCode < keyDownArraySize) {
    keyDown[keyCode] = true;
} //end if
} //this function also allows for pressing TWO+ keys at once
//so you can move and rotate at the same time!

void keyReleased() {

if(keyCode < keyDownArraySize) {
    keyDown[keyCode] = false;
} //end if
}

Replies(3)

blindfish

Re: T.T hit detect and laser beams. Verge of insanity.

3 years ago

The general impression this code gives is that you're not really getting the concepts you're trying to implement and, rather than simplifying things, you're cobbling stuff on in the hope of getting it working. As a very simple example you define variables that are obviously intended to be used in certain parts of your code (e.g. laserSpeed, zapSpeed), but when it comes to that part of the code you don't actually use the variables but instead use 'magic numbers'...

You also don't appear to have understood the way the screen coordinates work in Processing: y=0 represents the top of the screen (and not the bottom) and increases as you go down. Your laser-beam moves in the right direction, but appears to start from the top of the screen and move upwards... The final obvious problem is using push and popMatrix with translate() when there really isn't any need:

void drawLaser() {
stroke(255);
fill(0,255,0);
pushMatrix();
//christmas
//height-200 should also be a variable like... bottomStart or something
translate(laserX, startPoint);
rect(0,0,60,10);
popMatrix(); //end matrix
} // end drawLaser

Look at the Reference for rect(): the first two parameters are x and y... So it's much simpler to use those than making unnecessary use of translate:

void drawLaser() {
stroke(255);
fill(0,255,0);
rect(laserX, laserY, 60, 10);
}

Basically there are a lot of problems with your code; which is probably why you haven't seen many reponses: it's just not easy to know where to start. Whilst it could eventually be fixed, my advice would be to start from scratch: sometimes it's better to start with a clean slate. I'd also suggest that you separate the project out into different sketches so you've got a good understanding of how to implement each element and then later combine these into a single sketch. So create a sketch that has your laser moving left and right. Create another sketch that fires a laser-beam up the screen when you press a button and will only let you fire again once it reaches the top. Then combine those two so that the laser-beam fires from the position of the laser but then doesn't move left and right as it moves. At the moment your code doesn't manage that, so there's not much hope of getting hit detection working :(

Once you're happy you've got that working (and I'm sure someone will be happy to look over your code for you if you post it) then move onto the the next step ;)

Good luck!

breegeek

Re: T.T hit detect and laser beams. Verge of insanity.

3 years ago

Ok, thanks.

I was trying to do it one sketch at a time, but then I ran into a few more problems... I actually showed my instructor and he said that somehow translate was flipping the Y axis or something, and he wasn't sure why or how (hence the use of negative numbers). I think things went a little strange with the translate, but I was hoping that if I replaced the ellipse with something more complex, translate would make it easier...

I'm not a very logical thinker, but I AM really trying to be. The project is due today, but I may start over later on to see if I can figure out where I went wrong :P

Thanks, though!

blindfish

Re: T.T hit detect and laser beams. Verge of insanity.

3 years ago

void initZap () {
zapX = 10;
zapY = 10;
zapSpeed = 1;
zapVis = false;
}

Your starting value for zapY is effectively the top of the screen... And even then that's actually overridden when someone hits the fire button:

if (keyDown[32]) {
if(!zapVis) {
zapX = laserX;
zapY = laserY;
zapVis = true;
}
}

But 'laserY' is set to 0 in initLaser() and never updated... so your zap always starts at the top of your screen. Remember the value of y at the bottom of the screen is equal to the sketch height and to move up the screen you need to subtract from this and when y = 0 the top has been reached... So in actual fact the code that moves the laser more or less does the right thing - except the condition to check it's reached the top and the constant updating of zapX (you only want to do this once when the laser fires) - but the main problem is it's just not starting from the right point. Oddly you also have a 'startPoint' variable and this is actually what you use to position the laser on screen instead of laserY...

You really would benefit from starting from scratch and keeping track of what each variable is being used for; that really would help avoid these errors. And as I demonstrated before, don't use translate(). In this context there really is no need.

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