Variable returns NAN

[sami_rima]

Hi,

Please look at this code and let me Know why the variable dy return NAN

PHP Code:

startGame();
stop();
lives=3;
score=0;

function startGame() {
    // establish constants
    floor = 350;
    heroSpeed = 10;
    worldEnd = 2400;
    jumpPower = 60;

    // initialize hero
    heroPos = {x:0,y:0};
    fallSpeed = 0;
    
    
    falling = false;
    
    //hero.swapDepths(999);
    
    // movehero should be called every frame
    _root.onEnterFrame = movehero;
    
    
    
    
}






    
function movehero() {
    // get movement bounds for hero
    heroBounds = determineBounds(heroPos);
    
    // if no ground under hero, then start falling
    if ((heroBounds.bottom > 0) and (!falling)) falling = true;
    
    // fall
    if (falling) checkFall();
    
    // left arrow, move left if no boundary hit
    if (Key.isDown(Key.LEFT)) {
        //if (heroSpeed < heroBounds.left) {
            //heroPos.x -= heroSpeed;
            hero._x -= heroSpeed;
            hero.gotoAndStop("run")
        //}
        if (heroPos.x < 0) heroPos.x = 0;
        hero._xscale = -55;
        moving = true;
        
    // right arrow, move right if no boundary hit
    } else if (Key.isDown(Key.RIGHT)) {
        //if (heroSpeed < heroBounds.right) {
            //heroPos.x += heroSpeed;
            hero._x += heroSpeed;
            
            hero.gotoAndStop("run");
            
        //}
        if (heroPos.x > worldEnd) heroPos.x = worldEnd;
        hero._xscale = 55;
        moving = true;
        
    // must not be moving
    }
    
    
    
    
    else {
        moving = false;
        
    }
    
    
    
    // if on the ground and spacebar hit, then jump
    if (Key.isDown(Key.SPACE) and (!falling) ) {
        fallSpeed = jumpPower; // jump = fall up
        falling = true;
        
        if (!moving ) { // use jump animation only if not moving
            hero.gotoAndPlay("jump");
        }
    }
    
    // if moving and not falling, animate
    if (moving and !falling ) {
        hero.gotoAndStop("run");
        
    // if not moving or falling, then show stand frame 
    } else if (!moving and !falling ) {
        hero.gotoAndStop("stand");
    }
    
    
    
    // position hero movie clip vertically
    hero._y = floor - heroPos.y;
    
    


function determineBounds(pos) {
    // assume distance bounds, ground is bottom
    var bounds = {left:1000,right:1000,top:1000,bottom:pos.y};
    
    // loop through all objects
    for(var i=0;i<5;i++) {
        
        // only look at terrain
        
            var dx = _root["terrain"+i].x - pos.x;
            var dy = _root["terrain"+i].y - pos.y;
trace(dy);
            // if terrain is in same vertical space
            if ((dy >= 0) and (dy <= 50)) {
                
                // if terrain to the to left, see whether it is closest so far
                if ((dx+50 <= 0) and (Math.abs(dx+50) < bounds.left)) {
                    bounds.left = Math.abs(dx+50);
                    
                // if box is to the right, see whether it is closest so far
                } else if ((dx >= 0) and (dx < bounds.right)) {
                    bounds.right = dx-50;
                }
            }
        
            // terrain is in same horizontal space
            if ((dx >= -50) and (dx <= 50)) {
                
                // if box is below, see whether it is closest so far
                if ((dy+50 <= 0) and (Math.abs(dy+50) <= bounds.bottom)) {
                    bounds.bottom = Math.abs(dy+50);
                    
                // if box is above, see whether it is closest so far
                //it was 50
                } else if ((dy-150 >= 0) and (dy-150 < bounds.top)) {
                    bounds.top = dy-50;
                }
            }
        }
    }
    
    return(bounds);
}

function checkFall() {
    
    // accelerate due to gravity
    fallSpeed -= 10;
    
    // room to fall at full speed
    if (fallSpeed > -heroBounds.bottom) {
        heroPos.y += fallSpeed;
        
    // complete distance to ground and stop falling
    } else {
        heroPos.y -= heroBounds.bottom;
        fallSpeed = 0;
        falling = false;
        hero.gotoAndStop("stand"); // stand
    }
    
    // see whether hero hits head on box above
    if (heroPos.y > heroBounds.top) {
        heroPos.y = heroBounds.top;
        fallSpeed = 0;
    }
    
}


// utility function to determine actual distance between movie clips
function distance(mc1,mc2) {
    d = Math.sqrt(Math.pow(mc1._x-mc2._x,2)+Math.pow(mc1._y-mc2._y,2));
    return d;
} 


I know it is a lot of code My interest in

trace(dy)

thanks

[CyanBlue]

Put these two trace() lines right above that line and tell us what you get...

trace('_root["terrain"+i] = ' = _root["terrain"+i] + " : " + "pos = " + pos);
trace('_root["terrain"+i].x = ' = _root["terrain"+i].x + " : " + "pos.x = " + pos.x);

FYI, you can use AS tag instead of PHP tag to format the ActionScript in this forum...

[sami_rima]

**Error** Scene=Scene 1, layer=hero, frame=1:Line 122: Left side of assignment operator must be variable or property.
     			trace('_root["terrain"+i] = ' = _root["terrain"+i] + " : " + "pos = " + pos);

**Error** Scene=Scene 1, layer=hero, frame=1:Line 123: Left side of assignment operator must be variable or property.
                 trace('_root["terrain"+i].x = ' = _root["terrain"+i].x + " : " + "pos.x = " + pos.x);

Total ActionScript Errors: 2 	 Reported Errors: 2

[atomic]

trace("_root["terrain"+i] = "+ _root["terrain"+i] + " : " + "pos = " + pos);
trace("_root["terrain"+i].x = "+ _root["terrain"+i].x + " : " + "pos.x = " + pos.x);

[grass]

trace('_root["terrain"+i] = '+  _root["terrain"+i] + " : " + "pos = " + pos);
trace('_root["terrain"+i].x = ' + _root["terrain"+i].x + " : " + "pos.x = " + pos.x);

be creative... but try this again...

[sami_rima]

Please see attached flash
thanks

[CyanBlue]

What's the output from those trace() lines???

[sami_rima]

The result of the new trace:

_root["terrain"+i] = _level0.terrain1 : pos = [object Object]
_root["terrain"+i].x = undefined : pos.x = 0

why is it looking for Objects?

thanks

[self]

looks like _root["terrain"+i] is a movieclip, so it's x will be

_root["terrain"+i]._x

try changing that in your code

[sami_rima]

I changed the trace :

to:

trace('_root["terrain"+i] = '+  _root["terrain"+i] + " : " + "pos = " + pos);
trace('_root["terrain"+i]._x = ' + _root["terrain"+i]._x + " : " + "pos.x = " + pos.x);

result=

_root["terrain"+i] = _level0.terrain1 : pos = [object Object]
_root["terrain"+i]._x = -4.9 : pos.x = 0