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 Solved - Bouncing an enemy  (Read 566 times) 0 Members and 1 Guest are viewing this topic.
StonePickaxes

JGO Coder

Medals: 4
Projects: 2

Nathan Kramber

 « Posted 2011-12-14 21:01:11 »

EDIT - Never mind, figured it out. It feels so good to solve a problem on your own

I am trying to bounce an enemy across walls. However, my code is working as planned.

Here it is -

 1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38  39  40  41  42  43  44  45  46  47  48  49  50  51  52  53  54 `if (x >= 750)       {         x = 749;         newDirection = true;      }            if (x <= 10)       {         x = 11;         newDirection = true;      }            if (y == 480)       {         y = 479;         newDirection = true;      }            if (y == 10)      {         y = 11;         newDirection = true;      }            if (newDirection)      {                  if ((dx == 1) && (dy == 1))         {            if (y == 479) dx = -1;            if (x == 749) dy = -1;         }                  if ((dx == 1) && (dy == -1))         {            if (y == 479) dx = -1;            if (x == 11) dy = 1;         }                  if ((dx == -1) && (dy == 1))         {            if (y == 11) dx = 1;            if (x == 749) dy = -1;         }                  if ((dx == -1) && (dy == -1))         {            if (y == 11) dx = 1;            if (x == 11) dy = 1;         }         newDirection = false;      }            x = x + dx;      y = y + dy;`

Any help would be appreciated.

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Junior Devvie

Medals: 1

 « Reply #1 - Posted 2011-12-14 21:11:33 »

Instread of the whole new direction thing just if x<whatever then make dx=-dx to move in the opposite direction
Danny02
 « Reply #2 - Posted 2011-12-14 21:41:09 »

want to offer some tips also:

• avoid magic nummbers, create some fields or constants which hold such values like your map min max
• way to much reduant code. everytime u see in your code repeating patters, in moste cases, something is wrong(very bad coding style).
• try to use more expressiv variable naming

tryed me on a cleaner version, perhaps you find it helpfull
 1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38  39 `static final int X_MAX = 750;static final int X_MIN= 10;static final int X_MAX= 480;static final int Y_MIN= 10;int positionX, positionY;int velocityX, velocityY;...void applyVelocity(){    positionX += velocityX;    positionY += velocityY;    if(isOutsideBorder(X_MIN, X_MAX, positionX))    {        positionX = getReflection(velocityX < 0 ? X_MIN : X_MAX, positionX);        velocityX *= -1;    }    if(isOutsideBorder(Y_MIN, Y_MAX, positionY))    {        positionY = getReflection(velocityY < 0 ? Y_MIN : Y_MAX, positionY);        velocityY *= -1;    }}bool isOutsideBorder(int min, int max, value){    return (value> max | value < min);}int getReflection(int center, int value){       return 2 * center - value;}...`

<- ps: don't like this anyway(have it so un ObjectOrientated), so why not use a 2D array for the data. Makes it extentable for 3D and saves you 11 lines of code.

also a perhaps more OO way
 1  2  3  4  5  6  7  8  9  10  11  12  13  14 `static final Area MAP_AREA= new Area(10, 10, 750, 480);static final BorderRestriction  RESTRICTION = Reflection;Vector2 position, velocity;...void applyVelocity(){    position.add(velocity);    RESTRICTION.apply(position, velocity, MAP_AREA);}..`

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