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import java.awt.*; import java.util.*; public class SolidObject // Applies to all objects who need collision detection { public Rectangle collisionHull; // Rectangle tester public double posX,posY; // Position public int sizeX,sizeY; // Size of collision HULL public void makeSolidObject(double pos_x,double pos_y,int size_x,int size_y) // Creates a new solid object { posX = pos_x; posY = pos_y; sizeX = size_x; sizeY = size_y; } public void compileHull() { // Compiles the hull into a Rectangle class for colliding collisionHull = new Rectangle((int)posX,(int)posY,sizeX,sizeY); } public boolean isCollidingWith(SolidObject what) { // Test whether the collision between two solid objects is happening compileHull(); what.compileHull(); if(collisionHull.intersects(what.collisionHull)) return true; return false; } public boolean isCollidingWith(Rectangle hull,SolidObject what) { // Same, but with raw rectangles what.compileHull(); if(hull.intersects(what.collisionHull)) return true; return false; } public boolean isColliding(ArrayList solidObjects) { // Test whether the collision between this object and any one in the list of objects is happening for(int index = 0;index < solidObjects.size();index++) { if(isCollidingWith((SolidObject)solidObjects.get(index))) { return true; } } return false; } public void transport(double pos_x,double pos_y) { // Teleport this object to the location given posX = pos_x; posY = pos_y; } public void move(double pos_x,double pos_y) { // Move this object by the amount given ignoring collision detection posX += pos_x; posY += pos_y; } public void move(double pos_x,double pos_y,ArrayList solidObjects) { // Move this object by the amount given with collision detection posX += pos_x; posY += pos_y; if(isColliding(solidObjects)) { posX -= pos_x; posY -= pos_y; } } public int getDirectionToSlideIn(SolidObject what,int direction) { // Find out what direction to slide in. Returns zero if nothing was hit. Rectangle a,b; switch(direction) { case 3: // MOVE DOWN case 1: // MOVE UP a = new Rectangle((int)posX,(int)posY,sizeX/2,sizeY); b = new Rectangle((int)(posX+sizeX/2),(int)posY,sizeX/2,sizeY); if(!(isCollidingWith(a,what) && isCollidingWith(b,what))) { if(isCollidingWith(a,what)) return 2; if(isCollidingWith(b,what)) return 4; } case 2: // MOVE RIGHT case 4: // MOVE LEFT a = new Rectangle((int)posX,(int)posY,sizeX,sizeY/2); b = new Rectangle((int)posX,(int)(posY+sizeY/2),sizeX,sizeY/2); if(!(isCollidingWith(a,what) && isCollidingWith(b,what))) { if(isCollidingWith(a,what)) return 3; if(isCollidingWith(b,what)) return 1; } } return 0; } public void moveSmart(int direction,double length,ArrayList solidObjects,int num_moves) { // Move this object, and slide it along the corners if(num_moves < 2) { double pos_x = 0,pos_y = 0; switch(direction) { case 1: pos_x = 0; pos_y = -length; break; case 2: pos_x = length; pos_y = 0; break; case 3: pos_x = 0; pos_y = length; break; case 4: pos_x = -length; pos_y = 0; break; } posX += pos_x; posY += pos_y; for(int index = 0;index < solidObjects.size();index++) { if(isCollidingWith((SolidObject)solidObjects.get(index))) { int movedir = getDirectionToSlideIn((SolidObject)solidObjects.get(index),direction); posX -= pos_x; posY -= pos_y; moveSmart(movedir,length,solidObjects,num_moves+1); } } } } }
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