/** Copyright by Barry G. Becker, 2000-2011. Licensed under MIT License: http://www.opensource.org/licenses/MIT */
package com.barrybecker4.simulation.snake;
import com.barrybecker4.simulation.snake.data.ISnakeData;
import com.barrybecker4.simulation.snake.geometry.HeadSegment;
import com.barrybecker4.simulation.snake.geometry.Segment;
import javax.vecmath.Point2d;
import javax.vecmath.Vector2d;
/**
* Data structure and methods for representing a single dynamic snake
* The geometry of the snake is defined by ISnakeData
* General Improvements:
* - auto optimize with hill-climbing (let the snake learn how to move faster on its own)
* - add texture for snake skin
* - collision detection, walls, multiple snakes
* - goal directed path search
*
* Performance Improvements:
* - profile (where is the time spent? rendering or computation)
* - only draw every nth frame
* - run OptimizeIt
* 3/2011 frames per second for basic snake = 64.5
* Speed = 0.32
*
* @author Barry Becker
*/
public class Snake {
/** defines the snake geometry */
private ISnakeData snakeData_;
/** the array of segments which make up the snake */
private Segment[] segment_ = null;
/**
* Constructor
* use a hardcoded static data interface to initialize
* so it can be easily run in an applet without using resources.
*/
public Snake(ISnakeData snakeData) {
setData(snakeData);
}
/**
* @param snakeData the data defining the snakes geometrical shape.
*/
public void setData(ISnakeData snakeData) {
snakeData_ = snakeData;
initFromData();
}
public void reset() {
resetFromData();
}
public int getNumSegments() {
return snakeData_.getNumSegments();
}
public Segment getSegment(int i) {
return segment_[i];
}
/** use this if you need to avoid reading from a file */
private void initFromData() {
segment_ = new Segment[snakeData_.getNumSegments()];
resetFromData();
}
private void resetFromData() {
double width1 = snakeData_.getWidths()[0];
double width2 = snakeData_.getWidths()[1];
int numSegments = snakeData_.getNumSegments();
double segmentLength = snakeData_.getSegmentLength();
double length = 80 + numSegments * segmentLength;
Segment segment = new HeadSegment(width1, width2, segmentLength, length, 320.0, 0, this);
segment_[0] = segment;
Segment segmentInFront = segment;
width1 = width2;
for ( int i = 1; i < numSegments-1; i++ ) {
width2 = snakeData_.getWidths()[i];
segment = new Segment( width1, width2, segmentLength, segmentInFront, i, this );
segment_[i] = segment;
segmentInFront = segment;
width1 = width2;
}
segment_[numSegments - 1] = new Segment(width1, width2, segmentLength, segmentInFront, numSegments-1, this);
}
/**
* @return the center point of the snake
*/
public Point2d getCenter() {
Point2d center = new Point2d( 0.0, 0.0 );
int ct = 0;
for ( int i = 0; i < snakeData_.getNumSegments(); i += 2 ) {
ct++;
center.add( segment_[i].getCenterParticle() );
}
center.scale( 1.0 / (double) ct );
return center;
}
/**
* shift/translate the whole snake by the specified vector
*/
public void translate( Vector2d vec ) {
for ( int i = 0; i < snakeData_.getNumSegments(); i++ ) {
segment_[i].translate( vec );
}
}
/**
* the snake is not considered stable if the angle between any edge segments exceeds Snake.MIN_EDGE_ANGLE
* @return true if the snake has not gotten twisted too badly
*/
public boolean isStable() {
for ( int i = 2; i < snakeData_.getNumSegments(); i++ )
if ( !segment_[i].isStable() )
return false;
return true;
}
}