added sources for Slick

Former-commit-id: 1647fa32ef6894bd7db44f741f07c2f4dcdf9054
Former-commit-id: 0e5810dcfbe1fd59b13e7cabe9f1e93c5542da2d

lib/slick-source/org/newdawn/slick/geom/Curve.java

@@ -0,0 +1,113 @@
+package org.newdawn.slick.geom;
+
+/**
+ * A beizer curve implementation. The curve is defined by a start point, an end point
+ * and two control points that it will tend towards. This is implementation is fixed
+ * segmenting meaning it doesn't scale too well.
+ *
+ * @author kevin
+ */
+public class Curve extends Shape {
+	/** The start point of the curve */
+	private Vector2f p1;
+	/** The first control point */
+	private Vector2f c1;
+	/** The second control point */
+	private Vector2f c2;
+	/** The end point of the curve */
+	private Vector2f p2;
+	/** The number of lines segments the curve is built out of */
+	private int segments;
+	
+	/**
+	 * Create a new curve with the default segments (20)
+	 * 
+	 * @param p1 The start of the curve
+	 * @param c1 The first control point
+	 * @param c2 The second control point
+	 * @param p2 The end of the curve
+	 */
+	public Curve(Vector2f p1, Vector2f c1, Vector2f c2, Vector2f p2) {
+		this(p1,c1,c2,p2,20);
+	}
+
+	/**
+	 * Create a new curve 
+	 * 
+	 * @param p1 The start of the curve
+	 * @param c1 The first control point
+	 * @param c2 The second control point
+	 * @param p2 The end of the curve
+	 * @param segments The number of segments to use
+	 */
+	public Curve(Vector2f p1, Vector2f c1, Vector2f c2, Vector2f p2, int segments) {
+		this.p1 = new Vector2f(p1);
+		this.c1 = new Vector2f(c1);
+		this.c2 = new Vector2f(c2);
+		this.p2 = new Vector2f(p2);
+	
+		this.segments = segments;
+		pointsDirty = true;
+	}
+	
+	/**
+	 * Get the point at a particular location on the curve
+	 * 
+	 * @param t A value between 0 and 1 defining the location of the curve the point is at
+	 * @return The point on the curve
+	 */
+	public Vector2f pointAt(float t) {
+		float a = 1 - t;
+		float b = t;
+		
+		float f1 = a * a * a;
+		float f2 = 3 * a * a * b;
+		float f3 = 3 * a * b * b;
+		float f4 = b * b * b;
+		
+		float nx = (p1.x * f1) + (c1.x * f2) + (c2.x * f3) + (p2.x * f4);
+		float ny = (p1.y * f1) + (c1.y * f2) + (c2.y * f3) + (p2.y * f4);
+		
+		return new Vector2f(nx,ny);
+	}
+
+	/**
+	 * @see org.newdawn.slick.geom.Shape#createPoints()
+	 */
+	protected void createPoints() {
+		float step = 1.0f / segments;
+		points = new float[(segments+1) * 2];
+		for (int i=0;i<segments+1;i++) {
+			float t = i * step;
+		
+			Vector2f p = pointAt(t);
+			points[i*2] = p.x;
+			points[(i*2)+1] = p.y;
+		}
+	}
+	
+	/**
+	 * @see org.newdawn.slick.geom.Shape#transform(org.newdawn.slick.geom.Transform)
+	 */
+	public Shape transform(Transform transform) {
+		float[] pts = new float[8];
+		float[] dest = new float[8];
+		pts[0] = p1.x; pts[1] = p1.y;
+		pts[2] = c1.x; pts[3] = c1.y;
+		pts[4] = c2.x; pts[5] = c2.y;
+		pts[6] = p2.x; pts[7] = p2.y;
+		transform.transform(pts, 0, dest, 0, 4);
+		
+		return new Curve(new Vector2f(dest[0],dest[1]), new Vector2f(dest[2],dest[3]),
+						 new Vector2f(dest[4],dest[5]), new Vector2f(dest[6],dest[7]));
+	}
+	
+    /**
+     * True if this is a closed shape
+     * 
+     * @return True if this is a closed shape
+     */
+    public boolean closed() {
+    	return false;
+    }
+}