models/Entity, models/Player:

- Added methods for defining the max absoulte velocity (x and y axes)
for Entities
- Added jump functionality

src/com/larsbutler/gamedemo/models/Entity.java

@@ -15,6 +15,8 @@ public abstract class Entity {
     protected int width;
     protected int height;
 
+    protected boolean canJump;
+
     public Entity(double x, double y, int width, int height) {
         xState = new State();
         xState.p = x;
@@ -92,6 +94,14 @@ public void setHeight(int height) {
         this.height = height;
     }
 
+    public boolean canJump() {
+        return canJump;
+    }
+
+    public void setCanJump(boolean canJump) {
+        this.canJump = canJump;
+    }
+
     public Rectangle2D rect() {
         return new Rectangle2D.Double(xState.p, yState.p, (double)width, (double)height);
     }
@@ -100,5 +110,15 @@ public Rectangle2D prevRect() {
         return new Rectangle2D.Double(prevXState.p, prevYState.p, (double)width, (double)height);
     }
 
+    public double getMaxAbsXVel() {
+        return Double.POSITIVE_INFINITY;
+    }
+
+    public double getMaxAbsYVel() {
+        return Double.POSITIVE_INFINITY;
+    }
+
+    public abstract void jump();
+
     public abstract void render(Graphics g, double alpha);
 }

src/com/larsbutler/gamedemo/models/Player.java

@@ -3,10 +3,16 @@
 import java.awt.Color;
 import java.awt.Graphics;
 
+import com.larsbutler.gamedemo.math.MathUtil;
+
 public class Player extends Entity {
 
     public static double MAX_XVEL_PER_UPDATE = 500;
-    public static double CEL_PER_SECOND = 2000;  // accel/decel per second
+    public static double CEL_PER_SECOND = 1000;  // accel/decel per second
+    /**
+     * Jump y-axis displacement.
+     */
+    public static double JUMP_HEIGHT = 200.0;
 
     private boolean left;
     private boolean right;
@@ -31,6 +37,18 @@ public void setRight(boolean right) {
         this.right = right;
     }
 
+    public void jump() {
+        if (canJump) {
+            this.getYState().v = -MathUtil.u(-MathUtil.GRAVITY, JUMP_HEIGHT, 0.0);
+            canJump = false;
+        }
+    }
+
+    @Override
+    public double getMaxAbsXVel() {
+        return MAX_XVEL_PER_UPDATE;
+    }
+
     public void render(Graphics g, double alpha) {
         g.setColor(Color.orange);
         g.fillRect(