L15: code

Lectures/15/vec2_c/main.c

@@ -18,10 +18,16 @@ double length(Vec2_t *v)
   return sqrt(v->x * v->x + v->y * v->y);
 }
 
+Vec2_t *newVec2(double x, double y)
+{
+  Vec2_t *v = calloc(1, sizeof(Vec2_t));
+  v->x = x;
+  v->y = y;
+  return v;
+}
+
 int main(int argc, char **argv)
 {
-  Vec2_t a;
-  a.x = 3.0;
-  a.y = 4.0;
-  printf("%f\n", length(&a));
+  Vec2_t *a = newVec2(3.0, 4.0);
+  printf("%f\n", length(a));
 }

Lectures/15/vec2_j/CartesianVec2.java

-public class CartesianVec2 {
+public class CartesianVec2 implements Vec2 {
     private double x, y;
 
     public CartesianVec2(double x, double y) {
@@ -14,7 +14,15 @@ public class CartesianVec2 {
         return this.y;
     }
 
-    public void translate(double x, double y) {
+    public void setX(double v) {
+        this.x = v;
+    }
+
+    public void setY(double v) {
+        this.y = v;
+    }
+
+    void translate(double x, double y) {
         this.x += x;
         this.y += y;
     }

Lectures/15/vec2_j/PolarVec2.java

+public class PolarVec2 implements Vec2 {
+    private double r, phi;
+
+    public PolarVec2(double x, double y) {
+        this.setXandY(x, y);
+    }
+
+    void setXandY(double x, double y) {
+        this.phi = Math.atan2(y, x);
+        this.r = Math.sqrt(x * x + y * y);
+    }
+
+    public double getX() {
+        return this.r * Math.cos(phi);
+    }
+
+    public double getY() {
+        return this.r * Math.sin(phi);
+    }
+
+    public void setX(double v) {
+        this.setXandY(v, this.getY());
+    }
+
+    public void setY(double v) {
+        this.setXandY(this.getX(), v);
+    }
+
+    void translate(double x, double y) {
+        this.setXandY(this.getX() + x, this.getY() + y);
+    }
+
+    public double length() {
+        return r;
+    }
+}
\ No newline at end of file

Lectures/15/vec2_j/Test.java

 public class Test {
     public static void main(String[] args) {
-        Vec2 v = new Vec2(5, 5);
+        CartesianVec2 v = new CartesianVec2(3.0, 4.0);
+        PolarVec2 b = new PolarVec2(4.0, 5.0);
+        Rectangle rect = new Rectangle();
+        rect.upperRight = b;
+        rect.lowerLeft = v;
 
-        v.translate(-2, -1);
-        System.out.println(v.length());
-
-        Rectangle r = new Rectangle();
-        r.lowerLeft = v;
-        v.translate(2, 2);
-        r.upperRight = v;
-        System.out.println(r.area());
+        // a.translate(-2, 5);
+        System.out.println(rect.area());
     }
 }
\ No newline at end of file

Lectures/15/vec2_j/Vec2.java

-public class Vec2 {
-    private double r, phi;
+public interface Vec2 {
+    void setX(double x);
 
-    public Vec2(double x, double y) {
-        this.setXandY(x, y);
-    }
+    void setY(double x);
 
-    private void setXandY(double x, double y) {
-        this.phi = Math.atan2(y, x);
-        this.r = Math.sqrt(x * x + y * y);
-    }
+    double getX();
 
-    public double getX() {
-        return this.r * Math.cos(this.phi);
-    }
+    double getY();
 
-    public double getY() {
-        return this.r * Math.sin(this.phi);
-    }
-
-    public void translate(double x, double y) {
-        this.setXandY(this.getX() + x, this.getY() + y);
-    }
-
-    public double length() {
-        return this.r;
-    }
+    double length();
 }
\ No newline at end of file