Added snowball effect

WinterHoliday/SnowMan.pde

@@ -12,6 +12,12 @@ public class SnowMan {
   int offsetMid = offsetBot - (radiusBot);
   int offsetTop = offsetMid - (2*radiusTop);
 
+  float snowballSize = 0;
+  float snowballX;
+  float snowballY;
+  float snowballThrowX;
+  float snowballThrowY;
+
   public SnowMan() {
     this.scale = height / 800.0;    // scale 1 for height = 800
     this.x = width/2;  // centered
@@ -124,14 +130,77 @@ public class SnowMan {
     float armY = offsetMid - (0.3 * radiusMid);
     float leftArmX =  x - (0.9 * radiusMid);
     float rightArmX = x + (0.9 * radiusMid);
-    float armLength = 1.0 * radiusMid;
+    float armLength = 1.2 * radiusMid;
     float armWidth =  0.1 * radiusMid;
 
     stroke(#4C322B);
     strokeWeight(armWidth);
     strokeCap(ROUND);
-    line(leftArmX, armY ,leftArmX - armLength, offsetMid - (radiusMid)); 
-    line(rightArmX, armY ,rightArmX + armLength, offsetMid - (radiusMid)); 
+
+    if( abs(mouseX - leftArmX) == 0 || abs(mouseX - rightArmX) == 0 ){
+      return;
+    }
+
+    // Left arm angle and lengths
+    float thetaL = atan( abs(mouseY - armY) / abs(mouseX - leftArmX) );
+    float leftHandX = armLength * cos(thetaL);
+    float leftHandY = armLength * sin(thetaL);
+
+    // If mouseX is farther to the right, add to x position
+    // If mouseY is farther below, add to the y position
+    leftHandX = ( mouseX > leftArmX ) ? leftHandX : -leftHandX;
+    leftHandY = ( mouseY > armY ) ? leftHandY : -leftHandY;
+
+    // Same for right arm
+    float thetaR = atan( abs(mouseY - armY) / abs(mouseX - rightArmX) );
+    float rightHandX = armLength * cos(thetaR);
+    float rightHandY = armLength * sin(thetaR);
+    rightHandX = ( mouseX > rightArmX ) ? rightHandX : -rightHandX;
+    rightHandY = ( mouseY > armY ) ? rightHandY : -rightHandY;
+
+    // Draw arms
+    line(leftArmX, armY , leftArmX + leftHandX, armY + leftHandY); 
+    line(rightArmX, armY , rightArmX + rightHandX, armY + rightHandY);
+
+    if( mousePressed ){
+      // Build an increasingly large snowball when pressing the mouse
+
+      snowballSize++;
+
+      strokeWeight(3);
+      stroke(0);
+      snowballThrowX = mouseX;
+      snowballThrowY = mouseY;
+      snowballX = leftArmX + leftHandX;
+      snowballY = armY + leftHandY;
+      circle(snowballX, snowballY, snowballSize);
+    } else {      
+      if( snowballSize > 0 ){
+        // We have a snowball to throw!
+
+        strokeWeight(3);
+        stroke(0);
+        circle( snowballX, snowballY, snowballSize);
+
+        if( snowballX < 0 || snowballX > width || snowballY < 0 || snowballY > height ){
+          // Snowball is off the screen, reset
+
+          snowballSize = 0;
+        } else {
+          // Snowball on the screen so move it
+
+          if( abs(snowballThrowX - leftArmX) == 0 ){
+            return;
+          }
+
+          float thetaS = atan( abs(snowballThrowY - armY) / abs(snowballThrowX - leftArmX) );
+          float snowballIncX = ( snowballThrowX > leftArmX ) ? 10 * cos(thetaS) : -10 * cos(thetaS);
+          float snowballIncY = ( snowballThrowY > armY ) ? 10 * sin(thetaS) : -10 * sin(thetaS);
+          snowballX += snowballIncX;
+          snowballY += snowballIncY;
+        }
+      }
+    }
 
     pop();
   }