From 4cebcb73590eec02da347a028962a2663eb60ea9 Mon Sep 17 00:00:00 2001
From: laa11004 <lynn.asselin@uconn.edu>
Date: Tue, 8 Dec 2015 20:37:25 -0500
Subject: [PATCH] rect/circle intersection tests hopefully completed

---
 RangeApp/circleTests.pde | 99 ++++++++++++++++++++++++++--------------
 1 file changed, 66 insertions(+), 33 deletions(-)

diff --git a/RangeApp/circleTests.pde b/RangeApp/circleTests.pde
index 45090ad..ccca477 100644
--- a/RangeApp/circleTests.pde
+++ b/RangeApp/circleTests.pde
@@ -1,41 +1,74 @@
+boolean rectCircleIntersect(BoundingBox bb, Point p, float r){
+  if( inBox(p, bb) ){ return true; } //circle center in rect
+  //if( circleContainsBox(bb, p._x, p._y, r)){ return true; }
+  if(dist(bb.x1,bb.y1, p._x, p._y) <= r || dist(bb.x1,bb.y2, p._x, p._y)<=r || dist(bb.x2,bb.y1, p._x, p._y)<= r || dist(bb.x2,bb.y2, p._x, p._y) <= r){ return true; }
+  if(boxContainsCircle(bb, p._x, p._y, r)){ return true; }
+  if(lineIntersectsCircle(bb.x1, bb.y1, bb.x1, bb.y2, p._x, p._y, r)){ return true; }//left:bottom->top
+  if(lineIntersectsCircle(bb.x1, bb.y2, bb.x2, bb.y2, p._x, p._y, r)){ return true; }//top:left->right
+  if(lineIntersectsCircle(bb.x2, bb.y1, bb.x2, bb.y2, p._x, p._y, r)){ return true; }//right:bottom->top
+  if(lineIntersectsCircle(bb.x1, bb.y1, bb.x2, bb.y1, p._x, p._y, r)){ return true; }//bottom: left->right
+  else{ return false; }
+}
 
-//import javax.vecmath.Vector2d;
-
-//boolean rectCircleIntersect(BoundingBox bb, Point p, float r){
-//  if( inBox(p, bb) ){ return true; } //circle center in rect
-//  else if(lineIntersectsCircle (bb.x1, bb.y1, bb.x1, bb.y2, p._x, p._y, r)){ return true; }//left:bottom->top
-//  else if(lineIntersectsCircle (bb.x1, bb.y2, bb.x2, bb.y2, p._x, p._y, r)){ return true; }//top:left->right
-//  else if(lineIntersectsCircle (bb.x2, bb.y1, bb.x2, bb.y2, p._x, p._y, r)){ return true; }//right:bottom->top
-//  else if(lineIntersectsCircle (bb.x1, bb.y1, bb.x2, bb.y1, p._x, p._y, r)){ return true; }//bottom: left->right
-//  else{ return false; }
-//}
+boolean circleContainsBox(BoundingBox bb, float cx, float cy, float r){//not currently using this for anything but I wrote it up and didn't know 
+ if(dist(bb.x1,bb.y1, cx, cy) <= r && dist(bb.x1,bb.y2, cx, cy)<=r && dist(bb.x2,bb.y1, cx, cy)<= r && dist(bb.x2,bb.y2, cx, cy) <= r){ return true; }
+ else{ return false;}
+}
 
-//boolean lineIntersectsCircle(float a1, float a2, float b1, float b2, float c1, float c2, float r) {
-//  Vector2d v = new Vector2d((double)b1-a1, (double)b2-a2);
-//  Vector2d c = new Vector2d((double)c1-a1, (double)c2-a2);
-//  double dpT = v.dot(c);//numerator of projection
-//  double dpB = c.dot(c);//denominator of projection
-//  double projScalar = dpT/dpB;//the 
-//  double orthX = c1-projScalar*(b1-a1);
-//  double orthY = c2-projScalar*(b2-a2);
-//  //if( !onLine(0) ){return true;
-//  if( distance(orthX, orthY, (double)c1-a1, (double)c2-a2) < r ) return true;
-//return false; 
-//}
+boolean boxContainsCircle(BoundingBox bb, float cx, float cy, float r){
+  float list[] = new float[4];
+  list[1] = dist(cx,cy,bb.x1,cy);
+  list[2] = dist(cx,cy,bb.x2,cy);
+  list[3] = dist(cx,cy,cx,bb.y2);
+  list[4] = dist(cx,cy,cx,bb.y1);
+  if(min(list) <= r) return true;
+  else return false;
+}
 
-double distance(double x1, double y1, double x2, double y2){ 
-  float t1 = (float)x2-(float)x1;
-  float t2 = (float)y2-(float)y1;
-  return sqrt(t1*t1+t2*t2);
+boolean lineIntersectsCircle(float a1, float a2, float b1, float b2, float c1, float c2, float r){
+  float dpTop = (b1-a1)*(c1-a1)+(b2-a2)*(c2-a2);
+  float len = sqrt((b1-a1)*(b1-a1)+(b2-a2)*(b2-a2));
+  float dpBot = len*len;
+  float projScalar = dpTop/dpBot;
+  float orthX = projScalar*(b1-a1);
+  float orthY = projScalar*(b2-a2);
+  if(!onLine(0.0,0.0,b1-a1,b2-a2,orthX,orthY)){//a1-a1=0,b1-b1=0
+    return false;
+  }
+  else{
+    if(dist(orthX, orthY, c1-a1, c2-a2) <= r){ 
+      return true; 
+    }
+    else{
+      return false; 
+    }
+  }
 }
 
-boolean onLine(double a1, double a2, double b1, double b2, double p1, double p2){//returns true if p is on segment ab
-  if( a1 == b1 ){//vertical line case
-    if( a2<=p2 && p2<=b2 ){ return true; }
-    else { return false; }
+boolean onLine(float a1,float a2, float b1, float b2, float p1, float p2){//returns true if p is on segment ab
+  if( a1==0 && b1==0 ){//vertical line case
+    if( a2<=p2 && p2<=b2 ){ 
+      return true; 
+  }
+    else { 
+      return false; 
+    }
   }
   else{// a2 == b2 horizontal line case
-    if( a1<=p1 && p1<=b1 ){ return true; }
-    else{ return false; }
+  if( a1<=p1 && p1<=b1 ){ 
+    return true; 
+  }
+    else{ 
+      return false; 
+    }
   }
-}
\ No newline at end of file
+}
+
+/* Useful test suite that can be put at the end of RangeApp constructor for testing
+boolean t1 = lineIntersectsCircle(2.0, 1.0 , 5.0,  1.0,  3.5,  3,  2);//horizontal case
+  //boolean t1 = lineIntersectsCircle(1.0, 2.0 , 1.0,  5.0,  3.5,  3,  2.0);//vertical case
+  if(t1){println("True");}
+ else{println("false");}
+
+*/
+