From e4b06adab54fbd906d75d1d5951f5fc5d3f62183 Mon Sep 17 00:00:00 2001
From: Shamus Hammons <jlhamm@acm.org>
Date: Thu, 7 May 2015 12:06:40 -0500
Subject: [PATCH] Fixed hit detection for Circles.

---
 src/drawingview.cpp | 90 +++++++++++++++++++++------------------------
 1 file changed, 42 insertions(+), 48 deletions(-)

diff --git a/src/drawingview.cpp b/src/drawingview.cpp
index 8104f82..15579c9 100644
--- a/src/drawingview.cpp
+++ b/src/drawingview.cpp
@@ -354,31 +354,26 @@ void DrawingView::RenderObjects(Painter * painter, std::vector<void *> & v)
 		switch (obj->type)
 		{
 		case OTLine:
-		{
-			Line * l = (Line *)obj;
-			painter->DrawLine(l->p[0], l->p[1]);
+			painter->DrawLine(obj->p[0], obj->p[1]);
 
-			if (l->hitPoint[0])
-				painter->DrawHandle(l->p[0]);
+			if (obj->hitPoint[0])
+				painter->DrawHandle(obj->p[0]);
 
-			if (l->hitPoint[1])
-				painter->DrawHandle(l->p[1]);
+			if (obj->hitPoint[1])
+				painter->DrawHandle(obj->p[1]);
 
 			break;
-		}
 		case OTCircle:
-		{
-			Circle * ci = (Circle *)obj;
 			painter->SetBrush(QBrush(Qt::NoBrush));
-			painter->DrawEllipse(ci->p[0], ci->radius[0], ci->radius[0]);
+			painter->DrawEllipse(obj->p[0], obj->radius[0], obj->radius[0]);
+
+			if (obj->hitPoint[0])
+				painter->DrawHandle(obj->p[0]);
+
 			break;
-		}
 		case OTArc:
-		{
-			Arc * a = (Arc *)obj;
-			painter->DrawArc(a->p[0], a->radius[0], a->angle[0], a->angle[1]);
+			painter->DrawArc(obj->p[0], obj->radius[0], obj->angle[0], obj->angle[1]);
 			break;
-		}
 		case OTDimension:
 		{
 			Dimension * d = (Dimension *)obj;
@@ -1160,13 +1155,12 @@ bool DrawingView::HitTestObjects(Point point)
 		{
 		case OTLine:
 		{
-			Line * l = (Line *)obj;
-			bool oldHP0 = l->hitPoint[0], oldHP1 = l->hitPoint[1], oldHO = l->hitObject;
-			l->hitPoint[0] = l->hitPoint[1] = l->hitObject = false;
-			Vector lineSegment = l->p[1] - l->p[0];
-			Vector v1 = point - l->p[0];
-			Vector v2 = point - l->p[1];
-			double t = Geometry::ParameterOfLineAndPoint(l->p[0], l->p[1], point);
+			bool oldHP0 = obj->hitPoint[0], oldHP1 = obj->hitPoint[1], oldHO = obj->hitObject;
+			obj->hitPoint[0] = obj->hitPoint[1] = obj->hitObject = false;
+			Vector lineSegment = obj->p[1] - obj->p[0];
+			Vector v1 = point - obj->p[0];
+			Vector v2 = point - obj->p[1];
+			double t = Geometry::ParameterOfLineAndPoint(obj->p[0], obj->p[1], point);
 			double distance;
 
 			if (t < 0.0)
@@ -1179,34 +1173,34 @@ bool DrawingView::HitTestObjects(Point point)
 					/ lineSegment.Magnitude());
 
 			if ((v1.Magnitude() * Global::zoom) < 8.0)
-			{
-				l->hitPoint[0] = true;
-//		snapPoint = l->p1;
-//		snapPointIsValid = true;
-			}
+				obj->hitPoint[0] = true;
 			else if ((v2.Magnitude() * Global::zoom) < 8.0)
-			{
-				l->hitPoint[1] = true;
-//		snapPoint = l->p2;
-//		snapPointIsValid = true;
-			}
+				obj->hitPoint[1] = true;
 			else if ((distance * Global::zoom) < 5.0)
-				l->hitObject = true;
+				obj->hitObject = true;
 
-//			bool oldHovered = l->hovered;
-			l->hovered = (l->hitPoint[0] || l->hitPoint[1] || l->hitObject ? true : false);
-//			l->hovered = l->hitObject;
+			obj->hovered = (obj->hitPoint[0] || obj->hitPoint[1] || obj->hitObject ? true : false);
 
-//			if (oldHovered != l->hovered)
-			if ((oldHP0 != l->hitPoint[0]) || (oldHP1 != l->hitPoint[1]) || (oldHO != l->hitObject))
+			if ((oldHP0 != obj->hitPoint[0]) || (oldHP1 != obj->hitPoint[1]) || (oldHO != obj->hitObject))
 				needUpdate = true;
 
 			break;
 		}
 		case OTCircle:
 		{
-			Circle * c = (Circle *)obj;
+			bool oldHP = obj->hitPoint[0], oldHO = obj->hitObject;
+			obj->hitPoint[0] = obj->hitObject = false;
+			double length = Vector::Magnitude(obj->p[0], point);
+
+			if ((length * Global::zoom) < 8.0)
+				obj->hitPoint[0] = true;
+			else if ((fabs(length - obj->radius[0]) * Global::zoom) < 2.0)
+				obj->hitObject = true;
 
+			obj->hovered = (obj->hitPoint[0] || obj->hitObject ? true : false);
+
+			if ((oldHP != obj->hitPoint[0]) || (oldHO != obj->hitObject))
+				needUpdate = true;
 
 			break;
 		}
@@ -1239,16 +1233,16 @@ void DrawingView::HandleObjectMovement(Point point)
 	{
 	case OTLine:
 	{
-		Line * l = (Line *)obj;
+//		Line * l = (Line *)obj;
 
-		if (l->hitPoint[0])
-			l->p[0] = point;
-		else if (l->hitPoint[1])
-			l->p[1] = point;
-		else if (l->hitObject)
+		if (obj->hitPoint[0])
+			obj->p[0] = point;
+		else if (obj->hitPoint[1])
+			obj->p[1] = point;
+		else if (obj->hitObject)
 		{
-			l->p[0] += delta;
-			l->p[1] += delta;
+			obj->p[0] += delta;
+			obj->p[1] += delta;
 		}
 
 		break;
-- 
2.37.2