Update for issue with testHashMethodNeedsToBeInComparingProtocol

src/Geometry-Tests/GEllipseTest.class.st

@@ -12,6 +12,12 @@ GEllipseTest >> actualClass [
 	^ GEllipse
 ]
 
+{ #category : #util }
+GEllipseTest >> sortedIntersectionsBetween: shape and: line [
+	^ (shape intersectionsWith: line) asOrderedCollection 
+		sorted: [ :a :b | a asPoint < b asPoint ].
+]
+
 { #category : #tests }
 GEllipseTest >> testArea [
 	ellipse := GEllipse center: 5 , -1 vertex: 10 , -1 coVertex: 5 , 2.
@@ -29,6 +35,13 @@ GEllipseTest >> testBoundaryContains [
 	self deny: (ellipse boundaryContains: 3, 0.13).
 ]
 
+{ #category : #tests }
+GEllipseTest >> testEmpty [
+	self should: [ GEllipse center: 0,0 vertex: 0,0 coVertex: 0,0. ] raise: Error.
+	self should: [ GEllipse center: 10,10 vertex: 10,10 coVertex: 10,10. ] raise: Error.
+	self should: [ GEllipse center: 0,0 vertex: 0,0 coVertex: 0,3. ] raise: Error.
+]
+
 { #category : #tests }
 GEllipseTest >> testEncompassingRectangle [
 	ellipse := GEllipse center: 4 , -1 vertex: 9 , -1 coVertex: 4 , 2.
@@ -210,6 +223,17 @@ GEllipseTest >> testMinorAxis [
 	self assert: ellipse minorAxis equals: (GSegment with: 10 , 8 with: 10 , 12)
 ]
 
+{ #category : #tests }
+GEllipseTest >> testNonEmpty [
+	| shape line intersections |
+	shape := GEllipse center: 0@0 vertex: 0@10 coVertex: 5@10.
+	line := GLine through: shape center and: 10@10.
+	intersections := self sortedIntersectionsBetween: shape and: line.
+	self assert: intersections isNotEmpty.
+	self assert: (intersections first asPoint closeTo: -7.4535599249993@ -7.4535599249993).
+	self assert: (intersections second asPoint closeTo: 7.4535599249993@ 7.4535599249993).
+]
+
 { #category : #tests }
 GEllipseTest >> testPerimeter [
 	ellipse := GEllipse center: 2,6 vertex: 7, 6 coVertex: 2,9.

src/Geometry/GEllipse.class.st

@@ -1,3 +1,13 @@
+"
+I am ellipse I have center and 2 vertices.
+
+Example
+
+```Smalltalk
+""circle radius = 10""
+GEllipse center: 0@0 vertex: 0@10 coVertex: 10@0
+``` 
+"
 Class {
 	#name : #GEllipse,
 	#superclass : #GShape,
@@ -11,6 +21,14 @@ Class {
 
 { #category : #'instance creation' }
 GEllipse class >> center: aGPoint vertex: aGPoint2 coVertex: aGPoint3 [
+	| d1 d2 zero |
+	d1 := aGPoint - aGPoint2.
+	d2 := aGPoint - aGPoint3.
+	zero := GVector x: 0 y: 0."Zero vector"
+	(d1 = zero and: [ d2 = zero ]) ifTrue: [ 
+		self error: 'This is not an ellipse but a point.'  ].
+	(d1 = zero or: [ d2 = zero ]) ifTrue: [ 
+		self error: 'This is not an ellipse but a line.' ].
 	^ self new
 		center: aGPoint;
 		vertex: aGPoint2;
@@ -133,6 +151,7 @@ GEllipse >> intersectionsWithLine: aGLine [
 	k := center y.
 	a := self semiMajorAxisLength.
 	b := self semiMinorAxisLength.
+
 	m := aGLine a / aGLine b negated.
 	c := aGLine c / aGLine b negated.
 	e := c - k.
@@ -148,8 +167,8 @@ GEllipse >> intersectionsWithLine: aGLine [
 	tk := t * k.
 	sqrtContent := (a2m2 + b2 - t2 - k2 + (2 * tk)).
 	sqrtContent >= 0 ifFalse: [ ^ {  } ]. "No intersections"
+
 	sqrt := (a2m2 + b2 - t2 - k2 + (2 * tk)) sqrt.
-
 	x1 := (h * b2 - (m * a2 * e) + (ab * sqrt)) / (a2m2 + b2).
 	x2 := (h * b2 - (m * a2 * e) - (ab * sqrt)) / (a2m2 + b2).
 	y1 := (b2 * t + (k * a2m2) + (abm * sqrt)) / (a2m2 + b2).

src/Geometry/GPoint.class.st

@@ -116,6 +116,11 @@ GPoint >> asGPoint [
 	^ self
 ]
 
+{ #category : #converting }
+GPoint >> asPoint [
+	^ self x @ self y
+]
+
 { #category : #accessing }
 GPoint >> coordinates [
 	^ coordinates

src/Geometry/GSegment.class.st

@@ -74,7 +74,7 @@ GSegment >> distanceTo: aGPoint [
 	^ self asGLine distanceTo: aGPoint
 ]
 
-{ #category : #initialization }
+{ #category : #comparing }
 GSegment >> hash [
 	^ v1 hash bitXor: v2 hash
 ]