The Inbox: ST80-ct.269.mcz

A new version of ST80 was added to project The Inbox:
http://source.squeak.org/inbox/ST80-ct.269.mcz

==================== Summary ====================

Name: ST80-ct.269
Author: ct
Time: 17 April 2021, 10:06:28.149652 pm
UUID: 2f319f7f-9553-0d47-94ea-f3398af6f4b4
Ancestors: ST80-mt.268

Reuse new Arc >> #computeVertices: to display arcs. Complements ST80-ct.240. Also added an extension point for modifying the granularity of arcs, #numberOfVertices.

Sorry for the confusion, this patch has somehow went down in my changes file. :-)

Benchmarks: Use anArc from Arc example and do: [anArc displayOn: Display] bench.
Before: 726 microseconds per run.
After: 650 microseconds per run.

=============== Diff against ST80-mt.268 ===============

Item was changed:
  Path subclass: #Arc
+ instanceVariableNames: 'quadrant radius center numberOfVertices'
- instanceVariableNames: 'quadrant radius center'
  classVariableNames: ''
  poolDictionaries: ''
  category: 'ST80-Paths'!
 
  !Arc commentStamp: '<historical>' prior: 0!
  Arcs are an unusual implementation of splines due to Ted Kaehler.  Imagine two lines that meet at a corner. Now imagine two moving points; one moves from the corner to the end on one line, the other moves from the end of the other line in to the corner.  Now imagine a series of lines drawn between those moving points at each step along the way (they form a sort of spider web pattern).  By connecting segments of the intersecting lines, a smooth curve is achieved that is tangent to both of the original lines.  Voila.!

Item was changed:
  ----- Method: Arc>>computeVertices: (in category 'displaying') -----
  computeVertices: size
 
  | dAngle dSin dCos point |
  dAngle := (90 / (size - 1)) degreesToRadians.
  dSin := dAngle sin.
  dCos := dAngle cos.
  point := (1 to: quadrant)
  inject: 0 @ radius
  into: [:p :i | p leftRotated].
  ^ (OrderedCollection new: size)
  add: (center + point) rounded;
+ addAll: ((2 to: size) collect: [:i |
- addAll: ((1 to: size - 1) collect: [:i |
  point := point * dCos + (point * dSin) leftRotated.
  (center + point) rounded]);
  yourself!

Item was changed:
  ----- Method: Arc>>displayOn:at:clippingBox:rule:fillColor: (in category 'displaying') -----
  displayOn: aDisplayMedium at: aPoint clippingBox: clipRect rule: anInteger fillColor: aForm
 
+ | line |
- | nSegments line angle sin cos xn yn |
- nSegments := 12.0.
  line := Line new.
  line form: self form.
+ (self computeVertices: self numberOfVertices) overlappingPairsDo: [:start :dest |
+ line
+ beginPoint: start;
+ endPoint: dest;
+ displayOn: aDisplayMedium
- angle := (90.0 / nSegments) degreesToRadians.
- sin := angle sin.
- cos := angle cos.
- quadrant = 1
- ifTrue:
- [xn := radius asFloat.
- yn := 0.0].
- quadrant = 2
- ifTrue:
- [xn := 0.0.
- yn := 0.0 - radius asFloat].
- quadrant = 3
- ifTrue:
- [xn := 0.0 - radius asFloat.
- yn := 0.0].
- quadrant = 4
- ifTrue:
- [xn := 0.0.
- yn := radius asFloat].
- nSegments asInteger
- timesRepeat:
- [ | xn1 yn1 |
- xn1 := xn * cos + (yn * sin).
- yn1 := yn * cos - (xn * sin).
- line beginPoint: center + (xn asInteger @ yn asInteger).
- line endPoint: center + (xn1 asInteger @ yn1 asInteger).
- line
- displayOn: aDisplayMedium
  at: aPoint
  clippingBox: clipRect
  rule: anInteger
+ fillColor: aForm]!
- fillColor: aForm.
- xn := xn1.
- yn := yn1]!

Item was added:
+ ----- Method: Arc>>numberOfVertices (in category 'accessing') -----
+ numberOfVertices
+
+ ^ numberOfVertices ifNil: [12]!

Item was added:
+ ----- Method: Arc>>numberOfVertices: (in category 'accessing') -----
+ numberOfVertices: anInteger
+
+ numberOfVertices := anInteger.!