[squeak-dev] About a new "Math" package ... (was: Proposal: Geometry Classes)

Marcel Taeumel marcel.taeumel at hpi.de
Tue Mar 9 13:05:58 UTC 2021


MathExtras might host low-level optimizations, as I exemplified:

> And I would like to add that "number crunching" part around fancy graphics (e.g. OpenGL through FFI) to "Math-Collections" or maybe "MathExtras-Collections", looking at all the subclasses of RawBitsArray.

:-) I assume that it may be beneficial to at least decide whether something is "core" or "extra". I would like to have this for "Math" from the beginning.

Best,
Marcel
Am 09.03.2021 13:10:39 schrieb Thiede, Christoph <christoph.thiede at student.hpi.uni-potsdam.de>:
Referring to the MathExtras proposal ... What is your general idea of an extra package? I know Morphic-Extras as a collection of non-necessary tools, helpers, and demos, but the general idea sounds kind of vague to me.

CollectionsExtras would be a place for Text enhancements such as attributes (so actually, we could also call it simply "TextSupport" or something like this), MathExtras would contain "math stuff that is not necessary" ...
Do you have any more precise idea of what classifies an extra package or would "MathSmorgasbord" be a franker name for the package? If yes, this would make me think about the coherency of such a package ... Just my 2 cents, of course. :)

Best,
Christoph
Von: Thiede, Christoph
Gesendet: Dienstag, 9. März 2021 12:56:04
An: squeak-dev
Betreff: AW: [squeak-dev] About a new "Math" package ... (was: Proposal: Geometry Classes)
 
Hi Marcel,

sounds interesting! I have a few thoughts regarding package dependencies.

As far as I understand, the dependency structure would look kind like this:

Kernel-Objects -> Math-Quantity (see senders of SmallInteger for example), Math-Analysis (see senders of #asFloat for example)

Math-Quantity -> Kernel (superclass), Math-Analysis (see senders of #asFloat)

Math-Analysis -> Kernel (superclass), Math-Quantity (maybe?)

Math-Geometry -> Kernel (of course), Math-Quantity (senders of SmallInteger), Math-Analysis (see senders of #asFloat)

Math-Collections would probably depend on all other packages?


The question is which of these dependencies can be eliminated and which are a problem at all.

What about Random? Do you want to keep it in Kernel, depending on Math?

What is about dependencies from Number (Kernel-Objects) to Float (Math-Analysis), for example, #asFloat, but also sophisticated things such as #sin? Do we want to create a bunch of extension methods for this?
In any case, I think the "math functions" protocol on Collection should become an extension protocol ("*Math-Analysis" or "*Math-Analysis-enumerating").
[http://www.hpi.de/]

Best,
Christoph
Von: Squeak-dev <squeak-dev-bounces at lists.squeakfoundation.org> im Auftrag von Taeumel, Marcel
Gesendet: Dienstag, 9. März 2021 10:50:09
An: squeak-dev
Betreff: [squeak-dev] About a new "Math" package ... (was: Proposal: Geometry Classes)
 
Hi all!

I think that we would rather need a "Math" package with "Math-Geometry" being one of multiple categories.

Please take a look at the following proposed classification:

Kernel-Objects (= not Kernel-Numbers)
  Magnitude
    Number

Math-Quantity
  Integer (+ subclasses)
  Fraction
  ScaledDecimal

Math-Analysis
  Complex
  Float (+ subclasses)
  Quaternion

Math-Geometry
  Point
  Line
  Rectangle
  Polygon
  Path

Math-Collections
  Vector2 (from 3DTransform, CroquetGL, etc.)
  Vector3
  Vector4
  Matrix2x3
  Matrix4x4
  VectorArray
  ...

It would involve some effort, especially to untangle "ST80-Paths" from graphics :-) Eventually, I would like to see Nicolas' efforts for "Complex" and "Quaternion" in Trunk. And I would like to add that "number crunching" part around fancy graphics (e.g. OpenGL through FFI) to "Math-Collections" or maybe "MathExtras-Collections", looking at all the subclasses of RawBitsArray.

May I add "Math" and "MathExtras" packages so that we can slowly get started? :-)

Best,
Marcel
Am 22.01.2019 18:32:10 schrieb patrick.rein at hpi.uni-potsdam.de <patrick.rein at hpi.uni-potsdam.de>:
Hi everyone,

during some recent clean-up an issue with geometry objects came up. As a result the following idea came up which I thereby would like to put out for an initial discussion.

In case we find that this might be useful, I would continue by implementing a first prototype of the package as a foundation of a more in-depth discussion later on.

Bests
Patrick

# Squeak Change Proposal - Geometry Package

## Why?
Squeak implements basic geometry logic in too many different places. For example intersection of different kinds of geometric objects is implemented all over Morphic, ST80, Balloon, Graphics, and Etoys. Such extensive scattering across packages and classes impedes modularity, that is, readability and extensibility. An example for this recently came up when we discovered an issue with testing for graphical intersections between PolygonMorph and RectangleMorph. It was not possible to compute that overlapping area because the class Rectangle omits to provide an important method. A quick fix would entail unnecessary dependencies (here: Morphic -> Balloon) or duplicated code (see also http://bugs.squeak.org/view.php?id=7872). Consequently, we might want to modularize the geometry objects and operations. As a side effect, dependent packages such as Morphic can be simplified a little bit (more).

## Scope
The proposed package should cover basic 2D geometric objects and their operations represented by the following classes:
- Point
- Line
- LineSegment
- Polygon
- Rectangle (as an optimization as it could be represented as a special Polygon already)

Most classes could simply be moved from their previous packages. Afterwards the interfaces would need to be made consistent with each other to allow interoperability of all geometry classes within the new package.

### Affected classes:
- All classes in ST80-Paths
- LineSegement, Bezier2Segment, Bezier3Segment (Balloon-Geometry)
- Rectangle, Quadrangle, Point (Graphics-Primitives)
- LineIntersections, LineIntersectionSegment, LineIntersectionEvent (Etoys-Squeakland-Graphics-Tools-Intersection)

## Open questions
- Should this become a single new package or a subcategory in the Graphics package?
- Should the package contain an Ellipses class?
- Should we model curved line segments as BezierLineSegments, CurvedLineSegment, or Arc?

## Risks
- This would potentially deprecate the existing ST80 geometry classes (ST80-Paths)
- Some of the new classes will cause name clashes with existing classes. For example Line is currently in ST-80 and represents a line segment, and the class LineSegment is a line segment but not in the geometric sense as it also incorporates arcs. Both names might then be used by new classes with different meanings. This might be mitigated by introducing a pre-/postfix for the names of the new classes.

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