Float vs double

[lizardking]

Hi

I've started to fix a few things in the lib. Currently I'm mainly interested in the Bezier functions and trying to get the Intersects(Line) method to work. Apart from a small bug that I found and fixed in the Utils.Roots method, I have also realized that there seems to be a problem with numeric precision.

Utils defines epsilon which is used in the between method to allow for approcimate values. While the defined epsilon value 0.000001 is working well in the org javascript code of the lib (https://github.com/Pomax/bezierjs) it is not working in C#. C# floats (32bit single precision) are not the same thing as floating point values (64bit double precision) in javascript.

I'm not sure what to do about this. The cleanest solution would be to convert everything to double. However, I'm not sure what impact this will have on the other classes in the lib. What do you think?

Best regards

[lizardking]

Forgot to mention that System.Numeric.Vectors does not support double yet (all float based).

[lizardking]

Managed to make the lib using double insted of float. Since System.Numerics only supports float, I've user https://www.nuget.org/packages/System.DoubleNumerics/3.1.3

Seems to work nicely. The problems if Intersects(Line) are gone.

Want me to create a pull request for those changes (tons of them) or do you prefer me to make a System.DoubleGeometry repo?

[xclud]

Hi lizardking,
I think this is a wise decision to switch from float to double. It is a breaking change but since we are pre-release, why not breaking it?

I appreciate your contribution. Please do a PR.

[lizardking]

Hi xclud I’m still working on the lib. To be able to test whether the methods work there is now a demo project which shows the methods in action. If like you can give it a try (https://github.com/lizardking/Bezier), but I don’t recommend to integrate it into the main repo yet. Some other points of interest: * There are now 2 versions of the lookup table and an ILookupTable interface. Your org version is now named LookUpTableEquidistant and the additional version is LookUpTableParaEquidistant (the points in the table all have the same t distance). * The project method of the lookup table has been improved quite a bit. I even found a bug in the org code of pomax in the Bezier.js lib. That is all fixed. The project method has also been added to the Bezier object (using the lookuptable behind scenes). * For now the System.DubleNumerics libs is integrated in the project. I seem to be to stupid to make the org version properly in the lib (some mess with the netstandard versions). * NetStandard 1 and netstandard 1.6 have been dropped. * The lookup table classes and polybezier have enumerators now so they can be used in foreach() constructs. * A bunch of methods has been renamed to maintain consistency (e.g. the was Break and Split both doing the same thing) and/or the make the names more self explanatory (e.g. OverLaps is now BoundingBoxOverlaps). * Some methods got additional overlads to make them easier to use in daily life (e.g. the is a version of the Project method which doesn’t have out parameters). If you find anything that need to be fixed, please let me know.

[dragouf]

@lizardking great. I was looking for the same; use double instead of float. I did part of this job and I see we did the same: edit MS sources to get Vector classes use double. And it seems you went further. Can I use your rewritten project now ? Is your rewrite work done ?

[lizardking]

Currently I am not doing any work on this lib, so you might use it as you please.

If you find any bugs, feel free to fix them to to provide the changes to the lib.

[dragouf]

@lizardking ok, thanks for your reply. When you stopped to worked on it it was working ? You used it in some projects ?

[lizardking]

I needed a Bezier lib for one of my projects. For that reason I converted the org javascript lib.

The merhods I needed in my project, mainly methods to deal with splitting curves seem to work well. For most other methods there are demo implementions in the lib project and they seem to work, bit I havent done a lot of testing.

Just test if the methods you need work as expected. If they do thats great, if they dont feel free to fix them.

[dragouf]

ok I see, thanks