MagickWand API underdocumented

[yecril71pl]

I find the MagickWand API insufficiently documented.
For example:

NewImageMagick: returns a wand required for all other methods in the API. +[Throws an exception upon failure. Use DestroyMagickWand to dispose. ]+

This is C API, we do not have implicit RAII here!

1. Can the pair Genesis/Terminus be called multiple times?
2. Are they idempotent?
3. Must the calls be balanced?
4. Are they reentrant?

[magick]

Can the pair Genesis/Terminus be called multiple times?

Yes.

Are they idempotent?

Yes.

Must the calls be balanced?

No, but recommended.

Are they reentrant?

Yes.

We added some more details to the NewMagickWand() methods. We expand the API documentation as time permits. Like many open-source projects we suffer from more work than volunteers.

[yecril71pl]

Like many open-source projects we suffer from more work than volunteers.

I have had to deal a lot with closed-source companies like Microsoft (I would give a hyperlink here but BBcode does not allow me to say rel="nofollow"); I would say your performance, your competence and your overall attitude is wonderful beyond comparison anyway.

Why do DestroyDrawingWand and DestroyPixelWand return pointers?

[anthony]

Why do DestroyDrawingWand and DestroyPixelWand return pointers?

So you can assign them back into the original Wand pointers. The value returned is just NULL.

Code: Select all

  wand=DestroyPixelWand(wand);

It makes the code a little more readable.

[magick]

It a secure programming technique. Always zero out pointers when you no longer use them. The Destroy*() methods simply return NULL.

[yecril71pl]

How do I interpret the value returned by MagickSetImageType?

[magick]

On success, MagickTrue is returned. If MagickFalse is returned, check image->exception for the reason MagickSetImageType() failed.