WebGLRenderer: added getPhysicalSize()

[WestLangley]

Actually, this method could be renamed to getDrawingBufferSize(), as opposed to using the physical/logical nomenclature.

Also, I updated the docs. Those changes may be up for discussion, too.

This PR was posted in response to #10238 (comment).

[Mugen87]

I prefer .getDrawingBufferSize(). In this way, it's more clear what kind of data the method actually returns. At least for me 😊 . Docs are okay 👍 .

[WestLangley]

getDrawingBufferSize() is fine, but how does one describe what getSize() returns, then?

Does the renderer's "size" have any meaning that is useful?

[Mugen87]

Um, good question 🤔 ! Let me think about this 😊

[pailhead]

What's the terminology used when dealing with css?

[Mugen87]

In the context of CSS and the devicePixelRatio, correct names would be:

.getPhysicalSize () and .getLogicalSize () instead of
.getDrawingBufferSize() and .getSize()

see https://stackoverflow.com/questions/8785643/what-exactly-is-device-pixel-ratio

But i'm not sure if this terminology is appropriate for a 3D library.

[pailhead]

It's a 3d library that exclusively renders to an element that already has a nomenclature in place. Makes sense for this to be as close to the terminology used in canvas/dom as possible?

[mrdoob]

.getDrawingBufferSize() kind of sound better to me too.

[mrdoob]

How about:

return {
    width: _width * _pixelRatio,
    height: _height * _pixelRatio
};

[WestLangley]

OK.

[WestLangley]

.getDrawingBufferSize() kind of sound better to me too.

Done!

[mrdoob]

Many thanks!