Optimize DrawNode

[smilediver]

This PR does some DrawNode optimizations:

• Disabled transform by default, which had significant performance impact by default.
• Use pod_vector for storing and growing buffers.
• Don't update actual vertex buffer every time drawXXX() is called.
• Avoid unnecessary allocations on some drawXXX() methods in _transform().

There's still a lot of drawXXX() methods that do unnecessary allocations that have a big impact on performance.

Also there are _lineWidth and _defaultLineWidth members that can be set by the user but do nothing. Seems like a bug that probably breaks old behavior.

[aismann]

There's still a lot of drawXXX() methods that do unnecessary allocations that have a big impact on performance.

@smilediver
Can you add comments like // To do: Improve: unnecessary allocations ... or better can you improve this methods too?

Also there are _lineWidth and _defaultLineWidth members that can be set by the user but do nothing. Seems like a bug that probably breaks old behavior.

See here:
DrawNode: setLineWitdh() is no longer working#1411
See here for more info:
#1411 (comment)

@halx99 @smilediver:
setLineWidth() should be deprecated.

[smilediver]

Can you add comments like // To do: Improve: unnecessary allocations ... or better can you improve this methods too?

It would be better if you did that, since you wrote it and know the code better.

setLineWidth() should be deprecated.

Maybe it's better to remove it completely, since it's not doing anything anyway, and will mislead people.

[aismann]

Can you add comments like // To do: Improve: unnecessary allocations ... or better can you improve this methods too?

It would be better if you did that, since you wrote it and know the code better.

setLineWidth() should be deprecated.

Maybe it's better to remove it completely, since it's not doing anything anyway, and will mislead people.

I will look after merge.

[halx99]

@aismann could we delete https://github.com/axmolengine/axmol/tree/dev/extensions/DrawNodeEx/src/DrawNodeEx?

[aismann]

@smilediver (@halx99)
Can you explain me what this means:
bool _trianglesDirty: 1 = false;

[aismann]

@aismann could we delete https://github.com/axmolengine/axmol/tree/dev/extensions/DrawNodeEx/src/DrawNodeEx?

I read to late, yes can deleted.

[smilediver]

Can you explain me what this means: bool _trianglesDirty: 1 = false;

It's a bit field: https://en.cppreference.com/w/cpp/language/bit_field