Shadows Tests

[lilleyse]

For #2594

These are most of the shadows tests unless I or anyone else can think of more. I have the globe test commented out for now but plan on figuring that out soon. After that, I'm not sure of the best way of testing terrain casting on terrain.

I also made some small code changes, a lot of which were related to first-frame type problems. Also Scene is a little smarter about not rendering with shadows if no shadow maps are in view.

[bagnell]

There are some jsHint failures:

Source/Scene/Scene.js
line 1753 col 13 'center' is defined but never used.
line 1755 col 13 'radiusSquared' is defined but never used.

⚠ 2 warnings

Specs/Scene/ShadowMapSpec.js
line 238 col 14 'loadGlobe' is defined but never used.

⚠ 1 warning

[bagnell]

This looks good to me. I'm also not sure how to test terrain. I have some failing tests on Linux with the Intel HD 4000, but there are a bunch of others that are failing with that graphics card too.

@pjcozzi Can you review and merge?

[pjcozzi]

JSHint is failing:

Source/Scene/Scene.js
  line 1753  col 13  'center' is defined but never used.
  line 1755  col 13  'radiusSquared' is defined but never used.
  ⚠  2 warnings
Specs/Scene/ShadowMapSpec.js
  line 238  col 14  'loadGlobe' is defined but never used.
  ⚠  1 warning
[22:03:45] 'jsHint' errored after 1.28 min
[22:03:45] Error in plugin 'gulp-jshint'
Message:
    JSHint failed for: Source/Scene/Scene.js, Specs/Scene/ShadowMapSpec.js

See https://travis-ci.org/AnalyticalGraphicsInc/cesium/builds/132971153

[pjcozzi]

Wow, these tests look really good.

Code coverage is pretty good, but it doesn't look hard to get ShadowMap.js to 100% (ignoring terrain). What do you this?

[pjcozzi]

After that, I'm not sure of the best way of testing terrain casting on terrain.

Remind me - what is the issue again? Something to do with loading?

We can include sample data, e.g., a really small quantized-mesh tileset, write a mock terrain provider that procedurally generates terrain if needed, and mock things as needed to get reasonably isolated tests.

[lilleyse]

By default the loaded tiles are really big so even if the shadow is drawn it is offscreen somewhere (I think). I tried changing the sseDenominator too, but no luck. Your suggestion seems good to me, I'll see how it goes.

[lilleyse]

Added the globe tests. This should be ready to go, but we can leave it open for a little while if we come up with new tests.

[lilleyse]

Actually it looks like some tests are still failing, I'll fix those now.

[lilleyse]

I think something about sharing the same Globe across tests was causing weird things to happen. This is ready now.

[pjcozzi]

This is all good with me. If you want more tests later, open up another PR.