Fix SSAO render pass

Fixes 3 issues in the SSAO shader:

1. Use texture formats (RGBA16F) required to be color-renderable in the OpenGL specification (see Req. Rend. column in the table below) instead of RGB16F
2. Remove depth texture after RenderDelegate because it is read in the RenderSSAO pass, which can cause problems in some OpenGL implementations
3. Fix implicit conversions from ivec2 to vec2 in the GLSL code

Warnings:

• please consider adding a changelog entry in a file ending with .md in Documentation/release/dev.

The warnings do not need to be fixed, but it is recommended to do so.

changed the description

@mwestphal please review

Is this tested ? If not, it should. If yes, I would expect a baseline change ?

SSAO is tested, but not the OpenGL ES implementation, but nothing is tested with OpenGL ES as far as I know

Got it.

@timothee.chabat please review

might be out of scope of this MR but would it make sense to store the SSAO texture and the Deph texture in respectively the alpha channel of the Position and Normal Texture ? We're wasting some GPU space

please put your MR descr in the commit message

+2 pending CI and comments

added 14 commits

• 9ebbe240...0377d68a - 13 commits from branch vtk:master
• 3b821ecc - Fix SSAO render pass

Compare with previous version

Warnings:

• please consider adding a changelog entry in a file ending with .md in Documentation/release/dev.

The warnings do not need to be fixed, but it is recommended to do so.

resolved all threads

Dashboard is clean, merging

Do: merge

mentioned in commit b4d1fcd6

merged

mentioned in commit spiros.tsalikis/paraview@f8a75dce

mentioned in commit mwestphal/paraview@a4ddac67

mentioned in merge request paraview/paraview!6161 (merged)