I couldn't reproduce either, but calling min() with different argument
data types and indexing vectors with an index not known at compile time
seem likely to cause problems.
Ref T52404, T52404.
Group texture fetches to hide latency. 3.2ms -> 2.2ms (constant time improvement, not depending on scene complexity)
Could optimize further with textureGather (require OpenGL 4.0).
We now floor the corner position and use this position as origin.
This gives us perfect derivatives in all cases even if very far from the origin.
Unfortunately this won't fix the low precision of coordinates used for computing the actual grid size, resulting in thick, non-smoothed lines.
Also did a bit of refactor how the axes are drawn.
Do not use the inverse perspective matrix inside the shader to recover world positions.
That leads to severe float imprecision leading to nasty artifacts.
Instead we compute the world view vector for each pixels and do a ray to plane intersection.
We are still getting low precision derivatives when going far away from the origin, and thus artifacts.
This commit also fixes the non-appearing negative Z axis in 3D view.
Shader stages need to agree about interpolation qualifiers. Apparently implicit smooth (the default) and explicit smooth are considered different by some GLSL compilers. Found by @letterrip on Linux + Intel.
Follow-up to 941e739d70
vertexColor output was not being written --> shader failed to link --> assert hit while setting that shader's uniforms.
Vertex attribs are smooth by default, so I shortened the declaration.
@fclem or @dfelinto: is color = 0 ok here?
Removed infinite details and went for decreasing details with the distance instead (like the axis aligned ortho view auto sized grid).
Separate drawing of the Z axis into 2 pass (using shading group) to render ordered transparency with the main grid pass.
We render selected meshes into another buffer and use a screen space shader to expand the color out of the mesh silouhette.
Pros: only one additionnal render pass is needed (like old outline code), and we have occluded informations.
Cons: memory usage is a problem. This method needs 2 color buffer to ping pong when expanding the outline and 1 depth buffer to test occluded fragments. This gives a 88 bits/pix memory footprint.
Idea: Since we don't need all color range but only some uniform colors (theme colors) we could manipulate only the color ID instead of the whole color this could cut the color buffer size and lower the memory footprint to 58 bits/pix.
It also adds nice occluded silouhette information for selected objects that are behind visible objects.
This methods is really heavy because it needs to render the wires twices.
