This is the unification of all overlays into one overlay engine as described in T65347.
I went over all the code making it more future proof with less hacks and removing old / not relevent parts.
Goals / Acheivements:
- Remove internal shader usage (only drw shaders)
- Remove viewportSize and viewportSizeInv and put them in gloabl ubo
- Fixed some drawing issues: Missing probe option and Missing Alt+B clipping of some shader
- Remove old (legacy) shaders dependancy (not using view UBO).
- Less shader variation (less compilation time at first load and less patching needed for vulkan)
- removed some geom shaders when I could
- Remove static e_data (except shaders storage where it is OK)
- Clear the way to fix some anoying limitations (dithered transparency, background image compositing etc...)
- Wireframe drawing now uses the same batching capabilities as workbench & eevee (indirect drawing).
- Reduced complexity, removed ~3000 Lines of code in draw (also removed a lot of unused shader in GPU).
- Post AA to avoid complexity and cost of MSAA.
Remaining issues:
- ~~Armature edits, overlay toggles, (... others?) are not refreshing viewport after AA is complete~~
- FXAA is not the best for wires, maybe investigate SMAA
- Maybe do something more temporally stable for AA.
- ~~Paint overlays are not working with AA.~~
- ~~infront objects are difficult to select.~~
- ~~the infront wires sometimes goes through they solid counterpart (missing clear maybe?) (toggle overlays on-off when using infront+wireframe overlay in solid shading)~~
Note: I made some decision to change slightly the appearance of some objects to simplify their drawing. Namely the empty arrows end (which is now hollow/wire) and distance points of the cameras/spots being done by lines.
Reviewed By: jbakker
Differential Revision: https://developer.blender.org/D6296
I've made a separate version of the geom shader that works with full
3D modelviewmat.
This commit also includes some fixup inside blf_batching_start().
This means smaller imm buffer usage.
This does not reduce the number of drawcalls.
This uses geometry shader which is slow for the GPU but given we are really
CPU bound on this case, it should not matter.
A perfect implementation would:
- Set the glyph coord in a bufferTexture and just send the glyph ID to the
GPU to read the bufferTexture.
- Use GWN_draw_primitive and draw 2*strllen triangle and just retrieve the
glyph ID and color based on gl_VertexID / 6.
- Stream fixed size buffer that the Driver can discard quickly but this is
the same as improving IMM directly.
Ignore texture matrix in the shader, stop messing with texture matrix in BLF code.
Use linear screen-space interpolation instead of perspective.
Avoid redundant call to glMatrixMode.
With USE_GLSL enabled, GPU_basic_shader(TEXTURE|COLOR) always rendered black. New shader uses a solid color + alpha channel of texture (which in our case is a font glyph). See fragment shader for details.
I prefer this approah -- multiple shaders that each do one thing well (and are easy to read/write/understand), instead of one shader that can do many things given the right options.
