Blender Git Loki

DRW: Add DRW_shgroup_stencil_set to set all stencil test values

This is to allow more fine tuning. The other function is
deprecated and need to be replace.

Revert "GPencil: Refactor: Change Mask Behavior"

This reverts commit eb3fe4c8486fe1253cf8725b6083238dca7d256e.

GPencil: Refactor: Fix broken selection

GPencil: Refactor: Change Mask Behavior

This is a work in progress Masking now done by a particular layer and
applied on all layers underneath.

Cleanup: Sort flag options

Merge branch 'greasepencil-object' into greasepencil-refactor

Merge branch 'master' into greasepencil-object

GPencil: Refactor: Speedup: Only blend pixels rendered in the layer

GPencil: Refactor: Implement Layer Masking

GPencil: Refactor: Fix Overlay Blend mode

There was a mistake in the implementation. The step were reversed and
alpha was affecting the blend result.

GPencil: Refactor: Add depth merge pass

This pass merge the stroke depth to the 3D depth buffer. This makes GP objs
to mask overlays correctly.

2D objects depth is using the object center depth only. This is to be
improved.

Cleanup: GPencil: CamelCase for uniforms

GPU: Framebuffer: Fix missing color mask

GPencil: Refactor: Fix 3D stroke offset

The offset was way too big.

GPencil: Refactor: Add depth test in the fragment shader

Now the GPencil object can correctly intersect the scene.

Previously (old implementation) 2D GPencil objects would poke through
in front meshes in certain situations (depending on stroke order). This is
now fixed.

This does not fix the intersection with the overlays.

GPencil: Refactor: Fix overlay blending math

A sign error in optimized code.

GPencil: Refactor: Add support for layer blending

This break the compatibility of old blend files as the old implementation
was done incorrectly.

With new implementation, the layer blending can affect multiple object
and in certain case affect even the rendered background. Old implementation
was only affecting the layers beneath, not other objects.

This implementation is also ready to support vfx on top.

Some blend modes (divide and subtract) have some limitations. They cannot
be propagated to other objects. This is because we would need to use
signed float buffers everywhere (for background render) so that fixed
function blending does not clamp the blending values.

DRW: Add subtract blend logic

This is to support subtract blending with Multiple Render Targets

GPU: Texture: Fix mistake in format classification

sRGBA format is well defined for use with framebuffers (based on 3.3 spec).

Cleanup: GPencil: Remove duplicated code