Blender Git Loki

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

GPencil: Refactor: Add offscreen compositing foundation

This put all Grease pencil drawing into a separate buffer that is then
composited on top of the rendered image.

This framebuffer has 2 RGB color target (one color and one alpha) to be
able to record any color blend types.

Moreover these buffers are floating point (R11_G11_B10) which will allow
the use of linear colors.

GPU: Framebuffer: Add GPU_framebuffer_multi_clear

This is to clear individual targets using a different color.

Merge branch 'greasepencil-object' into greasepencil-refactor

Conflicts:
source/blender/blenloader/intern/versioning_280.c

Merge branch 'master' into greasepencil-object

GPencil: Refactor: Fix broken shader & undefined behavior

GPencil: Refactor: Implement Stroke self overlap option

This is a novel approach were we use the depth buffer instead of the
stencil buffer. This allows up to ~1e24 different indices to draw to.
We use a DRW_STATE_DEPTH_GREATER to discard the fragment comming from the
same stroke.

Since we can have strokes that don't have this option, we use the point
indices instead of the stroke index to avoid changing the state during
drawing.