Packs a View's active section planes into a flat uniform buffer as
(normal.xyz, dist) per plane, ready for upload via gl.uniform4fv.
Active planes densely fill out[0 .. count*4 - 1] so a clipping shader's loop
bound (uSectionPlaneCount) stays uniform and inactive planes cost nothing;
the shader evaluates each plane as a single dot(normal, p) + dist > 0 test.
At most MAX_SECTION_PLANES planes are packed — extras are ignored.
Shared by the mesh (_bind), splat and splat-pick passes so the clip
convention can't drift between them.
Packs a View's active section planes into a flat uniform buffer as
(normal.xyz, dist)per plane, ready for upload viagl.uniform4fv.Active planes densely fill
out[0 .. count*4 - 1]so a clipping shader's loop bound (uSectionPlaneCount) stays uniform and inactive planes cost nothing; the shader evaluates each plane as a singledot(normal, p) + dist > 0test. At most MAX_SECTION_PLANES planes are packed — extras are ignored.Shared by the mesh (_bind), splat and splat-pick passes so the clip convention can't drift between them.