Liquid Simulation Display Options (GSoC 2020)

All the changes made in the branch `soc-2020-fluid-tools` are included in this patch.

**Major changes:**

=== Viewport Display ===

- //Raw voxel display// or //closest (nearest-neighbor)// interpolation for displaying the underlying voxel data of the simulation grids more clearly.
- An option to display //gridlines// when the slicing method is //single//.

==== Grid Display ====

- Visualization for flags, pressure and level-set representation grids with a fixed color coding based on Manta GUI.

==== Vector Display ====

- //**M**arker **A**nd **C**ell// grid visualization options for vector grids like velocity or external forces.
- Made vector display options available for external forces.

==== Coloring options for //gridlines// ====

- Range highlighting and cell filtering options for displaying the simulation grid data more precisely.
- Color gridlines with flags.

- Also, made slicing and interpolation options available for Volume Object.

Reviewed By: JacquesLucke, sebbas

Differential Revision: https://developer.blender.org/D8705

1 files changed, 2 insertions, 0 deletions

diff --git a/source/blender/draw/intern/draw_common.h b/source/blender/draw/intern/draw_common.h
index e3967678319..17db02d986f 100644
--- a/source/blender/draw/intern/draw_common.h
+++ b/source/blender/draw/intern/draw_common.h
@@ -196,6 +196,8 @@ void DRW_hair_free(void);
 void DRW_smoke_ensure(struct FluidModifierData *fmd, int highres);
 void DRW_smoke_ensure_coba_field(struct FluidModifierData *fmd);
 void DRW_smoke_ensure_velocity(struct FluidModifierData *fmd);
+void DRW_fluid_ensure_flags(struct FluidModifierData *fmd);
+void DRW_fluid_ensure_range_field(struct FluidModifierData *fmd);
 
 void DRW_smoke_free(struct FluidModifierData *fmd);
 void DRW_smoke_free_velocity(struct FluidModifierData *fmd);