Implement correct drawing of advanced Weight display features.

This adds existing behavior from calc_weightpaint_vert_array
that was missing from the new rendering code:

- No selected Vertex Group displays as a solid pink color.
- Zero weight displays as alert color depending on Options.
- Multipaint mode correctly displays collective weight.

In order to properly implement this variety, a data structure
holding all relevant parameters is introduced.

Reviewers: fclem, campbellbarton

Subscribers: jbakker

Differential Revision: https://developer.blender.org/D3722

1 files changed, 23 insertions, 2 deletions

diff --git a/source/blender/draw/intern/draw_cache_impl.h b/source/blender/draw/intern/draw_cache_impl.h
index d601bfc3a3e..444d5aeb12d 100644
--- a/source/blender/draw/intern/draw_cache_impl.h
+++ b/source/blender/draw/intern/draw_cache_impl.h
@@ -96,8 +96,29 @@ struct GPUBatch *DRW_lattice_batch_cache_get_all_edges(struct Lattice *lt, bool
 struct GPUBatch *DRW_lattice_batch_cache_get_all_verts(struct Lattice *lt);
 struct GPUBatch *DRW_lattice_batch_cache_get_overlay_verts(struct Lattice *lt);
 
-/* Mesh */
+/* Vertex Group Selection and display options */
+typedef struct VertexWeightSelection {
+	int defgroup_active;
+	int defgroup_tot;
+
+	short flags;
+	char alert_mode;
+
+	/* Set of all selected bones for Multipaint. */
+	int defgroup_sel_tot;
+	bool *defgroup_sel;
+} VertexWeightSelection;
+
+enum {
+	VWEIGHT_MULTIPAINT          = (1 << 0),
+	VWEIGHT_AUTO_NORMALIZE      = (1 << 1),
+};
 
+void DRW_vweight_selection_clear(struct VertexWeightSelection *sel);
+void DRW_vweight_selection_copy(struct VertexWeightSelection *sel, const struct VertexWeightSelection *src);
+bool DRW_vweight_selection_compare(const struct VertexWeightSelection *a, const struct VertexWeightSelection *b);
+
+/* Mesh */
 struct GPUBatch **DRW_mesh_batch_cache_get_surface_shaded(
         struct Mesh *me, struct GPUMaterial **gpumat_array, uint gpumat_array_len,
         char **auto_layer_names, int **auto_layer_is_srgb, int *auto_layer_count);
@@ -109,7 +130,7 @@ struct GPUBatch *DRW_mesh_batch_cache_get_weight_overlay_verts(struct Mesh *me);
 struct GPUBatch *DRW_mesh_batch_cache_get_all_edges(struct Mesh *me);
 struct GPUBatch *DRW_mesh_batch_cache_get_all_triangles(struct Mesh *me);
 struct GPUBatch *DRW_mesh_batch_cache_get_triangles_with_normals(struct Mesh *me);
-struct GPUBatch *DRW_mesh_batch_cache_get_triangles_with_normals_and_weights(struct Mesh *me, int defgroup);
+struct GPUBatch *DRW_mesh_batch_cache_get_triangles_with_normals_and_weights(struct Mesh *me, const struct VertexWeightSelection *vwsel);
 struct GPUBatch *DRW_mesh_batch_cache_get_triangles_with_normals_and_vert_colors(struct Mesh *me);
 struct GPUBatch *DRW_mesh_batch_cache_get_triangles_with_select_id(struct Mesh *me, bool use_hide, uint select_id_offset);
 struct GPUBatch *DRW_mesh_batch_cache_get_triangles_with_select_mask(struct Mesh *me, bool use_hide);