Add Custom Falloff Curve to the Vertex Weight Proximity Modifier.

The Vertex Weight Edit Modifier already got the Custom Curve, there was no
real reason for the proximity not to have it as well.

With some fixes by Bastien Montagne (@mont29).

Reviewed By: mont29

Differential Revision: https://developer.blender.org/D9594

source/blender/modifiers/intern/MOD_weightvgproximity.c

@@ -31,6 +31,7 @@
 
 #include "BLT_translation.h"
 
+#include "DNA_color_types.h" /* CurveMapping. */
 #include "DNA_defaults.h"
 #include "DNA_mesh_types.h"
 #include "DNA_meshdata_types.h"
@@ -39,6 +40,7 @@
 #include "DNA_screen_types.h"
 
 #include "BKE_bvhutils.h"
+#include "BKE_colortools.h" /* CurveMapping. */
 #include "BKE_context.h"
 #include "BKE_curve.h"
 #include "BKE_customdata.h"
@@ -54,6 +56,8 @@
 #include "UI_interface.h"
 #include "UI_resources.h"
 
+#include "BLO_read_write.h"
+
 #include "RNA_access.h"
 
 #include "DEG_depsgraph_build.h"
@@ -258,7 +262,8 @@ static void do_map(Object *ob,
                    const float min_d,
                    const float max_d,
                    short mode,
-                   const bool do_invert_mapping)
+                   const bool do_invert_mapping,
+                   CurveMapping *cmap)
 {
   const float range_inv = 1.0f / (max_d - min_d); /* invert since multiplication is faster */
   uint i = nidx;
@@ -294,7 +299,6 @@ static void do_map(Object *ob,
     }
   }
 
-  BLI_assert(mode != MOD_WVG_MAPPING_CURVE);
   if (do_invert_mapping || mode != MOD_WVG_MAPPING_NONE) {
     RNG *rng = NULL;
 
@@ -302,7 +306,7 @@ static void do_map(Object *ob,
       rng = BLI_rng_new_srandom(BLI_ghashutil_strhash(ob->id.name + 2));
     }
 
-    weightvg_do_map(nidx, weights, mode, do_invert_mapping, NULL, rng);
+    weightvg_do_map(nidx, weights, mode, do_invert_mapping, cmap, rng);
 
     if (rng) {
       BLI_rng_free(rng);
@@ -320,6 +324,25 @@ static void initData(ModifierData *md)
   BLI_assert(MEMCMP_STRUCT_AFTER_IS_ZERO(wmd, modifier));
 
   MEMCPY_STRUCT_AFTER(wmd, DNA_struct_default_get(WeightVGProximityModifierData), modifier);
+
+  wmd->cmap_curve = BKE_curvemapping_add(1, 0.0, 0.0, 1.0, 1.0);
+  BKE_curvemapping_init(wmd->cmap_curve);
+}
+
+static void freeData(ModifierData *md)
+{
+  WeightVGProximityModifierData *wmd = (WeightVGProximityModifierData *)md;
+  BKE_curvemapping_free(wmd->cmap_curve);
+}
+
+static void copyData(const ModifierData *md, ModifierData *target, const int flag)
+{
+  const WeightVGProximityModifierData *wmd = (const WeightVGProximityModifierData *)md;
+  WeightVGProximityModifierData *twmd = (WeightVGProximityModifierData *)target;
+
+  BKE_modifier_copydata_generic(md, target, flag);
+
+  twmd->cmap_curve = BKE_curvemapping_copy(wmd->cmap_curve);
 }
 
 static void requiredDataMask(Object *UNUSED(ob),
@@ -587,7 +610,8 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
          wmd->min_dist,
          wmd->max_dist,
          wmd->falloff_type,
-         (wmd->proximity_flags & MOD_WVG_PROXIMITY_INVERT_FALLOFF) != 0);
+         (wmd->proximity_flags & MOD_WVG_PROXIMITY_INVERT_FALLOFF) != 0,
+         wmd->cmap_curve);
 
   /* Do masking. */
   struct Scene *scene = DEG_get_evaluated_scene(ctx->depsgraph);
@@ -680,6 +704,9 @@ static void falloff_panel_draw(const bContext *UNUSED(C), Panel *panel)
   sub = uiLayoutRow(row, true);
   uiLayoutSetPropSep(sub, false);
   uiItemR(row, ptr, "invert_falloff", 0, "", ICON_ARROW_LEFTRIGHT);
+  if (RNA_enum_get(ptr, "falloff_type") == MOD_WVG_MAPPING_CURVE) {
+    uiTemplateCurveMapping(layout, ptr, "map_curve", 0, false, false, false, false);
+  }
   modifier_panel_end(layout, ptr);
 }
 
@@ -703,6 +730,25 @@ static void panelRegister(ARegionType *region_type)
       region_type, "influence", "Influence", NULL, influence_panel_draw, panel_type);
 }
 
+static void blendWrite(BlendWriter *writer, const ModifierData *md)
+{
+  const WeightVGProximityModifierData *wmd = (const WeightVGProximityModifierData *)md;
+
+  if (wmd->cmap_curve) {
+    BKE_curvemapping_blend_write(writer, wmd->cmap_curve);
+  }
+}
+
+static void blendRead(BlendDataReader *reader, ModifierData *md)
+{
+  WeightVGProximityModifierData *wmd = (WeightVGProximityModifierData *)md;
+
+  BLO_read_data_address(reader, &wmd->cmap_curve);
+  if (wmd->cmap_curve) {
+    BKE_curvemapping_blend_read(reader, wmd->cmap_curve);
+  }
+}
+
 ModifierTypeInfo modifierType_WeightVGProximity = {
     /* name */ "VertexWeightProximity",
     /* structName */ "WeightVGProximityModifierData",
@@ -713,7 +759,7 @@ ModifierTypeInfo modifierType_WeightVGProximity = {
         eModifierTypeFlag_SupportsEditmode | eModifierTypeFlag_UsesPreview,
     /* icon */ ICON_MOD_VERTEX_WEIGHT,
 
-    /* copyData */ BKE_modifier_copydata_generic,
+    /* copyData */ copyData,
 
     /* deformVerts */ NULL,
     /* deformMatrices */ NULL,
@@ -726,7 +772,7 @@ ModifierTypeInfo modifierType_WeightVGProximity = {
 
     /* initData */ initData,
     /* requiredDataMask */ requiredDataMask,
-    /* freeData */ NULL,
+    /* freeData */ freeData,
     /* isDisabled */ isDisabled,
     /* updateDepsgraph */ updateDepsgraph,
     /* dependsOnTime */ dependsOnTime,
@@ -735,6 +781,6 @@ ModifierTypeInfo modifierType_WeightVGProximity = {
     /* foreachTexLink */ foreachTexLink,
     /* freeRuntimeData */ NULL,
     /* panelRegister */ panelRegister,
-    /* blendWrite */ NULL,
-    /* blendRead */ NULL,
+    /* blendWrite */ blendWrite,
+    /* blendRead */ blendRead,
 };