Fix T64149: Texture paint can act as a canvas and brush at the same time

I don't know if it was the intended behavior or not, but having brush
and canvas data at the same time with dymanic paint, would lead to the
object trying to act as a brush and a canvas at the same time.

We can't currently handle this with the new depsgraph, and it could
legitimately lead to bad feedback loops.

So now, to be more consistent with the GUI, I've made it only use the
current set type (brush or canvas) as the final type of the object.
That is, you can only have a object be a brush or a canvas, not both at
the same time.

1 files changed, 4 insertions, 3 deletions

diff --git a/source/blender/modifiers/intern/MOD_dynamicpaint.c b/source/blender/modifiers/intern/MOD_dynamicpaint.c
index ce488a224aa..26ee75140a6 100644
--- a/source/blender/modifiers/intern/MOD_dynamicpaint.c
+++ b/source/blender/modifiers/intern/MOD_dynamicpaint.c
@@ -112,16 +112,17 @@ static Mesh *applyModifier(ModifierData *md, const ModifierEvalContext *ctx, Mes
   return mesh;
 }
 
-static bool is_brush_cb(Object *UNUSED(ob), ModifierData *pmd)
+static bool is_brush_cb(Object *UNUSED(ob), ModifierData *md)
 {
-  return ((DynamicPaintModifierData *)pmd)->brush != NULL;
+  DynamicPaintModifierData *pmd = (DynamicPaintModifierData *)md;
+  return (pmd->brush != NULL && pmd->type == MOD_DYNAMICPAINT_TYPE_BRUSH);
 }
 
 static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
 {
   DynamicPaintModifierData *pmd = (DynamicPaintModifierData *)md;
   /* Add relation from canvases to all brush objects. */
-  if (pmd->canvas != NULL) {
+  if (pmd->canvas != NULL && pmd->type == MOD_DYNAMICPAINT_TYPE_CANVAS) {
     for (DynamicPaintSurface *surface = pmd->canvas->surfaces.first; surface;
          surface = surface->next) {
       if (surface->effect & MOD_DPAINT_EFFECT_DO_DRIP) {