Weight Paint: 'Sample' now supports multi-paint

Since the coloring uses sum or average of the weights of all selected
groups, the weight pick tool should also use that instead of reading
the weight of the single active group that you can't see.

1 files changed, 3 insertions, 20 deletions

diff --git a/source/blender/blenkernel/intern/DerivedMesh.c b/source/blender/blenkernel/intern/DerivedMesh.c
index 1577a818180..dc7ef3055ee 100644
--- a/source/blender/blenkernel/intern/DerivedMesh.c
+++ b/source/blender/blenkernel/intern/DerivedMesh.c
@@ -1373,30 +1373,13 @@ static void calc_weightpaint_vert_color(
 
 	if ((defbase_sel_tot > 1) && (draw_flag & CALC_WP_MULTIPAINT)) {
 		/* Multi-Paint feature */
-		bool was_a_nonzero = false;
-		unsigned int i;
-
-		const MDeformWeight *dw = dv->dw;
-		for (i = dv->totweight; i != 0; i--, dw++) {
-			/* in multipaint, get the average if auto normalize is inactive
-			 * get the sum if it is active */
-			if (dw->def_nr < defbase_tot) {
-				if (defbase_sel[dw->def_nr]) {
-					if (dw->weight) {
-						input += dw->weight;
-						was_a_nonzero = true;
-					}
-				}
-			}
-		}
+		input = BKE_defvert_multipaint_collective_weight(
+		        dv, defbase_tot, defbase_sel, defbase_sel_tot, (draw_flag & CALC_WP_AUTO_NORMALIZE) != 0);
 
 		/* make it black if the selected groups have no weight on a vertex */
-		if (was_a_nonzero == false) {
+		if (input == 0.0f) {
 			show_alert_color = true;
 		}
-		else if ((draw_flag & CALC_WP_AUTO_NORMALIZE) == false) {
-			input /= defbase_sel_tot; /* get the average */
-		}
 	}
 	else {
 		/* default, non tricky behavior */