shrink-wrap constraint, improve and remove some limitations.

- ability to change the space the axis is projected in (so you can choose worldspace or -space, was always local-space before).
- support projecting on a negative axis, without this some very simple clamping is not possible if the direction happened not to be positive.
- add distance limit (same as modifier), without this single meshes surrounding an object would make the constraint impossible to use in some cases (it would snap to the wrong side).

note: this removes the ability to project on multiple axes at once but this option only added up directions and didnt project on multiple axes as you might expect.

1 files changed, 48 insertions, 20 deletions

diff --git a/source/blender/blenkernel/intern/constraint.c b/source/blender/blenkernel/intern/constraint.c
index 7b7d20a54e0..1f892432d80 100644
--- a/source/blender/blenkernel/intern/constraint.c
+++ b/source/blender/blenkernel/intern/constraint.c
@@ -3308,6 +3308,14 @@ static void shrinkwrap_id_looper(bConstraint *con, ConstraintIDFunc func, void *
 	func(con, (ID **)&data->target, FALSE, userdata);
 }
 
+static void shrinkwrap_new_data(void *cdata)
+{
+	bShrinkwrapConstraint *data = (bShrinkwrapConstraint *)cdata;
+
+	data->projAxis = OB_POSZ;
+	data->projAxisSpace = CONSTRAINT_SPACE_LOCAL;
+}
+
 static int shrinkwrap_get_tars(bConstraint *con, ListBase *list)
 {
 	if (con && list) {
@@ -3339,24 +3347,14 @@ static void shrinkwrap_get_tarmat(bConstraint *con, bConstraintOb *cob, bConstra
 	bShrinkwrapConstraint *scon = (bShrinkwrapConstraint *) con->data;
 	
 	if (VALID_CONS_TARGET(ct) && (ct->tar->type == OB_MESH) ) {
-		int fail = FALSE;
+		bool fail = false;
 		float co[3] = {0.0f, 0.0f, 0.0f};
-		float no[3] = {0.0f, 0.0f, 0.0f};
-		float dist;
 		
 		SpaceTransform transform;
 		DerivedMesh *target = object_get_derived_final(ct->tar);
-		BVHTreeRayHit hit;
-		BVHTreeNearest nearest;
 		
 		BVHTreeFromMesh treeData = {NULL};
 		
-		nearest.index = -1;
-		nearest.dist = FLT_MAX;
-		
-		hit.index = -1;
-		hit.dist = 100000.0f;  //TODO should use FLT_MAX.. but normal projection doenst yet supports it
-		
 		unit_m4(ct->matrix);
 		
 		if (target != NULL) {
@@ -3365,7 +3363,13 @@ static void shrinkwrap_get_tarmat(bConstraint *con, bConstraintOb *cob, bConstra
 			switch (scon->shrinkType) {
 				case MOD_SHRINKWRAP_NEAREST_SURFACE:
 				case MOD_SHRINKWRAP_NEAREST_VERTEX:
-					
+				{
+					BVHTreeNearest nearest;
+					float dist;
+
+					nearest.index = -1;
+					nearest.dist = FLT_MAX;
+
 					if (scon->shrinkType == MOD_SHRINKWRAP_NEAREST_VERTEX)
 						bvhtree_from_mesh_verts(&treeData, target, 0.0, 2, 6);
 					else
@@ -3386,30 +3390,54 @@ static void shrinkwrap_get_tarmat(bConstraint *con, bConstraintOb *cob, bConstra
 					}
 					space_transform_invert(&transform, co);
 					break;
-				
+				}
 				case MOD_SHRINKWRAP_PROJECT:
-					if (scon->projAxis & MOD_SHRINKWRAP_PROJECT_OVER_X_AXIS) no[0] = 1.0f;
-					if (scon->projAxis & MOD_SHRINKWRAP_PROJECT_OVER_Y_AXIS) no[1] = 1.0f;
-					if (scon->projAxis & MOD_SHRINKWRAP_PROJECT_OVER_Z_AXIS) no[2] = 1.0f;
+				{
+					BVHTreeRayHit hit;
+
+					float mat[4][4];
+					float no[3] = {0.0f, 0.0f, 0.0f};
+
+					/* TODO should use FLT_MAX.. but normal projection doenst yet supports it */
+					hit.index = -1;
+					hit.dist = (scon->projLimit == 0.0f) ? 100000.0f : scon->projLimit;
+
+					switch (scon->projAxis) {
+						case OB_POSX: case OB_POSY: case OB_POSZ:
+							no[scon->projAxis - OB_POSX] = 1.0f;
+							break;
+						case OB_NEGX: case OB_NEGY: case OB_NEGZ:
+							no[scon->projAxis - OB_NEGX] = -1.0f;
+							break;
+					}
 					
+					/* transform normal into requested space */
+					unit_m4(mat);
+					BKE_constraint_mat_convertspace(cob->ob, cob->pchan, mat, CONSTRAINT_SPACE_LOCAL, scon->projAxisSpace);
+					invert_m4(mat);
+					mul_mat3_m4_v3(mat, no);
+
 					if (normalize_v3(no) < FLT_EPSILON) {
 						fail = TRUE;
 						break;
 					}
-					
-					
+
 					bvhtree_from_mesh_faces(&treeData, target, scon->dist, 4, 6);
 					if (treeData.tree == NULL) {
 						fail = TRUE;
 						break;
 					}
+
 					
-					if (normal_projection_project_vertex(0, co, no, &transform, treeData.tree, &hit, treeData.raycast_callback, &treeData) == FALSE) {
+					if (BKE_shrinkwrap_project_normal(0, co, no, &transform, treeData.tree, &hit,
+					                                  treeData.raycast_callback, &treeData) == false)
+					{
 						fail = TRUE;
 						break;
 					}
 					copy_v3_v3(co, hit.co);
 					break;
+				}
 			}
 			
 			free_bvhtree_from_mesh(&treeData);
@@ -3446,7 +3474,7 @@ static bConstraintTypeInfo CTI_SHRINKWRAP = {
 	NULL, /* free data */
 	shrinkwrap_id_looper, /* id looper */
 	NULL, /* copy data */
-	NULL, /* new data */
+	shrinkwrap_new_data, /* new data */
 	shrinkwrap_get_tars, /* get constraint targets */
 	shrinkwrap_flush_tars, /* flush constraint targets */
 	shrinkwrap_get_tarmat, /* get a target matrix */