1 files changed, 203 insertions, 0 deletions
diff --git a/source/blender/editors/space_view3d/view3d_gizmo_preselect_type.c b/source/blender/editors/space_view3d/view3d_gizmo_preselect_type.c
new file mode 100644
index 00000000000..2934c55df6e
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+++ b/source/blender/editors/space_view3d/view3d_gizmo_preselect_type.c
@@ -0,0 +1,203 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file view3d_gizmo_preselect_type.c
+ *  \ingroup wm
+ *
+ * \name Preselection Gizmo
+ *
+ * Use for tools to hover over data before activation.
+ *
+ * \note This is a slight mis-use of gizmo's, since clicking performs no action.
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_math.h"
+
+#include "BKE_context.h"
+#include "BKE_layer.h"
+#include "BKE_editmesh.h"
+
+#include "RNA_access.h"
+#include "RNA_define.h"
+
+#include "WM_api.h"
+#include "WM_types.h"
+
+#include "bmesh.h"
+
+#include "ED_screen.h"
+#include "ED_mesh.h"
+#include "ED_view3d.h"
+#include "ED_gizmo_library.h"
+
+/* -------------------------------------------------------------------- */
+/** \name Mesh Edge-Ring Pre-Select Gizmo API
+ *
+ * \{ */
+
+typedef struct MeshEdgeRingGizmo3D {
+	wmGizmo gizmo;
+	Object **objects;
+	uint     objects_len;
+	int object_index;
+	int edge_index;
+	struct EditMesh_PreSelEdgeRing *psel;
+} MeshEdgeRingGizmo3D;
+
+static void gizmo_preselect_edgering_draw(const bContext *UNUSED(C), wmGizmo *gz)
+{
+	MeshEdgeRingGizmo3D *gz_ring = (MeshEdgeRingGizmo3D *)gz;
+	if (gz_ring->object_index != -1) {
+		Object *ob = gz_ring->objects[gz_ring->object_index];
+		EDBM_preselect_edgering_draw(gz_ring->psel, ob->obmat);
+	}
+}
+
+static int gizmo_preselect_edgering_test_select(
+        bContext *C, wmGizmo *gz, const int mval[2])
+{
+	MeshEdgeRingGizmo3D *gz_ring = (MeshEdgeRingGizmo3D *)gz;
+	struct {
+		Object *ob;
+		BMEdge *eed;
+		float dist;
+		int ob_index;
+	} best = {
+		.dist = ED_view3d_select_dist_px(),
+	};
+
+	struct {
+		int object_index;
+		int edge_index;
+	} prev = {
+		.object_index = gz_ring->object_index,
+		.edge_index = gz_ring->edge_index,
+	};
+
+	if (gz_ring->objects == NULL) {
+		ViewLayer *view_layer = CTX_data_view_layer(C);
+		gz_ring->objects = BKE_view_layer_array_from_objects_in_edit_mode(
+		        view_layer, &gz_ring->objects_len);
+	}
+
+	ViewContext vc;
+	em_setup_viewcontext(C, &vc);
+	copy_v2_v2_int(vc.mval, mval);
+
+	for (uint ob_index = 0; ob_index < gz_ring->objects_len; ob_index++) {
+		Object *ob_iter = gz_ring->objects[ob_index];
+		ED_view3d_viewcontext_init_object(&vc, ob_iter);
+		BMEdge *eed_test = EDBM_edge_find_nearest_ex(&vc, &best.dist, NULL, false, false, NULL);
+		if (eed_test) {
+			best.ob = ob_iter;
+			best.eed = eed_test;
+			best.ob_index = ob_index;
+		}
+	}
+
+	BMesh *bm = NULL;
+	if (best.eed) {
+		gz_ring->object_index = best.ob_index;
+		bm = BKE_editmesh_from_object(gz_ring->objects[gz_ring->object_index])->bm;
+		BM_mesh_elem_index_ensure(bm, BM_EDGE);
+		gz_ring->edge_index = BM_elem_index_get(best.eed);
+	}
+	else {
+		gz_ring->object_index = -1;
+		gz_ring->edge_index = -1;
+	}
+
+
+	if ((prev.object_index == gz_ring->object_index) &&
+	    (prev.edge_index == gz_ring->edge_index))
+	{
+		/* pass (only recalculate on change) */
+	}
+	else {
+		if (best.eed) {
+			EDBM_preselect_edgering_update_from_edge(
+			        gz_ring->psel,
+			        bm, best.eed, 1);
+		}
+		else {
+			EDBM_preselect_edgering_clear(gz_ring->psel);
+		}
+
+		RNA_int_set(gz->ptr, "object_index", gz_ring->object_index);
+		RNA_int_set(gz->ptr, "edge_index", gz_ring->edge_index);
+
+		ARegion *ar = CTX_wm_region(C);
+		ED_region_tag_redraw(ar);
+	}
+
+	// return best.eed ? 0 : -1;
+	return -1;
+}
+
+static void gizmo_preselect_edgering_setup(wmGizmo *gz)
+{
+	MeshEdgeRingGizmo3D *gz_ring = (MeshEdgeRingGizmo3D *)gz;
+	if (gz_ring->psel == NULL) {
+		gz_ring->psel = EDBM_preselect_edgering_create();
+	}
+	gz_ring->object_index = -1;
+}
+
+static void gizmo_preselect_edgering_free(wmGizmo *gz)
+{
+	MeshEdgeRingGizmo3D *gz_ring = (MeshEdgeRingGizmo3D *)gz;
+	EDBM_preselect_edgering_destroy(gz_ring->psel);
+	gz_ring->psel = NULL;
+	MEM_SAFE_FREE(gz_ring->objects);
+}
+
+static int gizmo_preselect_edgering_invoke(
+        bContext *UNUSED(C), wmGizmo *UNUSED(gz), const wmEvent *UNUSED(event))
+{
+	return OPERATOR_PASS_THROUGH;
+}
+
+
+static void GIZMO_GT_preselect_edgering_3d(wmGizmoType *gzt)
+{
+	/* identifiers */
+	gzt->idname = "GIZMO_GT_preselect_edgering_3d";
+
+	/* api callbacks */
+	gzt->invoke = gizmo_preselect_edgering_invoke;
+	gzt->draw = gizmo_preselect_edgering_draw;
+	gzt->test_select = gizmo_preselect_edgering_test_select;
+	gzt->setup = gizmo_preselect_edgering_setup;
+	gzt->free = gizmo_preselect_edgering_free;
+
+	gzt->struct_size = sizeof(MeshEdgeRingGizmo3D);
+
+	RNA_def_int(gzt->srna, "object_index", -1, -1, INT_MAX, "Object Index", "", -1, INT_MAX);
+	RNA_def_int(gzt->srna, "edge_index", -1, -1, INT_MAX, "Edge Index", "", -1, INT_MAX);
+}
+
+void ED_gizmotypes_preselect_3d(void)
+{
+	WM_gizmotype_append(GIZMO_GT_preselect_edgering_3d);
+}
+
+/** \} */