Patch #37274: Circle select for node editor, by Henrik Aarnio (hjaarnio).

Circle select was missing from node editor, and C key was assigned to now defunct "show cyclic dependencies". This patch remaps the key and adds circle select operator.
Functions to check intersection between rctf/rcti and a circle were also added to rct.c for code cleanliness and consistency.

release/scripts/startup/bl_ui/space_node.py

@@ -169,6 +169,7 @@ class NODE_MT_select(Menu):
         layout = self.layout
 
         layout.operator("node.select_border")
+        layout.operator("node.select_circle")
 
         layout.separator()
         layout.operator("node.select_all").action = 'TOGGLE'

source/blender/blenlib/BLI_rect.h

@@ -74,6 +74,8 @@ bool BLI_rctf_isect_pt(const struct rctf *rect, const float x, const float y);
 bool BLI_rctf_isect_pt_v(const struct rctf *rect, const float xy[2]);
 bool BLI_rcti_isect_segment(const struct rcti *rect, const int s1[2], const int s2[2]);
 bool BLI_rctf_isect_segment(const struct rctf *rect, const float s1[2], const float s2[2]);
+bool BLI_rcti_isect_circle(const struct rcti *rect, const float xy[2], const float radius);
+bool BLI_rctf_isect_circle(const struct rctf *rect, const float xy[2], const float radius);
 bool BLI_rcti_inside_rcti(rcti *rct_a, const rcti *rct_b);
 bool BLI_rctf_inside_rctf(rctf *rct_a, const rctf *rct_b);
 void BLI_rcti_union(struct rcti *rcti1, const struct rcti *rcti2);

source/blender/blenlib/intern/rct.c

@@ -216,6 +216,32 @@ bool BLI_rctf_isect_segment(const rctf *rect, const float s1[2], const float s2[
 	}
 }
 
+bool BLI_rcti_isect_circle(const rcti *rect, const float xy[2], const float radius)
+{
+	float dx, dy;
+
+	if (xy[0] >= rect->xmin && xy[0] <= rect->xmax) dx = 0;
+	else dx = (xy[0] < rect->xmin) ? (rect->xmin - xy[0]) : (xy[0] - rect->xmax);
+
+	if (xy[1] >= rect->ymin && xy[1] <= rect->ymax) dy = 0;
+	else dy = (xy[1] < rect->ymin) ? (rect->ymin - xy[1]) : (xy[1] - rect->ymax);
+
+	return dx * dx + dy * dy <= radius * radius;
+}
+
+bool BLI_rctf_isect_circle(const rctf *rect, const float xy[2], const float radius)
+{
+	float dx, dy;
+
+	if (xy[0] >= rect->xmin && xy[0] <= rect->xmax) dx = 0;
+	else dx = (xy[0] < rect->xmin) ? (rect->xmin - xy[0]) : (xy[0] - rect->xmax);
+
+	if (xy[1] >= rect->ymin && xy[1] <= rect->ymax) dy = 0;
+	else dy = (xy[1] < rect->ymin) ? (rect->ymin - xy[1]) : (xy[1] - rect->ymax);
+
+	return dx * dx + dy * dy <= radius * radius;
+}
+
 void BLI_rctf_union(rctf *rct1, const rctf *rct2)
 {
 	if (rct1->xmin > rct2->xmin) rct1->xmin = rct2->xmin;

source/blender/editors/space_node/node_intern.h

@@ -116,6 +116,7 @@ void NODE_OT_select_all(struct wmOperatorType *ot);
 void NODE_OT_select_linked_to(struct wmOperatorType *ot);
 void NODE_OT_select_linked_from(struct wmOperatorType *ot);
 void NODE_OT_select_border(struct wmOperatorType *ot);
+void NODE_OT_select_circle(struct wmOperatorType *ot);
 void NODE_OT_select_lasso(struct wmOperatorType *ot);
 void NODE_OT_select_same_type(struct wmOperatorType *ot);
 void NODE_OT_select_same_type_step(struct wmOperatorType *ot);

source/blender/editors/space_node/node_ops.c

@@ -56,6 +56,7 @@ void node_operatortypes(void)
 	WM_operatortype_append(NODE_OT_select_linked_to);
 	WM_operatortype_append(NODE_OT_select_linked_from);
 	WM_operatortype_append(NODE_OT_select_border);
+	WM_operatortype_append(NODE_OT_select_circle);
 	WM_operatortype_append(NODE_OT_select_lasso);
 	WM_operatortype_append(NODE_OT_select_same_type);
 	WM_operatortype_append(NODE_OT_select_same_type_step);
@@ -232,6 +233,8 @@ void node_keymap(struct wmKeyConfig *keyconf)
 	kmi = WM_keymap_add_item(keymap, "NODE_OT_select_lasso", EVT_TWEAK_A, KM_ANY, KM_CTRL | KM_SHIFT | KM_ALT, 0);
 	RNA_boolean_set(kmi->ptr, "deselect", TRUE);
 
+	WM_keymap_add_item(keymap, "NODE_OT_select_circle", CKEY, KM_PRESS, 0, 0);
+
 	/* each of these falls through if not handled... */
 	kmi = WM_keymap_add_item(keymap, "NODE_OT_link", LEFTMOUSE, KM_PRESS, 0, 0);
 	RNA_boolean_set(kmi->ptr, "detach", FALSE);

source/blender/editors/space_node/node_select.c

@@ -514,6 +514,63 @@ void NODE_OT_select_border(wmOperatorType *ot)
 	RNA_def_boolean(ot->srna, "tweak", 0, "Tweak", "Only activate when mouse is not over a node - useful for tweak gesture");
 }
 
+/* ****** Circle Select ****** */
+
+static int node_circleselect_exec(bContext *C, wmOperator *op)
+{
+	SpaceNode *snode = CTX_wm_space_node(C);
+	ARegion *ar = CTX_wm_region(C);
+	bNode *node;
+
+	int x, y, radius, gesture_mode;
+	float offset[2];
+
+	float zoom  = (float)(BLI_rcti_size_x(&ar->winrct)) / (float)(BLI_rctf_size_x(&ar->v2d.cur));
+
+	gesture_mode = RNA_int_get(op->ptr, "gesture_mode");
+
+	/* get operator properties */
+	x = RNA_int_get(op->ptr, "x");
+	y = RNA_int_get(op->ptr, "y");
+	radius = RNA_int_get(op->ptr, "radius");
+
+	UI_view2d_region_to_view(&ar->v2d, x, y, &offset[0], &offset[1]);
+
+	for (node = snode->edittree->nodes.first; node; node = node->next) {
+		if (BLI_rctf_isect_circle(&node->totr, offset, radius / zoom)) {
+			nodeSetSelected(node, (gesture_mode == GESTURE_MODAL_SELECT));
+		}
+	}
+
+	WM_event_add_notifier(C, NC_NODE | NA_SELECTED, NULL);
+
+	return OPERATOR_FINISHED;
+}
+
+void NODE_OT_select_circle(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Circle Select";
+	ot->idname = "NODE_OT_select_circle";
+	ot->description = "Use circle selection to select nodes";
+
+	/* api callbacks */
+	ot->invoke = WM_gesture_circle_invoke;
+	ot->exec = node_circleselect_exec;
+	ot->modal = WM_gesture_circle_modal;
+
+	ot->poll = ED_operator_node_active;
+
+	/* flags */
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+	/* rna */
+	RNA_def_int(ot->srna, "x", 0, INT_MIN, INT_MAX, "X", "", INT_MIN, INT_MAX);
+	RNA_def_int(ot->srna, "y", 0, INT_MIN, INT_MAX, "Y", "", INT_MIN, INT_MAX);
+	RNA_def_int(ot->srna, "radius", 0, INT_MIN, INT_MAX, "Radius", "", INT_MIN, INT_MAX);
+	RNA_def_int(ot->srna, "gesture_mode", 0, INT_MIN, INT_MAX, "Gesture Mode", "", INT_MIN, INT_MAX);
+}
+
 /* ****** Lasso Select ****** */
 
 static int do_lasso_select_node(bContext *C, const int mcords[][2], short moves, short select)

source/blender/windowmanager/intern/wm_operators.c

@@ -4271,6 +4271,7 @@ static void gesture_circle_modal_keymap(wmKeyConfig *keyconf)
 	WM_modalkeymap_assign(keymap, "UV_OT_circle_select");
 	WM_modalkeymap_assign(keymap, "CLIP_OT_select_circle");
 	WM_modalkeymap_assign(keymap, "MASK_OT_select_circle");
+	WM_modalkeymap_assign(keymap, "NODE_OT_select_circle");
 
 }