Patch #35464: Marker placement for motion tracker by clicking on a desired location

Now button in the toolshelf behaves this way:
- User clicks on "Add Marker"
- Then he clicks where the marker should get placed

Patch by Marcos Couto (ocf) with own modifications.

3 files changed, 48 insertions, 25 deletions

diff --git a/source/blender/editors/space_clip/clip_intern.h b/source/blender/editors/space_clip/clip_intern.h
index f1851ef25a7..51cb83eecad 100644
--- a/source/blender/editors/space_clip/clip_intern.h
+++ b/source/blender/editors/space_clip/clip_intern.h
@@ -145,7 +145,7 @@ struct MovieTrackingTrack *tracking_marker_check_slide(struct bContext *C, const
                                                        int *area_r, int *action_r, int *corner_r);
 
 void CLIP_OT_add_marker(struct wmOperatorType *ot);
-void CLIP_OT_add_marker_at_center(struct wmOperatorType *ot);
+void CLIP_OT_add_marker_at_click(struct wmOperatorType *ot);
 void CLIP_OT_delete_track(struct wmOperatorType *ot);
 void CLIP_OT_delete_marker(struct wmOperatorType *ot);
 
diff --git a/source/blender/editors/space_clip/space_clip.c b/source/blender/editors/space_clip/space_clip.c
index fcb33474fa2..60420649093 100644
--- a/source/blender/editors/space_clip/space_clip.c
+++ b/source/blender/editors/space_clip/space_clip.c
@@ -465,7 +465,7 @@ static void clip_operatortypes(void)
 
 	/* markers */
 	WM_operatortype_append(CLIP_OT_add_marker);
-	WM_operatortype_append(CLIP_OT_add_marker_at_center);
+	WM_operatortype_append(CLIP_OT_add_marker_at_click);
 	WM_operatortype_append(CLIP_OT_slide_marker);
 	WM_operatortype_append(CLIP_OT_delete_track);
 	WM_operatortype_append(CLIP_OT_delete_marker);
diff --git a/source/blender/editors/space_clip/tracking_ops.c b/source/blender/editors/space_clip/tracking_ops.c
index 756492ea0f0..3f9b2aac0f1 100644
--- a/source/blender/editors/space_clip/tracking_ops.c
+++ b/source/blender/editors/space_clip/tracking_ops.c
@@ -72,6 +72,8 @@
 #include "RNA_access.h"
 #include "RNA_define.h"
 
+#include "BLF_translation.h"
+
 #include "PIL_time.h"
 
 #include "UI_view2d.h"
@@ -163,44 +165,65 @@ void CLIP_OT_add_marker(wmOperatorType *ot)
 
 /********************** add marker operator *********************/
 
-static int add_marker_at_center_invoke(bContext *C, wmOperator *UNUSED(op), const wmEvent *UNUSED(event))
+static int add_marker_at_click_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-	SpaceClip *sc = CTX_wm_space_clip(C);
-	MovieClip *clip = ED_space_clip_get_clip(sc);
-	ARegion *ar = CTX_wm_region(C);
-	float pos[2];
+	ED_area_headerprint(CTX_wm_area(C), IFACE_("Use LMB click to define location where place the marker"));
 
-	ED_clip_point_stable_pos(sc, ar,
-	                         BLI_rcti_size_x(&ar->winrct) / 2.0f,
-	                         BLI_rcti_size_y(&ar->winrct) / 2.0f,
-	                         &pos[0], &pos[1]);
+	/* add modal handler for ESC */
+	WM_event_add_modal_handler(C, op);
 
-	if (!add_marker(C, pos[0], pos[1])) {
-		return OPERATOR_CANCELLED;
-	}
+	return OPERATOR_RUNNING_MODAL;
+}
 
-	/* reset offset from locked position, so frame jumping wouldn't be so confusing */
-	sc->xlockof = 0;
-	sc->ylockof = 0;
+static int add_marker_at_click_modal(bContext *C, wmOperator *UNUSED(op), const wmEvent *event)
+{
+	 SpaceClip *sc = CTX_wm_space_clip(C);
+	 MovieClip *clip = ED_space_clip_get_clip(sc);
+	 ARegion *ar = CTX_wm_region(C);
+	 float pos[2];
 
-	WM_event_add_notifier(C, NC_MOVIECLIP | NA_EDITED, clip);
+	 switch(event->type) {
+	 	case MOUSEMOVE:
+			return OPERATOR_RUNNING_MODAL;
+			break;
 
-	return OPERATOR_FINISHED;
+	    case LEFTMOUSE:
+			ED_area_headerprint(CTX_wm_area(C), NULL);
+
+			ED_clip_point_stable_pos(sc, ar,
+			                         event->x - ar->winrct.xmin,
+			                         event->y - ar->winrct.ymin,
+			                         &pos[0], &pos[1]);
+
+			if (!add_marker(C, pos[0], pos[1]))
+				return OPERATOR_CANCELLED;
+
+			WM_event_add_notifier(C, NC_MOVIECLIP | NA_EDITED, clip);
+			return OPERATOR_FINISHED;
+			break;
+
+		case ESCKEY:
+			 ED_area_headerprint(CTX_wm_area(C), NULL);
+			 return OPERATOR_CANCELLED;
+    }
+
+   return OPERATOR_PASS_THROUGH;
 }
 
-void CLIP_OT_add_marker_at_center(wmOperatorType *ot)
+void CLIP_OT_add_marker_at_click(wmOperatorType *ot)
 {
 	/* identifiers */
-	ot->name = "Add Marker at Center";
-	ot->idname = "CLIP_OT_add_marker_at_center";
-	ot->description = "Place new marker at the center of visible frame";
+	ot->name = "Add Marker at Click";
+	ot->idname = "CLIP_OT_add_marker_at_click";
+	ot->description = "Place new marker at the desired (clicked) position";
 
 	/* api callbacks */
-	ot->invoke = add_marker_at_center_invoke;
+	ot->invoke = add_marker_at_click_invoke;
 	ot->poll = ED_space_clip_tracking_poll;
+	ot->modal = add_marker_at_click_modal;
 
 	/* flags */
-	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_BLOCKING;
 }
 
 /********************** delete track operator *********************/