Paint: decouple op->customdata from PaintStroke

Previously, all operators using `PaintStroke` would have to store
the stroke in `op->customdata`. That made it impossible to store
other operator specific data in `op->customdata` that was unrelated
to the stroke.

This patch changes it so that the `PaintStroke` is passed to api
functions as a separate argument, which allows storing the stroke
as a subfield of some other struct in `op->customdata`.

6 files changed, 80 insertions, 55 deletions

diff --git a/source/blender/editors/sculpt_paint/curves_sculpt_ops.cc b/source/blender/editors/sculpt_paint/curves_sculpt_ops.cc
index ead016174c9..c4421210379 100644
--- a/source/blender/editors/sculpt_paint/curves_sculpt_ops.cc
+++ b/source/blender/editors/sculpt_paint/curves_sculpt_ops.cc
@@ -59,9 +59,14 @@ static int sculpt_curves_stroke_invoke(bContext *C, wmOperator *op, const wmEven
   return OPERATOR_RUNNING_MODAL;
 }
 
+static int sculpt_curves_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
+{
+  return paint_stroke_modal(C, op, event, static_cast<PaintStroke *>(op->customdata));
+}
+
 static void sculpt_curves_stroke_cancel(bContext *C, wmOperator *op)
 {
-  paint_stroke_cancel(C, op);
+  paint_stroke_cancel(C, op, static_cast<PaintStroke *>(op->customdata));
 }
 
 static void SCULPT_CURVES_OT_brush_stroke(struct wmOperatorType *ot)
@@ -71,7 +76,7 @@ static void SCULPT_CURVES_OT_brush_stroke(struct wmOperatorType *ot)
   ot->description = "Sculpt curves using a brush";
 
   ot->invoke = sculpt_curves_stroke_invoke;
-  ot->modal = paint_stroke_modal;
+  ot->modal = sculpt_curves_stroke_modal;
   ot->cancel = sculpt_curves_stroke_cancel;
 
   ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
diff --git a/source/blender/editors/sculpt_paint/paint_image.c b/source/blender/editors/sculpt_paint/paint_image.c
index df9e2cf136f..ad8303418f4 100644
--- a/source/blender/editors/sculpt_paint/paint_image.c
+++ b/source/blender/editors/sculpt_paint/paint_image.c
@@ -685,7 +685,7 @@ static int paint_invoke(bContext *C, wmOperator *op, const wmEvent *event)
                                     event->type);
 
   if ((retval = op->type->modal(C, op, event)) == OPERATOR_FINISHED) {
-    paint_stroke_free(C, op);
+    paint_stroke_free(C, op, op->customdata);
     return OPERATOR_FINISHED;
   }
   /* add modal handler */
@@ -720,7 +720,17 @@ static int paint_exec(bContext *C, wmOperator *op)
                                     paint_stroke_done,
                                     0);
   /* frees op->customdata */
-  return paint_stroke_exec(C, op);
+  return paint_stroke_exec(C, op, op->customdata);
+}
+
+static int paint_modal(bContext *C, wmOperator *op, const wmEvent *event)
+{
+  return paint_stroke_modal(C, op, event, op->customdata);
+}
+
+static void paint_cancel(bContext *C, wmOperator *op)
+{
+  paint_stroke_cancel(C, op, op->customdata);
 }
 
 void PAINT_OT_image_paint(wmOperatorType *ot)
@@ -732,10 +742,10 @@ void PAINT_OT_image_paint(wmOperatorType *ot)
 
   /* api callbacks */
   ot->invoke = paint_invoke;
-  ot->modal = paint_stroke_modal;
+  ot->modal = paint_modal;
   ot->exec = paint_exec;
   ot->poll = image_paint_poll;
-  ot->cancel = paint_stroke_cancel;
+  ot->cancel = paint_cancel;
 
   /* flags */
   ot->flag = OPTYPE_BLOCKING;
diff --git a/source/blender/editors/sculpt_paint/paint_intern.h b/source/blender/editors/sculpt_paint/paint_intern.h
index f1e79b98b83..f7447ec31b8 100644
--- a/source/blender/editors/sculpt_paint/paint_intern.h
+++ b/source/blender/editors/sculpt_paint/paint_intern.h
@@ -62,7 +62,7 @@ struct PaintStroke *paint_stroke_new(struct bContext *C,
                                      StrokeRedraw redraw,
                                      StrokeDone done,
                                      int event_type);
-void paint_stroke_free(struct bContext *C, struct wmOperator *op);
+void paint_stroke_free(struct bContext *C, struct wmOperator *op, struct PaintStroke *stroke);
 
 /**
  * Returns zero if the stroke dots should not be spaced, non-zero otherwise.
@@ -84,9 +84,12 @@ bool paint_supports_jitter(enum ePaintMode mode);
  * Called in paint_ops.c, on each regeneration of key-maps.
  */
 struct wmKeyMap *paint_stroke_modal_keymap(struct wmKeyConfig *keyconf);
-int paint_stroke_modal(struct bContext *C, struct wmOperator *op, const struct wmEvent *event);
-int paint_stroke_exec(struct bContext *C, struct wmOperator *op);
-void paint_stroke_cancel(struct bContext *C, struct wmOperator *op);
+int paint_stroke_modal(struct bContext *C,
+                       struct wmOperator *op,
+                       const struct wmEvent *event,
+                       struct PaintStroke *stroke);
+int paint_stroke_exec(struct bContext *C, struct wmOperator *op, struct PaintStroke *stroke);
+void paint_stroke_cancel(struct bContext *C, struct wmOperator *op, struct PaintStroke *stroke);
 bool paint_stroke_flipped(struct PaintStroke *stroke);
 bool paint_stroke_inverted(struct PaintStroke *stroke);
 struct ViewContext *paint_stroke_view_context(struct PaintStroke *stroke);
diff --git a/source/blender/editors/sculpt_paint/paint_stroke.c b/source/blender/editors/sculpt_paint/paint_stroke.c
index 9bbfb81e08e..ebb5db8d712 100644
--- a/source/blender/editors/sculpt_paint/paint_stroke.c
+++ b/source/blender/editors/sculpt_paint/paint_stroke.c
@@ -505,16 +505,13 @@ static bool paint_stroke_use_jitter(ePaintMode mode, Brush *brush, bool invert)
 }
 
 /* Put the location of the next stroke dot into the stroke RNA and apply it to the mesh */
-static void paint_brush_stroke_add_step(bContext *C,
-                                        wmOperator *op,
-                                        const float mouse_in[2],
-                                        float pressure)
+static void paint_brush_stroke_add_step(
+    bContext *C, wmOperator *op, PaintStroke *stroke, const float mouse_in[2], float pressure)
 {
   Scene *scene = CTX_data_scene(C);
   Paint *paint = BKE_paint_get_active_from_context(C);
   ePaintMode mode = BKE_paintmode_get_active_from_context(C);
   Brush *brush = BKE_paint_brush(paint);
-  PaintStroke *stroke = op->customdata;
   UnifiedPaintSettings *ups = stroke->ups;
   float mouse_out[2];
   PointerRNA itemptr;
@@ -785,12 +782,12 @@ static float paint_space_stroke_spacing_variable(bContext *C,
  * towards the final mouse location. */
 static int paint_space_stroke(bContext *C,
                               wmOperator *op,
+                              PaintStroke *stroke,
                               const float final_mouse[2],
                               float final_pressure)
 {
   const Scene *scene = CTX_data_scene(C);
   ARegion *region = CTX_wm_region(C);
-  PaintStroke *stroke = op->customdata;
   UnifiedPaintSettings *ups = stroke->ups;
   Paint *paint = BKE_paint_get_active_from_context(C);
   ePaintMode mode = BKE_paintmode_get_active_from_context(C);
@@ -852,7 +849,7 @@ static int paint_space_stroke(bContext *C,
                                                            spacing / no_pressure_spacing);
 
       stroke->stroke_distance += spacing / stroke->zoom_2d;
-      paint_brush_stroke_add_step(C, op, mouse, pressure);
+      paint_brush_stroke_add_step(C, op, stroke, mouse, pressure);
 
       length -= spacing;
       pressure = stroke->last_pressure;
@@ -929,7 +926,7 @@ PaintStroke *paint_stroke_new(bContext *C,
   return stroke;
 }
 
-void paint_stroke_free(bContext *C, wmOperator *op)
+void paint_stroke_free(bContext *C, wmOperator *UNUSED(op), PaintStroke *stroke)
 {
   RegionView3D *rv3d = CTX_wm_region_view3d(C);
   if (rv3d) {
@@ -938,7 +935,6 @@ void paint_stroke_free(bContext *C, wmOperator *op)
 
   BKE_paint_set_overlay_override(0);
 
-  PaintStroke *stroke = op->customdata;
   if (stroke == NULL) {
     return;
   }
@@ -961,12 +957,11 @@ void paint_stroke_free(bContext *C, wmOperator *op)
 
   BLI_freelistN(&stroke->line);
 
-  MEM_SAFE_FREE(op->customdata);
+  MEM_SAFE_FREE(stroke);
 }
 
-static void stroke_done(bContext *C, wmOperator *op)
+static void stroke_done(bContext *C, wmOperator *op, PaintStroke *stroke)
 {
-  PaintStroke *stroke = op->customdata;
   UnifiedPaintSettings *ups = stroke->ups;
 
   /* reset rotation here to avoid doing so in cursor display */
@@ -988,7 +983,7 @@ static void stroke_done(bContext *C, wmOperator *op)
     }
   }
 
-  paint_stroke_free(C, op);
+  paint_stroke_free(C, op, stroke);
 }
 
 bool paint_space_stroke_enabled(Brush *br, ePaintMode mode)
@@ -1230,7 +1225,7 @@ static void paint_line_strokes_spacing(bContext *C,
       ups->overlap_factor = paint_stroke_integrate_overlap(stroke->brush, 1.0);
 
       stroke->stroke_distance += spacing / stroke->zoom_2d;
-      paint_brush_stroke_add_step(C, op, mouse, 1.0);
+      paint_brush_stroke_add_step(C, op, stroke, mouse, 1.0);
 
       length -= spacing;
       spacing_final = spacing;
@@ -1252,8 +1247,8 @@ static void paint_stroke_line_end(bContext *C,
   if (stroke->stroke_started && (br->flag & BRUSH_LINE)) {
     stroke->ups->overlap_factor = paint_stroke_integrate_overlap(br, 1.0);
 
-    paint_brush_stroke_add_step(C, op, stroke->last_mouse_position, 1.0);
-    paint_space_stroke(C, op, mouse, 1.0);
+    paint_brush_stroke_add_step(C, op, stroke, stroke->last_mouse_position, 1.0);
+    paint_space_stroke(C, op, stroke, mouse, 1.0);
   }
 }
 
@@ -1331,7 +1326,7 @@ static bool paint_stroke_curve_end(bContext *C, wmOperator *op, PaintStroke *str
           stroke->stroke_started = stroke->test_start(C, op, stroke->last_mouse_position);
 
           if (stroke->stroke_started) {
-            paint_brush_stroke_add_step(C, op, data + 2 * j, 1.0);
+            paint_brush_stroke_add_step(C, op, stroke, data + 2 * j, 1.0);
             paint_line_strokes_spacing(
                 C, op, stroke, spacing, &length_residue, data + 2 * j, data + 2 * (j + 1));
           }
@@ -1343,7 +1338,7 @@ static bool paint_stroke_curve_end(bContext *C, wmOperator *op, PaintStroke *str
       }
     }
 
-    stroke_done(C, op);
+    stroke_done(C, op, stroke);
 
 #ifdef DEBUG_TIME
     TIMEIT_END_AVERAGED(whole_stroke);
@@ -1384,11 +1379,10 @@ static void paint_stroke_line_constrain(PaintStroke *stroke, float mouse[2])
   }
 }
 
-int paint_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
+int paint_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event, PaintStroke *stroke)
 {
   Paint *p = BKE_paint_get_active_from_context(C);
   ePaintMode mode = BKE_paintmode_get_active_from_context(C);
-  PaintStroke *stroke = op->customdata;
   Brush *br = stroke->brush = BKE_paint_brush(p);
   PaintSample sample_average;
   float mouse[2];
@@ -1482,7 +1476,7 @@ int paint_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
       op->type->cancel(C, op);
     }
     else {
-      paint_stroke_cancel(C, op);
+      paint_stroke_cancel(C, op, stroke);
     }
     return OPERATOR_CANCELLED;
   }
@@ -1492,13 +1486,13 @@ int paint_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
       copy_v2_fl2(mouse, event->mval[0], event->mval[1]);
       paint_stroke_line_constrain(stroke, mouse);
       paint_stroke_line_end(C, op, stroke, mouse);
-      stroke_done(C, op);
+      stroke_done(C, op, stroke);
       return OPERATOR_FINISHED;
     }
   }
   else if (ELEM(event->type, EVT_RETKEY, EVT_SPACEKEY)) {
     paint_stroke_line_end(C, op, stroke, sample_average.mouse);
-    stroke_done(C, op);
+    stroke_done(C, op, stroke);
     return OPERATOR_FINISHED;
   }
   else if (br->flag & BRUSH_LINE) {
@@ -1530,7 +1524,7 @@ int paint_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
     if (paint_smooth_stroke(stroke, &sample_average, mode, mouse, &pressure)) {
       if (stroke->stroke_started) {
         if (paint_space_stroke_enabled(br, mode)) {
-          if (paint_space_stroke(C, op, mouse, pressure)) {
+          if (paint_space_stroke(C, op, stroke, mouse, pressure)) {
             redraw = true;
           }
         }
@@ -1538,7 +1532,7 @@ int paint_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
           float dmouse[2];
           sub_v2_v2v2(dmouse, mouse, stroke->last_mouse_position);
           stroke->stroke_distance += len_v2(dmouse);
-          paint_brush_stroke_add_step(C, op, mouse, pressure);
+          paint_brush_stroke_add_step(C, op, stroke, mouse, pressure);
           redraw = true;
         }
       }
@@ -1549,7 +1543,7 @@ int paint_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
    * instead of waiting till we have moved the space distance */
   if (first_dab && paint_space_stroke_enabled(br, mode) && !(br->flag & BRUSH_SMOOTH_STROKE)) {
     stroke->ups->overlap_factor = paint_stroke_integrate_overlap(br, 1.0);
-    paint_brush_stroke_add_step(C, op, sample_average.mouse, sample_average.pressure);
+    paint_brush_stroke_add_step(C, op, stroke, sample_average.mouse, sample_average.pressure);
     redraw = true;
   }
 
@@ -1572,10 +1566,8 @@ int paint_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
   return OPERATOR_RUNNING_MODAL;
 }
 
-int paint_stroke_exec(bContext *C, wmOperator *op)
+int paint_stroke_exec(bContext *C, wmOperator *op, PaintStroke *stroke)
 {
-  PaintStroke *stroke = op->customdata;
-
   /* only when executed for the first time */
   if (stroke->stroke_started == 0) {
     PropertyRNA *strokeprop;
@@ -1599,14 +1591,14 @@ int paint_stroke_exec(bContext *C, wmOperator *op)
 
   bool ok = (stroke->stroke_started != 0);
 
-  stroke_done(C, op);
+  stroke_done(C, op, stroke);
 
   return ok ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
-void paint_stroke_cancel(bContext *C, wmOperator *op)
+void paint_stroke_cancel(bContext *C, wmOperator *op, PaintStroke *stroke)
 {
-  stroke_done(C, op);
+  stroke_done(C, op, stroke);
 }
 
 ViewContext *paint_stroke_view_context(PaintStroke *stroke)
diff --git a/source/blender/editors/sculpt_paint/paint_vertex.c b/source/blender/editors/sculpt_paint/paint_vertex.c
index a82636023f8..8373f028109 100644
--- a/source/blender/editors/sculpt_paint/paint_vertex.c
+++ b/source/blender/editors/sculpt_paint/paint_vertex.c
@@ -2551,7 +2551,7 @@ static int wpaint_invoke(bContext *C, wmOperator *op, const wmEvent *event)
                                     event->type);
 
   if ((retval = op->type->modal(C, op, event)) == OPERATOR_FINISHED) {
-    paint_stroke_free(C, op);
+    paint_stroke_free(C, op, op->customdata);
     return OPERATOR_FINISHED;
   }
   /* add modal handler */
@@ -2575,7 +2575,7 @@ static int wpaint_exec(bContext *C, wmOperator *op)
                                     0);
 
   /* frees op->customdata */
-  paint_stroke_exec(C, op);
+  paint_stroke_exec(C, op, op->customdata);
 
   return OPERATOR_FINISHED;
 }
@@ -2588,7 +2588,12 @@ static void wpaint_cancel(bContext *C, wmOperator *op)
     ob->sculpt->cache = NULL;
   }
 
-  paint_stroke_cancel(C, op);
+  paint_stroke_cancel(C, op, op->customdata);
+}
+
+static int wpaint_modal(bContext *C, wmOperator *op, const wmEvent *event)
+{
+  return paint_stroke_modal(C, op, event, op->customdata);
 }
 
 void PAINT_OT_weight_paint(wmOperatorType *ot)
@@ -2600,7 +2605,7 @@ void PAINT_OT_weight_paint(wmOperatorType *ot)
 
   /* api callbacks */
   ot->invoke = wpaint_invoke;
-  ot->modal = paint_stroke_modal;
+  ot->modal = wpaint_modal;
   ot->exec = wpaint_exec;
   ot->poll = weight_paint_poll;
   ot->cancel = wpaint_cancel;
@@ -3497,7 +3502,7 @@ static int vpaint_invoke(bContext *C, wmOperator *op, const wmEvent *event)
                                     event->type);
 
   if ((retval = op->type->modal(C, op, event)) == OPERATOR_FINISHED) {
-    paint_stroke_free(C, op);
+    paint_stroke_free(C, op, op->customdata);
     return OPERATOR_FINISHED;
   }
 
@@ -3522,7 +3527,7 @@ static int vpaint_exec(bContext *C, wmOperator *op)
                                     0);
 
   /* frees op->customdata */
-  paint_stroke_exec(C, op);
+  paint_stroke_exec(C, op, op->customdata);
 
   return OPERATOR_FINISHED;
 }
@@ -3535,7 +3540,12 @@ static void vpaint_cancel(bContext *C, wmOperator *op)
     ob->sculpt->cache = NULL;
   }
 
-  paint_stroke_cancel(C, op);
+  paint_stroke_cancel(C, op, op->customdata);
+}
+
+static int vpaint_modal(bContext *C, wmOperator *op, const wmEvent *event)
+{
+  return paint_stroke_modal(C, op, event, op->customdata);
 }
 
 void PAINT_OT_vertex_paint(wmOperatorType *ot)
@@ -3547,7 +3557,7 @@ void PAINT_OT_vertex_paint(wmOperatorType *ot)
 
   /* api callbacks */
   ot->invoke = vpaint_invoke;
-  ot->modal = paint_stroke_modal;
+  ot->modal = vpaint_modal;
   ot->exec = vpaint_exec;
   ot->poll = vertex_paint_poll;
   ot->cancel = vpaint_cancel;
diff --git a/source/blender/editors/sculpt_paint/sculpt.c b/source/blender/editors/sculpt_paint/sculpt.c
index 68edf9cd54a..63611b473cb 100644
--- a/source/blender/editors/sculpt_paint/sculpt.c
+++ b/source/blender/editors/sculpt_paint/sculpt.c
@@ -5333,12 +5333,12 @@ static int sculpt_brush_stroke_invoke(bContext *C, wmOperator *op, const wmEvent
   ignore_background_click = RNA_boolean_get(op->ptr, "ignore_background_click");
 
   if (ignore_background_click && !over_mesh(C, op, event->xy[0], event->xy[1])) {
-    paint_stroke_free(C, op);
+    paint_stroke_free(C, op, op->customdata);
     return OPERATOR_PASS_THROUGH;
   }
 
   if ((retval = op->type->modal(C, op, event)) == OPERATOR_FINISHED) {
-    paint_stroke_free(C, op);
+    paint_stroke_free(C, op, op->customdata);
     return OPERATOR_FINISHED;
   }
   /* Add modal handler. */
@@ -5364,7 +5364,7 @@ static int sculpt_brush_stroke_exec(bContext *C, wmOperator *op)
                                     0);
 
   /* Frees op->customdata. */
-  paint_stroke_exec(C, op);
+  paint_stroke_exec(C, op, op->customdata);
 
   return OPERATOR_FINISHED;
 }
@@ -5382,7 +5382,7 @@ static void sculpt_brush_stroke_cancel(bContext *C, wmOperator *op)
     paint_mesh_restore_co(sd, ob);
   }
 
-  paint_stroke_cancel(C, op);
+  paint_stroke_cancel(C, op, op->customdata);
 
   if (ss->cache) {
     SCULPT_cache_free(ss->cache);
@@ -5392,6 +5392,11 @@ static void sculpt_brush_stroke_cancel(bContext *C, wmOperator *op)
   sculpt_brush_exit_tex(sd);
 }
 
+static int sculpt_brush_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
+{
+  return paint_stroke_modal(C, op, event, op->customdata);
+}
+
 void SCULPT_OT_brush_stroke(wmOperatorType *ot)
 {
   /* Identifiers. */
@@ -5401,7 +5406,7 @@ void SCULPT_OT_brush_stroke(wmOperatorType *ot)
 
   /* API callbacks. */
   ot->invoke = sculpt_brush_stroke_invoke;
-  ot->modal = paint_stroke_modal;
+  ot->modal = sculpt_brush_stroke_modal;
   ot->exec = sculpt_brush_stroke_exec;
   ot->poll = SCULPT_poll;
   ot->cancel = sculpt_brush_stroke_cancel;