Don't store PBVH locally, but always read from sculptsession.

Still early development, nothing working yet.

source/blender/editors/sculpt_paint/CMakeLists.txt

@@ -33,6 +33,7 @@ set(SRC
   paint_image_ops_paint.cc
   paint_image_2d.c
   paint_image_2d_curve_mask.cc
+  paint_image_3d.cc
   paint_image_proj.c
   paint_mask.c
   paint_ops.c

source/blender/editors/sculpt_paint/paint_image_3d.cc

@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2022 Blender Foundation. All rights reserved. */
+
+/** \file
+ * \ingroup edsculpt
+ * \brief 3D perspective painting.
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "DNA_mesh_types.h"
+#include "DNA_meshdata_types.h"
+#include "DNA_object_types.h"
+#include "DNA_scene_types.h"
+
+#include "DEG_depsgraph.h"
+#include "DEG_depsgraph_query.h"
+
+#include "BKE_context.h"
+#include "BKE_mesh.h"
+#include "BKE_object.h"
+#include "BKE_paint.h"
+#include "BKE_pbvh.h"
+
+#include "BLI_math.h"
+
+#include "paint_image_3d.hh"
+
+#include "CLG_log.h"
+
+static CLG_LogRef LOG = {"ed.sculpt_paint.image3d"};
+
+namespace blender::ed::sculpt_paint::image3d {
+
+struct StrokeHandle {
+  Object *ob = nullptr;
+  Image *image = nullptr;
+
+  virtual ~StrokeHandle()
+  {
+    image = nullptr;
+    ob = nullptr;
+  }
+
+  PBVH *get_pbvh()
+  {
+    BLI_assert(ob != nullptr);
+    BLI_assert(ob->sculpt != nullptr);
+    BLI_assert(ob->sculpt->pbvh != nullptr);
+    return ob->sculpt->pbvh;
+  }
+};
+
+struct StrokeHandle *stroke_new(bContext *C, Object *ob)
+{
+  CLOG_INFO(&LOG, 2, "create new stroke");
+  Depsgraph *depsgraph = CTX_data_depsgraph_pointer(C);
+
+  ToolSettings *ts = CTX_data_tool_settings(C);
+  BLI_assert_msg(ts->imapaint.mode == IMAGEPAINT_MODE_IMAGE, "Only Image mode implemented");
+  Image *image = ts->imapaint.canvas;
+  CLOG_INFO(&LOG, 2, " paint target image: %s", image->id.name);
+
+  if (ob->sculpt == nullptr) {
+    BKE_object_sculpt_data_create(ob);
+  }
+  PBVH *pbvh = BKE_sculpt_object_pbvh_ensure(depsgraph, ob);
+  BLI_assert_msg(pbvh != nullptr, "Unable to retrieve PBVH from sculptsession");
+
+  StrokeHandle *stroke_handle = MEM_new<StrokeHandle>("StrokeHandle");
+  stroke_handle->image = image;
+  stroke_handle->ob = ob;
+
+  return stroke_handle;
+}
+
+void stroke_update(struct StrokeHandle *stroke_handle, float2 prev_mouse, float2 mouse)
+{
+  CLOG_INFO(&LOG, 2, "new stroke step");
+  // See SCULPT_do_paint_brush?
+}
+
+void stroke_free(struct StrokeHandle *stroke_handle)
+{
+  CLOG_INFO(&LOG, 2, "free stroke");
+  MEM_delete(stroke_handle);
+}
+
+}  // namespace blender::ed::sculpt_paint::image3d

source/blender/editors/sculpt_paint/paint_image_3d.hh

@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2022 Blender Foundation. All rights reserved. */
+
+/** \file
+ * \ingroup edsculpt
+ */
+
+#pragma once
+
+extern "C" {
+/* Forward declarations. */
+struct bContext;
+struct Object;
+}
+
+#include "BLI_math_vec_types.hh"
+
+namespace blender::ed::sculpt_paint::image3d {
+struct StrokeHandle;
+
+struct StrokeHandle *stroke_new(bContext *C, Object *ob);
+void stroke_update(struct StrokeHandle *stroke_handle, float2 prev_mouse, float2 mouse);
+void stroke_free(struct StrokeHandle *stroke_handle);
+
+}  // namespace blender::ed::sculpt_paint::image3d

source/blender/editors/sculpt_paint/paint_image_ops_paint.cc

@@ -36,6 +36,8 @@
 
 #include "paint_intern.h"
 
+#include "paint_image_3d.hh"
+
 namespace blender::ed::sculpt_paint::image::ops::paint {
 
 /**
@@ -211,6 +213,57 @@ class ProjectionPaintMode : public AbstractPaintMode {
   }
 };
 
+class PerspectivePaintMode : public AbstractPaintMode {
+
+ public:
+  void *paint_new_stroke(
+      bContext *C, wmOperator *UNUSED(op), Object *ob, const float mouse[2], int mode) override
+  {
+    return image3d::stroke_new(C, ob);
+  }
+
+  void paint_stroke(bContext *C,
+                    void *stroke_handle,
+                    float prev_mouse[2],
+                    float mouse[2],
+                    int eraser,
+                    float pressure,
+                    float distance,
+                    float size) override
+  {
+    image3d::stroke_update(static_cast<image3d::StrokeHandle *>(stroke_handle), prev_mouse, mouse);
+  };
+
+  void paint_stroke_redraw(const bContext *C, void *stroke_handle, bool final) override
+  {
+  }
+
+  void paint_stroke_done(void *stroke_handle) override
+  {
+    image3d::stroke_free(static_cast<image3d::StrokeHandle *>(stroke_handle));
+  }
+
+  void paint_gradient_fill(const bContext *C,
+                           const Scene *scene,
+                           Brush *brush,
+                           struct PaintStroke *stroke,
+                           void *stroke_handle,
+                           float mouse_start[2],
+                           float mouse_end[2]) override
+  {
+  }
+
+  void paint_bucket_fill(const bContext *C,
+                         const Scene *scene,
+                         Brush *brush,
+                         struct PaintStroke *stroke,
+                         void *stroke_handle,
+                         float mouse_start[2],
+                         float mouse_end[2]) override
+  {
+  }
+};
+
 struct PaintOperation {
   AbstractPaintMode *mode = nullptr;
 
@@ -301,7 +354,13 @@ static PaintOperation *texture_paint_init(bContext *C, wmOperator *op, const flo
       WM_event_add_notifier(C, NC_SCENE | ND_TOOLSETTINGS, nullptr);
       return nullptr;
     }
+
+/* Set to 1 to switch back to original implementation. */
+#if 0
     pop->mode = MEM_new<ProjectionPaintMode>("ProjectionPaintMode");
+#else
+    pop->mode = MEM_new<PerspectivePaintMode>("PerspectivePaintMode");
+#endif
   }
   else {
     pop->mode = MEM_new<ImagePaintMode>("ImagePaintMode");

source/blender/editors/util/ed_util.c

@@ -154,6 +154,9 @@ void ED_editors_init(bContext *C)
         else if (mode == OB_MODE_WEIGHT_PAINT) {
           ED_object_wpaintmode_enter_ex(bmain, depsgraph, scene, ob);
         }
+        else if (mode == OB_MODE_TEXTURE_PAINT) {
+          ED_object_texture_paint_mode_enter_ex(bmain, scene, ob);
+        }
         else {
           BLI_assert_unreachable();
         }

source/blender/makesdna/DNA_object_enums.h

@@ -49,7 +49,8 @@ typedef enum eDrawType {
    OB_MODE_VERTEX_GPENCIL)
 
 /** Any mode that uses Object.sculpt. */
-#define OB_MODE_ALL_SCULPT (OB_MODE_SCULPT | OB_MODE_VERTEX_PAINT | OB_MODE_WEIGHT_PAINT)
+#define OB_MODE_ALL_SCULPT \
+  (OB_MODE_SCULPT | OB_MODE_VERTEX_PAINT | OB_MODE_WEIGHT_PAINT | OB_MODE_TEXTURE_PAINT)
 
 /** Any mode that uses weightpaint. */
 #define OB_MODE_ALL_WEIGHT_PAINT (OB_MODE_WEIGHT_PAINT | OB_MODE_WEIGHT_GPENCIL)