Cleanup: Split paint_canvas into BKE and ED.

The BKE part is needed for the 3d texture paiting brush to be part of blender
kernel.

3 files changed, 98 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_paint.h b/source/blender/blenkernel/BKE_paint.h
index 1b296277b8f..db773d34cdc 100644
--- a/source/blender/blenkernel/BKE_paint.h
+++ b/source/blender/blenkernel/BKE_paint.h
@@ -42,6 +42,7 @@ struct Object;
 struct PBVH;
 struct Paint;
 struct PaintCurve;
+struct PaintModeSettings;
 struct Palette;
 struct PaletteColor;
 struct Scene;
@@ -725,6 +726,12 @@ enum {
   SCULPT_MASK_LAYER_CALC_LOOP = (1 << 1),
 };
 
+/* paint_canvas.cc */
+struct Image *BKE_paint_canvas_image_get(const struct PaintModeSettings *settings,
+                                         struct Object *ob);
+int BKE_paint_canvas_uvmap_layer_index_get(const struct PaintModeSettings *settings,
+                                           struct Object *ob);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/blenkernel/CMakeLists.txt b/source/blender/blenkernel/CMakeLists.txt
index aca8cdf916e..c8af4bb69b8 100644
--- a/source/blender/blenkernel/CMakeLists.txt
+++ b/source/blender/blenkernel/CMakeLists.txt
@@ -235,6 +235,7 @@ set(SRC
   intern/outliner_treehash.c
   intern/packedFile.c
   intern/paint.c
+  intern/paint_canvas.cc
   intern/paint_toolslots.c
   intern/particle.c
   intern/particle_child.c
diff --git a/source/blender/blenkernel/intern/paint_canvas.cc b/source/blender/blenkernel/intern/paint_canvas.cc
new file mode 100644
index 00000000000..c1145164642
--- /dev/null
+++ b/source/blender/blenkernel/intern/paint_canvas.cc
@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#include "BLI_compiler_compat.h"
+
+#include "DNA_material_types.h"
+#include "DNA_mesh_types.h"
+#include "DNA_scene_types.h"
+
+#include "BKE_customdata.h"
+#include "BKE_material.h"
+#include "BKE_paint.h"
+
+namespace blender::bke::paint::canvas {
+static TexPaintSlot *get_active_slot(Object *ob)
+{
+  Material *mat = BKE_object_material_get(ob, ob->actcol);
+  if (mat == nullptr) {
+    return nullptr;
+  }
+  if (mat->texpaintslot == nullptr) {
+    return nullptr;
+  }
+  if (mat->paint_active_slot >= mat->tot_slots) {
+    return nullptr;
+  }
+
+  TexPaintSlot *slot = &mat->texpaintslot[mat->paint_active_slot];
+  return slot;
+}
+
+}  // namespace blender::bke::paint::canvas
+
+extern "C" {
+
+using namespace blender::bke::paint::canvas;
+
+Image *BKE_paint_canvas_image_get(const struct PaintModeSettings *settings, struct Object *ob)
+{
+  switch (settings->canvas_source) {
+    case PAINT_CANVAS_SOURCE_COLOR_ATTRIBUTE:
+      return nullptr;
+    case PAINT_CANVAS_SOURCE_IMAGE:
+      return settings->canvas_image;
+    case PAINT_CANVAS_SOURCE_MATERIAL: {
+      TexPaintSlot *slot = get_active_slot(ob);
+      if (slot == nullptr) {
+        break;
+      }
+      return slot->ima;
+    }
+  }
+  return nullptr;
+}
+
+int BKE_paint_canvas_uvmap_layer_index_get(const struct PaintModeSettings *settings,
+                                           struct Object *ob)
+{
+  switch (settings->canvas_source) {
+    case PAINT_CANVAS_SOURCE_COLOR_ATTRIBUTE:
+      return -1;
+    case PAINT_CANVAS_SOURCE_IMAGE: {
+      /* Use active uv map of the object. */
+      if (ob->type != OB_MESH) {
+        return -1;
+      }
+
+      const Mesh *mesh = static_cast<Mesh *>(ob->data);
+      return CustomData_get_active_layer_index(&mesh->ldata, CD_MLOOPUV);
+    }
+    case PAINT_CANVAS_SOURCE_MATERIAL: {
+      /* Use uv map of the canvas. */
+      TexPaintSlot *slot = get_active_slot(ob);
+      if (slot == nullptr) {
+        break;
+      }
+
+      if (ob->type != OB_MESH) {
+        return -1;
+      }
+
+      if (slot->uvname == nullptr) {
+        return -1;
+      }
+
+      const Mesh *mesh = static_cast<Mesh *>(ob->data);
+      return CustomData_get_named_layer_index(&mesh->ldata, CD_MLOOPUV, slot->uvname);
+    }
+  }
+  return -1;
+}
+}