Merge branch 'master' into temp-ui-button-type-refactortemp-ui-button-type-refactor

46 files changed, 822 insertions, 836 deletions

diff --git a/source/blender/windowmanager/WM_api.h b/source/blender/windowmanager/WM_api.h
index 482589e2ccb..07746af4b60 100644
--- a/source/blender/windowmanager/WM_api.h
+++ b/source/blender/windowmanager/WM_api.h
@@ -16,8 +16,7 @@
  * The Original Code is Copyright (C) 2007 Blender Foundation.
  * All rights reserved.
  */
-#ifndef __WM_API_H__
-#define __WM_API_H__
+#pragma once
 
 /** \file
  * \ingroup wm
@@ -99,7 +98,7 @@ void WM_main(struct bContext *C) ATTR_NORETURN;
 
 void WM_init_splash(struct bContext *C);
 
-void WM_init_opengl(struct Main *bmain);
+void WM_init_opengl(void);
 
 void WM_check(struct bContext *C);
 void WM_reinit_gizmomap_all(struct Main *bmain);
@@ -744,8 +743,13 @@ void *WM_jobs_customdata_get(struct wmJob *);
 void WM_jobs_customdata_set(struct wmJob *, void *customdata, void (*free)(void *));
 void WM_jobs_timer(struct wmJob *, double timestep, unsigned int note, unsigned int endnote);
 void WM_jobs_delay_start(struct wmJob *, double delay_time);
+
+typedef void (*wm_jobs_start_callback)(void *custom_data,
+                                       short *stop,
+                                       short *do_update,
+                                       float *progress);
 void WM_jobs_callbacks(struct wmJob *,
-                       void (*startjob)(void *, short *, short *, float *),
+                       wm_jobs_start_callback startjob,
                        void (*initjob)(void *),
                        void (*update)(void *),
                        void (*endjob)(void *));
@@ -899,5 +903,3 @@ bool WM_xr_session_state_viewer_pose_matrix_info_get(const wmXrData *xr,
 #ifdef __cplusplus
 }
 #endif
-
-#endif /* __WM_API_H__ */
diff --git a/source/blender/windowmanager/WM_keymap.h b/source/blender/windowmanager/WM_keymap.h
index 53a3fd5ebda..15be21bdbc4 100644
--- a/source/blender/windowmanager/WM_keymap.h
+++ b/source/blender/windowmanager/WM_keymap.h
@@ -17,8 +17,7 @@
  * All rights reserved.
  */
 
-#ifndef __WM_KEYMAP_H__
-#define __WM_KEYMAP_H__
+#pragma once
 
 /** \file
  * \ingroup wm
@@ -194,5 +193,3 @@ const char *WM_bool_as_string(bool test);
 #ifdef __cplusplus
 }
 #endif
-
-#endif /* __WM_KEYMAP_H__ */
diff --git a/source/blender/windowmanager/WM_message.h b/source/blender/windowmanager/WM_message.h
index 1527d514e9b..25d5bae392b 100644
--- a/source/blender/windowmanager/WM_message.h
+++ b/source/blender/windowmanager/WM_message.h
@@ -18,9 +18,6 @@
  * \ingroup wm
  */
 
-#ifndef __WM_MESSAGE_H__
-#define __WM_MESSAGE_H__
+#pragma once
 
 #include "message_bus/wm_message_bus.h"
-
-#endif /* __WM_MESSAGE_H__ */
diff --git a/source/blender/windowmanager/WM_toolsystem.h b/source/blender/windowmanager/WM_toolsystem.h
index 163f37be974..13d1666dc95 100644
--- a/source/blender/windowmanager/WM_toolsystem.h
+++ b/source/blender/windowmanager/WM_toolsystem.h
@@ -13,8 +13,7 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
-#ifndef __WM_TOOLSYSTEM_H__
-#define __WM_TOOLSYSTEM_H__
+#pragma once
 
 /** \file
  * \ingroup wm
@@ -140,5 +139,3 @@ void WM_toolsystem_refresh_screen_all(struct Main *bmain);
 #ifdef __cplusplus
 }
 #endif
-
-#endif /* __WM_TOOLSYSTEM_API_H__ */
diff --git a/source/blender/windowmanager/WM_types.h b/source/blender/windowmanager/WM_types.h
index 4acce793707..efe600a846a 100644
--- a/source/blender/windowmanager/WM_types.h
+++ b/source/blender/windowmanager/WM_types.h
@@ -106,8 +106,7 @@
  * \endcode
  */
 
-#ifndef __WM_TYPES_H__
-#define __WM_TYPES_H__
+#pragma once
 
 struct ID;
 struct ImBuf;
@@ -361,6 +360,7 @@ typedef struct wmNotifier {
 #define ND_LOD (30 << 16)
 #define ND_DRAW_RENDER_VIEWPORT \
   (31 << 16) /* for camera & sequencer viewport update, also /w NC_SCENE */
+#define ND_SHADERFX (32 << 16)
 
 /* NC_MATERIAL Material */
 #define ND_SHADING (30 << 16)
@@ -927,5 +927,3 @@ extern struct CLG_LogRef *WM_LOG_MSGBUS_SUB;
 #ifdef __cplusplus
 }
 #endif
-
-#endif /* __WM_TYPES_H__ */
diff --git a/source/blender/windowmanager/gizmo/WM_gizmo_api.h b/source/blender/windowmanager/gizmo/WM_gizmo_api.h
index 07a3f0445bb..a4412ecce5c 100644
--- a/source/blender/windowmanager/gizmo/WM_gizmo_api.h
+++ b/source/blender/windowmanager/gizmo/WM_gizmo_api.h
@@ -26,8 +26,7 @@
  * Only included in WM_api.h
  */
 
-#ifndef __WM_GIZMO_API_H__
-#define __WM_GIZMO_API_H__
+#pragma once
 
 struct ARegion;
 struct GHashIterator;
@@ -52,6 +51,10 @@ struct wmWindowManager;
 
 #include "wm_gizmo_fn.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* -------------------------------------------------------------------- */
 /* wmGizmo */
 
@@ -396,4 +399,6 @@ void WM_gizmo_group_tag_remove(struct wmGizmoGroup *gzgroup);
 bool WM_gizmo_group_type_poll(const struct bContext *C, const struct wmGizmoGroupType *gzgt);
 void WM_gizmo_group_refresh(const struct bContext *C, struct wmGizmoGroup *gzgroup);
 
-#endif /* __WM_GIZMO_API_H__ */
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/windowmanager/gizmo/WM_gizmo_types.h b/source/blender/windowmanager/gizmo/WM_gizmo_types.h
index 3863e3bd797..bddf54b846f 100644
--- a/source/blender/windowmanager/gizmo/WM_gizmo_types.h
+++ b/source/blender/windowmanager/gizmo/WM_gizmo_types.h
@@ -26,8 +26,7 @@
  * Only included in WM_types.h and lower level files.
  */
 
-#ifndef __WM_GIZMO_TYPES_H__
-#define __WM_GIZMO_TYPES_H__
+#pragma once
 
 #include "BLI_compiler_attrs.h"
 
@@ -40,6 +39,10 @@ struct wmKeyConfig;
 
 #include "DNA_listBase.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* -------------------------------------------------------------------- */
 /* Enum Typedef's */
 
@@ -506,4 +509,6 @@ typedef enum eWM_GizmoFlagMapDrawStep {
 } eWM_GizmoFlagMapDrawStep;
 #define WM_GIZMOMAP_DRAWSTEP_MAX 2
 
-#endif /* __WM_GIZMO_TYPES_H__ */
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/windowmanager/gizmo/intern/wm_gizmo.c b/source/blender/windowmanager/gizmo/intern/wm_gizmo.c
index e687af15982..87cb4d5f584 100644
--- a/source/blender/windowmanager/gizmo/intern/wm_gizmo.c
+++ b/source/blender/windowmanager/gizmo/intern/wm_gizmo.c
@@ -29,7 +29,6 @@
 #include "BKE_context.h"
 
 #include "GPU_batch.h"
-#include "GPU_glew.h"
 
 #include "RNA_access.h"
 #include "RNA_define.h"
@@ -453,9 +452,7 @@ bool wm_gizmo_select_and_highlight(bContext *C, wmGizmoMap *gzmap, wmGizmo *gz)
     wm_gizmomap_highlight_set(gzmap, C, gz, gz->highlight_part);
     return true;
   }
-  else {
-    return false;
-  }
+  return false;
 }
 
 /**
diff --git a/source/blender/windowmanager/gizmo/intern/wm_gizmo_group.c b/source/blender/windowmanager/gizmo/intern/wm_gizmo_group.c
index 67f30f0d7ee..b64d544962d 100644
--- a/source/blender/windowmanager/gizmo/intern/wm_gizmo_group.c
+++ b/source/blender/windowmanager/gizmo/intern/wm_gizmo_group.c
@@ -166,12 +166,10 @@ int WM_gizmo_cmp_temp_fl(const void *gz_a_ptr, const void *gz_b_ptr)
   if (gz_a->temp.f < gz_b->temp.f) {
     return -1;
   }
-  else if (gz_a->temp.f > gz_b->temp.f) {
+  if (gz_a->temp.f > gz_b->temp.f) {
     return 1;
   }
-  else {
-    return 0;
-  }
+  return 0;
 }
 
 int WM_gizmo_cmp_temp_fl_reverse(const void *gz_a_ptr, const void *gz_b_ptr)
@@ -181,12 +179,10 @@ int WM_gizmo_cmp_temp_fl_reverse(const void *gz_a_ptr, const void *gz_b_ptr)
   if (gz_a->temp.f < gz_b->temp.f) {
     return 1;
   }
-  else if (gz_a->temp.f > gz_b->temp.f) {
+  if (gz_a->temp.f > gz_b->temp.f) {
     return -1;
   }
-  else {
-    return 0;
-  }
+  return 0;
 }
 
 static bool wm_gizmo_keymap_uses_event_modifier(wmWindowManager *wm,
@@ -396,10 +392,9 @@ static int gizmo_select_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSE
 
     return OPERATOR_FINISHED;
   }
-  else {
-    BLI_assert(0);
-    return (OPERATOR_CANCELLED | OPERATOR_PASS_THROUGH);
-  }
+
+  BLI_assert(0);
+  return (OPERATOR_CANCELLED | OPERATOR_PASS_THROUGH);
 }
 
 void GIZMOGROUP_OT_gizmo_select(wmOperatorType *ot)
@@ -476,9 +471,7 @@ static bool gizmo_tweak_start_and_finish(
     }
     return true;
   }
-  else {
-    return false;
-  }
+  return false;
 }
 
 static void gizmo_tweak_finish(bContext *C, wmOperator *op, const bool cancel, bool clear_modal)
diff --git a/source/blender/windowmanager/gizmo/intern/wm_gizmo_intern.h b/source/blender/windowmanager/gizmo/intern/wm_gizmo_intern.h
index 00df6edef22..953722f28e9 100644
--- a/source/blender/windowmanager/gizmo/intern/wm_gizmo_intern.h
+++ b/source/blender/windowmanager/gizmo/intern/wm_gizmo_intern.h
@@ -18,8 +18,7 @@
  * \ingroup wm
  */
 
-#ifndef __WM_GIZMO_INTERN_H__
-#define __WM_GIZMO_INTERN_H__
+#pragma once
 
 struct BLI_Buffer;
 struct wmGizmoMap;
@@ -142,5 +141,3 @@ bool wm_gizmomap_deselect_all(struct wmGizmoMap *gzmap);
 void wm_gizmomap_select_array_shrink(struct wmGizmoMap *gzmap, int len_subtract);
 void wm_gizmomap_select_array_push_back(struct wmGizmoMap *gzmap, wmGizmo *gz);
 void wm_gizmomap_select_array_remove(struct wmGizmoMap *gzmap, wmGizmo *gz);
-
-#endif
diff --git a/source/blender/windowmanager/gizmo/intern/wm_gizmo_map.c b/source/blender/windowmanager/gizmo/intern/wm_gizmo_map.c
index 6ed6c485e89..cecd324ff28 100644
--- a/source/blender/windowmanager/gizmo/intern/wm_gizmo_map.c
+++ b/source/blender/windowmanager/gizmo/intern/wm_gizmo_map.c
@@ -38,7 +38,6 @@
 #include "ED_select_utils.h"
 #include "ED_view3d.h"
 
-#include "GPU_glew.h"
 #include "GPU_matrix.h"
 #include "GPU_select.h"
 #include "GPU_state.h"
@@ -264,11 +263,10 @@ bool WM_gizmomap_minmax(const wmGizmoMap *gzmap,
     }
     return i != 0;
   }
-  else {
-    bool ok = false;
-    BLI_assert(!"TODO");
-    return ok;
-  }
+
+  bool ok = false;
+  BLI_assert(!"TODO");
+  return ok;
 }
 
 /**
@@ -548,7 +546,7 @@ static void gizmo_draw_select_3d_loop(const bContext *C,
       /* pass */
     }
     else {
-      glDepthMask(!is_depth_skip);
+      GPU_depth_mask(!is_depth_skip);
       is_depth_skip_prev = is_depth_skip;
     }
 
@@ -565,7 +563,7 @@ static void gizmo_draw_select_3d_loop(const bContext *C,
     GPU_depth_test(false);
   }
   if (is_depth_skip_prev) {
-    glDepthMask(true);
+    GPU_depth_mask(true);
   }
 }
 
@@ -582,7 +580,7 @@ static int gizmo_find_intersected_3d_intern(wmGizmo **visible_gizmos,
   Depsgraph *depsgraph = CTX_data_depsgraph_pointer(C);
   rcti rect;
   /* Almost certainly overkill, but allow for many custom gizmos. */
-  GLuint buffer[MAXPICKBUF];
+  uint buffer[MAXPICKBUF];
   short hits;
 
   BLI_rcti_init_pt_radius(&rect, co, hotspot);
@@ -625,7 +623,7 @@ static int gizmo_find_intersected_3d_intern(wmGizmo **visible_gizmos,
 
     GPU_matrix_unproject_with_precalc(&unproj_precalc, co_screen, co_3d_origin);
 
-    GLuint *buf_iter = buffer;
+    uint *buf_iter = buffer;
     int hit_found = -1;
     float dot_best = FLT_MAX;
 
@@ -648,10 +646,9 @@ static int gizmo_find_intersected_3d_intern(wmGizmo **visible_gizmos,
     }
     return hit_found;
   }
-  else {
-    const GLuint *hit_near = GPU_select_buffer_near(buffer, hits);
-    return hit_near ? hit_near[3] : -1;
-  }
+
+  const uint *hit_near = GPU_select_buffer_near(buffer, hits);
+  return hit_near ? hit_near[3] : -1;
 }
 
 /**
diff --git a/source/blender/windowmanager/gizmo/intern/wm_gizmo_target_props.c b/source/blender/windowmanager/gizmo/intern/wm_gizmo_target_props.c
index 2dc03d1419c..b056ed40943 100644
--- a/source/blender/windowmanager/gizmo/intern/wm_gizmo_target_props.c
+++ b/source/blender/windowmanager/gizmo/intern/wm_gizmo_target_props.c
@@ -70,9 +70,7 @@ wmGizmoProperty *WM_gizmo_target_property_find(wmGizmo *gz, const char *idname)
   if (index != -1) {
     return WM_gizmo_target_property_at_index(gz, index);
   }
-  else {
-    return NULL;
-  }
+  return NULL;
 }
 
 void WM_gizmo_target_property_def_rna_ptr(wmGizmo *gz,
@@ -195,9 +193,7 @@ float WM_gizmo_target_property_float_get(const wmGizmo *gz, wmGizmoProperty *gz_
   if (gz_prop->index == -1) {
     return RNA_property_float_get(&gz_prop->ptr, gz_prop->prop);
   }
-  else {
-    return RNA_property_float_get_index(&gz_prop->ptr, gz_prop->prop, gz_prop->index);
-  }
+  return RNA_property_float_get_index(&gz_prop->ptr, gz_prop->prop, gz_prop->index);
 }
 
 void WM_gizmo_target_property_float_set(bContext *C,
@@ -255,9 +251,7 @@ bool WM_gizmo_target_property_float_range_get(const wmGizmo *gz,
       gz_prop->custom_func.range_get_fn(gz, gz_prop, range);
       return true;
     }
-    else {
-      return false;
-    }
+    return false;
   }
 
   float step, precision;
diff --git a/source/blender/windowmanager/gizmo/wm_gizmo_fn.h b/source/blender/windowmanager/gizmo/wm_gizmo_fn.h
index 58b58fa01d0..418e848e35b 100644
--- a/source/blender/windowmanager/gizmo/wm_gizmo_fn.h
+++ b/source/blender/windowmanager/gizmo/wm_gizmo_fn.h
@@ -20,13 +20,16 @@
  * Callback function definitions, needed for both Types & API headers.
  */
 
-#ifndef __WM_GIZMO_FN_H__
-#define __WM_GIZMO_FN_H__
+#pragma once
 
 #include "BLI_compiler_attrs.h"
 
 struct wmMsgBus;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* wmGizmoGroup */
 typedef bool (*wmGizmoGroupFnPoll)(const struct bContext *,
                                    struct wmGizmoGroupType *) ATTR_WARN_UNUSED_RESULT;
@@ -85,4 +88,6 @@ typedef struct wmGizmoPropertyFnParams {
   void *user_data;
 } wmGizmoPropertyFnParams;
 
-#endif /* __WM_GIZMO_FN_H__ */
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/windowmanager/gizmo/wm_gizmo_wmapi.h b/source/blender/windowmanager/gizmo/wm_gizmo_wmapi.h
index cc9ccc5f4bb..18b3f40aba6 100644
--- a/source/blender/windowmanager/gizmo/wm_gizmo_wmapi.h
+++ b/source/blender/windowmanager/gizmo/wm_gizmo_wmapi.h
@@ -28,14 +28,17 @@
  * Only included in wm.h and lower level files.
  */
 
-#ifndef __WM_GIZMO_WMAPI_H__
-#define __WM_GIZMO_WMAPI_H__
+#pragma once
 
 struct wmEventHandler_Gizmo;
 struct wmEventHandler_Op;
 struct wmGizmoMap;
 struct wmOperatorType;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* -------------------------------------------------------------------- */
 /* wmGizmo */
 
@@ -92,4 +95,6 @@ struct ListBase *wm_gizmomap_groups_get(wmGizmoMap *gzmap);
 
 void wm_gizmomaptypes_free(void);
 
-#endif /* __WM_GIZMO_WMAPI_H__ */
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/windowmanager/intern/wm.c b/source/blender/windowmanager/intern/wm.c
index 2112477e62a..43c08a2b980 100644
--- a/source/blender/windowmanager/intern/wm.c
+++ b/source/blender/windowmanager/intern/wm.c
@@ -293,7 +293,7 @@ void WM_keyconfig_init(bContext *C)
 
   /* initialize only after python init is done, for keymaps that
    * use python operators */
-  if (CTX_py_init_get(C) && (wm->initialized & WM_KEYCONFIG_IS_INITIALIZED) == 0) {
+  if (CTX_py_init_get(C) && (wm->initialized & WM_KEYCONFIG_IS_INIT) == 0) {
     /* create default key config, only initialize once,
      * it's persistent across sessions */
     if (!(wm->defaultconf->flag & KEYCONF_INIT_DEFAULT)) {
@@ -308,7 +308,7 @@ void WM_keyconfig_init(bContext *C)
     WM_keyconfig_update_tag(NULL, NULL);
     WM_keyconfig_update(wm);
 
-    wm->initialized |= WM_KEYCONFIG_IS_INITIALIZED;
+    wm->initialized |= WM_KEYCONFIG_IS_INIT;
   }
 }
 
@@ -334,7 +334,7 @@ void WM_check(bContext *C)
 
   if (!G.background) {
     /* case: fileread */
-    if ((wm->initialized & WM_WINDOW_IS_INITIALIZED) == 0) {
+    if ((wm->initialized & WM_WINDOW_IS_INIT) == 0) {
       WM_keyconfig_init(C);
       WM_autosave_init(wm);
     }
@@ -345,9 +345,9 @@ void WM_check(bContext *C)
 
   /* case: fileread */
   /* note: this runs in bg mode to set the screen context cb */
-  if ((wm->initialized & WM_WINDOW_IS_INITIALIZED) == 0) {
-    ED_screens_initialize(bmain, wm);
-    wm->initialized |= WM_WINDOW_IS_INITIALIZED;
+  if ((wm->initialized & WM_WINDOW_IS_INIT) == 0) {
+    ED_screens_init(bmain, wm);
+    wm->initialized |= WM_WINDOW_IS_INIT;
   }
 }
 
diff --git a/source/blender/windowmanager/intern/wm_cursors.c b/source/blender/windowmanager/intern/wm_cursors.c
index 2af68956923..08d6df340d0 100644
--- a/source/blender/windowmanager/intern/wm_cursors.c
+++ b/source/blender/windowmanager/intern/wm_cursors.c
@@ -319,15 +319,15 @@ bool wm_cursor_arrow_move(wmWindow *win, const wmEvent *event)
       wm_cursor_warp_relative(win, 0, fac);
       return 1;
     }
-    else if (event->type == EVT_DOWNARROWKEY) {
+    if (event->type == EVT_DOWNARROWKEY) {
       wm_cursor_warp_relative(win, 0, -fac);
       return 1;
     }
-    else if (event->type == EVT_LEFTARROWKEY) {
+    if (event->type == EVT_LEFTARROWKEY) {
       wm_cursor_warp_relative(win, -fac, 0);
       return 1;
     }
-    else if (event->type == EVT_RIGHTARROWKEY) {
+    if (event->type == EVT_RIGHTARROWKEY) {
       wm_cursor_warp_relative(win, fac, 0);
       return 1;
     }
diff --git a/source/blender/windowmanager/intern/wm_dragdrop.c b/source/blender/windowmanager/intern/wm_dragdrop.c
index ad3fc7a1302..ec18a401fa4 100644
--- a/source/blender/windowmanager/intern/wm_dragdrop.c
+++ b/source/blender/windowmanager/intern/wm_dragdrop.c
@@ -39,7 +39,6 @@
 #include "BKE_context.h"
 #include "BKE_idtype.h"
 
-#include "GPU_glew.h"
 #include "GPU_shader.h"
 #include "GPU_state.h"
 #include "GPU_viewport.h"
@@ -297,7 +296,7 @@ void WM_drag_add_ID(wmDrag *drag, ID *id, ID *from_parent)
       }
       return;
     }
-    else if (GS(drag_id->id->name) != GS(id->name)) {
+    if (GS(drag_id->id->name) != GS(id->name)) {
       BLI_assert(!"All dragged IDs must have the same type");
       return;
     }
@@ -356,7 +355,7 @@ static const char *wm_drag_name(wmDrag *drag)
       if (single) {
         return id->name + 2;
       }
-      else if (id) {
+      if (id) {
         return BKE_idtype_idcode_to_name_plural(GS(id->name));
       }
       break;
@@ -424,9 +423,8 @@ void wm_drags_draw(bContext *C, wmWindow *win, rcti *rect)
                                y,
                                drag->imb->x,
                                drag->imb->y,
-                               GL_RGBA,
-                               GL_UNSIGNED_BYTE,
-                               GL_NEAREST,
+                               GPU_RGBA8,
+                               false,
                                drag->imb->rect,
                                drag->scale,
                                drag->scale,
diff --git a/source/blender/windowmanager/intern/wm_draw.c b/source/blender/windowmanager/intern/wm_draw.c
index 2b679dfefde..fe4c98394a3 100644
--- a/source/blender/windowmanager/intern/wm_draw.c
+++ b/source/blender/windowmanager/intern/wm_draw.c
@@ -51,7 +51,7 @@
 #include "ED_screen.h"
 #include "ED_view3d.h"
 
-#include "GPU_draw.h"
+#include "GPU_context.h"
 #include "GPU_framebuffer.h"
 #include "GPU_immediate.h"
 #include "GPU_state.h"
@@ -106,11 +106,11 @@ static void wm_paintcursor_draw(bContext *C, ScrArea *area, ARegion *region)
 
       if (pc->poll == NULL || pc->poll(C)) {
         /* Prevent drawing outside region. */
-        glEnable(GL_SCISSOR_TEST);
-        glScissor(region->winrct.xmin,
-                  region->winrct.ymin,
-                  BLI_rcti_size_x(&region->winrct) + 1,
-                  BLI_rcti_size_y(&region->winrct) + 1);
+        GPU_scissor_test(true);
+        GPU_scissor(region->winrct.xmin,
+                    region->winrct.ymin,
+                    BLI_rcti_size_x(&region->winrct) + 1,
+                    BLI_rcti_size_y(&region->winrct) + 1);
 
         if (ELEM(win->grabcursor, GHOST_kGrabWrap, GHOST_kGrabHide)) {
           int x = 0, y = 0;
@@ -121,7 +121,7 @@ static void wm_paintcursor_draw(bContext *C, ScrArea *area, ARegion *region)
           pc->draw(C, win->eventstate->x, win->eventstate->y, pc->customdata);
         }
 
-        glDisable(GL_SCISSOR_TEST);
+        GPU_scissor_test(false);
       }
     }
   }
@@ -135,15 +135,8 @@ static void wm_paintcursor_draw(bContext *C, ScrArea *area, ARegion *region)
 
 static void wm_region_draw_overlay(bContext *C, ScrArea *area, ARegion *region)
 {
-  wmWindowManager *wm = CTX_wm_manager(C);
   wmWindow *win = CTX_wm_window(C);
 
-  /* Don't draw overlay with locked interface. Drawing could access scene data that another thread
-   * may be modifying. */
-  if (wm->is_interface_locked) {
-    return;
-  }
-
   wmViewport(&region->winrct);
   UI_SetTheme(area->spacetype, region->regiontype);
   region->type->draw_overlay(C, region);
@@ -214,7 +207,7 @@ static bool wm_draw_region_stereo_set(Main *bmain,
       if (region->regiontype == RGN_TYPE_PREVIEW) {
         return true;
       }
-      else if (region->regiontype == RGN_TYPE_WINDOW) {
+      if (region->regiontype == RGN_TYPE_WINDOW) {
         return (sseq->draw_flag & SEQ_DRAW_BACKDROP) != 0;
       }
     }
@@ -403,14 +396,8 @@ static void wm_draw_offscreen_texture_parameters(GPUOffScreen *offscreen)
   /* We don't support multisample textures here. */
   BLI_assert(GPU_texture_target(texture) == GL_TEXTURE_2D);
 
-  glBindTexture(GL_TEXTURE_2D, GPU_texture_opengl_bindcode(texture));
-
   /* No mipmaps or filtering. */
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
-  /* GL_TEXTURE_BASE_LEVEL = 0 by default */
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-  glBindTexture(GL_TEXTURE_2D, 0);
+  GPU_texture_mipmap_mode(texture, false, false);
 }
 
 static void wm_draw_region_buffer_create(ARegion *region, bool stereo, bool use_viewport)
@@ -473,8 +460,8 @@ static void wm_draw_region_bind(ARegion *region, int view)
 
     /* For now scissor is expected by region drawing, we could disable it
      * and do the enable/disable in the specific cases that setup scissor. */
-    glEnable(GL_SCISSOR_TEST);
-    glScissor(0, 0, region->winx, region->winy);
+    GPU_scissor_test(true);
+    GPU_scissor(0, 0, region->winx, region->winy);
   }
 
   region->draw_buffer->bound_view = view;
@@ -492,7 +479,7 @@ static void wm_draw_region_unbind(ARegion *region)
     GPU_viewport_unbind(region->draw_buffer->viewport);
   }
   else {
-    glDisable(GL_SCISSOR_TEST);
+    GPU_scissor_test(false);
     GPU_offscreen_unbind(region->draw_buffer->offscreen, false);
   }
 }
@@ -533,9 +520,7 @@ GPUTexture *wm_draw_region_texture(ARegion *region, int view)
   if (viewport) {
     return GPU_viewport_color_texture(viewport, view);
   }
-  else {
-    return GPU_offscreen_color_texture(region->draw_buffer->offscreen);
-  }
+  return GPU_offscreen_color_texture(region->draw_buffer->offscreen);
 }
 
 void wm_draw_region_blend(ARegion *region, int view, bool blend)
@@ -554,24 +539,10 @@ void wm_draw_region_blend(ARegion *region, int view, bool blend)
     alpha = 1.0f;
   }
 
-  /* setup actual texture */
-  GPUTexture *texture = wm_draw_region_texture(region, view);
-  glActiveTexture(GL_TEXTURE0);
-  glBindTexture(GL_TEXTURE_2D, GPU_texture_opengl_bindcode(texture));
-
   /* wmOrtho for the screen has this same offset */
   const float halfx = GLA_PIXEL_OFS / (BLI_rcti_size_x(&region->winrct) + 1);
   const float halfy = GLA_PIXEL_OFS / (BLI_rcti_size_y(&region->winrct) + 1);
 
-  if (blend) {
-    /* GL_ONE because regions drawn offscreen have premultiplied alpha. */
-    GPU_blend(true);
-    glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
-  }
-
-  GPUShader *shader = GPU_shader_get_builtin_shader(GPU_SHADER_2D_IMAGE_RECT_COLOR);
-  GPU_shader_bind(shader);
-
   rcti rect_geo = region->winrct;
   rect_geo.xmax += 1;
   rect_geo.ymax += 1;
@@ -598,26 +569,39 @@ void wm_draw_region_blend(ARegion *region, int view, bool blend)
     alpha = 1.0f;
   }
 
-  glUniform1i(GPU_shader_get_uniform(shader, "image"), 0);
-  glUniform4f(GPU_shader_get_uniform(shader, "rect_icon"),
-              rect_tex.xmin,
-              rect_tex.ymin,
-              rect_tex.xmax,
-              rect_tex.ymax);
-  glUniform4f(GPU_shader_get_uniform(shader, "rect_geom"),
-              rect_geo.xmin,
-              rect_geo.ymin,
-              rect_geo.xmax,
-              rect_geo.ymax);
-  glUniform4f(
-      GPU_shader_get_builtin_uniform(shader, GPU_UNIFORM_COLOR), alpha, alpha, alpha, alpha);
+  /* Not the same layout as rectf/recti. */
+  float rectt[4] = {rect_tex.xmin, rect_tex.ymin, rect_tex.xmax, rect_tex.ymax};
+  float rectg[4] = {rect_geo.xmin, rect_geo.ymin, rect_geo.xmax, rect_geo.ymax};
+
+  if (blend) {
+    /* GL_ONE because regions drawn offscreen have premultiplied alpha. */
+    GPU_blend_set_func(GPU_ONE, GPU_ONE_MINUS_SRC_ALPHA);
+    GPU_blend(true);
+  }
+
+  /* setup actual texture */
+  GPUTexture *texture = wm_draw_region_texture(region, view);
+
+  GPUShader *shader = GPU_shader_get_builtin_shader(GPU_SHADER_2D_IMAGE_RECT_COLOR);
+  GPU_shader_bind(shader);
+
+  int color_loc = GPU_shader_get_builtin_uniform(shader, GPU_UNIFORM_COLOR);
+  int rect_tex_loc = GPU_shader_get_uniform(shader, "rect_icon");
+  int rect_geo_loc = GPU_shader_get_uniform(shader, "rect_geom");
+  int texture_bind_loc = GPU_shader_get_texture_binding(shader, "image");
+
+  GPU_texture_bind(texture, texture_bind_loc);
+
+  GPU_shader_uniform_vector(shader, rect_tex_loc, 4, 1, rectt);
+  GPU_shader_uniform_vector(shader, rect_geo_loc, 4, 1, rectg);
+  GPU_shader_uniform_vector(shader, color_loc, 4, 1, (const float[4]){1, 1, 1, 1});
 
   GPU_draw_primitive(GPU_PRIM_TRI_STRIP, 4);
 
-  glBindTexture(GL_TEXTURE_2D, 0);
+  GPU_texture_unbind(texture);
 
   if (blend) {
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    GPU_blend_set_func(GPU_SRC_ALPHA, GPU_ONE_MINUS_SRC_ALPHA);
     GPU_blend(false);
   }
 }
@@ -736,8 +720,8 @@ static void wm_draw_window_offscreen(bContext *C, wmWindow *win, bool stereo)
 
       wm_draw_region_buffer_create(region, false, false);
       wm_draw_region_bind(region, 0);
-      glClearColor(0, 0, 0, 0);
-      glClear(GL_COLOR_BUFFER_BIT);
+      GPU_clear_color(0, 0, 0, 0);
+      GPU_clear(GPU_COLOR_BIT);
       ED_region_do_draw(C, region);
       wm_draw_region_unbind(region);
 
@@ -759,8 +743,8 @@ static void wm_draw_window_onscreen(bContext *C, wmWindow *win, int view)
    * Actually this is only a problem when resizing the window.
    * If it becomes a problem we should clear only when window size changes. */
 #if 0
-  glClearColor(0, 0, 0, 0);
-  glClear(GL_COLOR_BUFFER_BIT);
+  GPU_clear_color(0, 0, 0, 0);
+  GPU_clear(GPU_COLOR_BIT);
 #endif
 
   /* Blit non-overlapping area regions. */
@@ -844,11 +828,13 @@ static void wm_draw_window(bContext *C, wmWindow *win)
   }
   else if (win->stereo3d_format->display_mode == S3D_DISPLAY_PAGEFLIP) {
     /* For pageflip we simply draw to both back buffers. */
-    glDrawBuffer(GL_BACK_LEFT);
+    GPU_backbuffer_bind(GPU_BACKBUFFER_LEFT);
     wm_draw_window_onscreen(C, win, 0);
-    glDrawBuffer(GL_BACK_RIGHT);
+
+    GPU_backbuffer_bind(GPU_BACKBUFFER_RIGHT);
     wm_draw_window_onscreen(C, win, 1);
-    glDrawBuffer(GL_BACK);
+
+    GPU_backbuffer_bind(GPU_BACKBUFFER);
   }
   else if (ELEM(win->stereo3d_format->display_mode, S3D_DISPLAY_ANAGLYPH, S3D_DISPLAY_INTERLACE)) {
     /* For anaglyph and interlace, we draw individual regions with
@@ -874,8 +860,7 @@ static void wm_draw_window(bContext *C, wmWindow *win)
         GPU_offscreen_unbind(offscreen, false);
 
         /* Draw offscreen buffer to screen. */
-        glActiveTexture(GL_TEXTURE0);
-        glBindTexture(GL_TEXTURE_2D, GPU_texture_opengl_bindcode(texture));
+        GPU_texture_bind(texture, 0);
 
         wmWindowViewport(win);
         if (win->stereo3d_format->display_mode == S3D_DISPLAY_SIDEBYSIDE) {
@@ -885,7 +870,7 @@ static void wm_draw_window(bContext *C, wmWindow *win)
           wm_stereo3d_draw_topbottom(win, view);
         }
 
-        glBindTexture(GL_TEXTURE_2D, 0);
+        GPU_texture_unbind(texture);
       }
 
       GPU_offscreen_free(offscreen);
@@ -1012,7 +997,8 @@ void wm_draw_update(bContext *C)
   wmWindowManager *wm = CTX_wm_manager(C);
   wmWindow *win;
 
-  GPU_free_unused_buffers();
+  GPU_context_main_lock();
+  BKE_image_free_unused_gpu_textures();
 
   for (win = wm->windows.first; win; win = win->next) {
 #ifdef WIN32
@@ -1049,6 +1035,8 @@ void wm_draw_update(bContext *C)
 
   /* Draw non-windows (surfaces) */
   wm_surfaces_iter(C, wm_draw_surface);
+
+  GPU_context_main_unlock();
 }
 
 void wm_draw_region_clear(wmWindow *win, ARegion *UNUSED(region))
diff --git a/source/blender/windowmanager/intern/wm_event_system.c b/source/blender/windowmanager/intern/wm_event_system.c
index 53d6df915d6..0941dd49d23 100644
--- a/source/blender/windowmanager/intern/wm_event_system.c
+++ b/source/blender/windowmanager/intern/wm_event_system.c
@@ -591,13 +591,13 @@ static int wm_handler_ui_call(bContext *C,
     return WM_HANDLER_CONTINUE;
   }
 
-  /* UI is quite aggressive with swallowing events, like scrollwheel */
+  /* UI is quite aggressive with swallowing events, like scroll-wheel. */
   /* I realize this is not extremely nice code... when UI gets keymaps it can be maybe smarter */
   if (do_wheel_ui == false) {
     if (is_wheel) {
       return WM_HANDLER_CONTINUE;
     }
-    else if (wm_event_always_pass(event) == 0) {
+    if (wm_event_always_pass(event) == 0) {
       do_wheel_ui = true;
     }
   }
@@ -608,7 +608,7 @@ static int wm_handler_ui_call(bContext *C,
     return WM_UI_HANDLER_CONTINUE;
   }
 
-  /* we set context to where ui handler came from */
+  /* We set context to where UI handler came from. */
   if (handler->context.area) {
     CTX_wm_area_set(C, handler->context.area);
   }
@@ -783,7 +783,7 @@ bool WM_operator_poll(bContext *C, wmOperatorType *ot)
   if (ot->pyop_poll) {
     return ot->pyop_poll(C, ot);
   }
-  else if (ot->poll) {
+  if (ot->poll) {
     return ot->poll(C);
   }
 
@@ -810,7 +810,7 @@ bool WM_operator_check_ui_empty(wmOperatorType *ot)
     return true;
   }
 
-  /* Assume a ui callback will draw something. */
+  /* Assume a UI callback will draw something. */
   if (ot->ui) {
     return false;
   }
@@ -1095,7 +1095,7 @@ bool WM_operator_repeat_check(const bContext *UNUSED(C), wmOperator *op)
   if (op->type->exec != NULL) {
     return true;
   }
-  else if (op->opm) {
+  if (op->opm) {
     /* for macros, check all have exec() we can call */
     wmOperatorTypeMacro *otmacro;
     for (otmacro = op->opm->type->macro.first; otmacro; otmacro = otmacro->next) {
@@ -1816,10 +1816,10 @@ static bool wm_eventmatch(const wmEvent *winevent, const wmKeyMapItem *kmi)
         /* tablet events can occur on hover + keypress */
         return false;
       }
-      else if ((kmitype == TABLET_STYLUS) && (wmtab->active != EVT_TABLET_STYLUS)) {
+      if ((kmitype == TABLET_STYLUS) && (wmtab->active != EVT_TABLET_STYLUS)) {
         return false;
       }
-      else if ((kmitype == TABLET_ERASER) && (wmtab->active != EVT_TABLET_ERASER)) {
+      if ((kmitype == TABLET_ERASER) && (wmtab->active != EVT_TABLET_ERASER)) {
         return false;
       }
     }
@@ -2434,13 +2434,11 @@ static int wm_handlers_do_keymap_with_keymap_handler(
             }
             break;
           }
+          if (action & WM_HANDLER_HANDLED) {
+            CLOG_INFO(WM_LOG_HANDLERS, 2, "handled - and pass on! '%s'", kmi->idname);
+          }
           else {
-            if (action & WM_HANDLER_HANDLED) {
-              CLOG_INFO(WM_LOG_HANDLERS, 2, "handled - and pass on! '%s'", kmi->idname);
-            }
-            else {
-              CLOG_INFO(WM_LOG_HANDLERS, 2, "un-handled '%s'", kmi->idname);
-            }
+            CLOG_INFO(WM_LOG_HANDLERS, 2, "un-handled '%s'", kmi->idname);
           }
         }
       }
@@ -2492,16 +2490,14 @@ static int wm_handlers_do_keymap_with_gizmo_handler(
           }
           break;
         }
-        else {
-          if (action & WM_HANDLER_HANDLED) {
-            if (G.debug & (G_DEBUG_EVENTS | G_DEBUG_HANDLERS)) {
-              printf("%s:       handled - and pass on! '%s'\n", __func__, kmi->idname);
-            }
-          }
-          else {
-            PRINT("%s:       un-handled '%s'\n", __func__, kmi->idname);
+        if (action & WM_HANDLER_HANDLED) {
+          if (G.debug & (G_DEBUG_EVENTS | G_DEBUG_HANDLERS)) {
+            printf("%s:       handled - and pass on! '%s'\n", __func__, kmi->idname);
           }
         }
+        else {
+          PRINT("%s:       un-handled '%s'\n", __func__, kmi->idname);
+        }
       }
     }
   }
@@ -2707,7 +2703,7 @@ static int wm_handlers_do_intern(bContext *C, wmEvent *event, ListBase *handlers
        handler_base = handler_base_next) {
     handler_base_next = handler_base->next;
 
-    /* during this loop, ui handlers for nested menus can tag multiple handlers free */
+    /* During this loop, UI handlers for nested menus can tag multiple handlers free. */
     if (handler_base->flag & WM_HANDLER_DO_FREE) {
       /* pass */
     }
@@ -2829,7 +2825,7 @@ static int wm_handlers_do_intern(bContext *C, wmEvent *event, ListBase *handlers
 
     /* XXX code this for all modal ops, and ensure free only happens here */
 
-    /* modal ui handler can be tagged to be freed */
+    /* Modal UI handler can be tagged to be freed. */
     if (BLI_findindex(handlers, handler_base) !=
         -1) { /* could be freed already by regular modal ops */
       if (handler_base->flag & WM_HANDLER_DO_FREE) {
@@ -3126,13 +3122,9 @@ static bool wm_event_pie_filter(wmWindow *win, const wmEvent *event)
       win->lock_pie_event = EVENT_NONE;
       return false;
     }
-    else {
-      return true;
-    }
-  }
-  else {
-    return false;
+    return true;
   }
+  return false;
 }
 
 /**
@@ -3692,10 +3684,8 @@ wmKeyMap *WM_event_get_keymap_from_toolsystem_fallback(wmWindowManager *wm,
         handler->keymap_tool = area->runtime.tool;
         return km;
       }
-      else {
-        printf(
-            "Keymap: '%s' not found for tool '%s'\n", tref_rt->keymap, area->runtime.tool->idname);
-      }
+      printf(
+          "Keymap: '%s' not found for tool '%s'\n", tref_rt->keymap, area->runtime.tool->idname);
     }
   }
   return NULL;
@@ -3716,10 +3706,8 @@ wmKeyMap *WM_event_get_keymap_from_toolsystem(wmWindowManager *wm, wmEventHandle
         handler->keymap_tool = area->runtime.tool;
         return km;
       }
-      else {
-        printf(
-            "Keymap: '%s' not found for tool '%s'\n", tref_rt->keymap, area->runtime.tool->idname);
-      }
+      printf(
+          "Keymap: '%s' not found for tool '%s'\n", tref_rt->keymap, area->runtime.tool->idname);
     }
   }
   return NULL;
@@ -3775,12 +3763,10 @@ static bool event_or_prev_in_rect(const wmEvent *event, const rcti *rect)
   if (BLI_rcti_isect_pt(rect, event->x, event->y)) {
     return true;
   }
-  else if (event->type == MOUSEMOVE && BLI_rcti_isect_pt(rect, event->prevx, event->prevy)) {
+  if (event->type == MOUSEMOVE && BLI_rcti_isect_pt(rect, event->prevx, event->prevy)) {
     return true;
   }
-  else {
-    return false;
-  }
+  return false;
 }
 
 static bool handler_region_v2d_mask_test(const ARegion *region, const wmEvent *event)
@@ -3966,138 +3952,137 @@ static int convert_key(GHOST_TKey key)
   if (key >= GHOST_kKeyA && key <= GHOST_kKeyZ) {
     return (EVT_AKEY + ((int)key - GHOST_kKeyA));
   }
-  else if (key >= GHOST_kKey0 && key <= GHOST_kKey9) {
+  if (key >= GHOST_kKey0 && key <= GHOST_kKey9) {
     return (EVT_ZEROKEY + ((int)key - GHOST_kKey0));
   }
-  else if (key >= GHOST_kKeyNumpad0 && key <= GHOST_kKeyNumpad9) {
+  if (key >= GHOST_kKeyNumpad0 && key <= GHOST_kKeyNumpad9) {
     return (EVT_PAD0 + ((int)key - GHOST_kKeyNumpad0));
   }
-  else if (key >= GHOST_kKeyF1 && key <= GHOST_kKeyF24) {
+  if (key >= GHOST_kKeyF1 && key <= GHOST_kKeyF24) {
     return (EVT_F1KEY + ((int)key - GHOST_kKeyF1));
   }
-  else {
-    switch (key) {
-      case GHOST_kKeyBackSpace:
-        return EVT_BACKSPACEKEY;
-      case GHOST_kKeyTab:
-        return EVT_TABKEY;
-      case GHOST_kKeyLinefeed:
-        return EVT_LINEFEEDKEY;
-      case GHOST_kKeyClear:
-        return 0;
-      case GHOST_kKeyEnter:
-        return EVT_RETKEY;
-
-      case GHOST_kKeyEsc:
-        return EVT_ESCKEY;
-      case GHOST_kKeySpace:
-        return EVT_SPACEKEY;
-      case GHOST_kKeyQuote:
-        return EVT_QUOTEKEY;
-      case GHOST_kKeyComma:
-        return EVT_COMMAKEY;
-      case GHOST_kKeyMinus:
-        return EVT_MINUSKEY;
-      case GHOST_kKeyPlus:
-        return EVT_PLUSKEY;
-      case GHOST_kKeyPeriod:
-        return EVT_PERIODKEY;
-      case GHOST_kKeySlash:
-        return EVT_SLASHKEY;
-
-      case GHOST_kKeySemicolon:
-        return EVT_SEMICOLONKEY;
-      case GHOST_kKeyEqual:
-        return EVT_EQUALKEY;
-
-      case GHOST_kKeyLeftBracket:
-        return EVT_LEFTBRACKETKEY;
-      case GHOST_kKeyRightBracket:
-        return EVT_RIGHTBRACKETKEY;
-      case GHOST_kKeyBackslash:
-        return EVT_BACKSLASHKEY;
-      case GHOST_kKeyAccentGrave:
-        return EVT_ACCENTGRAVEKEY;
-
-      case GHOST_kKeyLeftShift:
-        return EVT_LEFTSHIFTKEY;
-      case GHOST_kKeyRightShift:
-        return EVT_RIGHTSHIFTKEY;
-      case GHOST_kKeyLeftControl:
-        return EVT_LEFTCTRLKEY;
-      case GHOST_kKeyRightControl:
-        return EVT_RIGHTCTRLKEY;
-      case GHOST_kKeyOS:
-        return EVT_OSKEY;
-      case GHOST_kKeyLeftAlt:
-        return EVT_LEFTALTKEY;
-      case GHOST_kKeyRightAlt:
-        return EVT_RIGHTALTKEY;
-      case GHOST_kKeyApp:
-        return EVT_APPKEY;
-
-      case GHOST_kKeyCapsLock:
-        return EVT_CAPSLOCKKEY;
-      case GHOST_kKeyNumLock:
-        return 0;
-      case GHOST_kKeyScrollLock:
-        return 0;
-
-      case GHOST_kKeyLeftArrow:
-        return EVT_LEFTARROWKEY;
-      case GHOST_kKeyRightArrow:
-        return EVT_RIGHTARROWKEY;
-      case GHOST_kKeyUpArrow:
-        return EVT_UPARROWKEY;
-      case GHOST_kKeyDownArrow:
-        return EVT_DOWNARROWKEY;
-
-      case GHOST_kKeyPrintScreen:
-        return 0;
-      case GHOST_kKeyPause:
-        return EVT_PAUSEKEY;
-
-      case GHOST_kKeyInsert:
-        return EVT_INSERTKEY;
-      case GHOST_kKeyDelete:
-        return EVT_DELKEY;
-      case GHOST_kKeyHome:
-        return EVT_HOMEKEY;
-      case GHOST_kKeyEnd:
-        return EVT_ENDKEY;
-      case GHOST_kKeyUpPage:
-        return EVT_PAGEUPKEY;
-      case GHOST_kKeyDownPage:
-        return EVT_PAGEDOWNKEY;
-
-      case GHOST_kKeyNumpadPeriod:
-        return EVT_PADPERIOD;
-      case GHOST_kKeyNumpadEnter:
-        return EVT_PADENTER;
-      case GHOST_kKeyNumpadPlus:
-        return EVT_PADPLUSKEY;
-      case GHOST_kKeyNumpadMinus:
-        return EVT_PADMINUS;
-      case GHOST_kKeyNumpadAsterisk:
-        return EVT_PADASTERKEY;
-      case GHOST_kKeyNumpadSlash:
-        return EVT_PADSLASHKEY;
-
-      case GHOST_kKeyGrLess:
-        return EVT_GRLESSKEY;
-
-      case GHOST_kKeyMediaPlay:
-        return EVT_MEDIAPLAY;
-      case GHOST_kKeyMediaStop:
-        return EVT_MEDIASTOP;
-      case GHOST_kKeyMediaFirst:
-        return EVT_MEDIAFIRST;
-      case GHOST_kKeyMediaLast:
-        return EVT_MEDIALAST;
-
-      default:
-        return EVT_UNKNOWNKEY; /* GHOST_kKeyUnknown */
-    }
+
+  switch (key) {
+    case GHOST_kKeyBackSpace:
+      return EVT_BACKSPACEKEY;
+    case GHOST_kKeyTab:
+      return EVT_TABKEY;
+    case GHOST_kKeyLinefeed:
+      return EVT_LINEFEEDKEY;
+    case GHOST_kKeyClear:
+      return 0;
+    case GHOST_kKeyEnter:
+      return EVT_RETKEY;
+
+    case GHOST_kKeyEsc:
+      return EVT_ESCKEY;
+    case GHOST_kKeySpace:
+      return EVT_SPACEKEY;
+    case GHOST_kKeyQuote:
+      return EVT_QUOTEKEY;
+    case GHOST_kKeyComma:
+      return EVT_COMMAKEY;
+    case GHOST_kKeyMinus:
+      return EVT_MINUSKEY;
+    case GHOST_kKeyPlus:
+      return EVT_PLUSKEY;
+    case GHOST_kKeyPeriod:
+      return EVT_PERIODKEY;
+    case GHOST_kKeySlash:
+      return EVT_SLASHKEY;
+
+    case GHOST_kKeySemicolon:
+      return EVT_SEMICOLONKEY;
+    case GHOST_kKeyEqual:
+      return EVT_EQUALKEY;
+
+    case GHOST_kKeyLeftBracket:
+      return EVT_LEFTBRACKETKEY;
+    case GHOST_kKeyRightBracket:
+      return EVT_RIGHTBRACKETKEY;
+    case GHOST_kKeyBackslash:
+      return EVT_BACKSLASHKEY;
+    case GHOST_kKeyAccentGrave:
+      return EVT_ACCENTGRAVEKEY;
+
+    case GHOST_kKeyLeftShift:
+      return EVT_LEFTSHIFTKEY;
+    case GHOST_kKeyRightShift:
+      return EVT_RIGHTSHIFTKEY;
+    case GHOST_kKeyLeftControl:
+      return EVT_LEFTCTRLKEY;
+    case GHOST_kKeyRightControl:
+      return EVT_RIGHTCTRLKEY;
+    case GHOST_kKeyOS:
+      return EVT_OSKEY;
+    case GHOST_kKeyLeftAlt:
+      return EVT_LEFTALTKEY;
+    case GHOST_kKeyRightAlt:
+      return EVT_RIGHTALTKEY;
+    case GHOST_kKeyApp:
+      return EVT_APPKEY;
+
+    case GHOST_kKeyCapsLock:
+      return EVT_CAPSLOCKKEY;
+    case GHOST_kKeyNumLock:
+      return 0;
+    case GHOST_kKeyScrollLock:
+      return 0;
+
+    case GHOST_kKeyLeftArrow:
+      return EVT_LEFTARROWKEY;
+    case GHOST_kKeyRightArrow:
+      return EVT_RIGHTARROWKEY;
+    case GHOST_kKeyUpArrow:
+      return EVT_UPARROWKEY;
+    case GHOST_kKeyDownArrow:
+      return EVT_DOWNARROWKEY;
+
+    case GHOST_kKeyPrintScreen:
+      return 0;
+    case GHOST_kKeyPause:
+      return EVT_PAUSEKEY;
+
+    case GHOST_kKeyInsert:
+      return EVT_INSERTKEY;
+    case GHOST_kKeyDelete:
+      return EVT_DELKEY;
+    case GHOST_kKeyHome:
+      return EVT_HOMEKEY;
+    case GHOST_kKeyEnd:
+      return EVT_ENDKEY;
+    case GHOST_kKeyUpPage:
+      return EVT_PAGEUPKEY;
+    case GHOST_kKeyDownPage:
+      return EVT_PAGEDOWNKEY;
+
+    case GHOST_kKeyNumpadPeriod:
+      return EVT_PADPERIOD;
+    case GHOST_kKeyNumpadEnter:
+      return EVT_PADENTER;
+    case GHOST_kKeyNumpadPlus:
+      return EVT_PADPLUSKEY;
+    case GHOST_kKeyNumpadMinus:
+      return EVT_PADMINUS;
+    case GHOST_kKeyNumpadAsterisk:
+      return EVT_PADASTERKEY;
+    case GHOST_kKeyNumpadSlash:
+      return EVT_PADSLASHKEY;
+
+    case GHOST_kKeyGrLess:
+      return EVT_GRLESSKEY;
+
+    case GHOST_kKeyMediaPlay:
+      return EVT_MEDIAPLAY;
+    case GHOST_kKeyMediaStop:
+      return EVT_MEDIASTOP;
+    case GHOST_kKeyMediaFirst:
+      return EVT_MEDIAFIRST;
+    case GHOST_kKeyMediaLast:
+      return EVT_MEDIALAST;
+
+    default:
+      return EVT_UNKNOWNKEY; /* GHOST_kKeyUnknown */
   }
 }
 
@@ -4834,7 +4819,7 @@ wmKeyMapItem *WM_event_match_keymap_item_from_handlers(bContext *C,
                                                        const wmEvent *event)
 {
   LISTBASE_FOREACH (wmEventHandler *, handler_base, handlers) {
-    /* during this loop, ui handlers for nested menus can tag multiple handlers free */
+    /* During this loop, UI handlers for nested menus can tag multiple handlers free. */
     if (handler_base->flag & WM_HANDLER_DO_FREE) {
       /* pass */
     }
diff --git a/source/blender/windowmanager/intern/wm_files.c b/source/blender/windowmanager/intern/wm_files.c
index d5a240a358e..ef4f2b4a62a 100644
--- a/source/blender/windowmanager/intern/wm_files.c
+++ b/source/blender/windowmanager/intern/wm_files.c
@@ -258,7 +258,7 @@ static void wm_window_match_keep_current_wm(const bContext *C,
   bScreen *screen = NULL;
 
   /* match oldwm to new dbase, only old files */
-  wm->initialized &= ~WM_WINDOW_IS_INITIALIZED;
+  wm->initialized &= ~WM_WINDOW_IS_INIT;
 
   /* when loading without UI, no matching needed */
   if (load_ui && (screen = CTX_wm_screen(C))) {
@@ -1027,13 +1027,6 @@ void wm_homefile_read(bContext *C,
                                    },
                                    NULL);
     }
-    if (BLI_listbase_is_empty(&U.themes)) {
-      if (G.debug & G_DEBUG) {
-        printf("\nNote: No (valid) '%s' found, fall back to built-in default.\n\n",
-               filepath_startup);
-      }
-      success = false;
-    }
     if (success) {
       if (update_defaults) {
         if (use_data) {
@@ -1411,10 +1404,8 @@ bool write_crash_blend(void)
     printf("written: %s\n", path);
     return 1;
   }
-  else {
-    printf("failed: %s\n", path);
-    return 0;
-  }
+  printf("failed: %s\n", path);
+  return 0;
 }
 
 /**
@@ -2098,9 +2089,7 @@ static int wm_homefile_read_invoke(bContext *C, wmOperator *op, const wmEvent *U
     wm_close_file_dialog(C, callback);
     return OPERATOR_INTERFACE;
   }
-  else {
-    return wm_homefile_read_exec(C, op);
-  }
+  return wm_homefile_read_exec(C, op);
 }
 
 static void read_homefile_props(wmOperatorType *ot)
@@ -2262,9 +2251,7 @@ static int wm_open_mainfile__discard_changes(bContext *C, wmOperator *op)
     wm_close_file_dialog(C, callback);
     return OPERATOR_INTERFACE;
   }
-  else {
-    return wm_open_mainfile_dispatch(C, op);
-  }
+  return wm_open_mainfile_dispatch(C, op);
 }
 
 static int wm_open_mainfile__select_file_path(bContext *C, wmOperator *op)
@@ -2335,9 +2322,7 @@ static int wm_open_mainfile__open(bContext *C, wmOperator *op)
     ED_view3d_local_collections_reset(C, (G.fileflags & G_FILE_NO_UI) != 0);
     return OPERATOR_FINISHED;
   }
-  else {
-    return OPERATOR_CANCELLED;
-  }
+  return OPERATOR_CANCELLED;
 }
 
 static OperatorDispatchTarget wm_open_mainfile_dispatch_targets[] = {
@@ -2482,9 +2467,7 @@ static int wm_revert_mainfile_exec(bContext *C, wmOperator *op)
   if (success) {
     return OPERATOR_FINISHED;
   }
-  else {
-    return OPERATOR_CANCELLED;
-  }
+  return OPERATOR_CANCELLED;
 }
 
 static bool wm_revert_mainfile_poll(bContext *UNUSED(C))
@@ -2579,9 +2562,7 @@ static int wm_recover_auto_save_exec(bContext *C, wmOperator *op)
   if (success) {
     return OPERATOR_FINISHED;
   }
-  else {
-    return OPERATOR_CANCELLED;
-  }
+  return OPERATOR_CANCELLED;
 }
 
 static int wm_recover_auto_save_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
diff --git a/source/blender/windowmanager/intern/wm_files_link.c b/source/blender/windowmanager/intern/wm_files_link.c
index c8574a5a7fb..6ccc5d79962 100644
--- a/source/blender/windowmanager/intern/wm_files_link.c
+++ b/source/blender/windowmanager/intern/wm_files_link.c
@@ -34,6 +34,7 @@
 #include "MEM_guardedalloc.h"
 
 #include "DNA_ID.h"
+#include "DNA_key_types.h"
 #include "DNA_scene_types.h"
 #include "DNA_screen_types.h"
 #include "DNA_windowmanager_types.h"
@@ -50,8 +51,10 @@
 
 #include "BKE_context.h"
 #include "BKE_global.h"
+#include "BKE_key.h"
 #include "BKE_layer.h"
 #include "BKE_lib_id.h"
+#include "BKE_lib_override.h"
 #include "BKE_lib_remap.h"
 #include "BKE_main.h"
 #include "BKE_report.h"
@@ -354,11 +357,11 @@ static int wm_link_append_exec(bContext *C, wmOperator *op)
     BKE_reportf(op->reports, RPT_ERROR, "'%s': not a library", path);
     return OPERATOR_CANCELLED;
   }
-  else if (!group) {
+  if (!group) {
     BKE_reportf(op->reports, RPT_ERROR, "'%s': nothing indicated", path);
     return OPERATOR_CANCELLED;
   }
-  else if (BLI_path_cmp(BKE_main_blendfile_path(bmain), libname) == 0) {
+  if (BLI_path_cmp(BKE_main_blendfile_path(bmain), libname) == 0) {
     BKE_reportf(op->reports, RPT_ERROR, "'%s': cannot use current file as library", path);
     return OPERATOR_CANCELLED;
   }
@@ -694,6 +697,92 @@ static int wm_lib_relocate_invoke(bContext *C, wmOperator *op, const wmEvent *UN
   return OPERATOR_CANCELLED;
 }
 
+static void lib_relocate_do_remap(Main *bmain,
+                                  ID *old_id,
+                                  ID *new_id,
+                                  ReportList *reports,
+                                  const bool do_reload,
+                                  const short remap_flags)
+{
+  BLI_assert(old_id);
+  if (do_reload) {
+    /* Since we asked for placeholders in case of missing IDs,
+     * we expect to always get a valid one. */
+    BLI_assert(new_id);
+  }
+  if (new_id) {
+#ifdef PRINT_DEBUG
+    printf("before remap of %s, old_id users: %d, new_id users: %d\n",
+           old_id->name,
+           old_id->us,
+           new_id->us);
+#endif
+    BKE_libblock_remap_locked(bmain, old_id, new_id, remap_flags);
+
+    if (old_id->flag & LIB_FAKEUSER) {
+      id_fake_user_clear(old_id);
+      id_fake_user_set(new_id);
+    }
+
+#ifdef PRINT_DEBUG
+    printf("after remap of %s, old_id users: %d, new_id users: %d\n",
+           old_id->name,
+           old_id->us,
+           new_id->us);
+#endif
+
+    /* In some cases, new_id might become direct link, remove parent of library in this case. */
+    if (new_id->lib->parent && (new_id->tag & LIB_TAG_INDIRECT) == 0) {
+      if (do_reload) {
+        BLI_assert(0); /* Should not happen in 'pure' reload case... */
+      }
+      new_id->lib->parent = NULL;
+    }
+  }
+
+  if (old_id->us > 0 && new_id && old_id->lib == new_id->lib) {
+    /* Note that this *should* not happen - but better be safe than sorry in this area,
+     * at least until we are 100% sure this cannot ever happen.
+     * Also, we can safely assume names were unique so far,
+     * so just replacing '.' by '~' should work,
+     * but this does not totally rules out the possibility of name collision. */
+    size_t len = strlen(old_id->name);
+    size_t dot_pos;
+    bool has_num = false;
+
+    for (dot_pos = len; dot_pos--;) {
+      char c = old_id->name[dot_pos];
+      if (c == '.') {
+        break;
+      }
+      if (c < '0' || c > '9') {
+        has_num = false;
+        break;
+      }
+      has_num = true;
+    }
+
+    if (has_num) {
+      old_id->name[dot_pos] = '~';
+    }
+    else {
+      len = MIN2(len, MAX_ID_NAME - 7);
+      BLI_strncpy(&old_id->name[len], "~000", 7);
+    }
+
+    id_sort_by_name(which_libbase(bmain, GS(old_id->name)), old_id, NULL);
+
+    BKE_reportf(
+        reports,
+        RPT_WARNING,
+        "Lib Reload: Replacing all references to old data-block '%s' by reloaded one failed, "
+        "old one (%d remaining users) had to be kept and was renamed to '%s'",
+        new_id->name,
+        old_id->us,
+        old_id->name);
+  }
+}
+
 static void lib_relocate_do(Main *bmain,
                             Library *library,
                             WMLinkAppendData *lapp_data,
@@ -725,6 +814,12 @@ static void lib_relocate_do(Main *bmain,
         /* We remove it from current Main, and add it to items to link... */
         /* Note that non-linkable IDs (like e.g. shapekeys) are also explicitly linked here... */
         BLI_remlink(lbarray[lba_idx], id);
+        /* Usual special code for ShapeKeys snowflakes... */
+        Key *old_key = BKE_key_from_id(id);
+        if (old_key != NULL) {
+          BLI_remlink(which_libbase(bmain, GS(old_key->id.name)), &old_key->id);
+        }
+
         item = wm_link_append_data_item_add(lapp_data, id->name + 2, idcode, id);
         BLI_bitmap_set_all(item->libraries, true, lapp_data->num_libraries);
 
@@ -757,6 +852,12 @@ static void lib_relocate_do(Main *bmain,
 
     BLI_assert(old_id);
     BLI_addtail(which_libbase(bmain, GS(old_id->name)), old_id);
+
+    /* Usual special code for ShapeKeys snowflakes... */
+    Key *old_key = BKE_key_from_id(old_id);
+    if (old_key != NULL) {
+      BLI_addtail(which_libbase(bmain, GS(old_key->id.name)), &old_key->id);
+    }
   }
 
   /* Since our (old) reloaded IDs were removed from main, the user count done for them in linking
@@ -773,82 +874,20 @@ static void lib_relocate_do(Main *bmain,
     ID *old_id = item->customdata;
     ID *new_id = item->new_id;
 
-    BLI_assert(old_id);
-    if (do_reload) {
-      /* Since we asked for placeholders in case of missing IDs,
-       * we expect to always get a valid one. */
-      BLI_assert(new_id);
-    }
-    if (new_id) {
-#ifdef PRINT_DEBUG
-      printf("before remap of %s, old_id users: %d, new_id users: %d\n",
-             old_id->name,
-             old_id->us,
-             new_id->us);
-#endif
-      BKE_libblock_remap_locked(bmain, old_id, new_id, remap_flags);
-
-      if (old_id->flag & LIB_FAKEUSER) {
-        id_fake_user_clear(old_id);
-        id_fake_user_set(new_id);
-      }
-
-#ifdef PRINT_DEBUG
-      printf("after remap of %s, old_id users: %d, new_id users: %d\n",
-             old_id->name,
-             old_id->us,
-             new_id->us);
-#endif
-
-      /* In some cases, new_id might become direct link, remove parent of library in this case. */
-      if (new_id->lib->parent && (new_id->tag & LIB_TAG_INDIRECT) == 0) {
-        if (do_reload) {
-          BLI_assert(0); /* Should not happen in 'pure' reload case... */
-        }
-        new_id->lib->parent = NULL;
-      }
+    lib_relocate_do_remap(bmain, old_id, new_id, reports, do_reload, remap_flags);
+    /* Usual special code for ShapeKeys snowflakes... */
+    Key **old_key_p = BKE_key_from_id_p(old_id);
+    if (old_key_p == NULL) {
+      continue;
     }
-
-    if (old_id->us > 0 && new_id && old_id->lib == new_id->lib) {
-      /* Note that this *should* not happen - but better be safe than sorry in this area,
-       * at least until we are 100% sure this cannot ever happen.
-       * Also, we can safely assume names were unique so far,
-       * so just replacing '.' by '~' should work,
-       * but this does not totally rules out the possibility of name collision. */
-      size_t len = strlen(old_id->name);
-      size_t dot_pos;
-      bool has_num = false;
-
-      for (dot_pos = len; dot_pos--;) {
-        char c = old_id->name[dot_pos];
-        if (c == '.') {
-          break;
-        }
-        else if (c < '0' || c > '9') {
-          has_num = false;
-          break;
-        }
-        has_num = true;
-      }
-
-      if (has_num) {
-        old_id->name[dot_pos] = '~';
-      }
-      else {
-        len = MIN2(len, MAX_ID_NAME - 7);
-        BLI_strncpy(&old_id->name[len], "~000", 7);
-      }
-
-      id_sort_by_name(which_libbase(bmain, GS(old_id->name)), old_id, NULL);
-
-      BKE_reportf(
-          reports,
-          RPT_WARNING,
-          "Lib Reload: Replacing all references to old data-block '%s' by reloaded one failed, "
-          "old one (%d remaining users) had to be kept and was renamed to '%s'",
-          new_id->name,
-          old_id->us,
-          old_id->name);
+    Key *old_key = *old_key_p;
+    Key *new_key = BKE_key_from_id(new_id);
+    if (old_key != NULL) {
+      *old_key_p = NULL;
+      id_us_min(&old_key->id);
+      lib_relocate_do_remap(bmain, &old_key->id, &new_key->id, reports, do_reload, remap_flags);
+      *old_key_p = old_key;
+      id_us_plus_no_lib(&old_key->id);
     }
   }
 
@@ -900,6 +939,23 @@ static void lib_relocate_do(Main *bmain,
     }
   }
 
+  /* Update overrides of reloaded linked data-blocks.
+   * Note that this will not necessarily fully update the override, it might need to be manually
+   * 're-generated' depending on changes in linked data. */
+  ID *id;
+  FOREACH_MAIN_ID_BEGIN (bmain, id) {
+    if (ID_IS_LINKED(id) || !ID_IS_OVERRIDE_LIBRARY_REAL(id) ||
+        (id->tag & LIB_TAG_PRE_EXISTING) == 0) {
+      continue;
+    }
+    if (id->override_library->reference->lib == library) {
+      BKE_lib_override_library_update(bmain, id);
+    }
+  }
+  FOREACH_MAIN_ID_END;
+
+  BKE_main_collection_sync(bmain);
+
   BKE_main_lib_objects_recalc_all(bmain);
   IMB_colormanagement_check_file_config(bmain);
 
diff --git a/source/blender/windowmanager/intern/wm_gesture.c b/source/blender/windowmanager/intern/wm_gesture.c
index 6b2a74138c9..5a66cbd10eb 100644
--- a/source/blender/windowmanager/intern/wm_gesture.c
+++ b/source/blender/windowmanager/intern/wm_gesture.c
@@ -209,7 +209,7 @@ static void wm_gesture_draw_line(wmGesture *gt)
   immBindBuiltinProgram(GPU_SHADER_2D_LINE_DASHED_UNIFORM_COLOR);
 
   float viewport_size[4];
-  glGetFloatv(GL_VIEWPORT, viewport_size);
+  GPU_viewport_size_get_f(viewport_size);
   immUniform2f("viewport_size", viewport_size[2], viewport_size[3]);
 
   immUniform1i("colors_len", 2); /* "advanced" mode */
@@ -252,7 +252,7 @@ static void wm_gesture_draw_rect(wmGesture *gt)
   immBindBuiltinProgram(GPU_SHADER_2D_LINE_DASHED_UNIFORM_COLOR);
 
   float viewport_size[4];
-  glGetFloatv(GL_VIEWPORT, viewport_size);
+  GPU_viewport_size_get_f(viewport_size);
   immUniform2f("viewport_size", viewport_size[2], viewport_size[3]);
 
   immUniform1i("colors_len", 2); /* "advanced" mode */
@@ -291,7 +291,7 @@ static void wm_gesture_draw_circle(wmGesture *gt)
   immBindBuiltinProgram(GPU_SHADER_2D_LINE_DASHED_UNIFORM_COLOR);
 
   float viewport_size[4];
-  glGetFloatv(GL_VIEWPORT, viewport_size);
+  GPU_viewport_size_get_f(viewport_size);
   immUniform2f("viewport_size", viewport_size[2], viewport_size[3]);
 
   immUniform1i("colors_len", 2); /* "advanced" mode */
@@ -355,39 +355,22 @@ static void draw_filled_lasso(wmGesture *gt)
 
     /* Additive Blending */
     GPU_blend(true);
-    glBlendFunc(GL_ONE, GL_ONE);
-
-    GLint unpack_alignment;
-    glGetIntegerv(GL_UNPACK_ALIGNMENT, &unpack_alignment);
-
-    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    GPU_blend_set_func(GPU_ONE, GPU_ONE);
 
     IMMDrawPixelsTexState state = immDrawPixelsTexSetup(GPU_SHADER_2D_IMAGE_SHUFFLE_COLOR);
     GPU_shader_bind(state.shader);
     GPU_shader_uniform_vector(
         state.shader, GPU_shader_get_uniform(state.shader, "shuffle"), 4, 1, red);
 
-    immDrawPixelsTex(&state,
-                     rect.xmin,
-                     rect.ymin,
-                     w,
-                     h,
-                     GL_RED,
-                     GL_UNSIGNED_BYTE,
-                     GL_NEAREST,
-                     pixel_buf,
-                     1.0f,
-                     1.0f,
-                     NULL);
+    immDrawPixelsTex(
+        &state, rect.xmin, rect.ymin, w, h, GL_R8, false, pixel_buf, 1.0f, 1.0f, NULL);
 
     GPU_shader_unbind();
 
-    glPixelStorei(GL_UNPACK_ALIGNMENT, unpack_alignment);
-
     MEM_freeN(pixel_buf);
 
     GPU_blend(false);
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    GPU_blend_set_func(GPU_SRC_ALPHA, GPU_ONE_MINUS_SRC_ALPHA);
   }
 
   MEM_freeN(mcoords);
@@ -415,7 +398,7 @@ static void wm_gesture_draw_lasso(wmGesture *gt, bool filled)
   immBindBuiltinProgram(GPU_SHADER_2D_LINE_DASHED_UNIFORM_COLOR);
 
   float viewport_size[4];
-  glGetFloatv(GL_VIEWPORT, viewport_size);
+  GPU_viewport_size_get_f(viewport_size);
   immUniform2f("viewport_size", viewport_size[2], viewport_size[3]);
 
   immUniform1i("colors_len", 2); /* "advanced" mode */
@@ -449,7 +432,7 @@ static void wm_gesture_draw_cross(wmWindow *win, wmGesture *gt)
   immBindBuiltinProgram(GPU_SHADER_2D_LINE_DASHED_UNIFORM_COLOR);
 
   float viewport_size[4];
-  glGetFloatv(GL_VIEWPORT, viewport_size);
+  GPU_viewport_size_get_f(viewport_size);
   immUniform2f("viewport_size", viewport_size[2], viewport_size[3]);
 
   immUniform1i("colors_len", 2); /* "advanced" mode */
diff --git a/source/blender/windowmanager/intern/wm_init_exit.c b/source/blender/windowmanager/intern/wm_init_exit.c
index cb5a039765a..85694dec9c8 100644
--- a/source/blender/windowmanager/intern/wm_init_exit.c
+++ b/source/blender/windowmanager/intern/wm_init_exit.c
@@ -59,6 +59,7 @@
 #include "BKE_font.h"
 #include "BKE_global.h"
 #include "BKE_icons.h"
+#include "BKE_image.h"
 #include "BKE_keyconfig.h"
 #include "BKE_lib_remap.h"
 #include "BKE_main.h"
@@ -120,7 +121,6 @@
 #include "UI_interface.h"
 #include "UI_resources.h"
 
-#include "GPU_draw.h"
 #include "GPU_init_exit.h"
 #include "GPU_material.h"
 
@@ -171,7 +171,7 @@ void WM_init_state_start_with_console_set(bool value)
  */
 static bool opengl_is_init = false;
 
-void WM_init_opengl(Main *bmain)
+void WM_init_opengl(void)
 {
   /* must be called only once */
   BLI_assert(opengl_is_init == false);
@@ -185,9 +185,6 @@ void WM_init_opengl(Main *bmain)
   DRW_opengl_context_create();
 
   GPU_init();
-  GPU_set_mipmap(bmain, true);
-  GPU_set_linear_mipmap(true);
-  GPU_set_anisotropic(U.anisotropic_filter);
 
   GPU_pass_cache_init();
 
@@ -315,7 +312,7 @@ void WM_init(bContext *C, int argc, const char **argv)
     /* sets 3D mouse deadzone */
     WM_ndof_deadzone_set(U.ndof_deadzone);
 #endif
-    WM_init_opengl(G_MAIN);
+    WM_init_opengl();
 
     if (!WM_platform_support_perform_checks()) {
       exit(-1);
@@ -351,7 +348,7 @@ void WM_init(bContext *C, int argc, const char **argv)
   BKE_material_copybuf_clear();
   ED_render_clear_mtex_copybuf();
 
-  // glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+  // GPU_blend_set_func(GPU_SRC_ALPHA, GPU_ONE_MINUS_SRC_ALPHA, GPU_ONE, GPU_ONE_MINUS_SRC_ALPHA);
 
   wm_history_file_read();
 
@@ -578,7 +575,7 @@ void WM_exit_ex(bContext *C, const bool do_python)
   BKE_subdiv_exit();
 
   if (opengl_is_init) {
-    GPU_free_unused_buffers();
+    BKE_image_free_unused_gpu_textures();
   }
 
   BKE_blender_free(); /* blender.c, does entire library and spacetypes */
@@ -656,13 +653,6 @@ void WM_exit_ex(bContext *C, const bool do_python)
 
   BKE_blender_atexit();
 
-  if (MEM_get_memory_blocks_in_use() != 0) {
-    size_t mem_in_use = MEM_get_memory_in_use() + MEM_get_memory_in_use();
-    printf("Error: Not freed memory blocks: %u, total unfreed memory %f MB\n",
-           MEM_get_memory_blocks_in_use(),
-           (double)mem_in_use / 1024 / 1024);
-    MEM_printmemlist();
-  }
   wm_autosave_delete();
 
   BKE_tempdir_session_purge();
diff --git a/source/blender/windowmanager/intern/wm_jobs.c b/source/blender/windowmanager/intern/wm_jobs.c
index c10f03f3dab..c9b125901e7 100644
--- a/source/blender/windowmanager/intern/wm_jobs.c
+++ b/source/blender/windowmanager/intern/wm_jobs.c
@@ -86,7 +86,7 @@ struct wmJob {
    * This performs the actual parallel work.
    * Executed in worker thread(s).
    */
-  void (*startjob)(void *, short *stop, short *do_update, float *progress);
+  wm_jobs_start_callback startjob;
   /**
    * Called if thread defines so (see `do_update` flag), and max once per timer step.
    * Executed in main thread.
@@ -344,9 +344,7 @@ void *WM_jobs_customdata_get(wmJob *wm_job)
   if (!wm_job->customdata) {
     return wm_job->run_customdata;
   }
-  else {
-    return wm_job->customdata;
-  }
+  return wm_job->customdata;
 }
 
 void WM_jobs_customdata_set(wmJob *wm_job, void *customdata, void (*free)(void *))
@@ -378,7 +376,7 @@ void WM_jobs_delay_start(wmJob *wm_job, double delay_time)
 }
 
 void WM_jobs_callbacks(wmJob *wm_job,
-                       void (*startjob)(void *, short *, short *, float *),
+                       wm_jobs_start_callback startjob,
                        void (*initjob)(void *),
                        void (*update)(void *),
                        void (*endjob)(void *))
diff --git a/source/blender/windowmanager/intern/wm_keymap.c b/source/blender/windowmanager/intern/wm_keymap.c
index d7102a1e8af..d7ff2689a86 100644
--- a/source/blender/windowmanager/intern/wm_keymap.c
+++ b/source/blender/windowmanager/intern/wm_keymap.c
@@ -321,9 +321,7 @@ bool WM_keyconfig_remove(wmWindowManager *wm, wmKeyConfig *keyconf)
 
     return true;
   }
-  else {
-    return false;
-  }
+  return false;
 }
 
 void WM_keyconfig_clear(wmKeyConfig *keyconf)
@@ -363,7 +361,7 @@ void WM_keyconfig_set_active(wmWindowManager *wm, const char *idname)
   WM_keyconfig_update(wm);
 
   BLI_strncpy(U.keyconfigstr, idname, sizeof(U.keyconfigstr));
-  if (wm->initialized & WM_KEYCONFIG_IS_INITIALIZED) {
+  if (wm->initialized & WM_KEYCONFIG_IS_INIT) {
     U.runtime.is_dirty = true;
   }
 
@@ -448,9 +446,7 @@ bool WM_keymap_remove(wmKeyConfig *keyconf, wmKeyMap *keymap)
 
     return true;
   }
-  else {
-    return false;
-  }
+  return false;
 }
 
 bool WM_keymap_poll(bContext *C, wmKeyMap *keymap)
@@ -551,9 +547,7 @@ bool WM_keymap_remove_item(wmKeyMap *keymap, wmKeyMapItem *kmi)
     WM_keyconfig_update_tag(keymap, NULL);
     return true;
   }
-  else {
-    return false;
-  }
+  return false;
 }
 
 /** \} */
@@ -1122,7 +1116,7 @@ const char *WM_key_event_string(const short type, const bool compact)
         if (platform == MACOS) {
           return key_event_glyph_or_text(font_id, IFACE_("Cmd"), "\xe2\x8c\x98");
         }
-        else if (platform == MSWIN) {
+        if (platform == MSWIN) {
           return key_event_glyph_or_text(font_id, IFACE_("Win"), "\xe2\x9d\x96");
         }
         return IFACE_("OS");
diff --git a/source/blender/windowmanager/intern/wm_operator_type.c b/source/blender/windowmanager/intern/wm_operator_type.c
index 650d5bbe015..457cd0f16be 100644
--- a/source/blender/windowmanager/intern/wm_operator_type.c
+++ b/source/blender/windowmanager/intern/wm_operator_type.c
@@ -606,9 +606,7 @@ char *WM_operatortype_description(struct bContext *C,
       if (description[0]) {
         return description;
       }
-      else {
-        MEM_freeN(description);
-      }
+      MEM_freeN(description);
     }
   }
 
@@ -621,9 +619,7 @@ char *WM_operatortype_description(struct bContext *C,
   if (info && info[0]) {
     return BLI_strdup(info);
   }
-  else {
-    return NULL;
-  }
+  return NULL;
 }
 
 /** \} */
diff --git a/source/blender/windowmanager/intern/wm_operators.c b/source/blender/windowmanager/intern/wm_operators.c
index 525f96329b7..6a3f4f6a364 100644
--- a/source/blender/windowmanager/intern/wm_operators.c
+++ b/source/blender/windowmanager/intern/wm_operators.c
@@ -864,19 +864,17 @@ int WM_generic_select_modal(bContext *C, wmOperator *op, const wmEvent *event)
       }
       return ret_value | OPERATOR_PASS_THROUGH;
     }
-    else {
-      /* If we are in init phase, and cannot validate init of modal operations,
-       * just fall back to basic exec.
-       */
-      RNA_property_boolean_set(op->ptr, wait_to_deselect_prop, false);
+    /* If we are in init phase, and cannot validate init of modal operations,
+     * just fall back to basic exec.
+     */
+    RNA_property_boolean_set(op->ptr, wait_to_deselect_prop, false);
 
-      ret_value = op->type->exec(C, op);
-      OPERATOR_RETVAL_CHECK(ret_value);
+    ret_value = op->type->exec(C, op);
+    OPERATOR_RETVAL_CHECK(ret_value);
 
-      return ret_value | OPERATOR_PASS_THROUGH;
-    }
+    return ret_value | OPERATOR_PASS_THROUGH;
   }
-  else if (event->type == init_event_type && event->val == KM_RELEASE) {
+  if (event->type == init_event_type && event->val == KM_RELEASE) {
     RNA_property_boolean_set(op->ptr, wait_to_deselect_prop, false);
 
     ret_value = op->type->exec(C, op);
@@ -884,7 +882,7 @@ int WM_generic_select_modal(bContext *C, wmOperator *op, const wmEvent *event)
 
     return ret_value | OPERATOR_PASS_THROUGH;
   }
-  else if (ELEM(event->type, MOUSEMOVE, INBETWEEN_MOUSEMOVE)) {
+  if (ELEM(event->type, MOUSEMOVE, INBETWEEN_MOUSEMOVE)) {
     const int drag_delta[2] = {
         mval[0] - event->mval[0],
         mval[1] - event->mval[1],
@@ -895,11 +893,9 @@ int WM_generic_select_modal(bContext *C, wmOperator *op, const wmEvent *event)
     if (WM_event_drag_test_with_delta(event, drag_delta)) {
       return OPERATOR_FINISHED | OPERATOR_PASS_THROUGH;
     }
-    else {
-      /* Important not to return anything other than PASS_THROUGH here,
-       * otherwise it prevents underlying tweak detection code to work properly. */
-      return OPERATOR_PASS_THROUGH;
-    }
+    /* Important not to return anything other than PASS_THROUGH here,
+     * otherwise it prevents underlying tweak detection code to work properly. */
+    return OPERATOR_PASS_THROUGH;
   }
 
   return OPERATOR_RUNNING_MODAL | OPERATOR_PASS_THROUGH;
@@ -1151,9 +1147,7 @@ int WM_operator_confirm_or_exec(bContext *C, wmOperator *op, const wmEvent *UNUS
   if (confirm) {
     return WM_operator_confirm_message(C, op, NULL);
   }
-  else {
-    return op->type->exec(C, op);
-  }
+  return op->type->exec(C, op);
 }
 
 /* op->invoke, opens fileselect if path property not set, otherwise executes */
@@ -1162,10 +1156,8 @@ int WM_operator_filesel(bContext *C, wmOperator *op, const wmEvent *UNUSED(event
   if (RNA_struct_property_is_set(op->ptr, "filepath")) {
     return WM_operator_call_notest(C, op); /* call exec direct */
   }
-  else {
-    WM_event_add_fileselect(C, op);
-    return OPERATOR_RUNNING_MODAL;
-  }
+  WM_event_add_fileselect(C, op);
+  return OPERATOR_RUNNING_MODAL;
 }
 
 bool WM_operator_filesel_ensure_ext_imtype(wmOperator *op, const struct ImageFormatData *im_format)
@@ -2120,7 +2112,7 @@ typedef struct {
   int slow_mouse[2];
   bool slow_mode;
   Dial *dial;
-  unsigned int gltex;
+  GPUTexture *texture;
   ListBase orig_paintcursors;
   bool use_secondary_tex;
   void *cursor;
@@ -2224,11 +2216,15 @@ static void radial_control_set_tex(RadialControl *rc)
                rc->image_id_ptr.data,
                rc->use_secondary_tex,
                !ELEM(rc->subtype, PROP_NONE, PROP_PIXEL, PROP_DISTANCE)))) {
-        glGenTextures(1, &rc->gltex);
-        glBindTexture(GL_TEXTURE_2D, rc->gltex);
-        glTexImage2D(
-            GL_TEXTURE_2D, 0, GL_R8, ibuf->x, ibuf->y, 0, GL_RED, GL_FLOAT, ibuf->rect_float);
-        glBindTexture(GL_TEXTURE_2D, 0);
+
+        rc->texture = GPU_texture_create_nD(
+            ibuf->x, ibuf->y, 0, 2, ibuf->rect_float, GPU_R8, GPU_DATA_FLOAT, 0, false, NULL);
+        GPU_texture_filter_mode(rc->texture, true);
+
+        GPU_texture_bind(rc->texture, 0);
+        GPU_texture_swizzle_set(rc->texture, "111r");
+        GPU_texture_unbind(rc->texture);
+
         MEM_freeN(ibuf->rect_float);
         MEM_freeN(ibuf);
       }
@@ -2264,19 +2260,9 @@ static void radial_control_paint_tex(RadialControl *rc, float radius, float alph
   GPUVertFormat *format = immVertexFormat();
   uint pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
 
-  if (rc->gltex) {
-
+  if (rc->texture) {
     uint texCoord = GPU_vertformat_attr_add(format, "texCoord", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
 
-    glActiveTexture(GL_TEXTURE0);
-    glBindTexture(GL_TEXTURE_2D, rc->gltex);
-
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-
-    GLint swizzleMask[] = {GL_ZERO, GL_ZERO, GL_ZERO, GL_RED};
-    glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_SWIZZLE_RGBA, swizzleMask);
-
     /* set up rotation if available */
     if (rc->rot_prop) {
       rot = RNA_property_float_get(&rc->rot_ptr, rc->rot_prop);
@@ -2284,10 +2270,10 @@ static void radial_control_paint_tex(RadialControl *rc, float radius, float alph
       GPU_matrix_rotate_2d(RAD2DEGF(rot));
     }
 
-    immBindBuiltinProgram(GPU_SHADER_2D_IMAGE_MASK_UNIFORM_COLOR);
+    immBindBuiltinProgram(GPU_SHADER_2D_IMAGE_COLOR);
 
     immUniformColor3fvAlpha(col, alpha);
-    immUniform1i("image", 0);
+    immBindTexture("image", rc->texture);
 
     /* draw textured quad */
     immBegin(GPU_PRIM_TRI_FAN, 4);
@@ -2306,6 +2292,8 @@ static void radial_control_paint_tex(RadialControl *rc, float radius, float alph
 
     immEnd();
 
+    GPU_texture_unbind(rc->texture);
+
     /* undo rotation */
     if (rc->rot_prop) {
       GPU_matrix_pop();
@@ -2326,7 +2314,7 @@ static void radial_control_paint_curve(uint pos, Brush *br, float radius, int li
   GPU_line_width(2.0f);
   immUniformColor4f(0.8f, 0.8f, 0.8f, 0.85f);
   float step = (radius * 2.0f) / (float)line_segments;
-  BKE_curvemapping_initialize(br->curve);
+  BKE_curvemapping_init(br->curve);
   immBegin(GPU_PRIM_LINES, line_segments * 2);
   for (int i = 0; i < line_segments; i++) {
     float h1 = BKE_brush_curve_strength_clamped(br, fabsf((i * step) - radius), radius);
@@ -2540,10 +2528,8 @@ static int radial_control_get_path(PointerRNA *ctx_ptr,
     if (flags & RC_PROP_ALLOW_MISSING) {
       return 1;
     }
-    else {
-      BKE_reportf(op->reports, RPT_ERROR, "Could not resolve path '%s'", name);
-      return 0;
-    }
+    BKE_reportf(op->reports, RPT_ERROR, "Could not resolve path '%s'", name);
+    return 0;
   }
 
   /* check property type */
@@ -2595,13 +2581,12 @@ static int radial_control_get_properties(bContext *C, wmOperator *op)
                                (RC_PROP_ALLOW_MISSING | RC_PROP_REQUIRE_BOOL))) {
     return 0;
   }
+
+  if (use_secondary_prop && RNA_property_boolean_get(&use_secondary_ptr, use_secondary_prop)) {
+    data_path = "data_path_secondary";
+  }
   else {
-    if (use_secondary_prop && RNA_property_boolean_get(&use_secondary_ptr, use_secondary_prop)) {
-      data_path = "data_path_secondary";
-    }
-    else {
-      data_path = "data_path_primary";
-    }
+    data_path = "data_path_primary";
   }
 
   if (!radial_control_get_path(&ctx_ptr, op, data_path, &rc->ptr, &rc->prop, 0, 0)) {
@@ -2668,7 +2653,7 @@ static int radial_control_get_properties(bContext *C, wmOperator *op)
   if (!radial_control_get_path(&ctx_ptr, op, "image_id", &rc->image_id_ptr, NULL, 0, 0)) {
     return 0;
   }
-  else if (rc->image_id_ptr.data) {
+  if (rc->image_id_ptr.data) {
     /* extra check, pointer must be to an ID */
     if (!RNA_struct_is_ID(rc->image_id_ptr.type)) {
       BKE_report(op->reports, RPT_ERROR, "Pointer from path image_id is not an ID");
@@ -2803,7 +2788,9 @@ static void radial_control_cancel(bContext *C, wmOperator *op)
    * new value is displayed in sliders/numfields */
   WM_event_add_notifier(C, NC_WINDOW, NULL);
 
-  glDeleteTextures(1, &rc->gltex);
+  if (rc->texture != NULL) {
+    GPU_texture_free(rc->texture);
+  }
 
   MEM_freeN(rc);
 }
@@ -2843,171 +2830,169 @@ static int radial_control_modal(bContext *C, wmOperator *op, const wmEvent *even
     radial_control_update_header(op, C);
     return OPERATOR_RUNNING_MODAL;
   }
-  else {
-    handled = false;
-    switch (event->type) {
-      case EVT_ESCKEY:
-      case RIGHTMOUSE:
-        /* canceled; restore original value */
-        radial_control_set_value(rc, rc->initial_value);
-        ret = OPERATOR_CANCELLED;
-        break;
-
-      case LEFTMOUSE:
-      case EVT_PADENTER:
-      case EVT_RETKEY:
-        /* done; value already set */
-        RNA_property_update(C, &rc->ptr, rc->prop);
-        ret = OPERATOR_FINISHED;
-        break;
-
-      case MOUSEMOVE:
-        if (!has_numInput) {
-          if (rc->slow_mode) {
-            if (rc->subtype == PROP_ANGLE) {
-              float position[2] = {event->x, event->y};
-
-              /* calculate the initial angle here first */
-              delta[0] = rc->initial_mouse[0] - rc->slow_mouse[0];
-              delta[1] = rc->initial_mouse[1] - rc->slow_mouse[1];
-
-              /* precision angle gets calculated from dial and gets added later */
-              angle_precision = -0.1f * BLI_dial_angle(rc->dial, position);
-            }
-            else {
-              delta[0] = rc->initial_mouse[0] - rc->slow_mouse[0];
-              delta[1] = 0.0f;
 
-              if (rc->zoom_prop) {
-                RNA_property_float_get_array(&rc->zoom_ptr, rc->zoom_prop, zoom);
-                delta[0] /= zoom[0];
-              }
+  handled = false;
+  switch (event->type) {
+    case EVT_ESCKEY:
+    case RIGHTMOUSE:
+      /* canceled; restore original value */
+      radial_control_set_value(rc, rc->initial_value);
+      ret = OPERATOR_CANCELLED;
+      break;
 
-              dist = len_v2(delta);
+    case LEFTMOUSE:
+    case EVT_PADENTER:
+    case EVT_RETKEY:
+      /* done; value already set */
+      RNA_property_update(C, &rc->ptr, rc->prop);
+      ret = OPERATOR_FINISHED;
+      break;
 
-              delta[0] = event->x - rc->slow_mouse[0];
+    case MOUSEMOVE:
+      if (!has_numInput) {
+        if (rc->slow_mode) {
+          if (rc->subtype == PROP_ANGLE) {
+            float position[2] = {event->x, event->y};
 
-              if (rc->zoom_prop) {
-                delta[0] /= zoom[0];
-              }
+            /* calculate the initial angle here first */
+            delta[0] = rc->initial_mouse[0] - rc->slow_mouse[0];
+            delta[1] = rc->initial_mouse[1] - rc->slow_mouse[1];
 
-              dist = dist + 0.1f * (delta[0]);
-            }
+            /* precision angle gets calculated from dial and gets added later */
+            angle_precision = -0.1f * BLI_dial_angle(rc->dial, position);
           }
           else {
-            delta[0] = rc->initial_mouse[0] - event->x;
-            delta[1] = rc->initial_mouse[1] - event->y;
+            delta[0] = rc->initial_mouse[0] - rc->slow_mouse[0];
+            delta[1] = 0.0f;
+
             if (rc->zoom_prop) {
               RNA_property_float_get_array(&rc->zoom_ptr, rc->zoom_prop, zoom);
               delta[0] /= zoom[0];
-              delta[1] /= zoom[1];
             }
-            if (rc->subtype == PROP_ANGLE) {
-              dist = len_v2(delta);
-            }
-            else {
-              dist = clamp_f(-delta[0], 0.0f, FLT_MAX);
+
+            dist = len_v2(delta);
+
+            delta[0] = event->x - rc->slow_mouse[0];
+
+            if (rc->zoom_prop) {
+              delta[0] /= zoom[0];
             }
-          }
 
-          /* calculate new value and apply snapping  */
-          switch (rc->subtype) {
-            case PROP_NONE:
-            case PROP_DISTANCE:
-            case PROP_PIXEL:
-              new_value = dist;
-              if (snap) {
-                new_value = ((int)new_value + 5) / 10 * 10;
-              }
-              break;
-            case PROP_PERCENTAGE:
-              new_value = ((dist - WM_RADIAL_CONTROL_DISPLAY_MIN_SIZE) /
-                           WM_RADIAL_CONTROL_DISPLAY_WIDTH) *
-                          100.0f;
-              if (snap) {
-                new_value = ((int)(new_value + 2.5f)) / 5 * 5;
-              }
-              break;
-            case PROP_FACTOR:
-              new_value = (WM_RADIAL_CONTROL_DISPLAY_SIZE - dist) /
-                          WM_RADIAL_CONTROL_DISPLAY_WIDTH;
-              if (snap) {
-                new_value = ((int)ceil(new_value * 10.f) * 10.0f) / 100.f;
-              }
-              /* Invert new value to increase the factor moving the mouse to the right */
-              new_value = 1 - new_value;
-              break;
-            case PROP_ANGLE:
-              new_value = atan2f(delta[1], delta[0]) + (float)M_PI + angle_precision;
-              new_value = fmod(new_value, 2.0f * (float)M_PI);
-              if (new_value < 0.0f) {
-                new_value += 2.0f * (float)M_PI;
-              }
-              if (snap) {
-                new_value = DEG2RADF(((int)RAD2DEGF(new_value) + 5) / 10 * 10);
-              }
-              break;
-            default:
-              new_value = dist; /* dummy value, should this ever happen? - campbell */
-              break;
+            dist = dist + 0.1f * (delta[0]);
           }
-
-          /* clamp and update */
-          CLAMP(new_value, rc->min_value, rc->max_value);
-          radial_control_set_value(rc, new_value);
-          rc->current_value = new_value;
-          handled = true;
-          break;
         }
-        break;
-
-      case EVT_LEFTSHIFTKEY:
-      case EVT_RIGHTSHIFTKEY: {
-        if (event->val == KM_PRESS) {
-          rc->slow_mouse[0] = event->x;
-          rc->slow_mouse[1] = event->y;
-          rc->slow_mode = true;
+        else {
+          delta[0] = rc->initial_mouse[0] - event->x;
+          delta[1] = rc->initial_mouse[1] - event->y;
+          if (rc->zoom_prop) {
+            RNA_property_float_get_array(&rc->zoom_ptr, rc->zoom_prop, zoom);
+            delta[0] /= zoom[0];
+            delta[1] /= zoom[1];
+          }
           if (rc->subtype == PROP_ANGLE) {
-            float initial_position[2] = {UNPACK2(rc->initial_mouse)};
-            float current_position[2] = {UNPACK2(rc->slow_mouse)};
-            rc->dial = BLI_dial_initialize(initial_position, 0.0f);
-            /* immediately set the position to get a an initial direction */
-            BLI_dial_angle(rc->dial, current_position);
+            dist = len_v2(delta);
           }
-          handled = true;
-        }
-        if (event->val == KM_RELEASE) {
-          rc->slow_mode = false;
-          handled = true;
-          if (rc->dial) {
-            MEM_freeN(rc->dial);
-            rc->dial = NULL;
+          else {
+            dist = clamp_f(-delta[0], 0.0f, FLT_MAX);
           }
         }
+
+        /* calculate new value and apply snapping  */
+        switch (rc->subtype) {
+          case PROP_NONE:
+          case PROP_DISTANCE:
+          case PROP_PIXEL:
+            new_value = dist;
+            if (snap) {
+              new_value = ((int)new_value + 5) / 10 * 10;
+            }
+            break;
+          case PROP_PERCENTAGE:
+            new_value = ((dist - WM_RADIAL_CONTROL_DISPLAY_MIN_SIZE) /
+                         WM_RADIAL_CONTROL_DISPLAY_WIDTH) *
+                        100.0f;
+            if (snap) {
+              new_value = ((int)(new_value + 2.5f)) / 5 * 5;
+            }
+            break;
+          case PROP_FACTOR:
+            new_value = (WM_RADIAL_CONTROL_DISPLAY_SIZE - dist) / WM_RADIAL_CONTROL_DISPLAY_WIDTH;
+            if (snap) {
+              new_value = ((int)ceil(new_value * 10.f) * 10.0f) / 100.f;
+            }
+            /* Invert new value to increase the factor moving the mouse to the right */
+            new_value = 1 - new_value;
+            break;
+          case PROP_ANGLE:
+            new_value = atan2f(delta[1], delta[0]) + (float)M_PI + angle_precision;
+            new_value = fmod(new_value, 2.0f * (float)M_PI);
+            if (new_value < 0.0f) {
+              new_value += 2.0f * (float)M_PI;
+            }
+            if (snap) {
+              new_value = DEG2RADF(((int)RAD2DEGF(new_value) + 5) / 10 * 10);
+            }
+            break;
+          default:
+            new_value = dist; /* dummy value, should this ever happen? - campbell */
+            break;
+        }
+
+        /* clamp and update */
+        CLAMP(new_value, rc->min_value, rc->max_value);
+        radial_control_set_value(rc, new_value);
+        rc->current_value = new_value;
+        handled = true;
         break;
       }
+      break;
+
+    case EVT_LEFTSHIFTKEY:
+    case EVT_RIGHTSHIFTKEY: {
+      if (event->val == KM_PRESS) {
+        rc->slow_mouse[0] = event->x;
+        rc->slow_mouse[1] = event->y;
+        rc->slow_mode = true;
+        if (rc->subtype == PROP_ANGLE) {
+          float initial_position[2] = {UNPACK2(rc->initial_mouse)};
+          float current_position[2] = {UNPACK2(rc->slow_mouse)};
+          rc->dial = BLI_dial_init(initial_position, 0.0f);
+          /* immediately set the position to get a an initial direction */
+          BLI_dial_angle(rc->dial, current_position);
+        }
+        handled = true;
+      }
+      if (event->val == KM_RELEASE) {
+        rc->slow_mode = false;
+        handled = true;
+        if (rc->dial) {
+          MEM_freeN(rc->dial);
+          rc->dial = NULL;
+        }
+      }
+      break;
     }
+  }
 
-    /* Modal numinput inactive, try to handle numeric inputs last... */
-    if (!handled && event->val == KM_PRESS && handleNumInput(C, &rc->num_input, event)) {
-      applyNumInput(&rc->num_input, &numValue);
+  /* Modal numinput inactive, try to handle numeric inputs last... */
+  if (!handled && event->val == KM_PRESS && handleNumInput(C, &rc->num_input, event)) {
+    applyNumInput(&rc->num_input, &numValue);
 
-      if (rc->subtype == PROP_ANGLE) {
-        numValue = fmod(numValue, 2.0f * (float)M_PI);
-        if (numValue < 0.0f) {
-          numValue += 2.0f * (float)M_PI;
-        }
+    if (rc->subtype == PROP_ANGLE) {
+      numValue = fmod(numValue, 2.0f * (float)M_PI);
+      if (numValue < 0.0f) {
+        numValue += 2.0f * (float)M_PI;
       }
+    }
 
-      CLAMP(numValue, rc->min_value, rc->max_value);
-      new_value = numValue;
+    CLAMP(numValue, rc->min_value, rc->max_value);
+    new_value = numValue;
 
-      radial_control_set_value(rc, new_value);
+    radial_control_set_value(rc, new_value);
 
-      rc->current_value = new_value;
-      radial_control_update_header(op, C);
-      return OPERATOR_RUNNING_MODAL;
-    }
+    rc->current_value = new_value;
+    radial_control_update_header(op, C);
+    return OPERATOR_RUNNING_MODAL;
   }
 
   ED_region_tag_redraw(CTX_wm_region(C));
@@ -3919,6 +3904,7 @@ static void gesture_box_modal_keymap(wmKeyConfig *keyconf)
   WM_modalkeymap_assign(keymap, "CLIP_OT_select_box");
   WM_modalkeymap_assign(keymap, "CLIP_OT_graph_select_box");
   WM_modalkeymap_assign(keymap, "MASK_OT_select_box");
+  WM_modalkeymap_assign(keymap, "PAINT_OT_mask_box_gesture");
   WM_modalkeymap_assign(keymap, "VIEW2D_OT_zoom_border");
   WM_modalkeymap_assign(keymap, "VIEW3D_OT_clip_border");
   WM_modalkeymap_assign(keymap, "VIEW3D_OT_render_border");
diff --git a/source/blender/windowmanager/intern/wm_platform_support.h b/source/blender/windowmanager/intern/wm_platform_support.h
index a8e20f6bcdf..6346f517343 100644
--- a/source/blender/windowmanager/intern/wm_platform_support.h
+++ b/source/blender/windowmanager/intern/wm_platform_support.h
@@ -20,11 +20,8 @@
 /** \file
  * \ingroup wm
  */
-#ifndef __WM_PLATFORM_SUPPORT_H__
-#define __WM_PLATFORM_SUPPORT_H__
+#pragma once
 
 #include "BLI_sys_types.h"
 
 bool WM_platform_support_perform_checks(void);
-
-#endif
diff --git a/source/blender/windowmanager/intern/wm_playanim.c b/source/blender/windowmanager/intern/wm_playanim.c
index 948e8d9fb74..d0a70596957 100644
--- a/source/blender/windowmanager/intern/wm_playanim.c
+++ b/source/blender/windowmanager/intern/wm_playanim.c
@@ -58,6 +58,7 @@
 #include "BIF_glutil.h"
 
 #include "GPU_context.h"
+#include "GPU_framebuffer.h"
 #include "GPU_immediate.h"
 #include "GPU_immediate_util.h"
 #include "GPU_init_exit.h"
@@ -309,13 +310,14 @@ static void playanim_toscreen(
   CLAMP(offs_x, 0.0f, 1.0f);
   CLAMP(offs_y, 0.0f, 1.0f);
 
-  glClearColor(0.1, 0.1, 0.1, 0.0);
-  glClear(GL_COLOR_BUFFER_BIT);
+  GPU_clear_color(0.1, 0.1, 0.1, 0.0);
+  GPU_clear(GPU_COLOR_BIT);
 
   /* checkerboard for case alpha */
   if (ibuf->planes == 32) {
     GPU_blend(true);
-    glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+    GPU_blend_set_func_separate(
+        GPU_SRC_ALPHA, GPU_ONE_MINUS_SRC_ALPHA, GPU_ONE, GPU_ONE_MINUS_SRC_ALPHA);
 
     imm_draw_box_checker_2d_ex(offs_x,
                                offs_y,
@@ -333,9 +335,8 @@ static void playanim_toscreen(
                    offs_y + (ps->draw_flip[1] ? span_y : 0.0f),
                    ibuf->x,
                    ibuf->y,
-                   GL_RGBA,
-                   GL_UNSIGNED_BYTE,
-                   GL_NEAREST,
+                   GPU_RGBA8,
+                   false,
                    ibuf->rect,
                    ((ps->draw_flip[0] ? -1.0f : 1.0f)) * (ps->zoom / (float)ps->win_x),
                    ((ps->draw_flip[1] ? -1.0f : 1.0f)) * (ps->zoom / (float)ps->win_y),
@@ -542,7 +543,6 @@ static void build_pict_list_ex(
       totframes--;
     }
   }
-  return;
 }
 
 static void build_pict_list(PlayState *ps, const char *first, int totframes, int fstep, int fontid)
@@ -1059,8 +1059,8 @@ static int ghost_event_proc(GHOST_EventHandle evt, GHOST_TUserDataPtr ps_void)
       /* zoom always show entire image */
       ps->zoom = MIN2(zoomx, zoomy);
 
-      glViewport(0, 0, ps->win_x, ps->win_y);
-      glScissor(0, 0, ps->win_x, ps->win_y);
+      GPU_viewport(0, 0, ps->win_x, ps->win_y);
+      GPU_scissor(0, 0, ps->win_x, ps->win_y);
 
       playanim_gl_matrix();
 
@@ -1316,13 +1316,13 @@ static char *wm_main_playanim_intern(int argc, const char **argv)
     maxwiny = ibuf->y * (1 + (maxwiny / ibuf->y));
   }
 
-  glClearColor(0.1, 0.1, 0.1, 0.0);
-  glClear(GL_COLOR_BUFFER_BIT);
+  GPU_clear_color(0.1, 0.1, 0.1, 0.0);
+  GPU_clear(GPU_COLOR_BIT);
 
   int win_x, win_y;
   playanim_window_get_size(&win_x, &win_y);
-  glViewport(0, 0, win_x, win_y);
-  glScissor(0, 0, win_x, win_y);
+  GPU_viewport(0, 0, win_x, win_y);
+  GPU_scissor(0, 0, win_x, win_y);
   playanim_gl_matrix();
 
   GHOST_SwapWindowBuffers(g_WS.ghost_window);
diff --git a/source/blender/windowmanager/intern/wm_stereo.c b/source/blender/windowmanager/intern/wm_stereo.c
index 8ae343d5eb5..9667ed5b631 100644
--- a/source/blender/windowmanager/intern/wm_stereo.c
+++ b/source/blender/windowmanager/intern/wm_stereo.c
@@ -40,6 +40,7 @@
 
 #include "ED_screen.h"
 
+#include "GPU_extensions.h"
 #include "GPU_immediate.h"
 #include "GPU_texture.h"
 #include "GPU_viewport.h"
@@ -147,13 +148,6 @@ void wm_stereo3d_draw_topbottom(wmWindow *win, int view)
   immUnbindProgram();
 }
 
-static bool wm_stereo3d_quadbuffer_supported(void)
-{
-  GLboolean stereo = GL_FALSE;
-  glGetBooleanv(GL_STEREO, &stereo);
-  return stereo == GL_TRUE;
-}
-
 static bool wm_stereo3d_is_fullscreen_required(eStereoDisplayMode stereo_display)
 {
   return ELEM(stereo_display, S3D_DISPLAY_SIDEBYSIDE, S3D_DISPLAY_TOPBOTTOM);
@@ -325,7 +319,7 @@ int wm_stereo3d_set_exec(bContext *C, wmOperator *op)
     }
     /* pageflip requires a new window to be created with the proper OS flags */
     else if ((win_dst = wm_window_copy_test(C, win_src, false, false))) {
-      if (wm_stereo3d_quadbuffer_supported()) {
+      if (GPU_stereo_quadbuffer_support()) {
         BKE_report(op->reports, RPT_INFO, "Quad-buffer window successfully created");
       }
       else {
@@ -359,12 +353,11 @@ int wm_stereo3d_set_exec(bContext *C, wmOperator *op)
     WM_event_add_notifier(C, NC_WINDOW, NULL);
     return OPERATOR_FINISHED;
   }
-  else {
-    /* without this, the popup won't be freed freed properly T44688 */
-    CTX_wm_window_set(C, win_src);
-    win_src->stereo3d_format->display_mode = prev_display_mode;
-    return OPERATOR_CANCELLED;
-  }
+
+  /* without this, the popup won't be freed freed properly T44688 */
+  CTX_wm_window_set(C, win_src);
+  win_src->stereo3d_format->display_mode = prev_display_mode;
+  return OPERATOR_CANCELLED;
 }
 
 int wm_stereo3d_set_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
@@ -374,9 +367,7 @@ int wm_stereo3d_set_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(ev
   if (wm_stereo3d_set_properties(C, op)) {
     return wm_stereo3d_set_exec(C, op);
   }
-  else {
-    return WM_operator_props_dialog_popup(C, op, 250);
-  }
+  return WM_operator_props_dialog_popup(C, op, 250);
 }
 
 void wm_stereo3d_set_draw(bContext *UNUSED(C), wmOperator *op)
diff --git a/source/blender/windowmanager/intern/wm_subwindow.c b/source/blender/windowmanager/intern/wm_subwindow.c
index 5483d79c075..0cb76404258 100644
--- a/source/blender/windowmanager/intern/wm_subwindow.c
+++ b/source/blender/windowmanager/intern/wm_subwindow.c
@@ -29,7 +29,6 @@
 #include "DNA_screen_types.h"
 #include "DNA_windowmanager_types.h"
 
-#include "GPU_glew.h"
 #include "GPU_matrix.h"
 #include "GPU_viewport.h"
 
@@ -40,8 +39,8 @@ void wmViewport(const rcti *winrct)
   int width = BLI_rcti_size_x(winrct) + 1;
   int height = BLI_rcti_size_y(winrct) + 1;
 
-  glViewport(winrct->xmin, winrct->ymin, width, height);
-  glScissor(winrct->xmin, winrct->ymin, width, height);
+  GPU_viewport(winrct->xmin, winrct->ymin, width, height);
+  GPU_scissor(winrct->xmin, winrct->ymin, width, height);
 
   wmOrtho2_pixelspace(width, height);
   GPU_matrix_identity_set();
@@ -79,8 +78,8 @@ void wmPartialViewport(rcti *drawrct, const rcti *winrct, const rcti *partialrct
     scissor_height += 1;
   }
 
-  glViewport(0, 0, width, height);
-  glScissor(x, y, scissor_width, scissor_height);
+  GPU_viewport(0, 0, width, height);
+  GPU_scissor(x, y, scissor_width, scissor_height);
 
   wmOrtho2_pixelspace(width, height);
   GPU_matrix_identity_set();
@@ -91,8 +90,8 @@ void wmWindowViewport(wmWindow *win)
   int width = WM_window_pixels_x(win);
   int height = WM_window_pixels_y(win);
 
-  glViewport(0, 0, width, height);
-  glScissor(0, 0, width, height);
+  GPU_viewport(0, 0, width, height);
+  GPU_scissor(0, 0, width, height);
 
   wmOrtho2_pixelspace(width, height);
   GPU_matrix_identity_set();
diff --git a/source/blender/windowmanager/intern/wm_window.c b/source/blender/windowmanager/intern/wm_window.c
index e1b2285313c..e0dcd746aea 100644
--- a/source/blender/windowmanager/intern/wm_window.c
+++ b/source/blender/windowmanager/intern/wm_window.c
@@ -89,6 +89,7 @@
 #include "GPU_init_exit.h"
 #include "GPU_platform.h"
 #include "GPU_state.h"
+#include "GPU_texture.h"
 
 #include "UI_resources.h"
 
@@ -354,10 +355,8 @@ wmWindow *wm_window_copy_test(bContext *C,
     WM_event_add_notifier_ex(wm, CTX_wm_window(C), NC_WINDOW | NA_ADDED, NULL);
     return win_dst;
   }
-  else {
-    wm_window_close(C, wm, win_dst);
-    return NULL;
-  }
+  wm_window_close(C, wm, win_dst);
+  return NULL;
 }
 
 /** \} */
@@ -648,10 +647,10 @@ static void wm_window_ghostwindow_add(wmWindowManager *wm,
     }
 #endif
     /* until screens get drawn, make it nice gray */
-    glClearColor(0.55, 0.55, 0.55, 0.0);
+    GPU_clear_color(0.55, 0.55, 0.55, 1.0f);
     /* Crash on OSS ATI: bugs.launchpad.net/ubuntu/+source/mesa/+bug/656100 */
     if (!GPU_type_matches(GPU_DEVICE_ATI, GPU_OS_UNIX, GPU_DRIVER_OPENSOURCE)) {
-      glClear(GL_COLOR_BUFFER_BIT);
+      GPU_clear(GPU_COLOR_BIT);
     }
 
     /* needed here, because it's used before it reads userdef */
@@ -812,9 +811,7 @@ static bool wm_window_update_size_position(wmWindow *win)
     win->posy = posy;
     return true;
   }
-  else {
-    return false;
-  }
+  return false;
 }
 
 /**
@@ -839,11 +836,10 @@ wmWindow *WM_window_open(bContext *C, const rcti *rect)
   if (win->ghostwin) {
     return win;
   }
-  else {
-    wm_window_close(C, wm, win);
-    CTX_wm_window_set(C, win_prev);
-    return NULL;
-  }
+
+  wm_window_close(C, wm, win);
+  CTX_wm_window_set(C, win_prev);
+  return NULL;
 }
 
 /**
@@ -968,13 +964,12 @@ wmWindow *WM_window_open_temp(bContext *C,
     GHOST_SetTitle(win->ghostwin, title);
     return win;
   }
-  else {
-    /* very unlikely! but opening a new window can fail */
-    wm_window_close(C, wm, win);
-    CTX_wm_window_set(C, win_prev);
 
-    return NULL;
-  }
+  /* very unlikely! but opening a new window can fail */
+  wm_window_close(C, wm, win);
+  CTX_wm_window_set(C, win_prev);
+
+  return NULL;
 }
 
 /* ****************** Operators ****************** */
@@ -1205,7 +1200,7 @@ static int ghost_event_proc(GHOST_EventHandle evt, GHOST_TUserDataPtr C_void_ptr
     /* Ghost now can call this function for life resizes,
      * but it should return if WM didn't initialize yet.
      * Can happen on file read (especially full size window). */
-    if ((wm->initialized & WM_WINDOW_IS_INITIALIZED) == 0) {
+    if ((wm->initialized & WM_WINDOW_IS_INIT) == 0) {
       return 1;
     }
     if (!ghostwin) {
@@ -1214,15 +1209,13 @@ static int ghost_event_proc(GHOST_EventHandle evt, GHOST_TUserDataPtr C_void_ptr
       puts("<!> event has no window");
       return 1;
     }
-    else if (!GHOST_ValidWindow(g_system, ghostwin)) {
+    if (!GHOST_ValidWindow(g_system, ghostwin)) {
       /* XXX - should be checked, why are we getting an event here, and */
       /* what is it? */
       puts("<!> event has invalid window");
       return 1;
     }
-    else {
-      win = GHOST_GetWindowUserData(ghostwin);
-    }
+    win = GHOST_GetWindowUserData(ghostwin);
 
     switch (type) {
       case GHOST_kEventWindowDeactivate:
@@ -2054,9 +2047,7 @@ void WM_window_pixel_sample_read(const wmWindowManager *wm,
     GPU_context_active_set(win->gpuctx);
   }
 
-  glReadBuffer(GL_FRONT);
-  glReadPixels(pos[0], pos[1], 1, 1, GL_RGB, GL_FLOAT, r_col);
-  glReadBuffer(GL_BACK);
+  GPU_frontbuffer_read_pixels(pos[0], pos[1], 1, 1, 3, GPU_DATA_FLOAT, r_col);
 
   if (setup_context) {
     if (wm->windrawable) {
@@ -2089,10 +2080,7 @@ uint *WM_window_pixels_read(wmWindowManager *wm, wmWindow *win, int r_size[2])
   const uint rect_len = r_size[0] * r_size[1];
   uint *rect = MEM_mallocN(sizeof(*rect) * rect_len, __func__);
 
-  glReadBuffer(GL_FRONT);
-  glReadPixels(0, 0, r_size[0], r_size[1], GL_RGBA, GL_UNSIGNED_BYTE, rect);
-  glFinish();
-  glReadBuffer(GL_BACK);
+  GPU_frontbuffer_read_pixels(0, 0, r_size[0], r_size[1], 4, GPU_DATA_UNSIGNED_BYTE, rect);
 
   if (setup_context) {
     if (wm->windrawable) {
diff --git a/source/blender/windowmanager/intern/wm_window_private.h b/source/blender/windowmanager/intern/wm_window_private.h
index 115539861d7..c208d07ee37 100644
--- a/source/blender/windowmanager/intern/wm_window_private.h
+++ b/source/blender/windowmanager/intern/wm_window_private.h
@@ -20,8 +20,7 @@
 /** \file
  * \ingroup wm
  */
-#ifndef __WM_WINDOW_PRIVATE_H__
-#define __WM_WINDOW_PRIVATE_H__
+#pragma once
 
 #include "BLI_sys_types.h"
 #include "GHOST_Types.h"
@@ -38,5 +37,3 @@ void WM_ghost_show_message_box(const char *title,
                                const char *continue_label,
                                const char *link,
                                GHOST_DialogOptions dialog_options);
-
-#endif
diff --git a/source/blender/windowmanager/message_bus/intern/wm_message_bus_intern.h b/source/blender/windowmanager/message_bus/intern/wm_message_bus_intern.h
index ccf7034e3e0..24c0192fe14 100644
--- a/source/blender/windowmanager/message_bus/intern/wm_message_bus_intern.h
+++ b/source/blender/windowmanager/message_bus/intern/wm_message_bus_intern.h
@@ -18,8 +18,7 @@
  * \ingroup wm
  */
 
-#ifndef __WM_MESSAGE_BUS_INTERN_H__
-#define __WM_MESSAGE_BUS_INTERN_H__
+#pragma once
 
 #include "../wm_message_bus.h"
 
@@ -47,5 +46,3 @@ BLI_INLINE wmMsg *wm_msg_subscribe_value_msg_cast_mut(wmMsgSubscribeKey *key)
 {
   return &((wmMsgSubscribeKey_Generic *)key)->msg;
 }
-
-#endif /* __WM_MESSAGE_BUS_INTERN_H__ */
diff --git a/source/blender/windowmanager/message_bus/wm_message_bus.h b/source/blender/windowmanager/message_bus/wm_message_bus.h
index 8020be3017a..23a53eace52 100644
--- a/source/blender/windowmanager/message_bus/wm_message_bus.h
+++ b/source/blender/windowmanager/message_bus/wm_message_bus.h
@@ -18,8 +18,7 @@
  * \ingroup wm
  */
 
-#ifndef __WM_MESSAGE_BUS_H__
-#define __WM_MESSAGE_BUS_H__
+#pragma once
 
 #include "RNA_types.h"
 #include <stdio.h>
@@ -34,6 +33,10 @@ struct wmMsgSubscribeKey;
 struct wmMsgSubscribeValue;
 struct wmMsgSubscribeValueLink;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef void (*wmMsgNotifyFn)(struct bContext *C,
                               struct wmMsgSubscribeKey *msg_key,
                               struct wmMsgSubscribeValue *msg_val);
@@ -287,4 +290,6 @@ void WM_msg_publish_ID(struct wmMsgBus *mbus, struct ID *id);
   } \
   ((void)0)
 
-#endif /* __WM_MESSAGE_BUS_H__ */
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/windowmanager/wm.h b/source/blender/windowmanager/wm.h
index 16aa5cb44db..baa47098bd3 100644
--- a/source/blender/windowmanager/wm.h
+++ b/source/blender/windowmanager/wm.h
@@ -21,8 +21,7 @@
  * \ingroup wm
  */
 
-#ifndef __WM_H__
-#define __WM_H__
+#pragma once
 
 struct ARegion;
 struct ReportList;
@@ -30,6 +29,10 @@ struct wmWindow;
 
 #include "gizmo/wm_gizmo_wmapi.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct wmPaintCursor {
   struct wmPaintCursor *next, *prev;
 
@@ -97,4 +100,6 @@ void wm_stereo3d_set_cancel(bContext *C, wmOperator *op);
 void wm_open_init_load_ui(wmOperator *op, bool use_prefs);
 void wm_open_init_use_scripts(wmOperator *op, bool use_prefs);
 
+#ifdef __cplusplus
+}
 #endif
diff --git a/source/blender/windowmanager/wm_cursors.h b/source/blender/windowmanager/wm_cursors.h
index 7a28aeb3c70..b85616deda5 100644
--- a/source/blender/windowmanager/wm_cursors.h
+++ b/source/blender/windowmanager/wm_cursors.h
@@ -21,12 +21,15 @@
  * \ingroup wm
  */
 
-#ifndef __WM_CURSORS_H__
-#define __WM_CURSORS_H__
+#pragma once
 
 struct wmEvent;
 struct wmWindow;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef enum WMCursorType {
   WM_CURSOR_DEFAULT = 1,
   WM_CURSOR_TEXT_EDIT,
@@ -77,4 +80,6 @@ typedef enum WMCursorType {
 void wm_init_cursor_data(void);
 bool wm_cursor_arrow_move(struct wmWindow *win, const struct wmEvent *event);
 
-#endif /* __WM_CURSORS_H__ */
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/windowmanager/wm_draw.h b/source/blender/windowmanager/wm_draw.h
index ff2fc25333a..4997361b485 100644
--- a/source/blender/windowmanager/wm_draw.h
+++ b/source/blender/windowmanager/wm_draw.h
@@ -21,15 +21,16 @@
  * \ingroup wm
  */
 
-#ifndef __WM_DRAW_H__
-#define __WM_DRAW_H__
-
-#include "GPU_glew.h"
+#pragma once
 
 struct GPUOffScreen;
 struct GPUTexture;
 struct GPUViewport;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct wmDrawBuffer {
   struct GPUOffScreen *offscreen;
   struct GPUViewport *viewport;
@@ -50,4 +51,6 @@ void wm_draw_region_test(struct bContext *C, struct ScrArea *area, struct ARegio
 
 struct GPUTexture *wm_draw_region_texture(struct ARegion *region, int view);
 
-#endif /* __WM_DRAW_H__ */
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/windowmanager/wm_event_system.h b/source/blender/windowmanager/wm_event_system.h
index efcf40d03eb..787c840de8a 100644
--- a/source/blender/windowmanager/wm_event_system.h
+++ b/source/blender/windowmanager/wm_event_system.h
@@ -21,8 +21,7 @@
  * \ingroup wm
  */
 
-#ifndef __WM_EVENT_SYSTEM_H__
-#define __WM_EVENT_SYSTEM_H__
+#pragma once
 
 /* return value of handler-operator call */
 #define WM_HANDLER_CONTINUE 0
@@ -34,6 +33,10 @@ struct ARegion;
 struct GHOST_TabletData;
 struct ScrArea;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* wmKeyMap is in DNA_windowmanager.h, it's saveable */
 
 /** Custom types for handlers, for signaling, freeing */
@@ -165,4 +168,6 @@ void wm_dropbox_free(void);
 void wm_drags_check_ops(bContext *C, const wmEvent *event);
 void wm_drags_draw(bContext *C, wmWindow *win, rcti *rect);
 
-#endif /* __WM_EVENT_SYSTEM_H__ */
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/windowmanager/wm_event_types.h b/source/blender/windowmanager/wm_event_types.h
index ffed86abfe7..ed8f39fea48 100644
--- a/source/blender/windowmanager/wm_event_types.h
+++ b/source/blender/windowmanager/wm_event_types.h
@@ -23,8 +23,11 @@
  * Blender copied the conventions quite some, and expanded it with internal new defines (ton)
  */
 
-#ifndef __WM_EVENT_TYPES_H__
-#define __WM_EVENT_TYPES_H__
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 /* customdata type */
 enum {
@@ -489,4 +492,6 @@ enum {
   GESTURE_MODAL_CIRCLE_SIZE = 11,
 };
 
-#endif /* __WM_EVENT_TYPES_H__ */
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/windowmanager/wm_files.h b/source/blender/windowmanager/wm_files.h
index 42eab35cdb9..d54090a6025 100644
--- a/source/blender/windowmanager/wm_files.h
+++ b/source/blender/windowmanager/wm_files.h
@@ -21,13 +21,16 @@
  * \ingroup wm
  */
 
-#ifndef __WM_FILES_H__
-#define __WM_FILES_H__
+#pragma once
 
 struct Main;
 struct wmGenericCallback;
 struct wmOperatorType;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* wm_files.c */
 void wm_history_file_read(void);
 void wm_homefile_read(struct bContext *C,
@@ -68,4 +71,6 @@ void WM_OT_append(struct wmOperatorType *ot);
 void WM_OT_lib_relocate(struct wmOperatorType *ot);
 void WM_OT_lib_reload(struct wmOperatorType *ot);
 
-#endif /* __WM_FILES_H__ */
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/windowmanager/wm_surface.h b/source/blender/windowmanager/wm_surface.h
index bc1cc825e4b..06c29231361 100644
--- a/source/blender/windowmanager/wm_surface.h
+++ b/source/blender/windowmanager/wm_surface.h
@@ -22,11 +22,14 @@
  * Container to manage painting in an offscreen context.
  */
 
-#ifndef __WM_SURFACE_H__
-#define __WM_SURFACE_H__
+#pragma once
 
 struct bContext;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct wmSurface {
   struct wmSurface *next, *prev;
 
@@ -59,4 +62,6 @@ void wm_surface_clear_drawable(void);
 void wm_surface_set_drawable(wmSurface *surface, bool activate);
 void wm_surface_reset_drawable(void);
 
-#endif /* __WM_SURFACE_H__ */
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/windowmanager/wm_window.h b/source/blender/windowmanager/wm_window.h
index 5ca5711b4f2..336db7edb50 100644
--- a/source/blender/windowmanager/wm_window.h
+++ b/source/blender/windowmanager/wm_window.h
@@ -21,11 +21,14 @@
  * \ingroup wm
  */
 
-#ifndef __WM_WINDOW_H__
-#define __WM_WINDOW_H__
+#pragma once
 
 struct wmOperator;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* *************** internal api ************** */
 void wm_ghost_init(bContext *C);
 void wm_ghost_exit(void);
@@ -85,4 +88,6 @@ int wm_window_new_main_exec(bContext *C, struct wmOperator *op);
 
 void wm_test_autorun_warning(bContext *C);
 
-#endif /* __WM_WINDOW_H__ */
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/windowmanager/xr/intern/wm_xr_intern.h b/source/blender/windowmanager/xr/intern/wm_xr_intern.h
index 9b7e9a15948..9b7b81f769a 100644
--- a/source/blender/windowmanager/xr/intern/wm_xr_intern.h
+++ b/source/blender/windowmanager/xr/intern/wm_xr_intern.h
@@ -18,8 +18,7 @@
  * \ingroup wm
  */
 
-#ifndef __WM_XR_INTERN_H__
-#define __WM_XR_INTERN_H__
+#pragma once
 
 #include "CLG_log.h"
 
@@ -92,5 +91,3 @@ void wm_xr_session_gpu_binding_context_destroy(GHOST_ContextHandle context);
 
 void wm_xr_pose_to_viewmat(const GHOST_XrPose *pose, float r_viewmat[4][4]);
 void wm_xr_draw_view(const GHOST_XrDrawViewInfo *draw_view, void *customdata);
-
-#endif
diff --git a/source/blender/windowmanager/xr/intern/wm_xr_session.c b/source/blender/windowmanager/xr/intern/wm_xr_session.c
index 1baac10dbd8..b44f006cde8 100644
--- a/source/blender/windowmanager/xr/intern/wm_xr_session.c
+++ b/source/blender/windowmanager/xr/intern/wm_xr_session.c
@@ -41,8 +41,8 @@
 #include "wm_window.h"
 #include "wm_xr_intern.h"
 
-wmSurface *g_xr_surface = NULL;
-CLG_LogRef LOG = {"wm.xr"};
+static wmSurface *g_xr_surface = NULL;
+static CLG_LogRef LOG = {"wm.xr"};
 
 /* -------------------------------------------------------------------- */
 
@@ -159,6 +159,13 @@ static void wm_xr_session_draw_data_populate(wmXrData *xr_data,
   wm_xr_session_base_pose_calc(r_draw_data->scene, settings, &r_draw_data->base_pose);
 }
 
+typedef enum wmXrSessionStateEvent {
+  SESSION_STATE_EVENT_NONE = 0,
+  SESSION_STATE_EVENT_START,
+  SESSION_STATE_EVENT_RESET_TO_BASE_POSE,
+  SESSION_STATE_EVENT_POSITON_TRACKING_TOGGLE,
+} wmXrSessionStateEvent;
+
 static bool wm_xr_session_draw_data_needs_reset_to_base_pose(const wmXrSessionState *state,
                                                              const XrSessionSettings *settings)
 {
@@ -170,36 +177,63 @@ static bool wm_xr_session_draw_data_needs_reset_to_base_pose(const wmXrSessionSt
           (state->prev_base_pose_object != settings->base_pose_object));
 }
 
+static wmXrSessionStateEvent wm_xr_session_state_to_event(const wmXrSessionState *state,
+                                                          const XrSessionSettings *settings)
+{
+  if (!state->is_view_data_set) {
+    return SESSION_STATE_EVENT_START;
+  }
+  if (wm_xr_session_draw_data_needs_reset_to_base_pose(state, settings)) {
+    return SESSION_STATE_EVENT_RESET_TO_BASE_POSE;
+  }
+
+  const bool position_tracking_toggled = ((state->prev_settings_flag &
+                                           XR_SESSION_USE_POSITION_TRACKING) !=
+                                          (settings->flag & XR_SESSION_USE_POSITION_TRACKING));
+  if (position_tracking_toggled) {
+    return SESSION_STATE_EVENT_POSITON_TRACKING_TOGGLE;
+  }
+
+  return SESSION_STATE_EVENT_NONE;
+}
+
 void wm_xr_session_draw_data_update(const wmXrSessionState *state,
                                     const XrSessionSettings *settings,
                                     const GHOST_XrDrawViewInfo *draw_view,
                                     wmXrDrawData *draw_data)
 {
-  const bool position_tracking_toggled = ((state->prev_settings_flag &
-                                           XR_SESSION_USE_POSITION_TRACKING) !=
-                                          (settings->flag & XR_SESSION_USE_POSITION_TRACKING));
-  const bool use_position_tracking = settings->flag & XR_SESSION_USE_POSITION_TRACKING;
+  const wmXrSessionStateEvent event = wm_xr_session_state_to_event(state, settings);
+  const bool use_position_tracking = (settings->flag & XR_SESSION_USE_POSITION_TRACKING);
 
-  /* Set the eye position offset, it's used to offset the base pose when changing positional
-   * tracking. */
-  if (!state->is_view_data_set ||
-      wm_xr_session_draw_data_needs_reset_to_base_pose(state, settings)) {
-    /* Always use the exact base pose with no offset when starting the session. */
-    copy_v3_fl(draw_data->eye_position_ofs, 0.0f);
-  }
-  else if (position_tracking_toggled) {
-    if (use_position_tracking) {
+  switch (event) {
+    case SESSION_STATE_EVENT_START:
+      /* Always use the exact base pose with no offset when starting the session. */
       copy_v3_fl(draw_data->eye_position_ofs, 0.0f);
-    }
-    else {
-      /* Store the current local offset (local pose) so that we can apply that to the eyes. This
-       * way the eyes stay exactly where they are when disabling positional tracking. */
-      copy_v3_v3(draw_data->eye_position_ofs, draw_view->local_pose.position);
-    }
-  }
-  else if (!use_position_tracking) {
-    /* Keep previous offset when positional tracking is disabled. */
-    copy_v3_v3(draw_data->eye_position_ofs, state->prev_eye_position_ofs);
+      break;
+      /* This should be triggered by the VR add-on if a landmark changes. */
+    case SESSION_STATE_EVENT_RESET_TO_BASE_POSE:
+      if (use_position_tracking) {
+        /* Switch exactly to base pose, so use eye offset to cancel out current position delta. */
+        copy_v3_v3(draw_data->eye_position_ofs, draw_view->local_pose.position);
+      }
+      else {
+        copy_v3_fl(draw_data->eye_position_ofs, 0.0f);
+      }
+      break;
+    case SESSION_STATE_EVENT_POSITON_TRACKING_TOGGLE:
+      if (use_position_tracking) {
+        /* Keep the current position, and let the user move from there. */
+        copy_v3_v3(draw_data->eye_position_ofs, state->prev_eye_position_ofs);
+      }
+      else {
+        /* Back to the exact base-pose position. */
+        copy_v3_fl(draw_data->eye_position_ofs, 0.0f);
+      }
+      break;
+    case SESSION_STATE_EVENT_NONE:
+      /* Keep previous offset when positional tracking is disabled. */
+      copy_v3_v3(draw_data->eye_position_ofs, state->prev_eye_position_ofs);
+      break;
   }
 }
 
@@ -243,6 +277,8 @@ void wm_xr_session_state_update(const XrSessionSettings *settings,
   state->prev_base_pose_type = settings->base_pose_type;
   state->prev_base_pose_object = settings->base_pose_object;
   state->is_view_data_set = true;
+  /* Assume this was already done through wm_xr_session_draw_data_update(). */
+  state->force_reset_to_base_pose = false;
 }
 
 wmXrSessionState *WM_xr_session_state_handle_get(const wmXrData *xr)
@@ -299,9 +335,9 @@ bool WM_xr_session_state_viewer_pose_matrix_info_get(const wmXrData *xr,
 /**
  * \brief Call Ghost-XR to draw a frame
  *
- * Draw callback for the XR-session surface. It's expected to be called on each main loop iteration
- * and tells Ghost-XR to submit a new frame by drawing its views. Note that for drawing each view,
- * #wm_xr_draw_view() will be called through Ghost-XR (see GHOST_XrDrawViewFunc()).
+ * Draw callback for the XR-session surface. It's expected to be called on each main loop
+ * iteration and tells Ghost-XR to submit a new frame by drawing its views. Note that for drawing
+ * each view, #wm_xr_draw_view() will be called through Ghost-XR (see GHOST_XrDrawViewFunc()).
  */
 static void wm_xr_session_surface_draw(bContext *C)
 {
diff --git a/source/blender/windowmanager/xr/wm_xr.h b/source/blender/windowmanager/xr/wm_xr.h
index 33f79bc75b2..886f1315e8c 100644
--- a/source/blender/windowmanager/xr/wm_xr.h
+++ b/source/blender/windowmanager/xr/wm_xr.h
@@ -18,8 +18,7 @@
  * \ingroup wm
  */
 
-#ifndef __WM_XR_H__
-#define __WM_XR_H__
+#pragma once
 
 struct wmWindowManager;
 struct wmXrData;
@@ -31,5 +30,3 @@ bool wm_xr_init(wmWindowManager *wm);
 void wm_xr_exit(wmWindowManager *wm);
 void wm_xr_session_toggle(wmWindowManager *wm, wmXrSessionExitFn session_exit_fn);
 bool wm_xr_events_handle(wmWindowManager *wm);
-
-#endif