UI: Blend Preview Thumbnails Showing Workspace

This adds an option to use a capture of the entire main window as the
blend file preview thumbnail.

See D10492 for details and examples.

Differential Revision: https://developer.blender.org/D10492

Reviewed by Campbell Barton

release/datafiles/userdef/userdef_default.c

@@ -33,8 +33,8 @@
 const UserDef U_default = {
     .versionfile = BLENDER_FILE_VERSION,
     .subversionfile = BLENDER_FILE_SUBVERSION,
-    .flag = (USER_AUTOSAVE | USER_TOOLTIPS | USER_SAVE_PREVIEWS | USER_RELPATHS |
-             USER_RELEASECONFIRM | USER_SCRIPT_AUTOEXEC_DISABLE | USER_NONEGFRAMES),
+    .flag = (USER_AUTOSAVE | USER_TOOLTIPS | USER_RELPATHS | USER_RELEASECONFIRM |
+             USER_SCRIPT_AUTOEXEC_DISABLE | USER_NONEGFRAMES),
     .dupflag = USER_DUP_MESH | USER_DUP_CURVE | USER_DUP_SURF | USER_DUP_FONT | USER_DUP_MBALL |
                USER_DUP_LAMP | USER_DUP_ARM | USER_DUP_ACT | USER_DUP_LIGHTPROBE |
                USER_DUP_GPENCIL,
@@ -231,6 +231,7 @@ const UserDef U_default = {
     .collection_instance_empty_size = 1.0f,
 
     .statusbar_flag = STATUSBAR_SHOW_VERSION,
+    .file_preview_type = USER_FILE_PREVIEW_CAMERA,
 
     .runtime =
         {

release/scripts/startup/bl_ui/space_userpref.py

@@ -1414,7 +1414,7 @@ class USERPREF_PT_saveload_blend(SaveLoadPanel, CenterAlignMixIn, Panel):
 
         col = layout.column(heading="Save")
         col.prop(view, "use_save_prompt")
-        col.prop(paths, "use_save_preview_images")
+        col.prop(paths, "file_preview_type")
 
         col = layout.column(heading="Default To")
         col.prop(paths, "use_relative_paths")

source/blender/blenkernel/BKE_blender_version.h

@@ -39,7 +39,7 @@ extern "C" {
 
 /* Blender file format version. */
 #define BLENDER_FILE_VERSION BLENDER_VERSION
-#define BLENDER_FILE_SUBVERSION 20
+#define BLENDER_FILE_SUBVERSION 21
 
 /* Minimum Blender version that supports reading file written with the current
  * version. Older Blender versions will test this and show a warning if the file

source/blender/blenkernel/intern/icons.cc

@@ -634,7 +634,7 @@ void BKE_previewimg_blend_write(BlendWriter *writer, const PreviewImage *prv)
 
   PreviewImage prv_copy = *prv;
   /* don't write out large previews if not requested */
-  if (!(U.flag & USER_SAVE_PREVIEWS)) {
+  if (U.file_preview_type == USER_FILE_PREVIEW_NONE) {
     prv_copy.w[1] = 0;
     prv_copy.h[1] = 0;
     prv_copy.rect[1] = nullptr;

source/blender/blenloader/intern/versioning_userdef.c

@@ -885,6 +885,14 @@ void blo_do_versions_userdef(UserDef *userdef)
     BKE_addon_ensure(&userdef->addons, "pose_library");
   }
 
+  if (!USER_VERSION_ATLEAST(300, 21)) {
+    /* Deprecated userdef->flag USER_SAVE_PREVIEWS */
+    userdef->file_preview_type = (userdef->flag & USER_FLAG_UNUSED_5) ? USER_FILE_PREVIEW_CAMERA :
+                                                                        USER_FILE_PREVIEW_NONE;
+    /* Clear for reuse. */
+    userdef->flag &= ~USER_FLAG_UNUSED_5;
+  }
+
   /**
    * Versioning code until next subversion bump goes here.
    *

source/blender/makesdna/DNA_userdef_types.h

@@ -924,8 +924,9 @@ typedef struct UserDef {
   short sequencer_proxy_setup; /* eUserpref_SeqProxySetup */
 
   float collection_instance_empty_size;
-  char _pad10[3];
+  char _pad10[2];
 
+  char file_preview_type; /* eUserpref_File_Preview_Type */
   char statusbar_flag; /* eUserpref_StatusBar_Flag */
 
   struct WalkNavigation walk_navigation;
@@ -996,7 +997,7 @@ typedef enum eUserPref_Flag {
   USER_NONUMPAD = (1 << 13),
   USER_ADD_CURSORALIGNED = (1 << 14),
   USER_FILECOMPRESS = (1 << 15),
-  USER_SAVE_PREVIEWS = (1 << 16),
+  USER_FLAG_UNUSED_5 = (1 << 16), /* dirty */
   USER_CUSTOM_RANGE = (1 << 17),
   USER_ADD_EDITMODE = (1 << 18),
   USER_ADD_VIEWALIGNED = (1 << 19),
@@ -1010,6 +1011,13 @@ typedef enum eUserPref_Flag {
   USER_FLAG_UNUSED_27 = (1 << 27), /* dirty */
 } eUserPref_Flag;
 
+/** #UserDef.file_preview_type */
+typedef enum eUserpref_File_Preview_Type {
+  USER_FILE_PREVIEW_NONE = 0,
+  USER_FILE_PREVIEW_SCREENSHOT,
+  USER_FILE_PREVIEW_CAMERA,
+} eUserpref_File_Preview_Type;
+
 typedef enum eUserPref_PrefFlag {
   USER_PREF_FLAG_SAVE = (1 << 0),
 } eUserPref_PrefFlag;

source/blender/makesrna/intern/rna_userdef.c

@@ -6059,6 +6059,13 @@ static void rna_def_userdef_filepaths(BlenderRNA *brna)
       {0, NULL, 0, NULL, NULL},
   };
 
+  static const EnumPropertyItem preview_type_items[] = {
+      {USER_FILE_PREVIEW_NONE, "NONE", 0, "None", "Do not create blend previews"},
+      {USER_FILE_PREVIEW_SCREENSHOT, "SCREENSHOT", 0, "Screenshot", "Capture the entire window"},
+      {USER_FILE_PREVIEW_CAMERA, "CAMERA", 0, "Camera View", "Workbench render of scene"},
+      {0, NULL, 0, NULL, NULL},
+  };
+
   srna = RNA_def_struct(brna, "PreferencesFilePaths", NULL);
   RNA_def_struct_sdna(srna, "UserDef");
   RNA_def_struct_nested(brna, srna, "Preferences");
@@ -6214,12 +6221,9 @@ static void rna_def_userdef_filepaths(BlenderRNA *brna)
   RNA_def_property_ui_text(
       prop, "Recent Files", "Maximum number of recently opened files to remember");
 
-  prop = RNA_def_property(srna, "use_save_preview_images", PROP_BOOLEAN, PROP_NONE);
-  RNA_def_property_boolean_sdna(prop, NULL, "flag", USER_SAVE_PREVIEWS);
-  RNA_def_property_ui_text(prop,
-                           "Save Preview Images",
-                           "Enables automatic saving of preview images in the .blend file "
-                           "as well as a thumbnail of the .blend");
+  prop = RNA_def_property(srna, "file_preview_type", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_items(prop, preview_type_items);
+  RNA_def_property_ui_text(prop, "File Preview Type", "What type of blend preview to create");
 
   rna_def_userdef_filepaths_asset_library(brna);
 

source/blender/windowmanager/intern/wm_files.c

@@ -1515,14 +1515,64 @@ static void wm_history_file_update(void)
 /** \} */
 
 /* -------------------------------------------------------------------- */
-/** \name Save Main Blend-File (internal)
+/** \name Save Main Blend-File (internal) by capturing main window.
+ * \{ */
+
+static ImBuf *blend_file_thumb_from_screenshot(bContext *C, BlendThumbnail **thumb_pt)
+{
+  if (*thumb_pt) {
+    /* We are given a valid thumbnail data, so just generate image from it. */
+    return BKE_main_thumbnail_to_imbuf(NULL, *thumb_pt);
+  }
+
+  /* Redraw to remove menus that might be open. */
+  WM_redraw_windows(C);
+  WM_cursor_wait(true);
+
+  /* The window to capture should be a main window (without parent). */
+  wmWindow *win = CTX_wm_window(C);
+  while (win && win->parent) {
+    win = win->parent;
+  }
+
+  int win_size[2];
+  uint *buffer = WM_window_pixels_read(CTX_wm_manager(C), win, win_size);
+  ImBuf *ibuf = IMB_allocFromBuffer(buffer, NULL, win_size[0], win_size[1], 24);
+
+  if (ibuf) {
+    int ex = (ibuf->x > ibuf->y) ? BLEN_THUMB_SIZE :
+                                   (int)((ibuf->x / (float)ibuf->y) * BLEN_THUMB_SIZE);
+    int ey = (ibuf->x > ibuf->y) ? (int)((ibuf->y / (float)ibuf->x) * BLEN_THUMB_SIZE) :
+                                   BLEN_THUMB_SIZE;
+    /* Filesystem thumbnail image can be 256x256. */
+    IMB_scaleImBuf(ibuf, ex * 2, ey * 2);
+
+    /* Thumbnail inside blend should be 128x128. */
+    ImBuf *thumb_ibuf = IMB_dupImBuf(ibuf);
+    IMB_scaleImBuf(thumb_ibuf, ex, ey);
+
+    BlendThumbnail *thumb = BKE_main_thumbnail_from_imbuf(NULL, thumb_ibuf);
+    IMB_freeImBuf(thumb_ibuf);
+    MEM_freeN(buffer);
+    *thumb_pt = thumb;
+  }
+  WM_cursor_wait(false);
+
+  /* Must be freed by caller. */
+  return ibuf;
+}
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Save Main Blend-File (internal) by rendering scene
  * \{ */
 
 /* screen can be NULL */
-static ImBuf *blend_file_thumb(const bContext *C,
-                               Scene *scene,
-                               bScreen *screen,
-                               BlendThumbnail **thumb_pt)
+static ImBuf *blend_file_thumb_from_camera(const bContext *C,
+                                           Scene *scene,
+                                           bScreen *screen,
+                                           BlendThumbnail **thumb_pt)
 {
   /* will be scaled down, but gives some nice oversampling */
   ImBuf *ibuf;
@@ -1704,8 +1754,13 @@ static bool wm_file_write(bContext *C,
   /* Main now can store a '.blend' thumbnail, useful for background mode
    * or thumbnail customization. */
   main_thumb = thumb = bmain->blen_thumb;
-  if ((U.flag & USER_SAVE_PREVIEWS) && BLI_thread_is_main()) {
-    ibuf_thumb = blend_file_thumb(C, CTX_data_scene(C), CTX_wm_screen(C), &thumb);
+  if (BLI_thread_is_main()) {
+    if (U.file_preview_type == USER_FILE_PREVIEW_SCREENSHOT) {
+      ibuf_thumb = blend_file_thumb_from_screenshot(C, &thumb);
+    }
+    else if (U.file_preview_type == USER_FILE_PREVIEW_CAMERA) {
+      ibuf_thumb = blend_file_thumb_from_camera(C, CTX_data_scene(C), CTX_wm_screen(C), &thumb);
+    }
   }
 
   /* operator now handles overwrite checks */