VSE: Change grid line drawing

Add overlay option to disable grid drawing.
Reuse drawing code from other editors (timeline editor)
Add argument `display_minor_lines` to function
`UI_view2d_draw_lines_x__discrete_frames_or_seconds`
This way minor line drawing can be disabled and so it doesn't cause
too much visual noise. Also spacing seems to be too fine, so VSE uses 3x
what is defined in preferences.

Reviewed By: fsiddi, Severin

Differential Revision: https://developer.blender.org/D11790

3 files changed, 19 insertions, 1 deletions

diff --git a/source/blender/blenloader/intern/versioning_300.c b/source/blender/blenloader/intern/versioning_300.c
index fb22a88c28e..95440f78cd2 100644
--- a/source/blender/blenloader/intern/versioning_300.c
+++ b/source/blender/blenloader/intern/versioning_300.c
@@ -678,6 +678,19 @@ void blo_do_versions_300(FileData *fd, Library *UNUSED(lib), Main *bmain)
     }
   }
 
+  if (!MAIN_VERSION_ATLEAST(bmain, 300, 15)) {
+    LISTBASE_FOREACH (bScreen *, screen, &bmain->screens) {
+      LISTBASE_FOREACH (ScrArea *, area, &screen->areabase) {
+        LISTBASE_FOREACH (SpaceLink *, sl, &area->spacedata) {
+          if (sl->spacetype == SPACE_SEQ) {
+            SpaceSeq *sseq = (SpaceSeq *)sl;
+            sseq->flag |= SEQ_SHOW_GRID;
+          }
+        }
+      }
+    }
+  }
+
   /**
    * Versioning code until next subversion bump goes here.
    *
diff --git a/source/blender/blenloader/intern/versioning_defaults.c b/source/blender/blenloader/intern/versioning_defaults.c
index 10b24532014..6b54600f915 100644
--- a/source/blender/blenloader/intern/versioning_defaults.c
+++ b/source/blender/blenloader/intern/versioning_defaults.c
@@ -183,7 +183,7 @@ static void blo_update_defaults_screen(bScreen *screen,
     else if (area->spacetype == SPACE_SEQ) {
       SpaceSeq *seq = area->spacedata.first;
       seq->flag |= SEQ_SHOW_MARKERS | SEQ_SHOW_FCURVES | SEQ_ZOOM_TO_FIT | SEQ_SHOW_STRIP_OVERLAY |
-                   SEQ_SHOW_STRIP_SOURCE | SEQ_SHOW_STRIP_NAME | SEQ_SHOW_STRIP_DURATION;
+                   SEQ_SHOW_STRIP_SOURCE | SEQ_SHOW_STRIP_NAME | SEQ_SHOW_STRIP_DURATION | SEQ_SHOW_GRID;
 
       seq->render_size = SEQ_RENDER_SIZE_PROXY_100;
       seq->flag |= SEQ_USE_PROXIES;
diff --git a/source/blender/blenloader/intern/versioning_userdef.c b/source/blender/blenloader/intern/versioning_userdef.c
index 152dcbed6a4..c409f0a71fc 100644
--- a/source/blender/blenloader/intern/versioning_userdef.c
+++ b/source/blender/blenloader/intern/versioning_userdef.c
@@ -286,6 +286,11 @@ static void do_versions_theme(const UserDef *userdef, bTheme *btheme)
     FROM_DEFAULT_V4_UCHAR(space_spreadsheet.selected_highlight);
   }
 
+  if (!USER_VERSION_ATLEAST(300, 15)) {
+    copy_v4_uchar(btheme->space_sequencer.grid, 33);
+    btheme->space_sequencer.grid[3] = 255;
+  }
+
   /**
    * Versioning code until next subversion bump goes here.
    *