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

8 files changed, 31 insertions, 90 deletions

diff --git a/source/blender/editors/include/UI_view2d.h b/source/blender/editors/include/UI_view2d.h
index 8191a9a9062..4ee7df89487 100644
--- a/source/blender/editors/include/UI_view2d.h
+++ b/source/blender/editors/include/UI_view2d.h
@@ -143,17 +143,19 @@ void UI_view2d_view_orthoSpecial(struct ARegion *region, struct View2D *v2d, con
 void UI_view2d_view_restore(const struct bContext *C);
 
 /* grid drawing */
-void UI_view2d_constant_grid_draw(const struct View2D *v2d, float step);
 void UI_view2d_multi_grid_draw(
     const struct View2D *v2d, int colorid, float step, int level_size, int totlevels);
 
 void UI_view2d_draw_lines_y__values(const struct View2D *v2d);
 void UI_view2d_draw_lines_x__values(const struct View2D *v2d);
-void UI_view2d_draw_lines_x__discrete_values(const struct View2D *v2d);
-void UI_view2d_draw_lines_x__discrete_time(const struct View2D *v2d, const struct Scene *scene);
+void UI_view2d_draw_lines_x__discrete_values(const struct View2D *v2d, bool display_minor_lines);
+void UI_view2d_draw_lines_x__discrete_time(const struct View2D *v2d,
+                                           const struct Scene *scene,
+                                           bool display_minor_lines);
 void UI_view2d_draw_lines_x__discrete_frames_or_seconds(const struct View2D *v2d,
                                                         const struct Scene *scene,
-                                                        bool display_seconds);
+                                                        bool display_seconds,
+                                                        bool display_minor_lines);
 void UI_view2d_draw_lines_x__frames_or_seconds(const struct View2D *v2d,
                                                const struct Scene *scene,
                                                bool display_seconds);
diff --git a/source/blender/editors/interface/view2d.c b/source/blender/editors/interface/view2d.c
index db2766f1b19..23c8a0d35bf 100644
--- a/source/blender/editors/interface/view2d.c
+++ b/source/blender/editors/interface/view2d.c
@@ -1194,78 +1194,6 @@ void UI_view2d_view_restore(const bContext *C)
 /** \name Grid-Line Drawing
  * \{ */
 
-/* Draw a constant grid in given 2d-region */
-void UI_view2d_constant_grid_draw(const View2D *v2d, float step)
-{
-  float start_x, start_y;
-  int count_x, count_y;
-
-  start_x = v2d->cur.xmin;
-  if (start_x < 0.0) {
-    start_x += -(float)fmod(v2d->cur.xmin, step);
-  }
-  else {
-    start_x += (step - (float)fmod(v2d->cur.xmin, step));
-  }
-
-  if (start_x > v2d->cur.xmax) {
-    count_x = 0;
-  }
-  else {
-    count_x = (v2d->cur.xmax - start_x) / step + 1;
-  }
-
-  start_y = v2d->cur.ymin;
-  if (start_y < 0.0) {
-    start_y += -(float)fmod(v2d->cur.ymin, step);
-  }
-  else {
-    start_y += (step - (float)fabs(fmod(v2d->cur.ymin, step)));
-  }
-
-  if (start_y > v2d->cur.ymax) {
-    count_y = 0;
-  }
-  else {
-    count_y = (v2d->cur.ymax - start_y) / step + 1;
-  }
-
-  if (count_x > 0 || count_y > 0) {
-    GPUVertFormat *format = immVertexFormat();
-    const uint pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
-    const uint color = GPU_vertformat_attr_add(format, "color", GPU_COMP_F32, 3, GPU_FETCH_FLOAT);
-    float theme_color[3];
-
-    UI_GetThemeColorShade3fv(TH_BACK, -10, theme_color);
-
-    immBindBuiltinProgram(GPU_SHADER_2D_FLAT_COLOR);
-    immBegin(GPU_PRIM_LINES, count_x * 2 + count_y * 2 + 4);
-
-    immAttr3fv(color, theme_color);
-    for (int i = 0; i < count_x; start_x += step, i++) {
-      immVertex2f(pos, start_x, v2d->cur.ymin);
-      immVertex2f(pos, start_x, v2d->cur.ymax);
-    }
-
-    for (int i = 0; i < count_y; start_y += step, i++) {
-      immVertex2f(pos, v2d->cur.xmin, start_y);
-      immVertex2f(pos, v2d->cur.xmax, start_y);
-    }
-
-    /* X and Y axis */
-    UI_GetThemeColorShade3fv(TH_BACK, -18, theme_color);
-
-    immAttr3fv(color, theme_color);
-    immVertex2f(pos, 0.0f, v2d->cur.ymin);
-    immVertex2f(pos, 0.0f, v2d->cur.ymax);
-    immVertex2f(pos, v2d->cur.xmin, 0.0f);
-    immVertex2f(pos, v2d->cur.xmax, 0.0f);
-
-    immEnd();
-    immUnbindProgram();
-  }
-}
-
 /* Draw a multi-level grid in given 2d-region */
 void UI_view2d_multi_grid_draw(
     const View2D *v2d, int colorid, float step, int level_size, int totlevels)
diff --git a/source/blender/editors/interface/view2d_draw.c b/source/blender/editors/interface/view2d_draw.c
index 37c84b707fd..a9393b3a6e7 100644
--- a/source/blender/editors/interface/view2d_draw.c
+++ b/source/blender/editors/interface/view2d_draw.c
@@ -480,10 +480,11 @@ float UI_view2d_grid_resolution_y__values(const struct View2D *v2d)
 /* Line Drawing API
  **************************************************/
 
-void UI_view2d_draw_lines_x__discrete_values(const View2D *v2d)
+void UI_view2d_draw_lines_x__discrete_values(const View2D *v2d, bool display_minor_lines)
 {
   const uint major_line_distance = view2d_major_step_x__discrete(v2d);
-  view2d_draw_lines(v2d, major_line_distance, major_line_distance > 1, 'v');
+  view2d_draw_lines(
+      v2d, major_line_distance, display_minor_lines && (major_line_distance > 1), 'v');
 }
 
 void UI_view2d_draw_lines_x__values(const View2D *v2d)
@@ -498,21 +499,25 @@ void UI_view2d_draw_lines_y__values(const View2D *v2d)
   view2d_draw_lines(v2d, major_line_distance, true, 'h');
 }
 
-void UI_view2d_draw_lines_x__discrete_time(const View2D *v2d, const Scene *scene)
+void UI_view2d_draw_lines_x__discrete_time(const View2D *v2d,
+                                           const Scene *scene,
+                                           bool display_minor_lines)
 {
   const float major_line_distance = view2d_major_step_x__time(v2d, scene);
-  view2d_draw_lines(v2d, major_line_distance, major_line_distance > 1, 'v');
+  view2d_draw_lines(
+      v2d, major_line_distance, display_minor_lines && (major_line_distance > 1), 'v');
 }
 
 void UI_view2d_draw_lines_x__discrete_frames_or_seconds(const View2D *v2d,
                                                         const Scene *scene,
-                                                        bool display_seconds)
+                                                        bool display_seconds,
+                                                        bool display_minor_lines)
 {
   if (display_seconds) {
-    UI_view2d_draw_lines_x__discrete_time(v2d, scene);
+    UI_view2d_draw_lines_x__discrete_time(v2d, scene, display_minor_lines);
   }
   else {
-    UI_view2d_draw_lines_x__discrete_values(v2d);
+    UI_view2d_draw_lines_x__discrete_values(v2d, display_minor_lines);
   }
 }
 
@@ -521,7 +526,7 @@ void UI_view2d_draw_lines_x__frames_or_seconds(const View2D *v2d,
                                                bool display_seconds)
 {
   if (display_seconds) {
-    UI_view2d_draw_lines_x__discrete_time(v2d, scene);
+    UI_view2d_draw_lines_x__discrete_time(v2d, scene, true);
   }
   else {
     UI_view2d_draw_lines_x__values(v2d);
diff --git a/source/blender/editors/space_action/space_action.c b/source/blender/editors/space_action/space_action.c
index 28482faf6e3..5e5143723a6 100644
--- a/source/blender/editors/space_action/space_action.c
+++ b/source/blender/editors/space_action/space_action.c
@@ -196,7 +196,8 @@ static void action_main_region_draw(const bContext *C, ARegion *region)
   UI_view2d_view_ortho(v2d);
 
   /* time grid */
-  UI_view2d_draw_lines_x__discrete_frames_or_seconds(v2d, scene, saction->flag & SACTION_DRAWTIME);
+  UI_view2d_draw_lines_x__discrete_frames_or_seconds(
+      v2d, scene, saction->flag & SACTION_DRAWTIME, true);
 
   ED_region_draw_cb_draw(C, region, REGION_DRAW_PRE_VIEW);
 
diff --git a/source/blender/editors/space_clip/space_clip.c b/source/blender/editors/space_clip/space_clip.c
index 326c221a2e3..aef3385f2dc 100644
--- a/source/blender/editors/space_clip/space_clip.c
+++ b/source/blender/editors/space_clip/space_clip.c
@@ -1112,7 +1112,7 @@ static void dopesheet_region_draw(const bContext *C, ARegion *region)
   UI_view2d_view_ortho(v2d);
 
   /* time grid */
-  UI_view2d_draw_lines_x__discrete_frames_or_seconds(v2d, scene, sc->flag & SC_SHOW_SECONDS);
+  UI_view2d_draw_lines_x__discrete_frames_or_seconds(v2d, scene, sc->flag & SC_SHOW_SECONDS, true);
 
   /* data... */
   clip_draw_dopesheet_main(sc, region, scene);
diff --git a/source/blender/editors/space_nla/space_nla.c b/source/blender/editors/space_nla/space_nla.c
index 011cd7e2651..987d06cfe5c 100644
--- a/source/blender/editors/space_nla/space_nla.c
+++ b/source/blender/editors/space_nla/space_nla.c
@@ -239,7 +239,7 @@ static void nla_main_region_draw(const bContext *C, ARegion *region)
   UI_view2d_view_ortho(v2d);
 
   /* time grid */
-  UI_view2d_draw_lines_x__discrete_frames_or_seconds(v2d, scene, snla->flag & SNLA_DRAWTIME);
+  UI_view2d_draw_lines_x__discrete_frames_or_seconds(v2d, scene, snla->flag & SNLA_DRAWTIME, true);
 
   ED_region_draw_cb_draw(C, region, REGION_DRAW_PRE_VIEW);
 
diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index a2652d88ebf..3f8dea8b533 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -1981,7 +1981,7 @@ static void draw_seq_backdrop(View2D *v2d)
   /* Lines separating the horizontal bands. */
   i = max_ii(1, ((int)v2d->cur.ymin) - 1);
   int line_len = (int)v2d->cur.ymax - i + 1;
-  immUniformThemeColor(TH_GRID);
+  immUniformThemeColorShade(TH_GRID, 10);
   immBegin(GPU_PRIM_LINES, line_len * 2);
   while (line_len--) {
     immVertex2f(pos, v2d->cur.xmax, i);
@@ -2419,7 +2419,12 @@ void draw_timeline_seq(const bContext *C, ARegion *region)
   /* Get timeline bound-box, needed for the scroll-bars. */
   SEQ_timeline_boundbox(scene, SEQ_active_seqbase_get(ed), &v2d->tot);
   draw_seq_backdrop(v2d);
-  UI_view2d_constant_grid_draw(v2d, FPS);
+  if ((sseq->flag & SEQ_SHOW_STRIP_OVERLAY) && (sseq->flag & SEQ_SHOW_GRID)) {
+    U.v2d_min_gridsize *= 3;
+    UI_view2d_draw_lines_x__discrete_frames_or_seconds(
+        v2d, scene, (sseq->flag & SEQ_DRAWFRAMES) == 0, false);
+    U.v2d_min_gridsize /= 3;
+  }
 
   /* Only draw backdrop in timeline view. */
   if (sseq->view == SEQ_VIEW_SEQUENCE && sseq->draw_flag & SEQ_DRAW_BACKDROP) {
diff --git a/source/blender/editors/space_sequencer/space_sequencer.c b/source/blender/editors/space_sequencer/space_sequencer.c
index cf26d1e3243..6de95f0995a 100644
--- a/source/blender/editors/space_sequencer/space_sequencer.c
+++ b/source/blender/editors/space_sequencer/space_sequencer.c
@@ -100,7 +100,7 @@ static SpaceLink *sequencer_create(const ScrArea *UNUSED(area), const Scene *sce
   sseq->mainb = SEQ_DRAW_IMG_IMBUF;
   sseq->flag = SEQ_SHOW_GPENCIL | SEQ_USE_ALPHA | SEQ_SHOW_MARKERS | SEQ_SHOW_FCURVES |
                SEQ_ZOOM_TO_FIT | SEQ_SHOW_STRIP_OVERLAY | SEQ_SHOW_STRIP_NAME |
-               SEQ_SHOW_STRIP_SOURCE | SEQ_SHOW_STRIP_DURATION;
+               SEQ_SHOW_STRIP_SOURCE | SEQ_SHOW_STRIP_DURATION | SEQ_SHOW_GRID;
 
   /* Tool header. */
   region = MEM_callocN(sizeof(ARegion), "tool header for sequencer");