UI: improve graph editor channels drawing

The channel color squares are no longer positioned under the visibility
icon, since contrast is poor. Instead they are thinner and drawn on the
left side, before the visibility icon. If the curve is hidden, the color
gets less opaque.

Differential Revision: https://developer.blender.org/D5882

1 files changed, 23 insertions, 9 deletions

diff --git a/source/blender/editors/animation/anim_channels_defines.c b/source/blender/editors/animation/anim_channels_defines.c
index 2ec1634fa38..177b8296b55 100644
--- a/source/blender/editors/animation/anim_channels_defines.c
+++ b/source/blender/editors/animation/anim_channels_defines.c
@@ -3984,6 +3984,10 @@ void ANIM_channel_setting_set(bAnimContext *ac,
 #define SLIDER_WIDTH (4 * U.widget_unit)
 // min-width of rename textboxes
 #define RENAME_TEXT_MIN_WIDTH (U.widget_unit)
+// width of graph editor color bands
+#define GRAPH_COLOR_BAND_WIDTH (0.3f * U.widget_unit)
+// extra offset for the visibility icons in the graph editor
+#define GRAPH_ICON_VISIBILITY_OFFSET (GRAPH_COLOR_BAND_WIDTH * 1.5f)
 
 /* Helper - Check if a channel needs renaming */
 static bool achannel_is_being_renamed(const bAnimContext *ac,
@@ -4059,9 +4063,6 @@ void ANIM_channel_draw(
     offset += ICON_WIDTH;
   }
 
-  /* turn off blending, since not needed anymore... */
-  GPU_blend(false);
-
   /* step 4) draw special toggles  .................................
    * - in Graph Editor, checkboxes for visibility in curves area
    * - in NLA Editor, glowing dots for solo/not solo...
@@ -4071,7 +4072,7 @@ void ANIM_channel_draw(
     if ((ac->spacetype == SPACE_GRAPH) &&
         (acf->has_setting(ac, ale, ACHANNEL_SETTING_VISIBLE) ||
          acf->has_setting(ac, ale, ACHANNEL_SETTING_ALWAYS_VISIBLE))) {
-      /* for F-Curves, draw color-preview of curve behind checkbox */
+      /* for F-Curves, draw color-preview of curve left to the visibility icon */
       if (ELEM(ale->type, ANIMTYPE_FCURVE, ANIMTYPE_NLACURVE)) {
         FCurve *fcu = (FCurve *)ale->data;
         uint pos = GPU_vertformat_attr_add(
@@ -4082,17 +4083,26 @@ void ANIM_channel_draw(
         /* F-Curve channels need to have a special 'color code' box drawn,
          * which is colored with whatever color the curve has stored.
          */
-        immUniformColor3fv(fcu->color);
 
-        /* just a solid color rect
-         */
-        immRectf(pos, offset, yminc, offset + ICON_WIDTH, ymaxc);
+        /* If the curve is hidden, make the rect less opaque. */
+        float rect_alpha = (fcu->flag & FCURVE_VISIBLE) ? 1 : 0.3f;
+        immUniformColor3fvAlpha(fcu->color, rect_alpha);
 
+        immRectf(pos, offset, yminc, offset + GRAPH_COLOR_BAND_WIDTH, ymaxc);
         immUnbindProgram();
       }
+
+      /* turn off blending, since not needed anymore... */
+      GPU_blend(false);
+
       /* icon is drawn as widget now... */
       if (acf->has_setting(ac, ale, ACHANNEL_SETTING_VISIBLE)) {
-        offset += ICON_WIDTH;
+        if (ELEM(ale->type, ANIMTYPE_FCURVE, ANIMTYPE_NLACURVE)) {
+          offset += ICON_WIDTH + GRAPH_ICON_VISIBILITY_OFFSET;
+        }
+        else {
+          offset += ICON_WIDTH;
+        }
       }
       if (acf->has_setting(ac, ale, ACHANNEL_SETTING_ALWAYS_VISIBLE)) {
         offset += ICON_WIDTH;
@@ -4781,6 +4791,10 @@ void ANIM_channel_draw_widgets(const bContext *C,
       }
       /* visibility toggle  */
       if (acf->has_setting(ac, ale, ACHANNEL_SETTING_VISIBLE)) {
+        /* For F-curves, add the extra space for the color bands. */
+        if (ELEM(ale->type, ANIMTYPE_FCURVE, ANIMTYPE_NLACURVE)) {
+          offset += GRAPH_ICON_VISIBILITY_OFFSET;
+        }
         draw_setting_widget(ac, ale, acf, block, offset, ymid, ACHANNEL_SETTING_VISIBLE);
         offset += ICON_WIDTH;
       }