Fix T76595: Indicate the Active Keyframe in Graph Editortemp-fcurve-active-keyframe-D7737

Currently there is a panel that says "Active Keyframe" for numerically editing one keyframe's values, but in the code there is no concept of the "active keyframe."

This patch adds an "active keyframe index" to each FCurve, and displays it with a theme color for the active vertex (which didn't exist before) if the FCurve is active.

{F8536092 size=full}

The active keyframe is not currently set for select operations other than basic click-select, which mirrors the behavior in the 3D view.

Reviewed By: Severin, looch

Maniphest Tasks: T76595

Differential Revision: https://developer.blender.org/D7737

1 files changed, 76 insertions, 0 deletions

diff --git a/source/blender/editors/space_graph/graph_draw.c b/source/blender/editors/space_graph/graph_draw.c
index af7a7d9a4de..97a950b1ed5 100644
--- a/source/blender/editors/space_graph/graph_draw.c
+++ b/source/blender/editors/space_graph/graph_draw.c
@@ -211,6 +211,35 @@ static void draw_fcurve_selected_keyframe_vertices(
   immEnd();
 }
 
+/**
+ * Draw the extra indicator for the active point.
+ */
+static void draw_fcurve_active_vertex(const FCurve *fcu,
+                                      const View2D *v2d,
+                                      const bool edit,
+                                      const uint pos)
+{
+  const int active_keyframe_index = BKE_fcurve_active_keyframe_index(fcu);
+  if (!(fcu->flag & FCURVE_ACTIVE) || active_keyframe_index == FCURVE_ACTIVE_KEYFRAME_NONE) {
+    return;
+  }
+
+  const float fac = 0.05f * BLI_rctf_size_x(&v2d->cur);
+  const BezTriple *bezt = &fcu->bezt[active_keyframe_index];
+
+  if (!IN_RANGE(bezt->vec[1][0], (v2d->cur.xmin - fac), (v2d->cur.xmax + fac))) {
+    return;
+  }
+  if (!(bezt->f2 & SELECT)) {
+    return;
+  }
+
+  immBegin(GPU_PRIM_POINTS, 1);
+  immUniformThemeColor(TH_VERTEX_ACTIVE);
+  immVertex2fv(pos, bezt->vec[1]);
+  immEnd();
+}
+
 /* helper func - draw keyframe vertices only for an F-Curve */
 static void draw_fcurve_keyframe_vertices(FCurve *fcu, View2D *v2d, bool edit, uint pos)
 {
@@ -220,6 +249,7 @@ static void draw_fcurve_keyframe_vertices(FCurve *fcu, View2D *v2d, bool edit, u
 
   draw_fcurve_selected_keyframe_vertices(fcu, v2d, edit, false, pos);
   draw_fcurve_selected_keyframe_vertices(fcu, v2d, edit, true, pos);
+  draw_fcurve_active_vertex(fcu, v2d, edit, pos);
 
   immUnbindProgram();
 }
@@ -270,6 +300,39 @@ static void draw_fcurve_selected_handle_vertices(
   immEnd();
 }
 
+/**
+ * Draw the extra handles for the active point.
+ */
+static void draw_fcurve_active_handle_vertices(const FCurve *fcu,
+                                               const bool sel_handle_only,
+                                               const uint pos)
+{
+  const int active_keyframe_index = BKE_fcurve_active_keyframe_index(fcu);
+  if (!(fcu->flag & FCURVE_ACTIVE) || active_keyframe_index == FCURVE_ACTIVE_KEYFRAME_NONE) {
+    return;
+  }
+
+  const BezTriple *bezt = &fcu->bezt[active_keyframe_index];
+
+  if (sel_handle_only && !BEZT_ISSEL_ANY(bezt)) {
+    return;
+  }
+
+  float active_col[4];
+  UI_GetThemeColor4fv(TH_VERTEX_ACTIVE, active_col);
+  immUniform4fv("outlineColor", active_col);
+  immUniformColor3fvAlpha(active_col, 0.01f); /* Almost invisible - only keep for smoothness. */
+  immBeginAtMost(GPU_PRIM_POINTS, 2);
+
+  if ((bezt->f1 & SELECT)) {
+    immVertex2fv(pos, bezt->vec[0]);
+  }
+  if ((bezt->f3 & SELECT)) {
+    immVertex2fv(pos, bezt->vec[2]);
+  }
+  immEnd();
+}
+
 /* helper func - draw handle vertices only for an F-Curve (if it is not protected) */
 static void draw_fcurve_handle_vertices(FCurve *fcu, View2D *v2d, bool sel_handle_only, uint pos)
 {
@@ -282,6 +345,7 @@ static void draw_fcurve_handle_vertices(FCurve *fcu, View2D *v2d, bool sel_handl
 
   draw_fcurve_selected_handle_vertices(fcu, v2d, false, sel_handle_only, pos);
   draw_fcurve_selected_handle_vertices(fcu, v2d, true, sel_handle_only, pos);
+  draw_fcurve_active_handle_vertices(fcu, sel_handle_only, pos);
 
   immUnbindProgram();
 }
@@ -1224,10 +1288,22 @@ void graph_draw_curves(bAnimContext *ac, SpaceGraph *sipo, ARegion *region, shor
    * draw curve, then handle-lines, and finally vertices in this order so that
    * the data will be layered correctly
    */
+  bAnimListElem *ale_active_fcurve = NULL;
   for (ale = anim_data.first; ale; ale = ale->next) {
+    const FCurve *fcu = (FCurve *)ale->key_data;
+    if (fcu->flag & FCURVE_ACTIVE) {
+      ale_active_fcurve = ale;
+      continue;
+    }
     draw_fcurve(ac, sipo, region, ale);
   }
 
+  /* Draw the active FCurve last so that it (especially the active keyframe)
+   * shows on top of the other curves. */
+  if (ale_active_fcurve != NULL) {
+    draw_fcurve(ac, sipo, region, ale_active_fcurve);
+  }
+
   /* free list of curves */
   ANIM_animdata_freelist(&anim_data);
 }