add curve editor presets

Source/Editor/GUI/CurveEditor.Contents.cs

@@ -522,6 +522,16 @@ namespace FlaxEditor.GUI
                             cm.AddButton("Show whole curve", _editor.ShowWholeCurve);
                             cm.AddButton("Reset view", _editor.ResetView);
                         }
+                        cm.AddSeparator();
+                        var presetCm = cm.AddChildMenu("Apply preset");
+                        foreach (var value in Enum.GetValues(typeof(CurvePreset)))
+                        {
+                            CurvePreset preset = (CurvePreset)value;
+                            string name = Utilities.Utils.GetPropertyNameUI(preset.ToString());
+                            var b = presetCm.ContextMenu.AddButton(name, () => _editor.ApplyPreset(preset));
+                            b.Enabled = !(_editor is LinearCurveEditor<T> && (preset != CurvePreset.Constant && preset != CurvePreset.Linear));
+                        }
+                        
                         _editor.OnShowContextMenu(cm, selectionCount);
                         cm.Show(this, location);
                     }
@@ -619,6 +629,33 @@ namespace FlaxEditor.GUI
             }
         }
 
+        /// <summary>
+        /// A list of avaliable curve presets for the <see cref="CurveEditor{T}"/>.
+        /// </summary>
+        public enum CurvePreset
+        {
+            /// <summary>
+            /// A curve where every point has the same value.
+            /// </summary>
+            Constant,
+            /// <summary>
+            /// A curve linear curve.
+            /// </summary>
+            Linear,
+            /// <summary>
+            /// A curve that starts a slowly and then accelerates until the end.
+            /// </summary>
+            EaseIn,
+            /// <summary>
+            /// A curve that starts a steep and then flattens until the end.
+            /// </summary>
+            EaseOut,
+            /// <summary>
+            /// A combination of the <see cref="CurvePreset.EaseIn"/> and <see cref="CurvePreset.EaseOut"/> preset.
+            /// </summary>
+            Smoothstep
+        }
+
         /// <inheritdoc />
         public override void OnKeyframesDeselect(IKeyframesEditor editor)
         {

Source/Editor/GUI/CurveEditor.cs

@@ -326,6 +326,28 @@ namespace FlaxEditor.GUI
         private Color _labelsColor;
         private Font _labelsFont;
 
+        /// <summary>
+        /// Preset values for <see cref="CurvePreset"/> to be applied to a <see cref="CurveEditor{T}"/>.
+        /// </summary>
+        public Dictionary<CurvePreset, object[]> PresetValues = new Dictionary<CurvePreset, object[]>
+        {
+            { CurvePreset.Constant, new object[] { true, // LinearTangent
+                                                0f, 0.5f, 0f, 0f, // Time, value, tangent in, tangent out
+                                                1f, 0.5f, 0f, 0f } },
+            { CurvePreset.EaseIn, new object[] { false,
+                                                0f, 0f, 0f, 0f,
+                                                1f, 1f, -1.4f, 0f } },
+            { CurvePreset.EaseOut, new object[] { false,
+                                                1f, 1f, 0f, 0f,
+                                                0f, 0f, 0f, 1.4f } },
+            { CurvePreset.Linear, new object[] { true,
+                                                0f, 0f, 0f, 0f,
+                                                1f, 1f, 0f, 0f } },
+            { CurvePreset.Smoothstep, new object[] { false,
+                                                0f, 0f, 0f, 0f,
+                                                1f, 1f, 0f, 0f } },
+        };
+
         /// <summary>
         /// The keyframe UI points.
         /// </summary>
@@ -568,6 +590,28 @@ namespace FlaxEditor.GUI
         /// <param name="indicesToRemove">The list of indices of the keyframes to remove.</param>
         protected abstract void RemoveKeyframesInternal(HashSet<int> indicesToRemove);
 
+        /// <summary>
+        /// Tries to convert a float to the type of the type wildcard of the curve editor.
+        /// </summary>
+        /// <param name="value">The float.</param>
+        /// <returns>The converted value.</returns>
+        public static object ConvertCurvePresetValueToCurveEditorType(float value)
+        {
+            if (typeof(T) == typeof(Float2))
+                return new Float2(value);
+            if (typeof(T) == typeof(Float3))
+                return new Float3(value);
+            if (typeof(T) == typeof(Float4))
+                return new Float4(value);
+            if (typeof(T) == typeof(Vector2))
+                return new Vector2(value);
+            if (typeof(T) == typeof(Vector3))
+                return new Vector3(value);
+            if (typeof(T) == typeof(Vector4))
+                return new Vector4(value);
+            return value;
+        }
+
         /// <summary>
         /// Called when showing a context menu. Can be used to add custom buttons with actions.
         /// </summary>
@@ -752,6 +796,17 @@ namespace FlaxEditor.GUI
             ShowCurve(false);
         }
 
+        /// <summary>
+        /// Applies a <see cref="CurvePreset"/> to the curve editor.
+        /// </summary>
+        /// <param name="preset">The preset.</param>
+        public virtual void ApplyPreset(CurvePreset preset)
+        {
+            // Remove existing keyframes
+            SelectAll();
+            RemoveKeyframes();
+        }
+
         /// <inheritdoc />
         public override void Evaluate(out object result, float time, bool loop = false)
         {
@@ -1580,6 +1635,22 @@ namespace FlaxEditor.GUI
 
             base.OnDestroy();
         }
+
+        /// <inheritdoc />
+        public override void ApplyPreset(CurvePreset preset)
+        {
+            base.ApplyPreset(preset);
+
+            object[] data = PresetValues[preset];
+            for (int i = 1; i < data.Length; i += 4)
+            {
+                float time = (float)data[i];
+                object value = ConvertCurvePresetValueToCurveEditorType((float)data[i + 1]);
+                AddKeyframe(time, value);
+            }
+
+            ShowWholeCurve();
+        }
     }
 
     /// <summary>
@@ -2396,5 +2467,28 @@ namespace FlaxEditor.GUI
 
             base.OnDestroy();
         }
+
+        /// <inheritdoc />
+        public override void ApplyPreset(CurvePreset preset)
+        {
+            base.ApplyPreset(preset);
+
+            object[] data = PresetValues[preset];
+            for (int i = 1; i < data.Length; i += 4)
+            {
+                float time = (float)data[i];
+                object value = ConvertCurvePresetValueToCurveEditorType((float)data[i + 1]);
+                object tangentIn = ConvertCurvePresetValueToCurveEditorType((float)data[i + 2]);
+                object tangentOut = ConvertCurvePresetValueToCurveEditorType((float)data[i + 3]);
+
+                AddKeyframe(time, value, tangentIn, tangentOut);
+            }
+
+            SelectAll();
+            if ((bool)data[0])
+                SetTangentsLinear();
+
+            ShowWholeCurve();
+        }
     }
 }