Enable ConstantInterpolation for fcurves

Change-Id: If51c8377f5b29433feaa520a7586f0608b7510f1
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

2 files changed, 23 insertions, 2 deletions

diff --git a/src/animation/backend/fcurve.cpp b/src/animation/backend/fcurve.cpp
index edb2b6df8..c4361a37a 100644
--- a/src/animation/backend/fcurve.cpp
+++ b/src/animation/backend/fcurve.cpp
@@ -71,8 +71,7 @@ float FCurve::evaluateAtTime(float localTime) const
 
         switch (keyframe0.interpolation) {
         case QKeyFrame::ConstantInterpolation:
-            qWarning("Constant interpolation not implemented yet");
-            break;
+            return keyframe0.value;
         case QKeyFrame::LinearInterpolation:
             if (localTime >= t0 && localTime <= t1 && t1 > t0) {
                 float t = (localTime - t0) / (t1 - t0);
diff --git a/tests/auto/animation/fcurve/tst_fcurve.cpp b/tests/auto/animation/fcurve/tst_fcurve.cpp
index e3e8db50d..c2dbe33aa 100644
--- a/tests/auto/animation/fcurve/tst_fcurve.cpp
+++ b/tests/auto/animation/fcurve/tst_fcurve.cpp
@@ -90,9 +90,31 @@ private Q_SLOTS:
         QCOMPARE(fcurve.endTime(), 0.0f);
     }
 
+    void checkEvaluateAtTime_data()
+    {
+
+        QTest::addColumn<float>("time");
+        QTest::addColumn<float>("expectedValue");
+
+        QTest::addRow("Constant_before_time") << 0.0f << 1.0f;
+        QTest::addRow("Constant_1.5") << 1.5f << 1.0f;
+        QTest::addRow("Constant_2.5") << 2.5f << 2.0f;
+        QTest::addRow("Constant_after_time") << 3.5f << 4.0f;
+    }
+
     void checkEvaluateAtTime()
     {
+        QFETCH(float, time);
+        QFETCH(float, expectedValue);
+
+        FCurve curve;
+        curve.appendKeyframe(1.0, Keyframe{1.0, {0.0, 0.0}, {0.0,0.0}, QKeyFrame::ConstantInterpolation});
+        curve.appendKeyframe(2.0, Keyframe{2.0, {0.0, 0.0}, {0.0,0.0}, QKeyFrame::ConstantInterpolation});
+        curve.appendKeyframe(3.0, Keyframe{4.0, {0.0, 0.0}, {0.0,0.0}, QKeyFrame::ConstantInterpolation});
+
+        float actualValue = curve.evaluateAtTime(time);
 
+        QCOMPARE(expectedValue, actualValue);
     }
 };