From c70b545ba11cdcbc2c797cf68dbc2859a8e0cab7 Mon Sep 17 00:00:00 2001
From: Gabriel Ozouf <gabriel.ozouf@numworks.com>
Date: Tue, 9 Jun 2020 14:05:15 +0200
Subject: [PATCH] [apps/shared] Cache lookup on function evaluation

When evaluating a ContinuousFunction for a float value, the function
will first try to ask its cache (if it has been filled beforehand).

Change-Id: I519d2d3dcf344ba63e30a0f011db2306c7141315
---
 apps/shared/continuous_function.cpp | 12 ++++++++++++
 apps/shared/continuous_function.h   |  4 +++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/apps/shared/continuous_function.cpp b/apps/shared/continuous_function.cpp
index 042e42ea6..b00f69046 100644
--- a/apps/shared/continuous_function.cpp
+++ b/apps/shared/continuous_function.cpp
@@ -351,6 +351,18 @@ Poincare::Expression ContinuousFunction::sumBetweenBounds(double start, double e
    * the derivative table. */
 }
 
+Poincare::Coordinate2D<float> ContinuousFunction::checkForCacheHitAndEvaluate(float t, Poincare::Context * context) const {
+  Poincare::Coordinate2D<float> res(NAN, NAN);
+  if (cache()->filled()) {
+    res = cache()->valueForParameter(this, t);
+  }
+  if (std::isnan(res.x1()) || std::isnan(res.x2())) {
+    res = privateEvaluateXYAtParameter(t, context);
+    //res = Poincare::Coordinate2D<float>(privateEvaluateXYAtParameter(t, context).x1(), 0);
+  }
+  return res;
+}
+
 Ion::Storage::Record::ErrorStatus ContinuousFunction::setContent(const char * c, Poincare::Context * context) {
   cache()->clear();
   return ExpressionModelHandle::setContent(c, context);
diff --git a/apps/shared/continuous_function.h b/apps/shared/continuous_function.h
index 86769eca9..93e8c5998 100644
--- a/apps/shared/continuous_function.h
+++ b/apps/shared/continuous_function.h
@@ -47,7 +47,8 @@ public:
     return templatedApproximateAtParameter(t, context);
   }
   Poincare::Coordinate2D<float> evaluateXYAtParameter(float t, Poincare::Context * context) const override {
-    return privateEvaluateXYAtParameter<float>(t, context);
+    //return privateEvaluateXYAtParameter<float>(t, context);
+    return checkForCacheHitAndEvaluate(t, context);
   }
   Poincare::Coordinate2D<double> evaluateXYAtParameter(double t, Poincare::Context * context) const override {
     return privateEvaluateXYAtParameter<double>(t, context);
@@ -86,6 +87,7 @@ private:
   typedef Poincare::Coordinate2D<double> (*ComputePointOfInterest)(Poincare::Expression e, char * symbol, double start, double step, double max, Poincare::Context * context);
   Poincare::Coordinate2D<double> nextPointOfInterestFrom(double start, double step, double max, Poincare::Context * context, ComputePointOfInterest compute) const;
   template <typename T> Poincare::Coordinate2D<T> privateEvaluateXYAtParameter(T t, Poincare::Context * context) const;
+  Poincare::Coordinate2D<float> checkForCacheHitAndEvaluate(float t, Poincare::Context * context) const;
   /* RecordDataBuffer is the layout of the data buffer of Record
    * representing a ContinuousFunction. See comment on
    * Shared::Function::RecordDataBuffer about packing. */