From 73b462112134baa70033c1d278b0784b7b96dff4 Mon Sep 17 00:00:00 2001
From: 23rd <23rd@vivaldi.net>
Date: Wed, 12 Jul 2023 02:28:56 +0300
Subject: [PATCH] Cached current x-axis indices to reduce redundant
 calculations.

---
 .../SourceFiles/statistics/chart_widget.cpp   | 21 ++++++++++++++++---
 .../SourceFiles/statistics/chart_widget.h     |  2 ++
 .../statistics/linear_chart_view.cpp          | 12 +++--------
 .../statistics/linear_chart_view.h            |  1 +
 4 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/Telegram/SourceFiles/statistics/chart_widget.cpp b/Telegram/SourceFiles/statistics/chart_widget.cpp
index ca76e57a81..58d9c1010d 100644
--- a/Telegram/SourceFiles/statistics/chart_widget.cpp
+++ b/Telegram/SourceFiles/statistics/chart_widget.cpp
@@ -538,9 +538,18 @@ void ChartWidget::ChartAnimationController::setXPercentageLimits(
 	_animationValueXMax.start(xPercentageLimits.max);
 	_lastUserInteracted = now;
 
-	_finalHeightLimits = FindHeightLimitsBetweenXLimits(
-		chartData,
-		{ _animationValueXMin.to(), _animationValueXMax.to() });
+	const auto startXIndex = chartData.findStartIndex(
+		_animationValueXMin.to());
+	const auto endXIndex = chartData.findEndIndex(
+		startXIndex,
+		_animationValueXMax.to());
+	_currentXIndices = { float64(startXIndex), float64(endXIndex) };
+
+	_finalHeightLimits = Limits{
+		float64(FindMinValue(chartData, startXIndex, endXIndex)),
+		float64(FindMaxValue(chartData, startXIndex, endXIndex)),
+	};
+
 	_animationValueHeightMin = anim::value(
 		_animationValueHeightMin.current(),
 		_finalHeightLimits.min);
@@ -720,6 +729,10 @@ Limits ChartWidget::ChartAnimationController::currentXLimits() const {
 	return { _animationValueXMin.current(), _animationValueXMax.current() };
 }
 
+Limits ChartWidget::ChartAnimationController::currentXIndices() const {
+	return _currentXIndices;
+}
+
 Limits ChartWidget::ChartAnimationController::finalXLimits() const {
 	return { _animationValueXMin.to(), _animationValueXMax.to() };
 }
@@ -841,6 +854,7 @@ void ChartWidget::setupChartArea() {
 			Statistic::PaintLinearChartView(
 				p,
 				_chartData,
+				_animationController.currentXIndices(),
 				_animationController.currentXLimits(),
 				_animationController.currentHeightLimits(),
 				chartRect,
@@ -961,6 +975,7 @@ void ChartWidget::setupFooter() {
 			Statistic::PaintLinearChartView(
 				p,
 				_chartData,
+				{ 0., float64(_chartData.x.size() - 1) },
 				fullXLimits,
 				_footer->fullHeightLimits(),
 				r,
diff --git a/Telegram/SourceFiles/statistics/chart_widget.h b/Telegram/SourceFiles/statistics/chart_widget.h
index 345ea8d1b3..022e42579e 100644
--- a/Telegram/SourceFiles/statistics/chart_widget.h
+++ b/Telegram/SourceFiles/statistics/chart_widget.h
@@ -58,6 +58,7 @@ private:
 			std::vector<BottomCaptionLineData> &dateLines);
 
 		[[nodiscard]] Limits currentXLimits() const;
+		[[nodiscard]] Limits currentXIndices() const;
 		[[nodiscard]] Limits finalXLimits() const;
 		[[nodiscard]] Limits currentHeightLimits() const;
 		[[nodiscard]] Limits finalHeightLimits() const;
@@ -84,6 +85,7 @@ private:
 		anim::value _animValueBottomLineAlpha;
 
 		Limits _finalHeightLimits;
+		Limits _currentXIndices;
 
 		float _dtHeightSpeed = 0.;
 		Limits _dtCurrent;
diff --git a/Telegram/SourceFiles/statistics/linear_chart_view.cpp b/Telegram/SourceFiles/statistics/linear_chart_view.cpp
index 52ab5e7983..7d016495e1 100644
--- a/Telegram/SourceFiles/statistics/linear_chart_view.cpp
+++ b/Telegram/SourceFiles/statistics/linear_chart_view.cpp
@@ -19,6 +19,7 @@ namespace Statistic {
 void PaintLinearChartView(
 		QPainter &p,
 		const Data::StatisticalChart &chartData,
+		const Limits &xIndices,
 		const Limits &xPercentageLimits,
 		const Limits &heightLimits,
 		const QRect &rect,
@@ -32,21 +33,14 @@ void PaintLinearChartView(
 		const auto additionalP = (chartData.xPercentage.size() < 2)
 			? 0.
 			: (chartData.xPercentage.front() * rect.width());
-		const auto additionalPoints = 0;
 
 		auto first = true;
 		auto chartPath = QPainterPath();
 
-		const auto startXIndex = chartData.findStartIndex(
-			xPercentageLimits.min);
-		const auto endXIndex = chartData.findEndIndex(
-			startXIndex,
-			xPercentageLimits.max);
-
-		const auto localStart = std::max(0, startXIndex - additionalPoints);
+		const auto localStart = std::max(0, int(xIndices.min));
 		const auto localEnd = std::min(
 			int(chartData.xPercentage.size() - 1),
-			endXIndex + additionalPoints);
+			int(xIndices.max));
 
 		for (auto i = localStart; i <= localEnd; i++) {
 			if (line.y[i] < 0) {
diff --git a/Telegram/SourceFiles/statistics/linear_chart_view.h b/Telegram/SourceFiles/statistics/linear_chart_view.h
index 5f9b849c39..c41b268a03 100644
--- a/Telegram/SourceFiles/statistics/linear_chart_view.h
+++ b/Telegram/SourceFiles/statistics/linear_chart_view.h
@@ -19,6 +19,7 @@ struct DetailsPaintContext;
 void PaintLinearChartView(
 	QPainter &p,
 	const Data::StatisticalChart &chartData,
+	const Limits &xIndices,
 	const Limits &xPercentageLimits,
 	const Limits &heightLimits,
 	const QRect &rect,