Change: Add support for different horizontal graph scales.

Monthly data is stored for the current 24 months.
Quarterly data is stored for a further 2-6 years.
Yearly data is stored for a further 6-24 years.

src/graph_gui.cpp

@@ -8,6 +8,7 @@
 /** @file graph_gui.cpp GUI that shows performance graphs. */
 
 #include "stdafx.h"
+#include <ranges>
 #include "misc/history_func.hpp"
 #include "graph_gui.h"
 #include "window_gui.h"
@@ -174,6 +175,7 @@ protected:
 	static const int GRAPH_PAYMENT_RATE_STEPS = 20; ///< Number of steps on Payment rate graph.
 	static const int PAYMENT_GRAPH_X_STEP_DAYS    = 10; ///< X-axis step label for cargo payment rates "Days in transit".
 	static const int PAYMENT_GRAPH_X_STEP_SECONDS = 20; ///< X-axis step label for cargo payment rates "Seconds in transit".
+	static const int ECONOMY_YEAR_MINUTES = 12;  ///< Minutes per economic year.
 	static const int ECONOMY_QUARTER_MINUTES = 3;  ///< Minutes per economic quarter.
 	static const int ECONOMY_MONTH_MINUTES = 1;  ///< Minutes per economic month.
 
@@ -182,6 +184,24 @@ protected:
 	static const int MIN_GRAPH_NUM_LINES_Y  =   9; ///< Minimal number of horizontal lines to draw.
 	static const int MIN_GRID_PIXEL_SIZE    =  20; ///< Minimum distance between graph lines.
 
+	struct GraphScale {
+		StringID label = STR_NULL;
+		uint8_t month_increment = 0;
+		int16_t x_values_increment = 0;
+	};
+
+	static inline constexpr GraphScale MONTHLY_SCALE_WALLCLOCK[] = {
+		{STR_GRAPH_LAST_24_MINUTES_TIME_LABEL, HISTORY_MONTH.total_division, ECONOMY_MONTH_MINUTES},
+		{STR_GRAPH_LAST_72_MINUTES_TIME_LABEL, HISTORY_QUARTER.total_division, ECONOMY_QUARTER_MINUTES},
+		{STR_GRAPH_LAST_288_MINUTES_TIME_LABEL, HISTORY_YEAR.total_division, ECONOMY_YEAR_MINUTES},
+	};
+
+	static inline constexpr GraphScale MONTHLY_SCALE_CALENDAR[] = {
+		{STR_GRAPH_LAST_24_MONTHS, HISTORY_MONTH.total_division, ECONOMY_MONTH_MINUTES},
+		{STR_GRAPH_LAST_24_QUARTERS, HISTORY_QUARTER.total_division, ECONOMY_QUARTER_MINUTES},
+		{STR_GRAPH_LAST_24_YEARS, HISTORY_YEAR.total_division, ECONOMY_YEAR_MINUTES},
+	};
+
 	uint64_t excluded_data = 0; ///< bitmask of datasets hidden by the player.
 	uint64_t excluded_range = 0; ///< bitmask of ranges hidden by the player.
 	uint64_t masked_range = 0; ///< bitmask of ranges that are not available for the current data.
@@ -211,7 +231,9 @@ protected:
 	};
 	std::vector<DataSet> data{};
 
-	std::span<const StringID> ranges = {};
+	std::span<const StringID> ranges{};
+	std::span<const GraphScale> scales{};
+	uint8_t selected_scale = 0;
 
 	uint8_t highlight_data = UINT8_MAX; ///< Data set that should be highlighted, or UINT8_MAX for none.
 	uint8_t highlight_range = UINT8_MAX; ///< Data range that should be highlighted, or UINT8_MAX for none.
@@ -617,24 +639,34 @@ protected:
 		this->SetDirty();
 	}};
 
+	void UpdateMatrixSize(WidgetID widget, Dimension &size, Dimension &resize, auto labels)
+	{
+		size = {};
+		for (const StringID &str : labels) {
+			size = maxdim(size, GetStringBoundingBox(str, FS_SMALL));
+		}
+
+		size.width += WidgetDimensions::scaled.framerect.Horizontal();
+		size.height += WidgetDimensions::scaled.framerect.Vertical();
+
+		/* Set fixed height for number of ranges. */
+		size.height *= static_cast<uint>(std::size(labels));
+
+		resize.width = 0;
+		resize.height = 0;
+		this->GetWidget<NWidgetCore>(widget)->SetMatrixDimension(1, ClampTo<uint32_t>(std::size(labels)));
+	}
+
 public:
 	void UpdateWidgetSize(WidgetID widget, Dimension &size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension &fill, [[maybe_unused]] Dimension &resize) override
 	{
 		switch (widget) {
 			case WID_GRAPH_RANGE_MATRIX:
-				for (const StringID &str : this->ranges) {
-					size = maxdim(size, GetStringBoundingBox(str, FS_SMALL));
-				}
+				this->UpdateMatrixSize(widget, size, resize, this->ranges);
+				break;
 
-				size.width += WidgetDimensions::scaled.framerect.Horizontal();
-				size.height += WidgetDimensions::scaled.framerect.Vertical();
-
-				/* Set fixed height for number of ranges. */
-				size.height *= static_cast<uint>(std::size(this->ranges));
-
-				resize.width = 0;
-				resize.height = 0;
-				this->GetWidget<NWidgetCore>(WID_GRAPH_RANGE_MATRIX)->SetMatrixDimension(1, ClampTo<uint32_t>(std::size(this->ranges)));
+			case WID_GRAPH_SCALE_MATRIX:
+				this->UpdateMatrixSize(widget, size, resize, this->scales | std::views::transform(&GraphScale::label));
 				break;
 
 			case WID_GRAPH_GRAPH: {
@@ -701,6 +733,21 @@ public:
 				break;
 			}
 
+			case WID_GRAPH_SCALE_MATRIX: {
+				uint line_height = GetCharacterHeight(FS_SMALL) + WidgetDimensions::scaled.framerect.Vertical();
+				uint8_t selected_month_increment = this->scales[this->selected_scale].month_increment;
+				Rect line = r.WithHeight(line_height);
+				for (const auto &scale : this->scales) {
+					/* Redraw frame if selected */
+					if (selected_month_increment == scale.month_increment) DrawFrameRect(line, COLOUR_BROWN, FrameFlag::Lowered);
+
+					DrawString(line.Shrink(WidgetDimensions::scaled.framerect), scale.label, TC_BLACK, SA_CENTER, false, FS_SMALL);
+
+					line = line.Translate(0, line_height);
+				}
+				break;
+			}
+
 			default: break;
 		}
 	}
@@ -722,6 +769,18 @@ public:
 				break;
 			}
 
+			case WID_GRAPH_SCALE_MATRIX: {
+				int row = GetRowFromWidget(pt.y, widget, 0, GetCharacterHeight(FS_SMALL) + WidgetDimensions::scaled.framerect.Vertical());
+				const auto &scale = this->scales[row];
+				if (this->selected_scale != row) {
+					this->selected_scale = row;
+					this->month_increment = scale.month_increment;
+					this->x_values_increment = scale.x_values_increment;
+					this->InvalidateData();
+				}
+				break;
+			}
+
 			default: break;
 		}
 	}
@@ -1646,6 +1705,13 @@ struct IndustryProductionGraphWindow : BaseCargoGraphWindow {
 		this->InitializeWindow(window_number, STR_GRAPH_LAST_24_MINUTES_TIME_LABEL);
 	}
 
+	void OnInit() override
+	{
+		this->BaseCargoGraphWindow::OnInit();
+
+		this->scales = TimerGameEconomy::UsingWallclockUnits() ? MONTHLY_SCALE_WALLCLOCK : MONTHLY_SCALE_CALENDAR;
+	}
+
 	CargoTypes GetCargoTypes(WindowNumber window_number) const override
 	{
 		CargoTypes cargo_types{};
@@ -1673,7 +1739,7 @@ struct IndustryProductionGraphWindow : BaseCargoGraphWindow {
 
 	void UpdateStatistics(bool initialize) override
 	{
-		int mo = TimerGameEconomy::month - this->num_vert_lines;
+		int mo = (TimerGameEconomy::month / this->month_increment - this->num_vert_lines) * this->month_increment;
 		auto yr = TimerGameEconomy::year;
 		while (mo < 0) {
 			yr--;
@@ -1711,7 +1777,7 @@ struct IndustryProductionGraphWindow : BaseCargoGraphWindow {
 			transported.dash = 2;
 			auto transported_filler = Filler{transported, &Industry::ProducedHistory::transported};
 
-			FillFromHistory<GRAPH_NUM_MONTHS>(p.history, i->valid_history, produced_filler, transported_filler);
+			FillFromHistory<GRAPH_NUM_MONTHS>(p.history, i->valid_history, this->selected_scale, produced_filler, transported_filler);
 		}
 
 		for (const auto &a : i->accepted) {
@@ -1735,9 +1801,9 @@ struct IndustryProductionGraphWindow : BaseCargoGraphWindow {
 			auto waiting_filler = Filler{waiting, &Industry::AcceptedHistory::waiting};
 
 			if (a.history == nullptr) {
-				FillFromEmpty<GRAPH_NUM_MONTHS>(i->valid_history, accepted_filler, waiting_filler);
+				FillFromEmpty<GRAPH_NUM_MONTHS>(i->valid_history, this->selected_scale, accepted_filler, waiting_filler);
 			} else {
-				FillFromHistory<GRAPH_NUM_MONTHS>(*a.history, i->valid_history, accepted_filler, waiting_filler);
+				FillFromHistory<GRAPH_NUM_MONTHS>(*a.history, i->valid_history, this->selected_scale, accepted_filler, waiting_filler);
 			}
 		}
 
@@ -1758,7 +1824,7 @@ static constexpr NWidgetPart _nested_industry_production_widgets[] = {
 			NWidget(WWT_EMPTY, INVALID_COLOUR, WID_GRAPH_GRAPH), SetMinimalSize(495, 0), SetFill(1, 1), SetResize(1, 1),
 			NWidget(NWID_VERTICAL),
 				NWidget(NWID_SPACER), SetMinimalSize(0, 24), SetFill(0, 1),
-				NWidget(WWT_MATRIX, COLOUR_BROWN, WID_GRAPH_RANGE_MATRIX), SetFill(1, 0), SetResize(0, 0), SetMatrixDataTip(1, 0, STR_GRAPH_CARGO_PAYMENT_TOGGLE_CARGO),
+				NWidget(WWT_MATRIX, COLOUR_BROWN, WID_GRAPH_RANGE_MATRIX), SetFill(1, 0), SetResize(0, 0), SetMatrixDataTip(1, 0, STR_GRAPH_TOGGLE_RANGE),
 				NWidget(NWID_SPACER), SetMinimalSize(0, 4),
 				NWidget(WWT_PUSHTXTBTN, COLOUR_BROWN, WID_GRAPH_ENABLE_CARGOES), SetStringTip(STR_GRAPH_CARGO_ENABLE_ALL, STR_GRAPH_CARGO_TOOLTIP_ENABLE_ALL), SetFill(1, 0),
 				NWidget(WWT_PUSHTXTBTN, COLOUR_BROWN, WID_GRAPH_DISABLE_CARGOES), SetStringTip(STR_GRAPH_CARGO_DISABLE_ALL, STR_GRAPH_CARGO_TOOLTIP_DISABLE_ALL), SetFill(1, 0),
@@ -1767,6 +1833,8 @@ static constexpr NWidgetPart _nested_industry_production_widgets[] = {
 					NWidget(WWT_MATRIX, COLOUR_BROWN, WID_GRAPH_MATRIX), SetFill(1, 0), SetResize(0, 2), SetMatrixDataTip(1, 0, STR_GRAPH_CARGO_PAYMENT_TOGGLE_CARGO), SetScrollbar(WID_GRAPH_MATRIX_SCROLLBAR),
 					NWidget(NWID_VSCROLLBAR, COLOUR_BROWN, WID_GRAPH_MATRIX_SCROLLBAR),
 				EndContainer(),
+				NWidget(NWID_SPACER), SetMinimalSize(0, 4),
+				NWidget(WWT_MATRIX, COLOUR_BROWN, WID_GRAPH_SCALE_MATRIX), SetFill(1, 0), SetResize(0, 0), SetMatrixDataTip(1, 0, STR_GRAPH_SELECT_SCALE),
 				NWidget(NWID_SPACER), SetMinimalSize(0, 24), SetFill(0, 1),
 			EndContainer(),
 			NWidget(NWID_SPACER), SetMinimalSize(5, 0), SetFill(0, 1), SetResize(0, 1),

src/industry_cmd.cpp

@@ -1842,7 +1842,7 @@ static void DoCreateNewIndustry(Industry *i, TileIndex tile, IndustryType type,
 			p.history[LAST_MONTH].production += ScaleByCargoScale(p.rate * 8, false);
 		}
 
-		UpdateValidHistory(i->valid_history);
+		UpdateValidHistory(i->valid_history, TimerGameEconomy::month);
 	}
 
 	if (indspec->callback_mask.Test(IndustryCallbackMask::DecideColour)) {
@@ -2494,19 +2494,38 @@ void GenerateIndustries()
 	_industry_builder.Reset();
 }
 
+template <>
+Industry::ProducedHistory SumHistory(std::span<const Industry::ProducedHistory> history)
+{
+	uint32_t production = std::accumulate(std::begin(history), std::end(history), 0, [](uint32_t r, const auto &p) { return r + p.production; });
+	uint32_t transported = std::accumulate(std::begin(history), std::end(history), 0, [](uint32_t r, const auto &p) { return r + p.transported; });
+	auto count = std::size(history);
+	return {.production = ClampTo<uint16_t>(production / count), .transported = ClampTo<uint16_t>(transported / count)};
+}
+
+template <>
+Industry::AcceptedHistory SumHistory(std::span<const Industry::AcceptedHistory> history)
+{
+	uint32_t accepted = std::accumulate(std::begin(history), std::end(history), 0, [](uint32_t r, const auto &a) { return r + a.accepted; });
+	uint32_t waiting = std::accumulate(std::begin(history), std::end(history), 0, [](uint32_t r, const auto &a) { return r + a.waiting; });;
+	auto count = std::size(history);
+	return {.accepted = ClampTo<uint16_t>(accepted / count), .waiting = ClampTo<uint16_t>(waiting / count)};
+}
+
 /**
  * Monthly update of industry statistics.
  * @param i Industry to update.
  */
 static void UpdateIndustryStatistics(Industry *i)
 {
-	UpdateValidHistory(i->valid_history);
+	auto month = TimerGameEconomy::month;
+	UpdateValidHistory(i->valid_history, month);
 
 	for (auto &p : i->produced) {
 		if (IsValidCargoType(p.cargo)) {
 			if (p.history[THIS_MONTH].production != 0) i->last_prod_year = TimerGameEconomy::year;
 
-			RotateHistory(p.history);
+			RotateHistory(p.history, i->valid_history, month);
 		}
 	}
 
@@ -2515,7 +2534,7 @@ static void UpdateIndustryStatistics(Industry *i)
 		if (a.history == nullptr) continue;
 
 		(*a.history)[THIS_MONTH].waiting = GetAndResetAccumulatedAverage<uint16_t>(a.accumulated_waiting);
-		RotateHistory(*a.history);
+		RotateHistory(*a.history, i->valid_history, month);
 	}
 }
 

src/lang/english.txt

@@ -622,6 +622,14 @@ STR_GRAPH_COMPANY_VALUES_CAPTION                                :{WHITE}Company
 
 STR_GRAPH_LAST_24_MINUTES_TIME_LABEL                            :{TINY_FONT}{BLACK}Last 24 minutes
 STR_GRAPH_LAST_72_MINUTES_TIME_LABEL                            :{TINY_FONT}{BLACK}Last 72 minutes
+STR_GRAPH_LAST_288_MINUTES_TIME_LABEL                           :{TINY_FONT}{BLACK}Last 288 minutes
+
+STR_GRAPH_LAST_24_MONTHS                                        :{TINY_FONT}{BLACK}2 years (monthly)
+STR_GRAPH_LAST_24_QUARTERS                                      :{TINY_FONT}{BLACK}6 years (quarterly)
+STR_GRAPH_LAST_24_YEARS                                         :{TINY_FONT}{BLACK}24 years (yearly)
+
+STR_GRAPH_TOGGLE_RANGE                                          :Toggle graph for this data range
+STR_GRAPH_SELECT_SCALE                                          :Change horizontal scale of graph
 
 STR_GRAPH_CARGO_PAYMENT_RATES_CAPTION                           :{WHITE}Cargo Payment Rates
 STR_GRAPH_CARGO_PAYMENT_RATES_DAYS                              :{TINY_FONT}{BLACK}Days in transit

src/misc/CMakeLists.txt

@@ -8,6 +8,7 @@ add_files(
     getoptdata.cpp
     getoptdata.h
     hashtable.hpp
+    history.cpp
     history_func.hpp
     history_type.hpp
     lrucache.hpp

src/misc/history.cpp

@@ -0,0 +1,71 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file history.cpp Implementation of functions for storing historical data. */
+
+#ifndef HISTORY_CPP
+#define HISTORY_CPP
+
+#include "../stdafx.h"
+
+#include "../core/bitmath_func.hpp"
+#include "history_type.hpp"
+#include "history_func.hpp"
+
+#include "../safeguards.h"
+
+static void UpdateValidHistory(ValidHistoryMask &valid_history, const HistoryRange &hr, uint cur_month)
+{
+	if (cur_month % hr.total_division != 0) return;
+	if (hr.division != 1 && !HasBit(valid_history, hr.first - hr.division)) return;
+
+	SB(valid_history, hr.first, hr.records, GB(valid_history, hr.first, hr.records) << 1ULL | 1ULL);
+}
+
+/**
+ * Update mask of valid records.
+ * @param[in,out] valid_history Valid history records.
+ * @param age Current economy month.
+ */
+void UpdateValidHistory(ValidHistoryMask &valid_history, uint cur_month)
+{
+	UpdateValidHistory(valid_history, HISTORY_MONTH, cur_month);
+	UpdateValidHistory(valid_history, HISTORY_QUARTER, cur_month);
+	UpdateValidHistory(valid_history, HISTORY_YEAR, cur_month);
+}
+
+static bool IsValidHistory(ValidHistoryMask valid_history, const HistoryRange &hr, uint age)
+{
+	if (hr.hr == nullptr) {
+		if (age < hr.periods) {
+			uint slot = hr.first + age;
+			return HasBit(valid_history, slot);
+		}
+	} else {
+		if (age * hr.division < static_cast<uint>(hr.hr->periods - hr.division)) {
+			uint start = age * hr.division + ((TimerGameEconomy::month / hr.hr->division) % hr.division);
+			return IsValidHistory(valid_history, *hr.hr, start/* + hr.division - 1*/);
+		}
+		if (age < hr.periods) {
+			uint slot = hr.first + age - ((hr.hr->periods / hr.division) - 1);
+			return HasBit(valid_history, slot);
+		}
+	}
+	return false;
+}
+
+bool IsValidHistory(ValidHistoryMask valid_history, uint period, uint age)
+{
+	switch (period) {
+		case 0: return IsValidHistory(valid_history, HISTORY_MONTH, age);
+		case 1: return IsValidHistory(valid_history, HISTORY_QUARTER, age);
+		case 2: return IsValidHistory(valid_history, HISTORY_YEAR, age);
+		default: NOT_REACHED();
+	}
+}
+
+#endif /* HISTORY_CPP */

src/misc/history_func.hpp

@@ -15,14 +15,18 @@
 #include "../timer/timer_game_economy.h"
 #include "history_type.hpp"
 
+void UpdateValidHistory(ValidHistoryMask &valid_history, uint cur_month);
+bool IsValidHistory(ValidHistoryMask valid_history, uint period, uint age);
+
 /**
- * Update mask of valid history records.
- * @param[in,out] valid_history Valid history records.
+ * Sum history data elements.
+ * @note The summation should prevent overflowing, and perform transformations relevant to the type of data.
+ * @tparam T type of history data element.
+ * @param history History elements to sum.
+ * @return Sum of history elements.
  */
-inline void UpdateValidHistory(ValidHistoryMask &valid_history)
-{
-	SB(valid_history, LAST_MONTH, HISTORY_RECORDS - LAST_MONTH, GB(valid_history, LAST_MONTH, HISTORY_RECORDS - LAST_MONTH) << 1ULL | 1ULL);
-}
+template <typename T>
+T SumHistory(typename std::span<const T> history);
 
 /**
  * Rotate history.
@@ -30,10 +34,28 @@ inline void UpdateValidHistory(ValidHistoryMask &valid_history)
  * @param history Historical data to rotate.
  */
 template <typename T>
-void RotateHistory(HistoryData<T> &history)
+void RotateHistory(HistoryData<T> &history, ValidHistoryMask valid_history, const HistoryRange &hr, uint cur_month)
 {
-	std::rotate(std::rbegin(history), std::rbegin(history) + 1, std::rend(history));
-	history[THIS_MONTH] = {};
+	if (cur_month % hr.total_division != 0) return;
+
+	std::move_backward(std::next(std::begin(history), hr.first), std::next(std::begin(history), hr.last - 1), std::next(std::begin(history), hr.last));
+
+	if (hr.division == 1) {
+		history[hr.first] = history[hr.first - 1];
+	} else if (HasBit(valid_history, hr.first - hr.division)) {
+		auto first = std::next(std::begin(history), hr.first - hr.division);
+		auto last = std::next(first, hr.division);
+		history[hr.first] = SumHistory<T>(std::span{first, last});
+	}
+}
+
+template <typename T>
+void RotateHistory(HistoryData<T> &history, ValidHistoryMask valid_history, uint cur_month)
+{
+	RotateHistory(history, valid_history, HISTORY_MONTH, cur_month);
+	RotateHistory(history, valid_history, HISTORY_QUARTER, cur_month);
+	RotateHistory(history, valid_history, HISTORY_YEAR, cur_month);
+	history.front() = {};
 }
 
 /**
@@ -49,18 +71,68 @@ T GetAndResetAccumulatedAverage(Taccrued &total)
 	return result;
 }
 
+template <typename T>
+bool GetHistory(const HistoryData<T> &history, ValidHistoryMask valid_history, const HistoryRange &hr, uint age, T &result)
+{
+	if (hr.hr == nullptr) {
+		if (age < hr.periods) {
+			uint slot = hr.first + age;
+			result = history[slot];
+			return HasBit(valid_history, slot);
+		}
+	} else {
+		if (age * hr.division < static_cast<uint>(hr.hr->periods - hr.division)) {
+			bool is_valid = false;
+			std::array<T, HISTORY_MAX_DIVISION> tmp_result; // No need to clear as we fill every element we use.
+			uint start = age * hr.division + ((TimerGameEconomy::month / hr.hr->division) % hr.division);
+			for (auto i = start; i != start + hr.division; ++i) {
+				is_valid |= GetHistory(history, valid_history, *hr.hr, i, tmp_result[i - start]);
+			}
+			result = SumHistory<T>(std::span{std::begin(tmp_result), hr.division});
+			return is_valid;
+		}
+		if (age < hr.periods) {
+			uint slot = hr.first + age - ((hr.hr->periods / hr.division) - 1);
+			result = history[slot];
+			return HasBit(valid_history, slot);
+		}
+	}
+	NOT_REACHED();
+}
+
+/**
+ * Get history data for the specified period and age within that period.
+ * @param history History data to extract from.
+ * @param valid_history Mask of valid history records.
+ * @param period Period to get.
+ * @param age Age of data to get.
+ * @param[out] result Variable to store historical value for period and age.
+ * @return True if the value is valid.
+ */
+template <typename T>
+bool GetHistory(const HistoryData<T> &history, ValidHistoryMask valid_history, uint period, uint age, T &result)
+{
+	switch (period) {
+		case 0: return GetHistory(history, valid_history, HISTORY_MONTH, age, result);
+		case 1: return GetHistory(history, valid_history, HISTORY_QUARTER, age, result);
+		case 2: return GetHistory(history, valid_history, HISTORY_YEAR, age, result);
+		default: NOT_REACHED();
+	}
+}
+
 /**
  * Fill some data with historical data.
  * @param history Historical data to fill from.
  * @param valid_history Mask of valid history records.
+ * @param period Period (monthly, quarterly, yearly) to fill with.
  * @param fillers Fillers to fill with history data.
  */
 template <uint N, typename T, typename... Tfillers>
-void FillFromHistory(const HistoryData<T> &history, ValidHistoryMask valid_history, Tfillers... fillers)
+void FillFromHistory(const HistoryData<T> &history, ValidHistoryMask valid_history, uint period, Tfillers... fillers)
 {
+	T data{};
 	for (uint i = 0; i != N; ++i) {
-		if (HasBit(valid_history, N - i)) {
-			auto &data = history[N - i];
+		if (GetHistory(history, valid_history, period, N - i - 1, data)) {
 			(fillers.Fill(i, data), ...);
 		} else {
 			(fillers.MakeInvalid(i), ...);
@@ -71,13 +143,14 @@ void FillFromHistory(const HistoryData<T> &history, ValidHistoryMask valid_histo
 /**
  * Fill some data with empty records.
  * @param valid_history Mask of valid history records.
+ * @param period Period (monthly, quarterly, yearly) to fill with.
  * @param fillers Fillers to fill with history data.
  */
 template <uint N, typename... Tfillers>
-void FillFromEmpty(ValidHistoryMask valid_history, Tfillers... fillers)
+void FillFromEmpty(ValidHistoryMask valid_history, uint period, Tfillers... fillers)
 {
 	for (uint i = 0; i != N; ++i) {
-		if (HasBit(valid_history, N - i)) {
+		if (IsValidHistory(valid_history, period, N - i - 1)) {
 			(fillers.MakeZero(i), ...);
 		} else {
 			(fillers.MakeInvalid(i), ...);

src/misc/history_type.hpp

@@ -10,7 +10,40 @@
 #ifndef HISTORY_TYPE_HPP
 #define HISTORY_TYPE_HPP
 
-static constexpr uint8_t HISTORY_RECORDS = 25;
+#include "../stdafx.h"
+
+static constexpr uint8_t HISTORY_PERIODS = 24;
+
+struct HistoryRange {
+	const HistoryRange *hr;
+	const uint8_t periods; ///< Number of periods for this range.
+	const uint8_t records; ///< Number of records needed for this range.
+	const uint8_t first; ///< Index of first element in history data.
+	const uint8_t last; ///< Index of last element in history data.
+	const uint8_t division; ///< Number of divisions of the previous history range.
+	const uint8_t total_division; ///< Number of divisions of the initial history range.
+
+	explicit constexpr HistoryRange(uint8_t periods) :
+		hr(nullptr), periods(periods), records(this->periods), first(1), last(this->first + this->records), division(1), total_division(1)
+	{
+	}
+
+	constexpr HistoryRange(const HistoryRange &hr, uint8_t division, uint8_t periods) :
+		hr(&hr), periods(periods), records(this->periods - ((hr.periods / division) - 1)), first(hr.last), last(this->first + this->records),
+		division(division), total_division(division * hr.total_division)
+	{
+	}
+};
+
+static constexpr HistoryRange HISTORY_MONTH{HISTORY_PERIODS};
+static constexpr HistoryRange HISTORY_QUARTER{HISTORY_MONTH, 3, HISTORY_PERIODS};
+static constexpr HistoryRange HISTORY_YEAR{HISTORY_QUARTER, 4, HISTORY_PERIODS};
+
+/** Maximum number of divisions from previous history range. */
+static constexpr uint8_t HISTORY_MAX_DIVISION = std::max({HISTORY_MONTH.division, HISTORY_QUARTER.division, HISTORY_YEAR.division});
+
+/** Total number of records require for all history data. */
+static constexpr uint8_t HISTORY_RECORDS = HISTORY_YEAR.last;
 
 static constexpr uint8_t THIS_MONTH = 0;
 static constexpr uint8_t LAST_MONTH = 1;

src/tests/CMakeLists.txt

@@ -3,6 +3,7 @@ add_test_files(
     bitmath_func.cpp
     enum_over_optimisation.cpp
     flatset_type.cpp
+    history_func.cpp
     landscape_partial_pixel_z.cpp
     math_func.cpp
     mock_environment.h

src/tests/history_func.cpp

@@ -0,0 +1,88 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file history_func.cpp Test functionality for misc/history_func. */
+
+#include "../stdafx.h"
+
+#include "../3rdparty/catch2/catch.hpp"
+
+#include "../misc/history_type.hpp"
+#include "../misc/history_func.hpp"
+
+#include "../safeguards.h"
+
+template <>
+uint16_t SumHistory(std::span<const uint16_t> history)
+{
+	uint32_t total = std::accumulate(std::begin(history), std::end(history), 0, [](uint32_t r, const uint16_t &value) { return r + value; });
+	return ClampTo<uint16_t>(total);
+}
+
+/**
+ * Helper to get history records and return the value, instead returning its validity.
+ * @param history History data to extract from.
+ * @param period Period to get.
+ * @param age Age of data to get.
+ * @return Historical value for the period and age.
+ */
+template <typename T>
+T GetHistory(const HistoryData<T> &history, uint period, uint age)
+{
+	T result;
+	switch (period) {
+		case 0: GetHistory(history, 0, HISTORY_MONTH, age, result); break;
+		case 1: GetHistory(history, 0, HISTORY_QUARTER, age, result); break;
+		case 2: GetHistory(history, 0, HISTORY_YEAR, age, result); break;
+		default: NOT_REACHED();
+	}
+	return result;
+}
+
+TEST_CASE("History Rotation and Reporting tests")
+{
+	HistoryData<uint16_t> history{};
+	ValidHistoryMask valid_history = 0;
+
+	/* Fill the history with decreasing data points for 24 years of history. This ensures that no data period should
+	 * contain the same value as another period. */
+	uint16_t i = 12 * HISTORY_PERIODS;
+	for (uint date = 1; date <= 12 * HISTORY_PERIODS; ++date, --i) {
+		history[THIS_MONTH] = i;
+		UpdateValidHistory(valid_history, date % 12);
+		RotateHistory(history, valid_history, date % 12);
+	}
+
+	/* With the decreasing sequence, the expected value is triangle number (x*x+n)/2 and the square of the total divisions.
+	 *   for quarters:  1 +  2 +  3 =  6,  4 +  5 +  6 = 15,  7 +  8 +  9 = 24, 10 + 11 + 12 = 33
+	 *                 13 + 14 + 15 = 42, 16 + 17 + 18 = 51, 19 + 20 + 21 = 60, 22 + 23 + 24 = 69...
+	 *      for years:  6 + 15 + 24 + 33 = 78, 42 + 51 + 60 + 69 = 222...
+	 */
+	for (uint j = 0; j < HISTORY_PERIODS; ++j) {
+		CHECK(GetHistory(history, 0, j) == (( 1 *  1 +  1) / 2) +  1 *  1 * j);
+		CHECK(GetHistory(history, 1, j) == (( 3 *  3 +  3) / 2) +  3 *  3 * j);
+		CHECK(GetHistory(history, 2, j) == ((12 * 12 + 12) / 2) + 12 * 12 * j);
+	}
+
+	/* Double-check quarter history matches summed month history. */
+	CHECK(GetHistory(history, 0,  0) + GetHistory(history, 0,  1) + GetHistory(history, 0,  2) == GetHistory(history, 1, 0));
+	CHECK(GetHistory(history, 0,  3) + GetHistory(history, 0,  4) + GetHistory(history, 0,  5) == GetHistory(history, 1, 1));
+	CHECK(GetHistory(history, 0,  6) + GetHistory(history, 0,  7) + GetHistory(history, 0,  8) == GetHistory(history, 1, 2));
+	CHECK(GetHistory(history, 0,  9) + GetHistory(history, 0, 10) + GetHistory(history, 0, 11) == GetHistory(history, 1, 3));
+	CHECK(GetHistory(history, 0, 12) + GetHistory(history, 0, 13) + GetHistory(history, 0, 14) == GetHistory(history, 1, 4));
+	CHECK(GetHistory(history, 0, 15) + GetHistory(history, 0, 16) + GetHistory(history, 0, 17) == GetHistory(history, 1, 5));
+	CHECK(GetHistory(history, 0, 18) + GetHistory(history, 0, 19) + GetHistory(history, 0, 20) == GetHistory(history, 1, 6));
+	CHECK(GetHistory(history, 0, 21) + GetHistory(history, 0, 22) + GetHistory(history, 0, 23) == GetHistory(history, 1, 7));
+
+	/* Double-check year history matches summed quarter history. */
+	CHECK(GetHistory(history, 1,  0) + GetHistory(history, 1,  1) + GetHistory(history, 1,  2) + GetHistory(history, 1,  3) == GetHistory(history, 2, 0));
+	CHECK(GetHistory(history, 1,  4) + GetHistory(history, 1,  5) + GetHistory(history, 1,  6) + GetHistory(history, 1,  7) == GetHistory(history, 2, 1));
+	CHECK(GetHistory(history, 1,  8) + GetHistory(history, 1,  9) + GetHistory(history, 1, 10) + GetHistory(history, 1, 11) == GetHistory(history, 2, 2));
+	CHECK(GetHistory(history, 1, 12) + GetHistory(history, 1, 13) + GetHistory(history, 1, 14) + GetHistory(history, 1, 15) == GetHistory(history, 2, 3));
+	CHECK(GetHistory(history, 1, 16) + GetHistory(history, 1, 17) + GetHistory(history, 1, 18) + GetHistory(history, 1, 19) == GetHistory(history, 2, 4));
+	CHECK(GetHistory(history, 1, 20) + GetHistory(history, 1, 21) + GetHistory(history, 1, 22) + GetHistory(history, 1, 23) == GetHistory(history, 2, 5));
+}

src/widgets/graph_widget.h

@@ -37,6 +37,7 @@ enum GraphWidgets : WidgetID {
 	WID_GRAPH_MATRIX_SCROLLBAR,///< Cargo list scrollbar.
 
 	WID_GRAPH_RANGE_MATRIX, ///< Range list.
+	WID_GRAPH_SCALE_MATRIX, ///< Horizontal axis scale list.
 
 	WID_PHG_DETAILED_PERFORMANCE, ///< Detailed performance.
 };