Functions related to slopes. More...

#include "core/math_func.hpp"
#include "slope_type.h"
#include "direction_type.h"
#include "tile_type.h"

Functions
static constexpr bool	IsValidCorner (Corner corner)
	Rangecheck for Corner enumeration.
static constexpr bool	IsSteepSlope (Slope s)
	Checks if a slope is steep.
static constexpr Slope	RemoveSteepSlope (Slope s)
	Removes a steep flag from a slope.
static constexpr bool	IsHalftileSlope (Slope s)
	Checks for non-continuous slope on halftile foundations.
static constexpr Slope	RemoveHalftileSlope (Slope s)
	Removes a halftile slope from a slope.
Slope	ComplementSlope (Slope s)
	Return the complement of a slope.
bool	IsSlopeWithOneCornerRaised (Slope s)
	Tests if a specific slope has exactly one corner raised.
Slope	SlopeWithOneCornerRaised (Corner corner)
	Returns the slope with a specific corner raised.
bool	HasSlopeHighestCorner (Slope s)
	Tests if a slope has a highest corner (i.e.
Corner	GetHighestSlopeCorner (Slope s)
	Returns the highest corner of a slope (one corner raised or a steep slope).
static constexpr Corner	GetHalftileSlopeCorner (Slope s)
	Returns the leveled halftile of a halftile slope.
static constexpr int	GetSlopeMaxZ (Slope s)
	Returns the height of the highest corner of a slope relative to TileZ (= minimal height).
static constexpr int	GetSlopeMaxPixelZ (Slope s)
	Returns the height of the highest corner of a slope relative to TileZ (= minimal height).
Corner	OppositeCorner (Corner corner)
	Returns the opposite corner.
bool	IsSlopeWithThreeCornersRaised (Slope s)
	Tests if a specific slope has exactly three corners raised.
Slope	SlopeWithThreeCornersRaised (Corner corner)
	Returns the slope with all except one corner raised.
Slope	SteepSlope (Corner corner)
	Returns a specific steep slope.
bool	IsInclinedSlope (Slope s)
	Tests if a specific slope is an inclined slope.
DiagDirection	GetInclinedSlopeDirection (Slope s)
	Returns the direction of an inclined slope.
Slope	InclinedSlope (DiagDirection dir)
	Returns the slope that is inclined in a specific direction.
static constexpr Slope	HalftileSlope (Slope s, Corner corner)
	Adds a halftile slope to a slope.
bool	IsFoundation (Foundation f)
	Tests whether the given foundation is a foundation.
bool	IsLeveledFoundation (Foundation f)
	Tests if the foundation is a leveled foundation.
bool	IsInclinedFoundation (Foundation f)
	Tests if the foundation is an inclined foundation.
bool	IsNonContinuousFoundation (Foundation f)
	Tests if a foundation is a non-continuous foundation, i.e.
Corner	GetHalftileFoundationCorner (Foundation f)
	Returns the halftile corner of a halftile-foundation.
bool	IsSpecialRailFoundation (Foundation f)
	Tests if a foundation is a special rail foundation for single horizontal/vertical track.
Corner	GetRailFoundationCorner (Foundation f)
	Returns the track corner of a special rail foundation.
Foundation	FlatteningFoundation (Slope s)
	Returns the foundation needed to flatten a slope.
Foundation	InclinedFoundation (Axis axis)
	Returns the along a specific axis inclined foundation.
Foundation	HalftileFoundation (Corner corner)
	Returns the halftile foundation for single horizontal/vertical track.
Foundation	SpecialRailFoundation (Corner corner)
	Returns the special rail foundation for single horizontal/vertical track.
uint	SlopeToSpriteOffset (Slope s)
	Returns the Sprite offset for a given Slope.

Detailed Description

Functions related to slopes.

Definition in file slope_func.h.

Function Documentation

◆ ComplementSlope()

Slope ComplementSlope ( Slope s )

inline

Return the complement of a slope.

This method returns the complement of a slope. The complement of a slope is a slope with raised corner which aren't raised in the given slope.

Precondition: The slope must neither be steep nor a halftile slope.

Parameters

s	The Slope to get the complement.

Returns: a complement Slope of the given slope.

Definition at line 86 of file slope_func.h.

References IsHalftileSlope(), IsSteepSlope(), and SLOPE_ELEVATED.

Referenced by CmdBuildTunnel(), DrawTrackBits(), DrawTrackDetails(), FlowRiver(), IsRoadAllowedHere(), IsSlopeWithThreeCornersRaised(), RiverMakeWider(), and SlopeWithThreeCornersRaised().

◆ FlatteningFoundation()

Foundation FlatteningFoundation ( Slope s )

inline

Returns the foundation needed to flatten a slope.

Parameters

s	The current Slope.

Returns: Either Foundation::None if the tile was already flat, or Foundation::Leveled.

Definition at line 377 of file slope_func.h.

References Leveled, None, and SLOPE_FLAT.

Referenced by GetBridgeFoundation(), GetFoundation_Industry(), GetFoundation_Object(), GetFoundation_Rail(), GetFoundation_Road(), and GetFoundation_Town().

◆ GetHalftileFoundationCorner()

Corner GetHalftileFoundationCorner ( Foundation f )

inline

Returns the halftile corner of a halftile-foundation.

Precondition: f != Foundation::SteepBoth

Parameters

f	The Foundation.

Returns: The Corner with track.

Definition at line 343 of file slope_func.h.

References HalfTileEnd, HalfTileW, IsInsideMM(), and to_underlying().

Referenced by ApplyFoundationToSlope(), DrawFoundation(), and DrawTrackBits().

◆ GetHalftileSlopeCorner()

constexpr Corner GetHalftileSlopeCorner ( Slope s )

inlinestaticconstexpr

Returns the leveled halftile of a halftile slope.

Precondition: The slope must be a halftile slope.

Parameters

s	The Slope.

Returns: The corner of the leveled halftile.

Definition at line 158 of file slope_func.h.

References IsHalftileSlope().

Referenced by DrawAutorailSelection(), DrawRailCatenaryRailway(), DrawTileSelection(), DrawTileSelectionRect(), DrawTrackDetails(), GetPartialPixelZ(), and GetSlopePixelZOnEdge().

◆ GetHighestSlopeCorner()

Corner GetHighestSlopeCorner ( Slope s )

inline

Returns the highest corner of a slope (one corner raised or a steep slope).

Precondition: The slope must be a slope with one corner raised or a steep slope. A halftile slope is ignored.

Parameters

s	The Slope.

Returns: Highest corner.

Definition at line 136 of file slope_func.h.

References RemoveHalftileSlope(), SLOPE_E, SLOPE_N, SLOPE_S, SLOPE_STEEP_E, SLOPE_STEEP_N, SLOPE_STEEP_S, SLOPE_STEEP_W, and SLOPE_W.

Referenced by ApplyFoundationToSlope(), CheckRoadSlope(), DrawFoundation(), DrawTrackBits(), DrawTrackDetails(), FloodHalftile(), GetRailFoundation(), GetRoadFoundation(), and RemoveRoad().

◆ GetInclinedSlopeDirection()

DiagDirection GetInclinedSlopeDirection ( Slope s )

inline

Returns the direction of an inclined slope.

Parameters

s A Slope

Returns: The direction the slope goes up in. Or DiagDirection::Invalid if the slope is not an inclined slope.

Definition at line 249 of file slope_func.h.

References Invalid, NE, NW, SE, SLOPE_NE, SLOPE_NW, SLOPE_SE, SLOPE_SW, and SW.

Referenced by AfterLoadGame(), CmdBuildDock(), CmdBuildLock(), CmdBuildTunnel(), GetOtherAqueductEnd(), BuildDocksToolbarWindow::OnPlaceObject(), BuildDocksToolbarWindow::OnPlacePresize(), RiverMakeWider(), and ShipTestUpDownOnLock().

◆ GetRailFoundationCorner()

Corner GetRailFoundationCorner ( Foundation f )

inline

Returns the track corner of a special rail foundation.

Parameters

f	The Foundation.

Returns: The Corner with track.

Definition at line 366 of file slope_func.h.

References IsSpecialRailFoundation(), RailW, and to_underlying().

Referenced by ApplyFoundationToSlope(), and DrawFoundation().

◆ GetSlopeMaxPixelZ()

constexpr int GetSlopeMaxPixelZ ( Slope s )

inlinestaticconstexpr

Returns the height of the highest corner of a slope relative to TileZ (= minimal height).

Parameters

s	The Slope.

Returns: Relative height of highest corner.

Definition at line 183 of file slope_func.h.

References GetSlopeMaxZ(), and TILE_HEIGHT.

Referenced by DrawClearLandFence(), DrawTile_Trees(), and GetPartialPixelZ().

◆ GetSlopeMaxZ()

constexpr int GetSlopeMaxZ ( Slope s )

inlinestaticconstexpr

Returns the height of the highest corner of a slope relative to TileZ (= minimal height).

Parameters

s	The Slope.

Returns: Relative height of highest corner.

Definition at line 170 of file slope_func.h.

References IsSteepSlope(), and SLOPE_FLAT.

Referenced by AutoslopeCheckForEntranceEdge(), CheckBuildableTile(), GetSlopeMaxPixelZ(), TerraformTile_Industry(), TerraformTile_Object(), TerraformTile_Road(), TerraformTile_Station(), and TerraformTile_Town().

◆ HalftileFoundation()

Foundation HalftileFoundation ( Corner corner )

inline

Returns the halftile foundation for single horizontal/vertical track.

Parameters

corner The Corner with the track.

Returns: The wanted Foundation.

Definition at line 399 of file slope_func.h.

References HalfTileW, and IsValidCorner().

Referenced by DrawTrackBits(), and GetRailFoundation().

◆ HalftileSlope()

constexpr Slope HalftileSlope	(	Slope	s,
		Corner	corner )

inlinestaticconstexpr

Adds a halftile slope to a slope.

Parameters

s	Slope without a halftile slope.
corner	The Corner of the halftile.

Returns: The Slope s with the halftile slope added.

Definition at line 284 of file slope_func.h.

References IsValidCorner(), and SLOPE_HALFTILE.

Referenced by ApplyFoundationToSlope().

◆ HasSlopeHighestCorner()

bool HasSlopeHighestCorner ( Slope s )

inline

Tests if a slope has a highest corner (i.e.

one corner raised or a steep slope).

Note: A halftile slope is ignored.

Parameters

s	The Slope.

Returns: true iff the slope has a highest corner.

Definition at line 123 of file slope_func.h.

References IsSlopeWithOneCornerRaised(), IsSteepSlope(), and RemoveHalftileSlope().

Referenced by GetBridgeFoundation().

◆ InclinedFoundation()

Foundation InclinedFoundation ( Axis axis )

inline

Returns the along a specific axis inclined foundation.

Parameters

axis The Axis.

Returns: The needed Foundation.

Definition at line 388 of file slope_func.h.

References InclinedX, InclinedY, and X.

Referenced by GetBridgeFoundation().

◆ InclinedSlope()

Slope InclinedSlope ( DiagDirection dir )

inline

Returns the slope that is inclined in a specific direction.

Parameters

dir	A DiagDirection

Returns: The Slope that goes up in direction dir.

Definition at line 266 of file slope_func.h.

References NE, NW, SE, SLOPE_NE, SLOPE_NW, SLOPE_SE, SLOPE_SW, and SW.

Referenced by AdjustTileh(), CanBuildDepotByTileh(), DrawRailCatenaryRailway(), GrowTownWithBridge(), and GrowTownWithTunnel().

◆ IsFoundation()

bool IsFoundation ( Foundation f )

inline

Tests whether the given foundation is a foundation.

Parameters

f	Maybe a Foundation.

Returns: true iff f is a foundation.

Definition at line 297 of file slope_func.h.

References None.

Referenced by ApplyFoundationToSlope(), and DrawFoundation().

◆ IsHalftileSlope()

constexpr bool IsHalftileSlope ( Slope s )

inlinestaticconstexpr

Checks for non-continuous slope on halftile foundations.

Parameters

s	The given Slope.

Returns: True if the slope is non-continuous, else false.

Definition at line 57 of file slope_func.h.

References SLOPE_HALFTILE.

Referenced by ComplementSlope(), DrawAutorailSelection(), DrawRailCatenaryRailway(), DrawTileSelection(), DrawTileSelectionRect(), DrawTrackDetails(), GetHalftileSlopeCorner(), GetPartialPixelZ(), GetSlopePixelZOnEdge(), GetSlopeZInCorner(), and IsSlopeWithThreeCornersRaised().

◆ IsInclinedFoundation()

bool IsInclinedFoundation ( Foundation f )

inline

Tests if the foundation is an inclined foundation.

Parameters

f	The Foundation.

Returns: true iff f is an inclined foundation.

Definition at line 319 of file slope_func.h.

References InclinedX, and InclinedY.

Referenced by DrawFoundation().

◆ IsInclinedSlope()

bool IsInclinedSlope ( Slope s )

inline

Tests if a specific slope is an inclined slope.

Parameters

s The Slope

Returns: true iff the slope is inclined.

Definition at line 238 of file slope_func.h.

References SLOPE_NE, SLOPE_NW, SLOPE_SE, and SLOPE_SW.

Referenced by CmdBuildCanal(), RiverFlowsDown(), and RiverMakeWider().

◆ IsLeveledFoundation()

bool IsLeveledFoundation ( Foundation f )

inline

Tests if the foundation is a leveled foundation.

Parameters

f	The Foundation.

Returns: true iff f is a leveled foundation.

Definition at line 308 of file slope_func.h.

References Leveled.

Referenced by ApplyFoundationToSlope(), and DrawFoundation().

◆ IsNonContinuousFoundation()

bool IsNonContinuousFoundation ( Foundation f )

inline

Tests if a foundation is a non-continuous foundation, i.e.

halftile-foundation or Foundation::SteepBoth.

Parameters

f	The Foundation.

Returns: true iff f is a non-continuous foundation

Definition at line 330 of file slope_func.h.

References HalfTileEnd, IsInsideMM(), and SteepBoth.

Referenced by ApplyFoundationToSlope(), DrawFoundation(), DrawTrackBits(), FloodHalftile(), and TileLoop_Rail().

◆ IsSlopeWithOneCornerRaised()

bool IsSlopeWithOneCornerRaised ( Slope s )

inline

Tests if a specific slope has exactly one corner raised.

Parameters

s The Slope

Returns: true iff exactly one corner is raised

Definition at line 98 of file slope_func.h.

References SLOPE_E, SLOPE_N, SLOPE_S, and SLOPE_W.

Referenced by CanPlantTreesOnTile(), CheckRoadSlope(), ClearTile_Rail(), ClearTile_Water(), CmdBuildSingleRail(), CmdPlantTree(), CmdRemoveSingleRail(), DoFloodTile(), FloodHalftile(), GetFloodingBehaviour(), GetRailFoundation(), GetRoadFoundation(), GetTileTrackStatus_Rail(), GrowTownWithTunnel(), HasSlopeHighestCorner(), IsSlopeWithThreeCornersRaised(), RiverMakeWider(), TerraformTile_Rail(), and TestAutoslopeOnRailTile().

◆ IsSlopeWithThreeCornersRaised()

bool IsSlopeWithThreeCornersRaised ( Slope s )

inline

Tests if a specific slope has exactly three corners raised.

Parameters

s The Slope

Returns: true iff exactly three corners are raised

Definition at line 205 of file slope_func.h.

References ComplementSlope(), IsHalftileSlope(), IsSlopeWithOneCornerRaised(), and IsSteepSlope().

Referenced by FloodHalftile(), GetRailFoundation(), RiverMakeWider(), and TileLoop_Rail().

◆ IsSpecialRailFoundation()

bool IsSpecialRailFoundation ( Foundation f )

inline

Tests if a foundation is a special rail foundation for single horizontal/vertical track.

Parameters

f	The Foundation.

Returns: true iff f is a special rail foundation for single horizontal/vertical track.

Definition at line 355 of file slope_func.h.

References End, IsInsideMM(), and RailW.

Referenced by ApplyFoundationToSlope(), DrawFoundation(), GetRailFoundationCorner(), and TerraformTile_Rail().

◆ IsSteepSlope()

constexpr bool IsSteepSlope ( Slope s )

inlinestaticconstexpr

Checks if a slope is steep.

Parameters

s	The given Slope.

Returns: True if the slope is steep, else false.

Definition at line 36 of file slope_func.h.

References SLOPE_STEEP.

Referenced by ApplyFoundationToSlope(), CanBuildDepotByTileh(), CanBuildHouseHere(), CheckBuildableTile(), CheckRailSlope(), CheckRoadSlope(), CmdBuildRoad(), CmdPlaceHouse(), ComplementSlope(), DrawFoundation(), DrawRailCatenaryRailway(), DrawTileSelection(), DrawTileSelectionRect(), DrawTrackBits(), FloodHalftile(), GetRailFoundation(), GetRoadFoundation(), GetSlopeMaxZ(), GrowTownWithTunnel(), HasSlopeHighestCorner(), IsSlopeWithThreeCornersRaised(), IsValidTileForWaypoint(), RemoveRoad(), RiverMakeWider(), TerraformTile_Industry(), TerraformTile_Object(), TerraformTile_Road(), TerraformTile_Town(), TileLoop_Rail(), and TownActionBuildStatue().

◆ IsValidCorner()

constexpr bool IsValidCorner ( Corner corner )

inlinestaticconstexpr

Rangecheck for Corner enumeration.

Parameters

corner A Corner.

Returns: true iff corner is in a valid range.

Definition at line 24 of file slope_func.h.

References IsInsideMM().

Referenced by CornerToTrackBits(), DrawRailCatenaryRailway(), DrawTrackBits(), DrawTrackFence(), HalftileFoundation(), HalftileSlope(), SlopeWithOneCornerRaised(), and SpecialRailFoundation().

◆ OppositeCorner()

Corner OppositeCorner ( Corner corner )

inline

Returns the opposite corner.

Parameters

corner A Corner.

Returns: The opposite corner to "corner".

Definition at line 194 of file slope_func.h.

Referenced by ApplyFoundationToSlope(), DrawAutorailSelection(), DrawTileSelectionRect(), DrawTrackBits(), DrawTrackDetails(), FloodHalftile(), GetRailFoundation(), and SteepSlope().

◆ RemoveHalftileSlope()

constexpr Slope RemoveHalftileSlope ( Slope s )

inlinestaticconstexpr

Removes a halftile slope from a slope.

Non-halftile slopes remain unmodified.

Parameters

s A Slope.

Returns: The slope s without its halftile slope.

Definition at line 70 of file slope_func.h.

References SLOPE_HALFTILE_MASK.

Referenced by DrawAutorailSelection(), DrawTileSelection(), DrawTrackFence(), GetHighestSlopeCorner(), GetPartialPixelZ(), GetSlopePixelZOnEdge(), HasSlopeHighestCorner(), IsRoadAllowedHere(), IsUphillTrackdir(), TestAutoslopeOnRailTile(), and TileLoop_Water().

◆ RemoveSteepSlope()

constexpr Slope RemoveSteepSlope ( Slope s )

staticconstexpr

Removes a steep flag from a slope.

Parameters

s	A Slope to get modified version of.

Returns: The slope s without the steep flag.

Definition at line 46 of file slope_func.h.

References SLOPE_STEEP.

Referenced by DrawFoundation(), IsRoadAllowedHere(), and TileLoop_Water().

◆ SlopeToSpriteOffset()

uint SlopeToSpriteOffset ( Slope s )

inline

Returns the Sprite offset for a given Slope.

Parameters

s	The Slope to get the offset for.

Returns: The sprite offset for this Slope.

Definition at line 423 of file slope_func.h.

References _slope_to_sprite_offset.

Referenced by DrawClearLandTile(), DrawRoughLandTile(), DrawTile_Clear(), DrawTile_Trees(), DrawTile_TunnelBridge(), DrawTile_Void(), DrawTileSelectionRect(), DrawTrackBits(), and GetRoadGroundSprite().

◆ SlopeWithOneCornerRaised()

Slope SlopeWithOneCornerRaised ( Corner corner )

inline

Returns the slope with a specific corner raised.

Parameters

corner The Corner.

Returns: The Slope with corner "corner" raised.

Definition at line 109 of file slope_func.h.

References IsValidCorner().

Referenced by ApplyFoundationToSlope(), CheckRoadSlope(), DrawFoundation(), DrawTileSelectionRect(), GetRailFoundation(), GetRoadFoundation(), GetSlopePixelZOnEdge(), GetSlopeZInCorner(), RemoveRoad(), and SlopeWithThreeCornersRaised().

◆ SlopeWithThreeCornersRaised()

Slope SlopeWithThreeCornersRaised ( Corner corner )

inline

Returns the slope with all except one corner raised.

Parameters

corner The Corner.

Returns: The Slope with all corners but "corner" raised.

Definition at line 216 of file slope_func.h.

References ComplementSlope(), and SlopeWithOneCornerRaised().

Referenced by ApplyFoundationToSlope(), DrawAutorailSelection(), DrawFoundation(), DrawTrackBits(), GetRailFoundation(), and SteepSlope().

◆ SpecialRailFoundation()

Foundation SpecialRailFoundation ( Corner corner )

inline

Returns the special rail foundation for single horizontal/vertical track.

Parameters

corner The Corner with the track.

Returns: The wanted Foundation.

Definition at line 411 of file slope_func.h.

References IsValidCorner(), and RailW.

Referenced by GetRailFoundation().

◆ SteepSlope()

Slope SteepSlope ( Corner corner )

inline

Returns a specific steep slope.

Parameters

corner A Corner.

Returns: The steep Slope with "corner" as highest corner.

Definition at line 227 of file slope_func.h.

References OppositeCorner(), SLOPE_STEEP, and SlopeWithThreeCornersRaised().

Referenced by GetSlopeZInCorner().