tron@3636: /* $Id$ */
tron@3636: 
rubidium@8604: /** @file slope_func.h Functions related to slopes. */
rubidium@8260: 
rubidium@8604: #ifndef SLOPE_FUNC_H
rubidium@8604: #define SLOPE_FUNC_H
tron@3636: 
rubidium@8609: #include "core/math_func.hpp"
rubidium@8604: #include "slope_type.h"
rubidium@8604: #include "direction_type.h"
rubidium@8634: #include "tile_type.h"
rubidium@8174: 
rubidium@8174: /**
rubidium@8199:  * Rangecheck for Corner enumeration.
rubidium@8199:  *
rubidium@8199:  * @param corner A #Corner.
rubidium@8199:  * @return true iff corner is in a valid range.
rubidium@8199:  */
rubidium@8199: static inline bool IsValidCorner(Corner corner)
rubidium@8199: {
skidd13@8450: 	return IsInsideMM(corner, 0, CORNER_END);
rubidium@8199: }
rubidium@8199: 
rubidium@8604: 
rubidium@8199: /**
truelight@7805:  * Checks if a slope is steep.
truelight@7805:  *
truelight@7805:  * @param s The given #Slope.
truelight@7805:  * @return True if the slope is steep, else false.
truelight@7805:  */
tron@3636: static inline bool IsSteepSlope(Slope s)
tron@3636: {
tron@3636: 	return (s & SLOPE_STEEP) != 0;
tron@3636: }
tron@3636: 
truelight@7805: /**
rubidium@8260:  * Checks for non-continuous slope on halftile foundations.
rubidium@8260:  *
rubidium@8260:  * @param s The given #Slope.
rubidium@8260:  * @return True if the slope is non-continuous, else false.
rubidium@8260:  */
rubidium@8260: static inline bool IsHalftileSlope(Slope s)
rubidium@8260: {
rubidium@8260: 	return (s & SLOPE_HALFTILE) != 0;
rubidium@8260: }
rubidium@8260: 
rubidium@8260: /**
frosch@8909:  * Removes a halftile slope from a slope
frosch@8909:  *
frosch@8909:  * Non-halftile slopes remain unmodified.
frosch@8909:  *
frosch@8909:  * @param s A #Slope.
frosch@8909:  * @return The slope s without it's halftile slope.
frosch@8909:  */
frosch@8909: static inline Slope RemoveHalftileSlope(Slope s)
frosch@8909: {
frosch@8909: 	return (Slope)(s & ~SLOPE_HALFTILE_MASK);
frosch@8909: }
frosch@8909: 
frosch@8909: /**
truelight@7805:  * Return the complement of a slope.
truelight@7805:  *
truelight@7805:  * This method returns the complement of a slope. The complement of a
truelight@7805:  * slope is a slope with raised corner which aren't raised in the given
truelight@7805:  * slope.
truelight@7805:  *
rubidium@8260:  * @pre The slope must neither be steep nor a halftile slope.
truelight@7805:  * @param s The #Slope to get the complement.
truelight@7805:  * @return a complement Slope of the given slope.
truelight@7805:  */
tron@3636: static inline Slope ComplementSlope(Slope s)
tron@3636: {
rubidium@8260: 	assert(!IsSteepSlope(s) && !IsHalftileSlope(s));
tron@3636: 	return (Slope)(0xF ^ s);
tron@3636: }
tron@3636: 
rubidium@7831: /**
frosch@8909:  * Tests if a specific slope has exactly one corner raised.
frosch@8909:  *
frosch@8909:  * @param s The #Slope
frosch@8909:  * @return true iff exactly one corner is raised
frosch@8909:  */
frosch@8909: static inline bool IsSlopeWithOneCornerRaised(Slope s)
frosch@8909: {
frosch@8909: 	return (s == SLOPE_W) || (s == SLOPE_S) || (s == SLOPE_E) || (s == SLOPE_N);
frosch@8909: }
frosch@8909: 
frosch@8909: /**
frosch@8909:  * Returns the slope with a specific corner raised.
frosch@8909:  *
frosch@8909:  * @param corner The #Corner.
frosch@8909:  * @return The #Slope with corner "corner" raised.
frosch@8909:  */
frosch@8909: static inline Slope SlopeWithOneCornerRaised(Corner corner)
frosch@8909: {
frosch@8909: 	assert(IsValidCorner(corner));
frosch@8909: 	return (Slope)(1 << corner);
frosch@8909: }
frosch@8909: 
frosch@8909: /**
rubidium@8199:  * Tests if a slope has a highest corner (i.e. one corner raised or a steep slope).
rubidium@8199:  *
rubidium@8260:  * Note: A halftile slope is ignored.
rubidium@8260:  *
rubidium@8199:  * @param s The #Slope.
rubidium@8199:  * @return  true iff the slope has a highest corner.
rubidium@8199:  */
rubidium@8199: static inline bool HasSlopeHighestCorner(Slope s)
rubidium@8199: {
frosch@8909: 	s = RemoveHalftileSlope(s);
frosch@8909: 	return IsSteepSlope(s) || IsSlopeWithOneCornerRaised(s);
rubidium@8199: }
rubidium@8199: 
rubidium@8199: /**
rubidium@7831:  * Returns the highest corner of a slope (one corner raised or a steep slope).
rubidium@7831:  *
rubidium@8260:  * @pre      The slope must be a slope with one corner raised or a steep slope. A halftile slope is ignored.
rubidium@7831:  * @param s  The #Slope.
rubidium@8174:  * @return   Highest corner.
rubidium@7831:  */
rubidium@8174: static inline Corner GetHighestSlopeCorner(Slope s)
rubidium@7831: {
frosch@8909: 	switch (RemoveHalftileSlope(s)) {
rubidium@7831: 		case SLOPE_W:
rubidium@8174: 		case SLOPE_STEEP_W: return CORNER_W;
rubidium@7831: 		case SLOPE_S:
rubidium@8174: 		case SLOPE_STEEP_S: return CORNER_S;
rubidium@7831: 		case SLOPE_E:
rubidium@8174: 		case SLOPE_STEEP_E: return CORNER_E;
rubidium@7831: 		case SLOPE_N:
rubidium@8174: 		case SLOPE_STEEP_N: return CORNER_N;
rubidium@7831: 		default: NOT_REACHED();
rubidium@7831: 	}
rubidium@7831: }
rubidium@7831: 
rubidium@8078: /**
rubidium@8260:  * Returns the leveled halftile of a halftile slope.
rubidium@8260:  *
rubidium@8260:  * @pre     The slope must be a halftile slope.
rubidium@8260:  * @param s The #Slope.
rubidium@8260:  * @return  The corner of the leveled halftile.
rubidium@8260:  */
rubidium@8260: static inline Corner GetHalftileSlopeCorner(Slope s)
rubidium@8260: {
rubidium@8260: 	assert(IsHalftileSlope(s));
rubidium@8260: 	return (Corner)((s >> 6) & 3);
rubidium@8260: }
rubidium@8260: 
rubidium@8260: /**
rubidium@8078:  * Returns the height of the highest corner of a slope relative to TileZ (= minimal height)
rubidium@8078:  *
rubidium@8078:  * @param s The #Slope.
rubidium@8078:  * @return Relative height of highest corner.
rubidium@8078:  */
rubidium@8078: static inline uint GetSlopeMaxZ(Slope s)
rubidium@8078: {
rubidium@8078: 	if (s == SLOPE_FLAT) return 0;
rubidium@8078: 	if (IsSteepSlope(s)) return 2 * TILE_HEIGHT;
rubidium@8078: 	return TILE_HEIGHT;
rubidium@8078: }
rubidium@8078: 
rubidium@8174: /**
rubidium@8174:  * Returns the opposite corner.
rubidium@8174:  *
rubidium@8174:  * @param corner A #Corner.
rubidium@8174:  * @return The opposite corner to "corner".
rubidium@8174:  */
rubidium@8174: static inline Corner OppositeCorner(Corner corner)
rubidium@8174: {
rubidium@8174: 	return (Corner)(corner ^ 2);
rubidium@8174: }
rubidium@8174: 
rubidium@8174: /**
frosch@8909:  * Tests if a specific slope has exactly three corners raised.
rubidium@8174:  *
frosch@8909:  * @param s The #Slope
frosch@8909:  * @return true iff exactly three corners are raised
rubidium@8174:  */
frosch@8909: static inline bool IsSlopeWithThreeCornersRaised(Slope s)
rubidium@8174: {
frosch@8909: 	return !IsHalftileSlope(s) && !IsSteepSlope(s) && IsSlopeWithOneCornerRaised(ComplementSlope(s));
rubidium@8174: }
rubidium@8174: 
rubidium@8174: /**
rubidium@8174:  * Returns the slope with all except one corner raised.
rubidium@8174:  *
rubidium@8174:  * @param corner The #Corner.
rubidium@8174:  * @return The #Slope with all corners but "corner" raised.
rubidium@8174:  */
rubidium@8174: static inline Slope SlopeWithThreeCornersRaised(Corner corner)
rubidium@8174: {
rubidium@8174: 	return ComplementSlope(SlopeWithOneCornerRaised(corner));
rubidium@8174: }
rubidium@8174: 
rubidium@8260: /**
frosch@8909:  * Returns a specific steep slope
frosch@8909:  *
frosch@8909:  * @param corner A #Corner.
frosch@8909:  * @return The steep #Slope with "corner" as highest corner.
frosch@8909:  */
frosch@8909: static inline Slope SteepSlope(Corner corner)
frosch@8909: {
frosch@8909: 	return (Slope)(SLOPE_STEEP | SlopeWithThreeCornersRaised(OppositeCorner(corner)));
frosch@8909: }
frosch@8909: 
frosch@8909: /**
frosch@8909:  * Tests if a specific slope is an inclined slope.
frosch@8909:  *
frosch@8909:  * @param s The #Slope
frosch@8909:  * @return true iff the slope is inclined.
frosch@8909:  */
frosch@8909: static inline bool IsInclinedSlope(Slope s)
frosch@8909: {
frosch@8909: 	return (s == SLOPE_NW) || (s == SLOPE_SW) || (s == SLOPE_SE) || (s == SLOPE_NE);
frosch@8909: }
frosch@8909: 
frosch@8909: /**
frosch@8909:  * Returns the direction of an inclined slope.
frosch@8909:  *
frosch@8909:  * @param s A #Slope
frosch@8909:  * @return The direction the slope goes up in. Or INVALID_DIAGDIR if the slope is not an inclined slope.
frosch@8909:  */
frosch@8909: static inline DiagDirection GetInclinedSlopeDirection(Slope s)
frosch@8909: {
frosch@8909: 	switch (s) {
frosch@8909: 		case SLOPE_NE: return DIAGDIR_NE;
frosch@8909: 		case SLOPE_SE: return DIAGDIR_SE;
frosch@8909: 		case SLOPE_SW: return DIAGDIR_SW;
frosch@8909: 		case SLOPE_NW: return DIAGDIR_NW;
frosch@8909: 		default: return INVALID_DIAGDIR;
frosch@8909: 	}
frosch@8909: }
frosch@8909: 
frosch@8909: /**
frosch@8909:  * Returns the slope, that is inclined in a specific direction.
frosch@8909:  *
frosch@8909:  * @param dir A #DiagDirection
frosch@8909:  * @return The #Slope that goes up in direction dir.
frosch@8909:  */
frosch@8909: static inline Slope InclinedSlope(DiagDirection dir)
frosch@8909: {
frosch@8909: 	switch (dir) {
frosch@8909: 		case DIAGDIR_NE: return SLOPE_NE;
frosch@8909: 		case DIAGDIR_SE: return SLOPE_SE;
frosch@8909: 		case DIAGDIR_SW: return SLOPE_SW;
frosch@8909: 		case DIAGDIR_NW: return SLOPE_NW;
frosch@8909: 		default: NOT_REACHED();
frosch@8909: 	}
frosch@8909: }
frosch@8909: 
frosch@8909: /**
rubidium@8260:  * Adds a halftile slope to a slope.
rubidium@8260:  *
rubidium@8260:  * @param s #Slope without a halftile slope.
rubidium@8260:  * @param corner The #Corner of the halftile.
rubidium@8260:  * @return The #Slope s with the halftile slope added.
rubidium@8260:  */
rubidium@8260: static inline Slope HalftileSlope(Slope s, Corner corner)
rubidium@8260: {
rubidium@8260: 	assert(IsValidCorner(corner));
rubidium@8260: 	return (Slope)(s | SLOPE_HALFTILE | (corner << 6));
rubidium@8260: }
rubidium@8260: 
rubidium@7831: 
rubidium@7831: /**
rubidium@7831:  * Tests for FOUNDATION_NONE.
rubidium@7831:  *
rubidium@7831:  * @param f  Maybe a #Foundation.
rubidium@7831:  * @return   true iff f is a foundation.
rubidium@7831:  */
rubidium@7831: static inline bool IsFoundation(Foundation f)
rubidium@7831: {
rubidium@7831: 	return f != FOUNDATION_NONE;
rubidium@7831: }
rubidium@7831: 
rubidium@7831: /**
rubidium@7831:  * Tests if the foundation is a leveled foundation.
rubidium@7831:  *
rubidium@7831:  * @param f  The #Foundation.
rubidium@7831:  * @return   true iff f is a leveled foundation.
rubidium@7831:  */
rubidium@7831: static inline bool IsLeveledFoundation(Foundation f)
rubidium@7831: {
rubidium@7831: 	return f == FOUNDATION_LEVELED;
rubidium@7831: }
rubidium@7831: 
rubidium@7831: /**
rubidium@7831:  * Tests if the foundation is an inclined foundation.
rubidium@7831:  *
rubidium@7831:  * @param f  The #Foundation.
rubidium@7831:  * @return   true iff f is an inclined foundation.
rubidium@7831:  */
rubidium@7831: static inline bool IsInclinedFoundation(Foundation f)
rubidium@7831: {
rubidium@7831: 	return (f == FOUNDATION_INCLINED_X) || (f == FOUNDATION_INCLINED_Y);
rubidium@7831: }
rubidium@7831: 
rubidium@7831: /**
rubidium@8266:  * Tests if a foundation is a non-continuous foundation, i.e. halftile-foundation or FOUNDATION_STEEP_BOTH.
rubidium@8266:  *
rubidium@8266:  * @param f  The #Foundation.
rubidium@8266:  * @return   true iff f is a non-continuous foundation
rubidium@8266:  */
rubidium@8266: static inline bool IsNonContinuousFoundation(Foundation f)
rubidium@8266: {
skidd13@8450: 	return IsInsideMM(f, FOUNDATION_STEEP_BOTH, FOUNDATION_HALFTILE_N + 1);
rubidium@8266: }
rubidium@8266: 
rubidium@8266: /**
rubidium@8266:  * Returns the halftile corner of a halftile-foundation
rubidium@8266:  *
rubidium@8266:  * @pre f != FOUNDATION_STEEP_BOTH
rubidium@8266:  *
rubidium@8266:  * @param f  The #Foundation.
rubidium@8266:  * @return   The #Corner with track.
rubidium@8266:  */
rubidium@8266: static inline Corner GetHalftileFoundationCorner(Foundation f)
rubidium@8266: {
skidd13@8450: 	assert(IsInsideMM(f, FOUNDATION_HALFTILE_W, FOUNDATION_HALFTILE_N + 1));
rubidium@8266: 	return (Corner)(f - FOUNDATION_HALFTILE_W);
rubidium@8266: }
rubidium@8266: 
rubidium@8266: /**
rubidium@8266:  * Tests if a foundation is a special rail foundation for single horizontal/vertical track.
rubidium@8266:  *
rubidium@8266:  * @param f  The #Foundation.
rubidium@8266:  * @return   true iff f is a special rail foundation for single horizontal/vertical track.
rubidium@8266:  */
rubidium@8266: static inline bool IsSpecialRailFoundation(Foundation f)
rubidium@8266: {
skidd13@8450: 	return IsInsideMM(f, FOUNDATION_RAIL_W, FOUNDATION_RAIL_N + 1);
rubidium@8266: }
rubidium@8266: 
rubidium@8266: /**
rubidium@8266:  * Returns the track corner of a special rail foundation
rubidium@8266:  *
rubidium@8266:  * @param f  The #Foundation.
rubidium@8266:  * @return   The #Corner with track.
rubidium@8266:  */
rubidium@8266: static inline Corner GetRailFoundationCorner(Foundation f)
rubidium@8266: {
rubidium@8266: 	assert(IsSpecialRailFoundation(f));
rubidium@8266: 	return (Corner)(f - FOUNDATION_RAIL_W);
rubidium@8266: }
rubidium@8266: 
rubidium@8266: /**
rubidium@7831:  * Returns the foundation needed to flatten a slope.
rubidium@7831:  * The returned foundation is either FOUNDATION_NONE if the tile was already flat, or FOUNDATION_LEVELED.
rubidium@7831:  *
rubidium@7831:  * @pre      The slope must not be steep.
rubidium@7831:  * @param s  The current #Slope.
rubidium@7831:  * @return   The needed #Foundation.
rubidium@7831:  */
rubidium@7831: static inline Foundation FlatteningFoundation(Slope s)
rubidium@7831: {
rubidium@7831: 	assert(!IsSteepSlope(s));
rubidium@7831: 	return (s == SLOPE_FLAT ? FOUNDATION_NONE : FOUNDATION_LEVELED);
rubidium@7831: }
rubidium@7831: 
rubidium@7831: /**
rubidium@7831:  * Returns the along a specific axis inclined foundation.
rubidium@7831:  *
rubidium@7831:  * @param axis  The #Axis.
rubidium@7831:  * @return      The needed #Foundation.
rubidium@7831:  */
rubidium@7831: static inline Foundation InclinedFoundation(Axis axis)
rubidium@7831: {
rubidium@7831: 	return (axis == AXIS_X ? FOUNDATION_INCLINED_X : FOUNDATION_INCLINED_Y);
rubidium@7831: }
rubidium@7831: 
rubidium@8266: /**
rubidium@8266:  * Returns the halftile foundation for single horizontal/vertical track.
rubidium@8266:  *
rubidium@8266:  * @param corner The #Corner with the track.
rubidium@8266:  * @return       The wanted #Foundation.
rubidium@8266:  */
rubidium@8266: static inline Foundation HalftileFoundation(Corner corner)
rubidium@8266: {
rubidium@8266: 	assert(IsValidCorner(corner));
rubidium@8266: 	return (Foundation)(FOUNDATION_HALFTILE_W + corner);
rubidium@8266: }
rubidium@8266: 
rubidium@8266: /**
rubidium@8266:  * Returns the special rail foundation for single horizontal/vertical track.
rubidium@8266:  *
rubidium@8266:  * @param corner The #Corner with the track.
rubidium@8266:  * @return       The wanted #Foundation.
rubidium@8266:  */
rubidium@8266: static inline Foundation SpecialRailFoundation(Corner corner)
rubidium@8266: {
rubidium@8266: 	assert(IsValidCorner(corner));
rubidium@8266: 	return (Foundation)(FOUNDATION_RAIL_W + corner);
rubidium@8266: }
rubidium@8266: 
rubidium@8604: #endif /* SLOPE_FUNC_H */