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(svn r11313) -Codechange: prepare several pieces of code so the can handle some new slopes. Patch by frosch.

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This commit is contained in:
rubidium
2007-10-20 16:50:48 +00:00
parent eadd6765e1
commit 99266a173c
7 changed files with 157 additions and 39 deletions
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85
src/slope.h
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@@ -8,6 +8,17 @@
#ifndef SLOPE_H
#define SLOPE_H
/**
* Enumeration of tile corners
*/
enum Corner {
CORNER_W = 0,
CORNER_S = 1,
CORNER_E = 2,
CORNER_N = 3,
CORNER_END
};
/**
* Enumeration for the slope-type.
*
@@ -15,6 +26,14 @@
* direction north, east, south and west. The top corner of a tile
* is the north-part of the tile. The whole slope is encoded with
* 5 bits, 4 bits for each corner and 1 bit for a steep-flag.
*
* For halftile slopes an extra 3 bits are used to represent this
* properly; 1 bit for a halftile-flag and 2 bits to encode which
* extra side (corner) is leveled when the slope of the first 5
* bits is applied. This means that there can only be one leveled
* slope for steep slopes, which is logical because two leveled
* slopes would mean that it is not a steep slope as halftile
* slopes only span one height level.
*/
enum Slope {
SLOPE_FLAT = 0x00, ///< a flat tile
@@ -37,18 +56,14 @@ enum Slope {
SLOPE_STEEP_W = SLOPE_STEEP | SLOPE_NWS, ///< a steep slope falling to east (from west)
SLOPE_STEEP_S = SLOPE_STEEP | SLOPE_WSE, ///< a steep slope falling to north (from south)
SLOPE_STEEP_E = SLOPE_STEEP | SLOPE_SEN, ///< a steep slope falling to west (from east)
SLOPE_STEEP_N = SLOPE_STEEP | SLOPE_ENW ///< a steep slope falling to south (from north)
};
SLOPE_STEEP_N = SLOPE_STEEP | SLOPE_ENW, ///< a steep slope falling to south (from north)
/**
* Enumeration of tile corners
*/
enum Corner {
CORNER_W = 0,
CORNER_S = 1,
CORNER_E = 2,
CORNER_N = 3,
CORNER_END
SLOPE_HALFTILE = 0x20, ///< one halftile is leveled (non continuous slope)
SLOPE_HALFTILE_MASK = 0xE0, ///< three bits used for halftile slopes
SLOPE_HALFTILE_W = SLOPE_HALFTILE | (CORNER_W << 6), ///< the west halftile is leveled (non continuous slope)
SLOPE_HALFTILE_S = SLOPE_HALFTILE | (CORNER_S << 6), ///< the south halftile is leveled (non continuous slope)
SLOPE_HALFTILE_E = SLOPE_HALFTILE | (CORNER_E << 6), ///< the east halftile is leveled (non continuous slope)
SLOPE_HALFTILE_N = SLOPE_HALFTILE | (CORNER_N << 6), ///< the north halftile is leveled (non continuous slope)
};
/**
@@ -73,6 +88,17 @@ static inline bool IsSteepSlope(Slope s)
return (s & SLOPE_STEEP) != 0;
}
/**
* Checks for non-continuous slope on halftile foundations.
*
* @param s The given #Slope.
* @return True if the slope is non-continuous, else false.
*/
static inline bool IsHalftileSlope(Slope s)
{
return (s & SLOPE_HALFTILE) != 0;
}
/**
* Return the complement of a slope.
*
@@ -80,37 +106,40 @@ static inline bool IsSteepSlope(Slope s)
* slope is a slope with raised corner which aren't raised in the given
* slope.
*
* @pre The slope must not be steep.
* @pre The slope must neither be steep nor a halftile slope.
* @param s The #Slope to get the complement.
* @return a complement Slope of the given slope.
*/
static inline Slope ComplementSlope(Slope s)
{
assert(!IsSteepSlope(s));
assert(!IsSteepSlope(s) && !IsHalftileSlope(s));
return (Slope)(0xF ^ s);
}
/**
* Tests if a slope has a highest corner (i.e. one corner raised or a steep slope).
*
* Note: A halftile slope is ignored.
*
* @param s The #Slope.
* @return true iff the slope has a highest corner.
*/
static inline bool HasSlopeHighestCorner(Slope s)
{
s = (Slope)(s & ~SLOPE_HALFTILE_MASK);
return IsSteepSlope(s) || (s == SLOPE_W) || (s == SLOPE_S) || (s == SLOPE_E) || (s == SLOPE_N);
}
/**
* Returns the highest corner of a slope (one corner raised or a steep slope).
*
* @pre The slope must be a slope with one corner raised or a steep slope.
* @pre The slope must be a slope with one corner raised or a steep slope. A halftile slope is ignored.
* @param s The #Slope.
* @return Highest corner.
*/
static inline Corner GetHighestSlopeCorner(Slope s)
{
switch (s) {
switch (s & ~SLOPE_HALFTILE_MASK) {
case SLOPE_W:
case SLOPE_STEEP_W: return CORNER_W;
case SLOPE_S:
@@ -123,6 +152,19 @@ static inline Corner GetHighestSlopeCorner(Slope s)
}
}
/**
* Returns the leveled halftile of a halftile slope.
*
* @pre The slope must be a halftile slope.
* @param s The #Slope.
* @return The corner of the leveled halftile.
*/
static inline Corner GetHalftileSlopeCorner(Slope s)
{
assert(IsHalftileSlope(s));
return (Corner)((s >> 6) & 3);
}
/**
* Returns the height of the highest corner of a slope relative to TileZ (= minimal height)
*
@@ -170,6 +212,19 @@ static inline Slope SlopeWithThreeCornersRaised(Corner corner)
return ComplementSlope(SlopeWithOneCornerRaised(corner));
}
/**
* Adds a halftile slope to a slope.
*
* @param s #Slope without a halftile slope.
* @param corner The #Corner of the halftile.
* @return The #Slope s with the halftile slope added.
*/
static inline Slope HalftileSlope(Slope s, Corner corner)
{
assert(IsValidCorner(corner));
return (Slope)(s | SLOPE_HALFTILE | (corner << 6));
}
/**
* Enumeration for Foundations.