summaryrefslogtreecommitdiff
path: root/src/macros.h
blob: 56dc219e3b0fad30b42f693bb3d4b6dce5885e3f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
/* $Id$ */

#ifndef MACROS_H
#define MACROS_H

/// Fetch n bits starting at bit s from x
#define GB(x, s, n) (((x) >> (s)) & ((1U << (n)) - 1))
/// Set n bits starting at bit s in x to d
#define SB(x, s, n, d) ((x) = ((x) & ~(((1U << (n)) - 1) << (s))) | ((d) << (s)))
/// Add i to the n bits starting at bit s in x
#define AB(x, s, n, i) ((x) = ((x) & ~(((1U << (n)) - 1) << (s))) | (((x) + ((i) << (s))) & (((1U << (n)) - 1) << (s))))

#ifdef min
#undef min
#endif

#ifdef max
#undef max
#endif

/* Objective C don't like templates */
#ifdef __cplusplus
template <typename T>
static inline T max(T a, T b)
{
	return a >= b ? a : b;
}
#endif

static inline int min(int a, int b) { if (a <= b) return a; return b; }

static inline uint minu(uint a, uint b) { if (a <= b) return a; return b; }


static inline int clamp(int a, int min, int max)
{
	if (a <= min) return min;
	if (a >= max) return max;
	return a;
}

static inline uint clampu(uint a, uint min, uint max)
{
	if (a <= min) return min;
	if (a >= max) return max;
	return a;
}

static inline int32 BIGMULSS(int32 a, int32 b, int shift) {
	return (int32)(((int64)(a) * (int64)(b)) >> (shift));
}

static inline uint32 BIGMULUS(uint32 a, uint32 b, int shift) {
	return (uint32)(((uint64)(a) * (uint64)(b)) >> (shift));
}

static inline int64 BIGMULS(int32 a, int32 b) {
	return (int64)(a) * (int64)(b);
}

/* OPT: optimized into an unsigned comparison */
//#define IS_INSIDE_1D(x, base, size) ((x) >= (base) && (x) < (base) + (size))
#define IS_INSIDE_1D(x, base, size) ( (uint)((x) - (base)) < ((uint)(size)) )

template <typename T>
static inline bool HASBIT(T x, int y)
{
	return (x & (((T)1) << y)) != 0;
}

template <typename T>
static inline T SETBIT(T& x, int y)
{
	return x |= (((T)1) << y);
}

template <typename T>
static inline T CLRBIT(T& x, int y)
{
	return x &= ~(((T)1) << y);
}

template <typename T>
static inline T TOGGLEBIT(T& x, int y)
{
	return x ^= (((T)1) << y);
}


// checking more bits. Maybe unneccessary, but easy to use
#define HASBITS(x,y) ((x) & (y))
#define SETBITS(x,y) ((x) |= (y))
#define CLRBITS(x,y) ((x) &= ~(y))

#define GENERAL_SPRITE_COLOR(color) ((color) + PALETTE_RECOLOR_START)
#define PLAYER_SPRITE_COLOR(owner) (GENERAL_SPRITE_COLOR(_player_colors[owner]))

extern const byte _ffb_64[128];
/* Returns the position of the first bit that is not zero, counted from the
 * left. Ie, 10110100 returns 2, 00000001 returns 0, etc. When x == 0 returns
 * 0.
 */
#define FIND_FIRST_BIT(x) _ffb_64[(x)]
/* Returns x with the first bit that is not zero, counted from the left, set
 * to zero. So, 10110100 returns 10110000, 00000001 returns 00000000, etc.
 */
#define KILL_FIRST_BIT(x) _ffb_64[(x)+64]

static inline int FindFirstBit2x64(int value)
{
/*
	int i = 0;
	if ( (byte) value == 0) {
		i += 8;
		value >>= 8;
	}
	return i + FIND_FIRST_BIT(value & 0x3F);

Faster ( or at least cleaner ) implementation below?
*/
	if (GB(value, 0, 8) == 0) {
		return FIND_FIRST_BIT(GB(value, 8, 6)) + 8;
	} else {
		return FIND_FIRST_BIT(GB(value, 0, 6));
	}

}

static inline int KillFirstBit2x64(int value)
{
	if (GB(value, 0, 8) == 0) {
		return KILL_FIRST_BIT(GB(value, 8, 6)) << 8;
	} else {
		return value & (KILL_FIRST_BIT(GB(value, 0, 6)) | 0x3F00);
	}
}

/** returns true if value a has only one bit set to 1 */
#define HAS_SINGLE_BIT(a) ( ((a) & ((a) - 1)) == 0)

/* [min,max), strictly less than */
#define IS_BYTE_INSIDE(a,min,max) ((byte)((a)-(min)) < (byte)((max)-(min)))
#define IS_INT_INSIDE(a,min,max) ((uint)((a)-(min)) < (uint)((max)-(min)))


#define CHANCE16(a,b) ((uint16)Random() <= (uint16)((65536 * (a)) / (b)))
#define CHANCE16R(a,b,r) ((uint16)(r=Random()) <= (uint16)((65536 * (a)) / (b)))
#define CHANCE16I(a,b,v) ((uint16)(v) <= (uint16)((65536 * (a)) / (b)))


#define for_each_bit(_i, _b)            \
	for (_i = 0; _b != 0; _i++, _b >>= 1) \
		if (_b & 1)

#define abs myabs

static inline int intxchg_(int *a, int b) { int t = *a; *a = b; return t; }
#define intswap(a,b) ((b) = intxchg_(&(a), (b)))
static inline int uintxchg_(uint *a, uint b) { uint t = *a; *a = b; return t; }
#define uintswap(a,b) ((b) = uintxchg_(&(a), (b)))


static inline uint16 ReadLE16Aligned(const void* x)
{
	return FROM_LE16(*(const uint16*)x);
}

static inline uint16 ReadLE16Unaligned(const void* x)
{
#ifdef OTTD_ALIGNMENT
	return ((const byte*)x)[0] | ((const byte*)x)[1] << 8;
#else
	return FROM_LE16(*(const uint16*)x);
#endif
}


/**
 * ROtate x Left/Right by n (must be >= 0)
 * @note Assumes a byte has 8 bits
 */
#define ROL(x, n) ((x) << (n) | (x) >> (sizeof(x) * 8 - (n)))
#define ROR(x, n) ((x) >> (n) | (x) << (sizeof(x) * 8 - (n)))

/**
 * Return the smallest multiple of n equal or greater than x
 * @note n must be a power of 2
 */
#define ALIGN(x, n) (((x) + (n) - 1) & ~((n) - 1))

/** return the largest value that can be entered in a variable.
 *  known to work for uint32.
 *  used by TGP to set the max value of the _patches.generation_seed in its definition
 */
#define MAX_UVALUE(type) ((type)~(type)0)

#endif /* MACROS_H */