Files
@ r10062:9a719b26b56e
Branch filter:
Location: cpp/openttd-patchpack/source/src/core/bitmath_func.cpp - annotation
r10062:9a719b26b56e
2.0 KiB
text/x-c
(svn r14229) -Feature: allow overriding the palette of the base GRFs. This way you can play with NewGRFs made for the Windows palette with the DOS palettes base GRFs (and vice versa). Note that for this to work correctly ALL NewGRFs must use the same palette; mix and match is not yet supported.
r7971:5de6852fd5c5 r7971:5de6852fd5c5 r9111:983de9c5a848 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r8000:8bece5ad1135 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r7971:5de6852fd5c5 r8000:8bece5ad1135 r8000:8bece5ad1135 r8055:1270040d620c r8000:8bece5ad1135 r8000:8bece5ad1135 r8005:db909f00ebe3 r8000:8bece5ad1135 r8000:8bece5ad1135 r8000:8bece5ad1135 r8000:8bece5ad1135 r8000:8bece5ad1135 r8000:8bece5ad1135 r8055:1270040d620c r8000:8bece5ad1135 r8000:8bece5ad1135 r8000:8bece5ad1135 r8000:8bece5ad1135 r8000:8bece5ad1135 r8055:1270040d620c r8055:1270040d620c r8055:1270040d620c r8055:1270040d620c r8055:1270040d620c r8055:1270040d620c r8000:8bece5ad1135 r8000:8bece5ad1135 r8000:8bece5ad1135 | /* $Id$ */
/** @file bitmath_func.cpp Functions related to bit mathematics. */
#include "../stdafx.h"
#include "bitmath_func.hpp"
const uint8 _ffb_64[64] = {
0, 0, 1, 0, 2, 0, 1, 0,
3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0,
3, 0, 1, 0, 2, 0, 1, 0,
5, 0, 1, 0, 2, 0, 1, 0,
3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0,
3, 0, 1, 0, 2, 0, 1, 0,
};
/**
* Search the first set bit in a 32 bit variable.
*
* This algorithm is a static implementation of a log
* conguence search algorithm. It checks the first half
* if there is a bit set search there further. And this
* way further. If no bit is set return 0.
*
* @param x The value to search
* @return The position of the first bit set
*/
uint8 FindFirstBit(uint32 x)
{
if (x == 0) return 0;
/* The macro FIND_FIRST_BIT is better to use when your x is
not more than 128. */
uint8 pos = 0;
if ((x & 0x0000ffff) == 0) { x >>= 16; pos += 16; }
if ((x & 0x000000ff) == 0) { x >>= 8; pos += 8; }
if ((x & 0x0000000f) == 0) { x >>= 4; pos += 4; }
if ((x & 0x00000003) == 0) { x >>= 2; pos += 2; }
if ((x & 0x00000001) == 0) { pos += 1; }
return pos;
}
/**
* Search the last set bit in a 64 bit variable.
*
* This algorithm is a static implementation of a log
* conguence search algorithm. It checks the second half
* if there is a bit set search there further. And this
* way further. If no bit is set return 0.
*
* @param x The value to search
* @return The position of the last bit set
*/
uint8 FindLastBit(uint64 x)
{
if (x == 0) return 0;
uint8 pos = 0;
if ((x & 0xffffffff00000000ULL) != 0) { x >>= 32; pos += 32; }
if ((x & 0x00000000ffff0000ULL) != 0) { x >>= 16; pos += 16; }
if ((x & 0x000000000000ff00ULL) != 0) { x >>= 8; pos += 8; }
if ((x & 0x00000000000000f0ULL) != 0) { x >>= 4; pos += 4; }
if ((x & 0x000000000000000cULL) != 0) { x >>= 2; pos += 2; }
if ((x & 0x0000000000000002ULL) != 0) { pos += 1; }
return pos;
}
|