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forked from 0ad/0ad
0ad/source/lib/lib.cpp
janwas c0ed950657 had to remove uint and ulong from lib/types.h due to conflict with other library.
this snowballed into a massive search+destroy of the hodgepodge of
mostly equivalent types we had in use (int, uint, unsigned, unsigned
int, i32, u32, ulong, uintN).

it is more efficient to use 64-bit types in 64-bit mode, so the
preferred default is size_t (for anything remotely resembling a size or
index). tile coordinates are ssize_t to allow more efficient conversion
to/from floating point. flags are int because we almost never need more
than 15 distinct bits, bit test/set is not slower and int is fastest to
type. finally, some data that is pretty much directly passed to OpenGL
is now typed accordingly.

after several hours, the code now requires fewer casts and less
guesswork.

other changes:
- unit and player IDs now have an "invalid id" constant in the
respective class to avoid casting and -1
- fix some endian/64-bit bugs in the map (un)packing. added a
convenience function to write/read a size_t.
- ia32: change CPUID interface to allow passing in ecx (required for
cache topology detection, which I need at work). remove some unneeded
functions from asm, replace with intrinsics where possible.

This was SVN commit r5942.
2008-05-11 18:48:32 +00:00

106 lines
1.7 KiB
C++

/**
* =========================================================================
* File : lib.cpp
* Project : 0 A.D.
* Description : various utility functions.
* =========================================================================
*/
// license: GPL; see lib/license.txt
#include "precompiled.h"
#include "lib.h"
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "lib/app_hooks.h"
#include "lib/sysdep/sysdep.h"
u16 addusw(u16 x, u16 y)
{
u32 t = x;
return (u16)std::min(t+y, 0xFFFFu);
}
u16 subusw(u16 x, u16 y)
{
long t = x;
return (u16)(std::max(t-y, 0l));
}
//-----------------------------------------------------------------------------
// type conversion
// these avoid a common mistake in using >> (ANSI requires shift count be
// less than the bit width of the type).
u32 u64_hi(u64 x)
{
return (u32)(x >> 32);
}
u32 u64_lo(u64 x)
{
return (u32)(x & 0xFFFFFFFF);
}
u16 u32_hi(u32 x)
{
return (u16)(x >> 16);
}
u16 u32_lo(u32 x)
{
return (u16)(x & 0xFFFF);
}
u64 u64_from_u32(u32 hi, u32 lo)
{
u64 x = (u64)hi;
x <<= 32;
x |= lo;
return x;
}
u32 u32_from_u16(u16 hi, u16 lo)
{
u32 x = (u32)hi;
x <<= 16;
x |= lo;
return x;
}
// input in [0, 1); convert to u8 range
u8 u8_from_double(double in)
{
if(!(0.0 <= in && in < 1.0))
{
debug_assert(0); // clampf not in [0,1)
return 255;
}
int l = (int)(in * 255.0);
debug_assert((unsigned)l <= 255u);
return (u8)l;
}
// input in [0, 1); convert to u16 range
u16 u16_from_double(double in)
{
if(!(0.0 <= in && in < 1.0))
{
debug_assert(0); // clampf not in [0,1)
return 65535;
}
long l = (long)(in * 65535.0);
debug_assert((unsigned long)l <= 65535u);
return (u16)l;
}