lib.cpp

Go to the documentation of this file.

/* Copyright (c) 2010 Wildfire Games
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * various utility functions.
 */

#include "precompiled.h"
#include "lib/lib.h"

#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "lib/app_hooks.h"
#include "lib/sysdep/sysdep.h"


//-----------------------------------------------------------------------------
// 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_WARN_ERR(ERR::LOGIC); // clampf not in [0,1)
        return 255;
    }

    int l = (int)(in * 255.0);
    ENSURE((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_WARN_ERR(ERR::LOGIC); // clampf not in [0,1)
        return 65535;
    }

    long l = (long)(in * 65535.0);
    ENSURE((unsigned long)l <= 65535u);
    return (u16)l;
}