You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
112 lines
2.8 KiB
112 lines
2.8 KiB
14 years ago
|
/*
|
||
|
|
* Copyright (c) 2005 Adrian Page <adrian@pagenet.plus.com>
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU General Public License as published by
|
||
|
|
* the Free Software Foundation; either version 2 of the License, or
|
||
|
|
* (at your option) any later version.
|
||
|
|
*
|
||
|
|
* This program is distributed in the hope that it will be useful,
|
||
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
* GNU General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU General Public License
|
||
|
|
* along with this program; if not, write to the Free Software
|
||
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef KIS_INTEGER_MATHS_H
|
||
|
|
#define KIS_INTEGER_MATHS_H
|
||
|
|
|
||
|
|
#define UINT8_MAX 255u
|
||
|
|
#define UINT8_MIN 0u
|
||
|
|
|
||
|
|
#define UINT16_MAX 65535u
|
||
|
|
#define UINT16_MIN 0u
|
||
|
|
|
||
|
|
#define UINT32_MAX (4294967295u)
|
||
|
|
#define UINT32_MIN 0u
|
||
|
|
|
||
|
|
#define INT16_MAX 32767
|
||
|
|
#define INT16_MIN -32768
|
||
|
|
|
||
|
|
/// take a and scale it up by 256*b/255
|
||
|
|
inline uint UINT8_SCALEBY(uint a, uint b)
|
||
|
|
{
|
||
|
|
uint c = a * b + 0x80u;
|
||
|
|
return (c >> 8) + c;
|
||
|
|
}
|
||
|
|
|
||
|
|
inline uint UINT8_MULT(uint a, uint b)
|
||
|
|
{
|
||
|
|
uint c = a * b + 0x80u;
|
||
|
|
return ((c >> 8) + c) >> 8;
|
||
|
|
}
|
||
|
|
|
||
|
|
inline uint UINT8_DIVIDE(uint a, uint b)
|
||
|
|
{
|
||
|
|
uint c = (a * UINT8_MAX + (b / 2u)) / b;
|
||
|
|
return c;
|
||
|
|
}
|
||
|
|
|
||
|
|
inline uint UINT8_BLEND(uint a, uint b, uint alpha)
|
||
|
|
{
|
||
|
|
// Basically we do a*alpha + b*(1-alpha)
|
||
|
|
// However refactored to (a-b)*alpha + b since that saves a multiplication
|
||
|
|
// Signed arithmetic is needed since a-b might be negative
|
||
|
|
int c = ((int(a) - int(b)) * int(alpha)) >> 8;
|
||
|
|
|
||
|
|
return uint(c + b);
|
||
|
|
}
|
||
|
|
|
||
|
|
inline uint UINT16_MULT(uint a, uint b)
|
||
|
|
{
|
||
|
|
uint c = a * b + 0x8000u;
|
||
|
|
return ((c >> 16) + c) >> 16;
|
||
|
|
}
|
||
|
|
|
||
|
|
inline int INT16_MULT(int a, int b)
|
||
|
|
{
|
||
|
|
return (a*b) / INT16_MAX;
|
||
|
|
}
|
||
|
|
|
||
|
|
inline uint UINT16_DIVIDE(uint a, uint b)
|
||
|
|
{
|
||
|
|
uint c = (a * UINT16_MAX + (b / 2u)) / b;
|
||
|
|
return c;
|
||
|
|
}
|
||
|
|
|
||
|
|
inline uint UINT16_BLEND(uint a, uint b, uint alpha)
|
||
|
|
{
|
||
|
|
// Basically we do a*alpha + b*(1-alpha)
|
||
|
|
// However refactored to (a-b)*alpha + b since that saves a multiplication
|
||
|
|
// Signed arithmetic is needed since a-b might be negative
|
||
|
|
int c = ((int(a) - int(b)) * int(alpha)) >> 16;
|
||
|
|
return uint(c + b);
|
||
|
|
}
|
||
|
|
|
||
|
|
inline uint UINT8_TO_UINT16(uint c)
|
||
|
|
{
|
||
|
|
return c | (c<<8);
|
||
|
|
}
|
||
|
|
|
||
|
|
inline uint UINT16_TO_UINT8(uint c)
|
||
|
|
{
|
||
|
|
//return round(c / 257.0);
|
||
|
|
//For all UINT16 this calculation is the same and a lot faster (off by c/65656 which for every c is 0)
|
||
|
|
c = c - (c >> 8) + 128;
|
||
|
|
return c >>8;
|
||
|
|
}
|
||
|
|
|
||
|
|
inline int INT16_BLEND(int a, int b, uint alpha)
|
||
|
|
{
|
||
|
|
// Basically we do a*alpha + b*(1-alpha)
|
||
|
|
// However refactored to (a-b)*alpha + b since that saves a multiplication
|
||
|
|
int c = ((int(a) - int(b)) * int(alpha)) >> 16;
|
||
|
|
return c + b;
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif
|
||
|
|
|