genode/repos/os/include/util/dither_matrix.h

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/*
* \brief Dithering matrix
* \date 2005-10-24
* \author Norman Feske <norman.feske@genode-labs.com>
*/
/*
* Copyright (C) 2005-2017 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU Affero General Public License version 3.
*/
#ifndef _INCLUDE__UTIL__DITHER_MATRIX_H_
#define _INCLUDE__UTIL__DITHER_MATRIX_H_
#include <base/stdint.h>
namespace Genode { class Dither_matrix; }
class Genode::Dither_matrix
{
private:
enum { SIZE = 16, MASK = SIZE - 1 };
public:
class Row
{
private:
const int *values;
Row(const int *values) : values(values) { }
friend class Genode::Dither_matrix;
public:
int value(unsigned x) const { return values[x & MASK]; }
};
static Row row(unsigned y)
{
static const int matrix[SIZE][SIZE] =
{
{ 0,192, 48,240, 12,204, 60,252, 3,195, 51,243, 15,207, 63,255 },
{ 128, 64,176,112,140, 76,188,124,131, 67,179,115,143, 79,191,127 },
{ 32,224, 16,208, 44,236, 28,220, 35,227, 19,211, 47,239, 31,223 },
{ 160, 96,144, 80,172,108,156, 92,163, 99,147, 83,175,111,159, 95 },
{ 8,200, 56,248, 4,196, 52,244, 11,203, 59,251, 7,199, 55,247 },
{ 136, 72,184,120,132, 68,180,116,139, 75,187,123,135, 71,183,119 },
{ 40,232, 24,216, 36,228, 20,212, 43,235, 27,219, 39,231, 23,215 },
{ 168,104,152, 88,164,100,148, 84,171,107,155, 91,167,103,151, 87 },
{ 2,194, 50,242, 14,206, 62,254, 1,193, 49,241, 13,205, 61,253 },
{ 130, 66,178,114,142, 78,190,126,129, 65,177,113,141, 77,189,125 },
{ 34,226, 18,210, 46,238, 30,222, 33,225, 17,209, 45,237, 29,221 },
{ 162, 98,146, 82,174,110,158, 94,161, 97,145, 81,173,109,157, 93 },
{ 10,202, 58,250, 6,198, 54,246, 9,201, 57,249, 5,197, 53,245 },
{ 138, 74,186,122,134, 70,182,118,137, 73,185,121,133, 69,181,117 },
{ 42,234, 26,218, 38,230, 22,214, 41,233, 25,217, 37,229, 21,213 },
{ 170,106,154, 90,166,102,150, 86,169,105,153, 89,165,101,149, 85 }
};
return Row(matrix[y & MASK]);
}
static inline int value(unsigned x, unsigned y)
{
return row(y).value(x);
}
};
#endif /* _INCLUDE__UTIL__DITHER_MATRIX_H_ */