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/* libs/graphics/sgl/SkBitmapSampler.h
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#ifndef SkBitmapSampler_DEFINED
#define SkBitmapSampler_DEFINED
#include "SkBitmap.h"
#include "SkPaint.h"
#include "SkShader.h"
typedef int (*SkTileModeProc)(int value, unsigned max);
class SkBitmapSampler {
public:
SkBitmapSampler(const SkBitmap&, bool filter, SkShader::TileMode tmx, SkShader::TileMode tmy);
virtual ~SkBitmapSampler() {}
const SkBitmap& getBitmap() const { return fBitmap; }
bool getFilterBitmap() const { return fFilterBitmap; }
SkShader::TileMode getTileModeX() const { return fTileModeX; }
SkShader::TileMode getTileModeY() const { return fTileModeY; }
/** Given a pixel center at [x,y], return the color sample
*/
virtual SkPMColor sample(SkFixed x, SkFixed y) const = 0;
virtual void setPaint(const SkPaint& paint);
// This is the factory for finding an optimal subclass
static SkBitmapSampler* Create(const SkBitmap&, bool filter,
SkShader::TileMode tmx, SkShader::TileMode tmy);
protected:
const SkBitmap& fBitmap;
uint16_t fMaxX, fMaxY;
bool fFilterBitmap;
SkShader::TileMode fTileModeX;
SkShader::TileMode fTileModeY;
SkTileModeProc fTileProcX;
SkTileModeProc fTileProcY;
// illegal
SkBitmapSampler& operator=(const SkBitmapSampler&);
};
static inline int fixed_clamp(SkFixed x)
{
#ifdef SK_CPU_HAS_CONDITIONAL_INSTR
if (x >> 16)
x = 0xFFFF;
if (x < 0)
x = 0;
#else
if (x >> 16)
{
if (x < 0)
x = 0;
else
x = 0xFFFF;
}
#endif
return x;
}
//////////////////////////////////////////////////////////////////////////////////////
static inline int fixed_repeat(SkFixed x)
{
return x & 0xFFFF;
}
static inline int fixed_mirror(SkFixed x)
{
SkFixed s = x << 15 >> 31;
// s is FFFFFFFF if we're on an odd interval, or 0 if an even interval
return (x ^ s) & 0xFFFF;
}
static inline bool is_pow2(int count)
{
SkASSERT(count > 0);
return (count & (count - 1)) == 0;
}
static inline int do_clamp(int index, unsigned max)
{
SkASSERT((int)max >= 0);
#ifdef SK_CPU_HAS_CONDITIONAL_INSTR
if (index > (int)max)
index = max;
if (index < 0)
index = 0;
#else
if ((unsigned)index > max)
{
if (index < 0)
index = 0;
else
index = max;
}
#endif
return index;
}
static inline int do_repeat_mod(int index, unsigned max)
{
SkASSERT((int)max >= 0);
if ((unsigned)index > max)
{
if (index < 0)
index = max - (~index % (max + 1));
else
index = index % (max + 1);
}
return index;
}
static inline int do_repeat_pow2(int index, unsigned max)
{
SkASSERT((int)max >= 0 && is_pow2(max + 1));
return index & max;
}
static inline int do_mirror_mod(int index, unsigned max)
{
SkASSERT((int)max >= 0);
// have to handle negatives so that
// -1 -> 0, -2 -> 1, -3 -> 2, etc.
// so we can't just cal abs
index ^= index >> 31;
if ((unsigned)index > max)
{
int mod = (max + 1) << 1;
index = index % mod;
if ((unsigned)index > max)
index = mod - index - 1;
}
return index;
}
static inline int do_mirror_pow2(int index, unsigned max)
{
SkASSERT((int)max >= 0 && is_pow2(max + 1));
int s = (index & (max + 1)) - 1;
s = ~(s >> 31);
// at this stage, s is FFFFFFFF if we're on an odd interval, or 0 if an even interval
return (index ^ s) & max;
}
#endif