blob: 36f5dac777e26c2ebc10c6ca2aadb4a5b45f7c72 [file] [log] [blame]
/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "include/effects/SkTableMaskFilter.h"
#include "include/core/SkFlattenable.h"
#include "include/core/SkMaskFilter.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkTypes.h"
#include "include/private/base/SkAlign.h"
#include "include/private/base/SkFixed.h"
#include "include/private/base/SkFloatingPoint.h"
#include "include/private/base/SkTPin.h"
#include "src/core/SkMask.h"
#include "src/core/SkMaskFilterBase.h"
#include "src/core/SkReadBuffer.h"
#include "src/core/SkWriteBuffer.h"
#include <cmath>
#include <cstdint>
#include <cstring>
class SkMatrix;
class SkTableMaskFilterImpl : public SkMaskFilterBase {
public:
explicit SkTableMaskFilterImpl(const uint8_t table[256]);
SkMask::Format getFormat() const override;
bool filterMask(SkMask*, const SkMask&, const SkMatrix&, SkIPoint*) const override;
protected:
~SkTableMaskFilterImpl() override;
void flatten(SkWriteBuffer&) const override;
private:
SK_FLATTENABLE_HOOKS(SkTableMaskFilterImpl)
SkTableMaskFilterImpl();
uint8_t fTable[256];
using INHERITED = SkMaskFilter;
};
SkTableMaskFilterImpl::SkTableMaskFilterImpl() {
for (int i = 0; i < 256; i++) {
fTable[i] = i;
}
}
SkTableMaskFilterImpl::SkTableMaskFilterImpl(const uint8_t table[256]) {
memcpy(fTable, table, sizeof(fTable));
}
SkTableMaskFilterImpl::~SkTableMaskFilterImpl() {}
bool SkTableMaskFilterImpl::filterMask(SkMask* dst, const SkMask& src,
const SkMatrix&, SkIPoint* margin) const {
if (src.fFormat != SkMask::kA8_Format) {
return false;
}
dst->fBounds = src.fBounds;
dst->fRowBytes = SkAlign4(dst->fBounds.width());
dst->fFormat = SkMask::kA8_Format;
dst->fImage = nullptr;
if (src.fImage) {
dst->fImage = SkMask::AllocImage(dst->computeImageSize());
const uint8_t* srcP = src.fImage;
uint8_t* dstP = dst->fImage;
const uint8_t* table = fTable;
int dstWidth = dst->fBounds.width();
int extraZeros = dst->fRowBytes - dstWidth;
for (int y = dst->fBounds.height() - 1; y >= 0; --y) {
for (int x = dstWidth - 1; x >= 0; --x) {
dstP[x] = table[srcP[x]];
}
srcP += src.fRowBytes;
// we can't just inc dstP by rowbytes, because if it has any
// padding between its width and its rowbytes, we need to zero those
// so that the bitters can read those safely if that is faster for
// them
dstP += dstWidth;
for (int i = extraZeros - 1; i >= 0; --i) {
*dstP++ = 0;
}
}
}
if (margin) {
margin->set(0, 0);
}
return true;
}
SkMask::Format SkTableMaskFilterImpl::getFormat() const {
return SkMask::kA8_Format;
}
void SkTableMaskFilterImpl::flatten(SkWriteBuffer& wb) const {
wb.writeByteArray(fTable, 256);
}
sk_sp<SkFlattenable> SkTableMaskFilterImpl::CreateProc(SkReadBuffer& buffer) {
uint8_t table[256];
if (!buffer.readByteArray(table, 256)) {
return nullptr;
}
return sk_sp<SkFlattenable>(SkTableMaskFilter::Create(table));
}
///////////////////////////////////////////////////////////////////////////////
SkMaskFilter* SkTableMaskFilter::Create(const uint8_t table[256]) {
return new SkTableMaskFilterImpl(table);
}
SkMaskFilter* SkTableMaskFilter::CreateGamma(SkScalar gamma) {
uint8_t table[256];
MakeGammaTable(table, gamma);
return new SkTableMaskFilterImpl(table);
}
SkMaskFilter* SkTableMaskFilter::CreateClip(uint8_t min, uint8_t max) {
uint8_t table[256];
MakeClipTable(table, min, max);
return new SkTableMaskFilterImpl(table);
}
void SkTableMaskFilter::MakeGammaTable(uint8_t table[256], SkScalar gamma) {
const float dx = 1 / 255.0f;
const float g = SkScalarToFloat(gamma);
float x = 0;
for (int i = 0; i < 256; i++) {
// float ee = powf(x, g) * 255;
table[i] = SkTPin(sk_float_round2int(powf(x, g) * 255), 0, 255);
x += dx;
}
}
void SkTableMaskFilter::MakeClipTable(uint8_t table[256], uint8_t min,
uint8_t max) {
if (0 == max) {
max = 1;
}
if (min >= max) {
min = max - 1;
}
SkASSERT(min < max);
SkFixed scale = (1 << 16) * 255 / (max - min);
memset(table, 0, min + 1);
for (int i = min + 1; i < max; i++) {
int value = SkFixedRoundToInt(scale * (i - min));
SkASSERT(value <= 255);
table[i] = value;
}
memset(table + max, 255, 256 - max);
#if 0
int j;
for (j = 0; j < 256; j++) {
if (table[j]) {
break;
}
}
SkDebugf("%d %d start [%d]", min, max, j);
for (; j < 256; j++) {
SkDebugf(" %d", table[j]);
}
SkDebugf("\n\n");
#endif
}