/*
* 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 "SkAAClip.h"
#include "SkAtomics.h"
#include "SkBlitter.h"
#include "SkColorData.h"
#include "SkRectPriv.h"
#include "SkPath.h"
#include "SkScan.h"
#include "SkUtils.h"
class AutoAAClipValidate {
public:
AutoAAClipValidate(const SkAAClip& clip) : fClip(clip) {
fClip.validate();
}
~AutoAAClipValidate() {
fClip.validate();
}
private:
const SkAAClip& fClip;
};
#ifdef SK_DEBUG
#define AUTO_AACLIP_VALIDATE(clip) AutoAAClipValidate acv(clip)
#else
#define AUTO_AACLIP_VALIDATE(clip)
#endif
///////////////////////////////////////////////////////////////////////////////
#define kMaxInt32 0x7FFFFFFF
#ifdef SK_DEBUG
static inline bool x_in_rect(int x, const SkIRect& rect) {
return (unsigned)(x - rect.fLeft) < (unsigned)rect.width();
}
#endif
static inline bool y_in_rect(int y, const SkIRect& rect) {
return (unsigned)(y - rect.fTop) < (unsigned)rect.height();
}
/*
* Data runs are packed [count, alpha]
*/
struct SkAAClip::YOffset {
int32_t fY;
uint32_t fOffset;
};
struct SkAAClip::RunHead {
int32_t fRefCnt;
int32_t fRowCount;
size_t fDataSize;
YOffset* yoffsets() {
return (YOffset*)((char*)this + sizeof(RunHead));
}
const YOffset* yoffsets() const {
return (const YOffset*)((const char*)this + sizeof(RunHead));
}
uint8_t* data() {
return (uint8_t*)(this->yoffsets() + fRowCount);
}
const uint8_t* data() const {
return (const uint8_t*)(this->yoffsets() + fRowCount);
}
static RunHead* Alloc(int rowCount, size_t dataSize) {
size_t size = sizeof(RunHead) + rowCount * sizeof(YOffset) + dataSize;
RunHead* head = (RunHead*)sk_malloc_throw(size);
head->fRefCnt = 1;
head->fRowCount = rowCount;
head->fDataSize = dataSize;
return head;
}
static int ComputeRowSizeForWidth(int width) {
// 2 bytes per segment, where each segment can store up to 255 for count
int segments = 0;
while (width > 0) {
segments += 1;
int n = SkMin32(width, 255);
width -= n;
}
return segments * 2; // each segment is row[0] + row[1] (n + alpha)
}
static RunHead* AllocRect(const SkIRect& bounds) {
SkASSERT(!bounds.isEmpty());
int width = bounds.width();
size_t rowSize = ComputeRowSizeForWidth(width);
RunHead* head = RunHead::Alloc(1, rowSize);
YOffset* yoff = head->yoffsets();
yoff->fY = bounds.height() - 1;
yoff->fOffset = 0;
uint8_t* row = head->data();
while (width > 0) {
int n = SkMin32(width, 255);
row[0] = n;
row[1] = 0xFF;
width -= n;
row += 2;
}
return head;
}
};
class SkAAClip::Iter {
public:
Iter(const SkAAClip&);
bool done() const { return fDone; }
int top() const { return fTop; }
int bottom() const { return fBottom; }
const uint8_t* data() const { return fData; }
void next();
private:
const YOffset* fCurrYOff;
const YOffset* fStopYOff;
const uint8_t* fData;
int fTop, fBottom;
bool fDone;
};
SkAAClip::Iter::Iter(const SkAAClip& clip) {
if (clip.isEmpty()) {
fDone = true;
fTop = fBottom = clip.fBounds.fBottom;
fData = nullptr;
fCurrYOff = nullptr;
fStopYOff = nullptr;
return;
}
const RunHead* head = clip.fRunHead;
fCurrYOff = head->yoffsets();
fStopYOff = fCurrYOff + head->fRowCount;
fData = head->data() + fCurrYOff->fOffset;
// setup first value
fTop = clip.fBounds.fTop;
fBottom = clip.fBounds.fTop + fCurrYOff->fY + 1;
fDone = false;
}
void SkAAClip::Iter::next() {
if (!fDone) {
const YOffset* prev = fCurrYOff;
const YOffset* curr = prev + 1;
SkASSERT(curr <= fStopYOff);
fTop = fBottom;
if (curr >= fStopYOff) {
fDone = true;
fBottom = kMaxInt32;
fData = nullptr;
} else {
fBottom += curr->fY - prev->fY;
fData += curr->fOffset - prev->fOffset;
fCurrYOff = curr;
}
}
}
#ifdef SK_DEBUG
// assert we're exactly width-wide, and then return the number of bytes used
static size_t compute_row_length(const uint8_t row[], int width) {
const uint8_t* origRow = row;
while (width > 0) {
int n = row[0];
SkASSERT(n > 0);
SkASSERT(n <= width);
row += 2;
width -= n;
}
SkASSERT(0 == width);
return row - origRow;
}
void SkAAClip::validate() const {
if (nullptr == fRunHead) {
SkASSERT(fBounds.isEmpty());
return;
}
SkASSERT(!fBounds.isEmpty());
const RunHead* head = fRunHead;
SkASSERT(head->fRefCnt > 0);
SkASSERT(head->fRowCount > 0);
const YOffset* yoff = head->yoffsets();
const YOffset* ystop = yoff + head->fRowCount;
const int lastY = fBounds.height() - 1;
// Y and offset must be monotonic
int prevY = -1;
int32_t prevOffset = -1;
while (yoff < ystop) {
SkASSERT(prevY < yoff->fY);
SkASSERT(yoff->fY <= lastY);
prevY = yoff->fY;
SkASSERT(prevOffset < (int32_t)yoff->fOffset);
prevOffset = yoff->fOffset;
const uint8_t* row = head->data() + yoff->fOffset;
size_t rowLength = compute_row_length(row, fBounds.width());
SkASSERT(yoff->fOffset + rowLength <= head->fDataSize);
yoff += 1;
}
// check the last entry;
--yoff;
SkASSERT(yoff->fY == lastY);
}
static void dump_one_row(const uint8_t* SK_RESTRICT row,
int width, int leading_num) {
if (leading_num) {
SkDebugf( "%03d ", leading_num );
}
while (width > 0) {
int n = row[0];
int val = row[1];
char out = '.';
if (val == 0xff) {
out = '*';
} else if (val > 0) {
out = '+';
}
for (int i = 0 ; i < n ; i++) {
SkDebugf( "%c", out );
}
row += 2;
width -= n;
}
SkDebugf( "\n" );
}
void SkAAClip::debug(bool compress_y) const {
Iter iter(*this);
const int width = fBounds.width();
int y = fBounds.fTop;
while (!iter.done()) {
if (compress_y) {
dump_one_row(iter.data(), width, iter.bottom() - iter.top() + 1);
} else {
do {
dump_one_row(iter.data(), width, 0);
} while (++y < iter.bottom());
}
iter.next();
}
}
#endif
///////////////////////////////////////////////////////////////////////////////
// Count the number of zeros on the left and right edges of the passed in
// RLE row. If 'row' is all zeros return 'width' in both variables.
static void count_left_right_zeros(const uint8_t* row, int width,
int* leftZ, int* riteZ) {
int zeros = 0;
do {
if (row[1]) {
break;
}
int n = row[0];
SkASSERT(n > 0);
SkASSERT(n <= width);
zeros += n;
row += 2;
width -= n;
} while (width > 0);
*leftZ = zeros;
if (0 == width) {
// this line is completely empty return 'width' in both variables
*riteZ = *leftZ;
return;
}
zeros = 0;
while (width > 0) {
int n = row[0];
SkASSERT(n > 0);
if (0 == row[1]) {
zeros += n;
} else {
zeros = 0;
}
row += 2;
width -= n;
}
*riteZ = zeros;
}
#ifdef SK_DEBUG
static void test_count_left_right_zeros() {
static bool gOnce;
if (gOnce) {
return;
}
gOnce = true;
const uint8_t data0[] = { 0, 0, 10, 0xFF };
const uint8_t data1[] = { 0, 0, 5, 0xFF, 2, 0, 3, 0xFF };
const uint8_t data2[] = { 7, 0, 5, 0, 2, 0, 3, 0xFF };
const uint8_t data3[] = { 0, 5, 5, 0xFF, 2, 0, 3, 0 };
const uint8_t data4[] = { 2, 3, 2, 0, 5, 0xFF, 3, 0 };
const uint8_t data5[] = { 10, 10, 10, 0 };
const uint8_t data6[] = { 2, 2, 2, 0, 2, 0xFF, 2, 0, 2, 0xFF, 2, 0 };
const uint8_t* array[] = {
data0, data1, data2, data3, data4, data5, data6
};
for (size_t i = 0; i < SK_ARRAY_COUNT(array); ++i) {
const uint8_t* data = array[i];
const int expectedL = *data++;
const int expectedR = *data++;
int L = 12345, R = 12345;
count_left_right_zeros(data, 10, &L, &R);
SkASSERT(expectedL == L);
SkASSERT(expectedR == R);
}
}
#endif
// modify row in place, trimming off (zeros) from the left and right sides.
// return the number of bytes that were completely eliminated from the left
static int trim_row_left_right(uint8_t* row, int width, int leftZ, int riteZ) {
int trim = 0;
while (leftZ > 0) {
SkASSERT(0 == row[1]);
int n = row[0];
SkASSERT(n > 0);
SkASSERT(n <= width);
width -= n;
row += 2;
if (n > leftZ) {
row[-2] = n - leftZ;
break;
}
trim += 2;
leftZ -= n;
SkASSERT(leftZ >= 0);
}
if (riteZ) {
// walk row to the end, and then we'll back up to trim riteZ
while (width > 0) {
int n = row[0];
SkASSERT(n <= width);
width -= n;
row += 2;
}
// now skip whole runs of zeros
do {
row -= 2;
SkASSERT(0 == row[1]);
int n = row[0];
SkASSERT(n > 0);
if (n > riteZ) {
row[0] = n - riteZ;
break;
}
riteZ -= n;
SkASSERT(riteZ >= 0);
} while (riteZ > 0);
}
return trim;
}
#ifdef SK_DEBUG
// assert that this row is exactly this width
static void assert_row_width(const uint8_t* row, int width) {
while (width > 0) {
int n = row[0];
SkASSERT(n > 0);
SkASSERT(n <= width);
width -= n;
row += 2;
}
SkASSERT(0 == width);
}
static void test_trim_row_left_right() {
static bool gOnce;
if (gOnce) {
return;
}
gOnce = true;
uint8_t data0[] = { 0, 0, 0, 10, 10, 0xFF };
uint8_t data1[] = { 2, 0, 0, 10, 5, 0, 2, 0, 3, 0xFF };
uint8_t data2[] = { 5, 0, 2, 10, 5, 0, 2, 0, 3, 0xFF };
uint8_t data3[] = { 6, 0, 2, 10, 5, 0, 2, 0, 3, 0xFF };
uint8_t data4[] = { 0, 0, 0, 10, 2, 0, 2, 0xFF, 2, 0, 2, 0xFF, 2, 0 };
uint8_t data5[] = { 1, 0, 0, 10, 2, 0, 2, 0xFF, 2, 0, 2, 0xFF, 2, 0 };
uint8_t data6[] = { 0, 1, 0, 10, 2, 0, 2, 0xFF, 2, 0, 2, 0xFF, 2, 0 };
uint8_t data7[] = { 1, 1, 0, 10, 2, 0, 2, 0xFF, 2, 0, 2, 0xFF, 2, 0 };
uint8_t data8[] = { 2, 2, 2, 10, 2, 0, 2, 0xFF, 2, 0, 2, 0xFF, 2, 0 };
uint8_t data9[] = { 5, 2, 4, 10, 2, 0, 2, 0, 2, 0, 2, 0xFF, 2, 0 };
uint8_t data10[] ={ 74, 0, 4, 150, 9, 0, 65, 0, 76, 0xFF };
uint8_t* array[] = {
data0, data1, data2, data3, data4,
data5, data6, data7, data8, data9,
data10
};
for (size_t i = 0; i < SK_ARRAY_COUNT(array); ++i) {
uint8_t* data = array[i];
const int trimL = *data++;
const int trimR = *data++;
const int expectedSkip = *data++;
const int origWidth = *data++;
assert_row_width(data, origWidth);
int skip = trim_row_left_right(data, origWidth, trimL, trimR);
SkASSERT(expectedSkip == skip);
int expectedWidth = origWidth - trimL - trimR;
assert_row_width(data + skip, expectedWidth);
}
}
#endif
bool SkAAClip::trimLeftRight() {
SkDEBUGCODE(test_trim_row_left_right();)
if (this->isEmpty()) {
return false;
}
AUTO_AACLIP_VALIDATE(*this);
const int width = fBounds.width();
RunHead* head = fRunHead;
YOffset* yoff = head->yoffsets();
YOffset* stop = yoff + head->fRowCount;
uint8_t* base = head->data();
// After this loop, 'leftZeros' & 'rightZeros' will contain the minimum
// number of zeros on the left and right of the clip. This information
// can be used to shrink the bounding box.
int leftZeros = width;
int riteZeros = width;
while (yoff < stop) {
int L, R;
count_left_right_zeros(base + yoff->fOffset, width, &L, &R);
SkASSERT(L + R < width || (L == width && R == width));
if (L < leftZeros) {
leftZeros = L;
}
if (R < riteZeros) {
riteZeros = R;
}
if (0 == (leftZeros | riteZeros)) {
// no trimming to do
return true;
}
yoff += 1;
}
SkASSERT(leftZeros || riteZeros);
if (width == leftZeros) {
SkASSERT(width == riteZeros);
return this->setEmpty();
}
this->validate();
fBounds.fLeft += leftZeros;
fBounds.fRight -= riteZeros;
SkASSERT(!fBounds.isEmpty());
// For now we don't realloc the storage (for time), we just shrink in place
// This means we don't have to do any memmoves either, since we can just
// play tricks with the yoff->fOffset for each row
yoff = head->yoffsets();
while (yoff < stop) {
uint8_t* row = base + yoff->fOffset;
SkDEBUGCODE((void)compute_row_length(row, width);)
yoff->fOffset += trim_row_left_right(row, width, leftZeros, riteZeros);
SkDEBUGCODE((void)compute_row_length(base + yoff->fOffset, width - leftZeros - riteZeros);)
yoff += 1;
}
return true;
}
static bool row_is_all_zeros(const uint8_t* row, int width) {
SkASSERT(width > 0);
do {
if (row[1]) {
return false;
}
int n = row[0];
SkASSERT(n <= width);
width -= n;
row += 2;
} while (width > 0);
SkASSERT(0 == width);
return true;
}
bool SkAAClip::trimTopBottom() {
if (this->isEmpty()) {
return false;
}
this->validate();
const int width = fBounds.width();
RunHead* head = fRunHead;
YOffset* yoff = head->yoffsets();
YOffset* stop = yoff + head->fRowCount;
const uint8_t* base = head->data();
// Look to trim away empty rows from the top.
//
int skip = 0;
while (yoff < stop) {
const uint8_t* data = base + yoff->fOffset;
if (!row_is_all_zeros(data, width)) {
break;
}
skip += 1;
yoff += 1;
}
SkASSERT(skip <= head->fRowCount);
if (skip == head->fRowCount) {
return this->setEmpty();
}
if (skip > 0) {
// adjust fRowCount and fBounds.fTop, and slide all the data up
// as we remove [skip] number of YOffset entries
yoff = head->yoffsets();
int dy = yoff[skip - 1].fY + 1;
for (int i = skip; i < head->fRowCount; ++i) {
SkASSERT(yoff[i].fY >= dy);
yoff[i].fY -= dy;
}
YOffset* dst = head->yoffsets();
size_t size = head->fRowCount * sizeof(YOffset) + head->fDataSize;
memmove(dst, dst + skip, size - skip * sizeof(YOffset));
fBounds.fTop += dy;
SkASSERT(!fBounds.isEmpty());
head->fRowCount -= skip;
SkASSERT(head->fRowCount > 0);
this->validate();
// need to reset this after the memmove
base = head->data();
}
// Look to trim away empty rows from the bottom.
// We know that we have at least one non-zero row, so we can just walk
// backwards without checking for running past the start.
//
stop = yoff = head->yoffsets() + head->fRowCount;
do {
yoff -= 1;
} while (row_is_all_zeros(base + yoff->fOffset, width));
skip = SkToInt(stop - yoff - 1);
SkASSERT(skip >= 0 && skip < head->fRowCount);
if (skip > 0) {
// removing from the bottom is easier than from the top, as we don't
// have to adjust any of the Y values, we just have to trim the array
memmove(stop - skip, stop, head->fDataSize);
fBounds.fBottom = fBounds.fTop + yoff->fY + 1;
SkASSERT(!fBounds.isEmpty());
head->fRowCount -= skip;
SkASSERT(head->fRowCount > 0);
}
this->validate();
return true;
}
// can't validate before we're done, since trimming is part of the process of
// making us valid after the Builder. Since we build from top to bottom, its
// possible our fBounds.fBottom is bigger than our last scanline of data, so
// we trim fBounds.fBottom back up.
//
// TODO: check for duplicates in X and Y to further compress our data
//
bool SkAAClip::trimBounds() {
if (this->isEmpty()) {
return false;
}
const RunHead* head = fRunHead;
const YOffset* yoff = head->yoffsets();
SkASSERT(head->fRowCount > 0);
const YOffset& lastY = yoff[head->fRowCount - 1];
SkASSERT(lastY.fY + 1 <= fBounds.height());
fBounds.fBottom = fBounds.fTop + lastY.fY + 1;
SkASSERT(lastY.fY + 1 == fBounds.height());
SkASSERT(!fBounds.isEmpty());
return this->trimTopBottom() && this->trimLeftRight();
}
///////////////////////////////////////////////////////////////////////////////
void SkAAClip::freeRuns() {
if (fRunHead) {
SkASSERT(fRunHead->fRefCnt >= 1);
if (1 == sk_atomic_dec(&fRunHead->fRefCnt)) {
sk_free(fRunHead);
}
}
}
SkAAClip::SkAAClip() {
fBounds.setEmpty();
fRunHead = nullptr;
}
SkAAClip::SkAAClip(const SkAAClip& src) {
SkDEBUGCODE(fBounds.setEmpty();) // need this for validate
fRunHead = nullptr;
*this = src;
}
SkAAClip::~SkAAClip() {
this->freeRuns();
}
SkAAClip& SkAAClip::operator=(const SkAAClip& src) {
AUTO_AACLIP_VALIDATE(*this);
src.validate();
if (this != &src) {
this->freeRuns();
fBounds = src.fBounds;
fRunHead = src.fRunHead;
if (fRunHead) {
sk_atomic_inc(&fRunHead->fRefCnt);
}
}
return *this;
}
bool operator==(const SkAAClip& a, const SkAAClip& b) {
a.validate();
b.validate();
if (&a == &b) {
return true;
}
if (a.fBounds != b.fBounds) {
return false;
}
const SkAAClip::RunHead* ah = a.fRunHead;
const SkAAClip::RunHead* bh = b.fRunHead;
// this catches empties and rects being equal
if (ah == bh) {
return true;
}
// now we insist that both are complex (but different ptrs)
if (!a.fRunHead || !b.fRunHead) {
return false;
}
return ah->fRowCount == bh->fRowCount &&
ah->fDataSize == bh->fDataSize &&
!memcmp(ah->data(), bh->data(), ah->fDataSize);
}
void SkAAClip::swap(SkAAClip& other) {
AUTO_AACLIP_VALIDATE(*this);
other.validate();
SkTSwap(fBounds, other.fBounds);
SkTSwap(fRunHead, other.fRunHead);
}
bool SkAAClip::set(const SkAAClip& src) {
*this = src;
return !this->isEmpty();
}
bool SkAAClip::setEmpty() {
this->freeRuns();
fBounds.setEmpty();
fRunHead = nullptr;
return false;
}
bool SkAAClip::setRect(const SkIRect& bounds) {
if (bounds.isEmpty()) {
return this->setEmpty();
}
AUTO_AACLIP_VALIDATE(*this);
#if 0
SkRect r;
r.set(bounds);
SkPath path;
path.addRect(r);
return this->setPath(path);
#else
this->freeRuns();
fBounds = bounds;
fRunHead = RunHead::AllocRect(bounds);
SkASSERT(!this->isEmpty());
return true;
#endif
}
bool SkAAClip::isRect() const {
if (this->isEmpty()) {
return false;
}
const RunHead* head = fRunHead;
if (head->fRowCount != 1) {
return false;
}
const YOffset* yoff = head->yoffsets();
if (yoff->fY != fBounds.fBottom - 1) {
return false;
}
const uint8_t* row = head->data() + yoff->fOffset;
int width = fBounds.width();
do {
if (row[1] != 0xFF) {
return false;
}
int n = row[0];
SkASSERT(n <= width);
width -= n;
row += 2;
} while (width > 0);
return true;
}
bool SkAAClip::setRect(const SkRect& r, bool doAA) {
if (r.isEmpty()) {
return this->setEmpty();
}
AUTO_AACLIP_VALIDATE(*this);
// TODO: special case this
SkPath path;
path.addRect(r);
return this->setPath(path, nullptr, doAA);
}
static void append_run(SkTDArray<uint8_t>& array, uint8_t value, int count) {
SkASSERT(count >= 0);
while (count > 0) {
int n = count;
if (n > 255) {
n = 255;
}
uint8_t* data = array.append(2);
data[0] = n;
data[1] = value;
count -= n;
}
}
bool SkAAClip::setRegion(const SkRegion& rgn) {
if (rgn.isEmpty()) {
return this->setEmpty();
}
if (rgn.isRect()) {
return this->setRect(rgn.getBounds());
}
#if 0
SkAAClip clip;
SkRegion::Iterator iter(rgn);
for (; !iter.done(); iter.next()) {
clip.op(iter.rect(), SkRegion::kUnion_Op);
}
this->swap(clip);
return !this->isEmpty();
#else
const SkIRect& bounds = rgn.getBounds();
const int offsetX = bounds.fLeft;
const int offsetY = bounds.fTop;
SkTDArray<YOffset> yArray;
SkTDArray<uint8_t> xArray;
yArray.setReserve(SkMin32(bounds.height(), 1024));
xArray.setReserve(SkMin32(bounds.width(), 512) * 128);
SkRegion::Iterator iter(rgn);
int prevRight = 0;
int prevBot = 0;
YOffset* currY = nullptr;
for (; !iter.done(); iter.next()) {
const SkIRect& r = iter.rect();
SkASSERT(bounds.contains(r));
int bot = r.fBottom - offsetY;
SkASSERT(bot >= prevBot);
if (bot > prevBot) {
if (currY) {
// flush current row
append_run(xArray, 0, bounds.width() - prevRight);
}
// did we introduce an empty-gap from the prev row?
int top = r.fTop - offsetY;
if (top > prevBot) {
currY = yArray.append();
currY->fY = top - 1;
currY->fOffset = xArray.count();
append_run(xArray, 0, bounds.width());
}
// create a new record for this Y value
currY = yArray.append();
currY->fY = bot - 1;
currY->fOffset = xArray.count();
prevRight = 0;
prevBot = bot;
}
int x = r.fLeft - offsetX;
append_run(xArray, 0, x - prevRight);
int w = r.fRight - r.fLeft;
append_run(xArray, 0xFF, w);
prevRight = x + w;
SkASSERT(prevRight <= bounds.width());
}
// flush last row
append_run(xArray, 0, bounds.width() - prevRight);
// now pack everything into a RunHead
RunHead* head = RunHead::Alloc(yArray.count(), xArray.bytes());
memcpy(head->yoffsets(), yArray.begin(), yArray.bytes());
memcpy(head->data(), xArray.begin(), xArray.bytes());
this->setEmpty();
fBounds = bounds;
fRunHead = head;
this->validate();
return true;
#endif
}
///////////////////////////////////////////////////////////////////////////////
const uint8_t* SkAAClip::findRow(int y, int* lastYForRow) const {
SkASSERT(fRunHead);
if (!y_in_rect(y, fBounds)) {
return nullptr;
}
y -= fBounds.y(); // our yoffs values are relative to the top
const YOffset* yoff = fRunHead->yoffsets();
while (yoff->fY < y) {
yoff += 1;
SkASSERT(yoff - fRunHead->yoffsets() < fRunHead->fRowCount);
}
if (lastYForRow) {
*lastYForRow = fBounds.y() + yoff->fY;
}
return fRunHead->data() + yoff->fOffset;
}
const uint8_t* SkAAClip::findX(const uint8_t data[], int x, int* initialCount) const {
SkASSERT(x_in_rect(x, fBounds));
x -= fBounds.x();
// first skip up to X
for (;;) {
int n = data[0];
if (x < n) {
if (initialCount) {
*initialCount = n - x;
}
break;
}
data += 2;
x -= n;
}
return data;
}
bool SkAAClip::quickContains(int left, int top, int right, int bottom) const {
if (this->isEmpty()) {
return false;
}
if (!fBounds.contains(left, top, right, bottom)) {
return false;
}
#if 0
if (this->isRect()) {
return true;
}
#endif
int lastY SK_INIT_TO_AVOID_WARNING;
const uint8_t* row = this->findRow(top, &lastY);
if (lastY < bottom) {
return false;
}
// now just need to check in X
int count;
row = this->findX(row, left, &count);
#if 0
return count >= (right - left) && 0xFF == row[1];
#else
int rectWidth = right - left;
while (0xFF == row[1]) {
if (count >= rectWidth) {
return true;
}
rectWidth -= count;
row += 2;
count = row[0];
}
return false;
#endif
}
///////////////////////////////////////////////////////////////////////////////
class SkAAClip::Builder {
SkIRect fBounds;
struct Row {
int fY;
int fWidth;
SkTDArray<uint8_t>* fData;
};
SkTDArray<Row> fRows;
Row* fCurrRow;
int fPrevY;
int fWidth;
int fMinY;
public:
Builder(const SkIRect& bounds) : fBounds(bounds) {
fPrevY = -1;
fWidth = bounds.width();
fCurrRow = nullptr;
fMinY = bounds.fTop;
}
~Builder() {
Row* row = fRows.begin();
Row* stop = fRows.end();
while (row < stop) {
delete row->fData;
row += 1;
}
}
const SkIRect& getBounds() const { return fBounds; }
void addRun(int x, int y, U8CPU alpha, int count) {
SkASSERT(count > 0);
SkASSERT(fBounds.contains(x, y));
SkASSERT(fBounds.contains(x + count - 1, y));
x -= fBounds.left();
y -= fBounds.top();
Row* row = fCurrRow;
if (y != fPrevY) {
SkASSERT(y > fPrevY);
fPrevY = y;
row = this->flushRow(true);
row->fY = y;
row->fWidth = 0;
SkASSERT(row->fData);
SkASSERT(0 == row->fData->count());
fCurrRow = row;
}
SkASSERT(row->fWidth <= x);
SkASSERT(row->fWidth < fBounds.width());
SkTDArray<uint8_t>& data = *row->fData;
int gap = x - row->fWidth;
if (gap) {
AppendRun(data, 0, gap);
row->fWidth += gap;
SkASSERT(row->fWidth < fBounds.width());
}
AppendRun(data, alpha, count);
row->fWidth += count;
SkASSERT(row->fWidth <= fBounds.width());
}
void addColumn(int x, int y, U8CPU alpha, int height) {
SkASSERT(fBounds.contains(x, y + height - 1));
this->addRun(x, y, alpha, 1);
this->flushRowH(fCurrRow);
y -= fBounds.fTop;
SkASSERT(y == fCurrRow->fY);
fCurrRow->fY = y + height - 1;
}
void addRectRun(int x, int y, int width, int height) {
SkASSERT(fBounds.contains(x + width - 1, y + height - 1));
this->addRun(x, y, 0xFF, width);
// we assum the rect must be all we'll see for these scanlines
// so we ensure our row goes all the way to our right
this->flushRowH(fCurrRow);
y -= fBounds.fTop;
SkASSERT(y == fCurrRow->fY);
fCurrRow->fY = y + height - 1;
}
void addAntiRectRun(int x, int y, int width, int height,
SkAlpha leftAlpha, SkAlpha rightAlpha) {
// According to SkBlitter.cpp, no matter whether leftAlpha is 0 or positive,
// we should always consider [x, x+1] as the left-most column and [x+1, x+1+width]
// as the rect with full alpha.
SkASSERT(fBounds.contains(x + width + (rightAlpha > 0 ? 1 : 0),
y + height - 1));
SkASSERT(width >= 0);
// Conceptually we're always adding 3 runs, but we should
// merge or omit them if possible.
if (leftAlpha == 0xFF) {
width++;
} else if (leftAlpha > 0) {
this->addRun(x++, y, leftAlpha, 1);
} else {
// leftAlpha is 0, ignore the left column
x++;
}
if (rightAlpha == 0xFF) {
width++;
}
if (width > 0) {
this->addRun(x, y, 0xFF, width);
}
if (rightAlpha > 0 && rightAlpha < 255) {
this->addRun(x + width, y, rightAlpha, 1);
}
// we assume the rect must be all we'll see for these scanlines
// so we ensure our row goes all the way to our right
this->flushRowH(fCurrRow);
y -= fBounds.fTop;
SkASSERT(y == fCurrRow->fY);
fCurrRow->fY = y + height - 1;
}
bool finish(SkAAClip* target) {
this->flushRow(false);
const Row* row = fRows.begin();
const Row* stop = fRows.end();
size_t dataSize = 0;
while (row < stop) {
dataSize += row->fData->count();
row += 1;
}
if (0 == dataSize) {
return target->setEmpty();
}
SkASSERT(fMinY >= fBounds.fTop);
SkASSERT(fMinY < fBounds.fBottom);
int adjustY = fMinY - fBounds.fTop;
fBounds.fTop = fMinY;
RunHead* head = RunHead::Alloc(fRows.count(), dataSize);
YOffset* yoffset = head->yoffsets();
uint8_t* data = head->data();
uint8_t* baseData = data;
row = fRows.begin();
SkDEBUGCODE(int prevY = row->fY - 1;)
while (row < stop) {
SkASSERT(prevY < row->fY); // must be monotonic
SkDEBUGCODE(prevY = row->fY);
yoffset->fY = row->fY - adjustY;
yoffset->fOffset = SkToU32(data - baseData);
yoffset += 1;
size_t n = row->fData->count();
memcpy(data, row->fData->begin(), n);
#ifdef SK_DEBUG
size_t bytesNeeded = compute_row_length(data, fBounds.width());
SkASSERT(bytesNeeded == n);
#endif
data += n;
row += 1;
}
target->freeRuns();
target->fBounds = fBounds;
target->fRunHead = head;
return target->trimBounds();
}
void dump() {
this->validate();
int y;
for (y = 0; y < fRows.count(); ++y) {
const Row& row = fRows[y];
SkDebugf("Y:%3d W:%3d", row.fY, row.fWidth);
const SkTDArray<uint8_t>& data = *row.fData;
int count = data.count();
SkASSERT(!(count & 1));
const uint8_t* ptr = data.begin();
for (int x = 0; x < count; x += 2) {
SkDebugf(" [%3d:%02X]", ptr[0], ptr[1]);
ptr += 2;
}
SkDebugf("\n");
}
}
void validate() {
#ifdef SK_DEBUG
if (false) { // avoid bit rot, suppress warning
test_count_left_right_zeros();
}
int prevY = -1;
for (int i = 0; i < fRows.count(); ++i) {
const Row& row = fRows[i];
SkASSERT(prevY < row.fY);
SkASSERT(fWidth == row.fWidth);
int count = row.fData->count();
const uint8_t* ptr = row.fData->begin();
SkASSERT(!(count & 1));
int w = 0;
for (int x = 0; x < count; x += 2) {
int n = ptr[0];
SkASSERT(n > 0);
w += n;
SkASSERT(w <= fWidth);
ptr += 2;
}
SkASSERT(w == fWidth);
prevY = row.fY;
}
#endif
}
// only called by BuilderBlitter
void setMinY(int y) {
fMinY = y;
}
private:
void flushRowH(Row* row) {
// flush current row if needed
if (row->fWidth < fWidth) {
AppendRun(*row->fData, 0, fWidth - row->fWidth);
row->fWidth = fWidth;
}
}
Row* flushRow(bool readyForAnother) {
Row* next = nullptr;
int count = fRows.count();
if (count > 0) {
this->flushRowH(&fRows[count - 1]);
}
if (count > 1) {
// are our last two runs the same?
Row* prev = &fRows[count - 2];
Row* curr = &fRows[count - 1];
SkASSERT(prev->fWidth == fWidth);
SkASSERT(curr->fWidth == fWidth);
if (*prev->fData == *curr->fData) {
prev->fY = curr->fY;
if (readyForAnother) {
curr->fData->rewind();
next = curr;
} else {
delete curr->fData;
fRows.removeShuffle(count - 1);
}
} else {
if (readyForAnother) {
next = fRows.append();
next->fData = new SkTDArray<uint8_t>;
}
}
} else {
if (readyForAnother) {
next = fRows.append();
next->fData = new SkTDArray<uint8_t>;
}
}
return next;
}
static void AppendRun(SkTDArray<uint8_t>& data, U8CPU alpha, int count) {
do {
int n = count;
if (n > 255) {
n = 255;
}
uint8_t* ptr = data.append(2);
ptr[0] = n;
ptr[1] = alpha;
count -= n;
} while (count > 0);
}
};
class SkAAClip::BuilderBlitter : public SkBlitter {
int fLastY;
/*
If we see a gap of 1 or more empty scanlines while building in Y-order,
we inject an explicit empty scanline (alpha==0)
See AAClipTest.cpp : test_path_with_hole()
*/
void checkForYGap(int y) {
SkASSERT(y >= fLastY);
if (fLastY > -SK_MaxS32) {
int gap = y - fLastY;
if (gap > 1) {
fBuilder->addRun(fLeft, y - 1, 0, fRight - fLeft);
}
}
fLastY = y;
}
public:
BuilderBlitter(Builder* builder) {
fBuilder = builder;
fLeft = builder->getBounds().fLeft;
fRight = builder->getBounds().fRight;
fMinY = SK_MaxS32;
fLastY = -SK_MaxS32; // sentinel
}
void finish() {
if (fMinY < SK_MaxS32) {
fBuilder->setMinY(fMinY);
}
}
/**
Must evaluate clips in scan-line order, so don't want to allow blitV(),
but an AAClip can be clipped down to a single pixel wide, so we
must support it (given AntiRect semantics: minimum width is 2).
Instead we'll rely on the runtime asserts to guarantee Y monotonicity;
any failure cases that misses may have minor artifacts.
*/
void blitV(int x, int y, int height, SkAlpha alpha) override {
if (height == 1) {
// We're still in scan-line order if height is 1
// This is useful for Analytic AA
const SkAlpha alphas[2] = {alpha, 0};
const int16_t runs[2] = {1, 0};
this->blitAntiH(x, y, alphas, runs);
} else {
this->recordMinY(y);
fBuilder->addColumn(x, y, alpha, height);
fLastY = y + height - 1;
}
}
void blitRect(int x, int y, int width, int height) override {
this->recordMinY(y);
this->checkForYGap(y);
fBuilder->addRectRun(x, y, width, height);
fLastY = y + height - 1;
}
virtual void blitAntiRect(int x, int y, int width, int height,
SkAlpha leftAlpha, SkAlpha rightAlpha) override {
this->recordMinY(y);
this->checkForYGap(y);
fBuilder->addAntiRectRun(x, y, width, height, leftAlpha, rightAlpha);
fLastY = y + height - 1;
}
void blitMask(const SkMask&, const SkIRect& clip) override
{ unexpected(); }
const SkPixmap* justAnOpaqueColor(uint32_t*) override {
return nullptr;
}
void blitH(int x, int y, int width) override {
this->recordMinY(y);
this->checkForYGap(y);
fBuilder->addRun(x, y, 0xFF, width);
}
virtual void blitAntiH(int x, int y, const SkAlpha alpha[],
const int16_t runs[]) override {
this->recordMinY(y);
this->checkForYGap(y);
for (;;) {
int count = *runs;
if (count <= 0) {
return;
}
// The supersampler's buffer can be the width of the device, so
// we may have to trim the run to our bounds. Previously, we assert that
// the extra spans are always alpha==0.
// However, the analytic AA is too sensitive to precision errors
// so it may have extra spans with very tiny alpha because after several
// arithmatic operations, the edge may bleed the path boundary a little bit.
// Therefore, instead of always asserting alpha==0, we assert alpha < 0x10.
int localX = x;
int localCount = count;
if (x < fLeft) {
SkASSERT(0x10 > *alpha);
int gap = fLeft - x;
SkASSERT(gap <= count);
localX += gap;
localCount -= gap;
}
int right = x + count;
if (right > fRight) {
SkASSERT(0x10 > *alpha);
localCount -= right - fRight;
SkASSERT(localCount >= 0);
}
if (localCount) {
fBuilder->addRun(localX, y, *alpha, localCount);
}
// Next run
runs += count;
alpha += count;
x += count;
}
}
private:
Builder* fBuilder;
int fLeft; // cache of builder's bounds' left edge
int fRight;
int fMinY;
/*
* We track this, in case the scan converter skipped some number of
* scanlines at the (relative to the bounds it was given). This allows
* the builder, during its finish, to trip its bounds down to the "real"
* top.
*/
void recordMinY(int y) {
if (y < fMinY) {
fMinY = y;
}
}
void unexpected() {
SK_ABORT("---- did not expect to get called here");
}
};
bool SkAAClip::setPath(const SkPath& path, const SkRegion* clip, bool doAA) {
AUTO_AACLIP_VALIDATE(*this);
if (clip && clip->isEmpty()) {
return this->setEmpty();
}
SkIRect ibounds;
path.getBounds().roundOut(&ibounds);
SkRegion tmpClip;
if (nullptr == clip) {
tmpClip.setRect(ibounds);
clip = &tmpClip;
}
// Since we assert that the BuilderBlitter will never blit outside the intersection
// of clip and ibounds, we create this snugClip to be that intersection and send it
// to the scan-converter.
SkRegion snugClip(*clip);
if (path.isInverseFillType()) {
ibounds = clip->getBounds();
} else {
if (ibounds.isEmpty() || !ibounds.intersect(clip->getBounds())) {
return this->setEmpty();
}
snugClip.op(ibounds, SkRegion::kIntersect_Op);
}
Builder builder(ibounds);
BuilderBlitter blitter(&builder);
if (doAA) {
SkScan::AntiFillPath(path, snugClip, &blitter, true);
} else {
SkScan::FillPath(path, snugClip, &blitter);
}
blitter.finish();
return builder.finish(this);
}
///////////////////////////////////////////////////////////////////////////////
typedef void (*RowProc)(SkAAClip::Builder&, int bottom,
const uint8_t* rowA, const SkIRect& rectA,
const uint8_t* rowB, const SkIRect& rectB);
typedef U8CPU (*AlphaProc)(U8CPU alphaA, U8CPU alphaB);
static U8CPU sectAlphaProc(U8CPU alphaA, U8CPU alphaB) {
// Multiply
return SkMulDiv255Round(alphaA, alphaB);
}
static U8CPU unionAlphaProc(U8CPU alphaA, U8CPU alphaB) {
// SrcOver
return alphaA + alphaB - SkMulDiv255Round(alphaA, alphaB);
}
static U8CPU diffAlphaProc(U8CPU alphaA, U8CPU alphaB) {
// SrcOut
return SkMulDiv255Round(alphaA, 0xFF - alphaB);
}
static U8CPU xorAlphaProc(U8CPU alphaA, U8CPU alphaB) {
// XOR
return alphaA + alphaB - 2 * SkMulDiv255Round(alphaA, alphaB);
}
static AlphaProc find_alpha_proc(SkRegion::Op op) {
switch (op) {
case SkRegion::kIntersect_Op:
return sectAlphaProc;
case SkRegion::kDifference_Op:
return diffAlphaProc;
case SkRegion::kUnion_Op:
return unionAlphaProc;
case SkRegion::kXOR_Op:
return xorAlphaProc;
default:
SkDEBUGFAIL("unexpected region op");
return sectAlphaProc;
}
}
class RowIter {
public:
RowIter(const uint8_t* row, const SkIRect& bounds) {
fRow = row;
fLeft = bounds.fLeft;
fBoundsRight = bounds.fRight;
if (row) {
fRight = bounds.fLeft + row[0];
SkASSERT(fRight <= fBoundsRight);
fAlpha = row[1];
fDone = false;
} else {
fDone = true;
fRight = kMaxInt32;
fAlpha = 0;
}
}
bool done() const { return fDone; }
int left() const { return fLeft; }
int right() const { return fRight; }
U8CPU alpha() const { return fAlpha; }
void next() {
if (!fDone) {
fLeft = fRight;
if (fRight == fBoundsRight) {
fDone = true;
fRight = kMaxInt32;
fAlpha = 0;
} else {
fRow += 2;
fRight += fRow[0];
fAlpha = fRow[1];
SkASSERT(fRight <= fBoundsRight);
}
}
}
private:
const uint8_t* fRow;
int fLeft;
int fRight;
int fBoundsRight;
bool fDone;
uint8_t fAlpha;
};
static void adjust_row(RowIter& iter, int& leftA, int& riteA, int rite) {
if (rite == riteA) {
iter.next();
leftA = iter.left();
riteA = iter.right();
}
}
#if 0 // UNUSED
static bool intersect(int& min, int& max, int boundsMin, int boundsMax) {
SkASSERT(min < max);
SkASSERT(boundsMin < boundsMax);
if (min >= boundsMax || max <= boundsMin) {
return false;
}
if (min < boundsMin) {
min = boundsMin;
}
if (max > boundsMax) {
max = boundsMax;
}
return true;
}
#endif
static void operatorX(SkAAClip::Builder& builder, int lastY,
RowIter& iterA, RowIter& iterB,
AlphaProc proc, const SkIRect& bounds) {
int leftA = iterA.left();
int riteA = iterA.right();
int leftB = iterB.left();
int riteB = iterB.right();
int prevRite = bounds.fLeft;
do {
U8CPU alphaA = 0;
U8CPU alphaB = 0;
int left, rite;
if (leftA < leftB) {
left = leftA;
alphaA = iterA.alpha();
if (riteA <= leftB) {
rite = riteA;
} else {
rite = leftA = leftB;
}
} else if (leftB < leftA) {
left = leftB;
alphaB = iterB.alpha();
if (riteB <= leftA) {
rite = riteB;
} else {
rite = leftB = leftA;
}
} else {
left = leftA; // or leftB, since leftA == leftB
rite = leftA = leftB = SkMin32(riteA, riteB);
alphaA = iterA.alpha();
alphaB = iterB.alpha();
}
if (left >= bounds.fRight) {
break;
}
if (rite > bounds.fRight) {
rite = bounds.fRight;
}
if (left >= bounds.fLeft) {
SkASSERT(rite > left);
builder.addRun(left, lastY, proc(alphaA, alphaB), rite - left);
prevRite = rite;
}
adjust_row(iterA, leftA, riteA, rite);
adjust_row(iterB, leftB, riteB, rite);
} while (!iterA.done() || !iterB.done());
if (prevRite < bounds.fRight) {
builder.addRun(prevRite, lastY, 0, bounds.fRight - prevRite);
}
}
static void adjust_iter(SkAAClip::Iter& iter, int& topA, int& botA, int bot) {
if (bot == botA) {
iter.next();
topA = botA;
SkASSERT(botA == iter.top());
botA = iter.bottom();
}
}
static void operateY(SkAAClip::Builder& builder, const SkAAClip& A,
const SkAAClip& B, SkRegion::Op op) {
AlphaProc proc = find_alpha_proc(op);
const SkIRect& bounds = builder.getBounds();
SkAAClip::Iter iterA(A);
SkAAClip::Iter iterB(B);
SkASSERT(!iterA.done());
int topA = iterA.top();
int botA = iterA.bottom();
SkASSERT(!iterB.done());
int topB = iterB.top();
int botB = iterB.bottom();
do {
const uint8_t* rowA = nullptr;
const uint8_t* rowB = nullptr;
int top, bot;
if (topA < topB) {
top = topA;
rowA = iterA.data();
if (botA <= topB) {
bot = botA;
} else {
bot = topA = topB;
}
} else if (topB < topA) {
top = topB;
rowB = iterB.data();
if (botB <= topA) {
bot = botB;
} else {
bot = topB = topA;
}
} else {
top = topA; // or topB, since topA == topB
bot = topA = topB = SkMin32(botA, botB);
rowA = iterA.data();
rowB = iterB.data();
}
if (top >= bounds.fBottom) {
break;
}
if (bot > bounds.fBottom) {
bot = bounds.fBottom;
}
SkASSERT(top < bot);
if (!rowA && !rowB) {
builder.addRun(bounds.fLeft, bot - 1, 0, bounds.width());
} else if (top >= bounds.fTop) {
SkASSERT(bot <= bounds.fBottom);
RowIter rowIterA(rowA, rowA ? A.getBounds() : bounds);
RowIter rowIterB(rowB, rowB ? B.getBounds() : bounds);
operatorX(builder, bot - 1, rowIterA, rowIterB, proc, bounds);
}
adjust_iter(iterA, topA, botA, bot);
adjust_iter(iterB, topB, botB, bot);
} while (!iterA.done() || !iterB.done());
}
bool SkAAClip::op(const SkAAClip& clipAOrig, const SkAAClip& clipBOrig,
SkRegion::Op op) {
AUTO_AACLIP_VALIDATE(*this);
if (SkRegion::kReplace_Op == op) {
return this->set(clipBOrig);
}
const SkAAClip* clipA = &clipAOrig;
const SkAAClip* clipB = &clipBOrig;
if (SkRegion::kReverseDifference_Op == op) {
SkTSwap(clipA, clipB);
op = SkRegion::kDifference_Op;
}
bool a_empty = clipA->isEmpty();
bool b_empty = clipB->isEmpty();
SkIRect bounds;
switch (op) {
case SkRegion::kDifference_Op:
if (a_empty) {
return this->setEmpty();
}
if (b_empty || !SkIRect::Intersects(clipA->fBounds, clipB->fBounds)) {
return this->set(*clipA);
}
bounds = clipA->fBounds;
break;
case SkRegion::kIntersect_Op:
if ((a_empty | b_empty) || !bounds.intersect(clipA->fBounds,
clipB->fBounds)) {
return this->setEmpty();
}
break;
case SkRegion::kUnion_Op:
case SkRegion::kXOR_Op:
if (a_empty) {
return this->set(*clipB);
}
if (b_empty) {
return this->set(*clipA);
}
bounds = clipA->fBounds;
bounds.join(clipB->fBounds);
break;
default:
SkDEBUGFAIL("unknown region op");
return !this->isEmpty();
}
SkASSERT(SkIRect::Intersects(bounds, clipB->fBounds));
SkASSERT(SkIRect::Intersects(bounds, clipB->fBounds));
Builder builder(bounds);
operateY(builder, *clipA, *clipB, op);
return builder.finish(this);
}
/*
* It can be expensive to build a local aaclip before applying the op, so
* we first see if we can restrict the bounds of new rect to our current
* bounds, or note that the new rect subsumes our current clip.
*/
bool SkAAClip::op(const SkIRect& rOrig, SkRegion::Op op) {
SkIRect rStorage;
const SkIRect* r = &rOrig;
switch (op) {
case SkRegion::kIntersect_Op:
if (!rStorage.intersect(rOrig, fBounds)) {
// no overlap, so we're empty
return this->setEmpty();
}
if (rStorage == fBounds) {
// we were wholly inside the rect, no change
return !this->isEmpty();
}
if (this->quickContains(rStorage)) {
// the intersection is wholly inside us, we're a rect
return this->setRect(rStorage);
}
r = &rStorage; // use the intersected bounds
break;
case SkRegion::kDifference_Op:
break;
case SkRegion::kUnion_Op:
if (rOrig.contains(fBounds)) {
return this->setRect(rOrig);
}
break;
default:
break;
}
SkAAClip clip;
clip.setRect(*r);
return this->op(*this, clip, op);
}
bool SkAAClip::op(const SkRect& rOrig, SkRegion::Op op, bool doAA) {
SkRect rStorage, boundsStorage;
const SkRect* r = &rOrig;
boundsStorage.set(fBounds);
switch (op) {
case SkRegion::kIntersect_Op:
case SkRegion::kDifference_Op:
if (!rStorage.intersect(rOrig, boundsStorage)) {
if (SkRegion::kIntersect_Op == op) {
return this->setEmpty();
} else { // kDifference
return !this->isEmpty();
}
}
r = &rStorage; // use the intersected bounds
break;
case SkRegion::kUnion_Op:
if (rOrig.contains(boundsStorage)) {
return this->setRect(rOrig);
}
break;
default:
break;
}
SkAAClip clip;
clip.setRect(*r, doAA);
return this->op(*this, clip, op);
}
bool SkAAClip::op(const SkAAClip& clip, SkRegion::Op op) {
return this->op(*this, clip, op);
}
///////////////////////////////////////////////////////////////////////////////
bool SkAAClip::translate(int dx, int dy, SkAAClip* dst) const {
if (nullptr == dst) {
return !this->isEmpty();
}
if (this->isEmpty()) {
return dst->setEmpty();
}
if (this != dst) {
sk_atomic_inc(&fRunHead->fRefCnt);
dst->freeRuns();
dst->fRunHead = fRunHead;
dst->fBounds = fBounds;
}
dst->fBounds.offset(dx, dy);
return true;
}
static void expand_row_to_mask(uint8_t* SK_RESTRICT mask,
const uint8_t* SK_RESTRICT row,
int width) {
while (width > 0) {
int n = row[0];
SkASSERT(width >= n);
memset(mask, row[1], n);
mask += n;
row += 2;
width -= n;
}
SkASSERT(0 == width);
}
void SkAAClip::copyToMask(SkMask* mask) const {
mask->fFormat = SkMask::kA8_Format;
if (this->isEmpty()) {
mask->fBounds.setEmpty();
mask->fImage = nullptr;
mask->fRowBytes = 0;
return;
}
mask->fBounds = fBounds;
mask->fRowBytes = fBounds.width();
size_t size = mask->computeImageSize();
mask->fImage = SkMask::AllocImage(size);
Iter iter(*this);
uint8_t* dst = mask->fImage;
const int width = fBounds.width();
int y = fBounds.fTop;
while (!iter.done()) {
do {
expand_row_to_mask(dst, iter.data(), width);
dst += mask->fRowBytes;
} while (++y < iter.bottom());
iter.next();
}
}
///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////
static void expandToRuns(const uint8_t* SK_RESTRICT data, int initialCount, int width,
int16_t* SK_RESTRICT runs, SkAlpha* SK_RESTRICT aa) {
// we don't read our initial n from data, since the caller may have had to
// clip it, hence the initialCount parameter.
int n = initialCount;
for (;;) {
if (n > width) {
n = width;
}
SkASSERT(n > 0);
runs[0] = n;
runs += n;
aa[0] = data[1];
aa += n;
data += 2;
width -= n;
if (0 == width) {
break;
}
// load the next count
n = data[0];
}
runs[0] = 0; // sentinel
}
SkAAClipBlitter::~SkAAClipBlitter() {
sk_free(fScanlineScratch);
}
void SkAAClipBlitter::ensureRunsAndAA() {
if (nullptr == fScanlineScratch) {
// add 1 so we can store the terminating run count of 0
int count = fAAClipBounds.width() + 1;
// we use this either for fRuns + fAA, or a scaline of a mask
// which may be as deep as 32bits
fScanlineScratch = sk_malloc_throw(count * sizeof(SkPMColor));
fRuns = (int16_t*)fScanlineScratch;
fAA = (SkAlpha*)(fRuns + count);
}
}
void SkAAClipBlitter::blitH(int x, int y, int width) {
SkASSERT(width > 0);
SkASSERT(fAAClipBounds.contains(x, y));
SkASSERT(fAAClipBounds.contains(x + width - 1, y));
const uint8_t* row = fAAClip->findRow(y);
int initialCount;
row = fAAClip->findX(row, x, &initialCount);
if (initialCount >= width) {
SkAlpha alpha = row[1];
if (0 == alpha) {
return;
}
if (0xFF == alpha) {
fBlitter->blitH(x, y, width);
return;
}
}
this->ensureRunsAndAA();
expandToRuns(row, initialCount, width, fRuns, fAA);
fBlitter->blitAntiH(x, y, fAA, fRuns);
}
static void merge(const uint8_t* SK_RESTRICT row, int rowN,
const SkAlpha* SK_RESTRICT srcAA,
const int16_t* SK_RESTRICT srcRuns,
SkAlpha* SK_RESTRICT dstAA,
int16_t* SK_RESTRICT dstRuns,
int width) {
SkDEBUGCODE(int accumulated = 0;)
int srcN = srcRuns[0];
// do we need this check?
if (0 == srcN) {
return;
}
for (;;) {
SkASSERT(rowN > 0);
SkASSERT(srcN > 0);
unsigned newAlpha = SkMulDiv255Round(srcAA[0], row[1]);
int minN = SkMin32(srcN, rowN);
dstRuns[0] = minN;
dstRuns += minN;
dstAA[0] = newAlpha;
dstAA += minN;
if (0 == (srcN -= minN)) {
srcN = srcRuns[0]; // refresh
srcRuns += srcN;
srcAA += srcN;
srcN = srcRuns[0]; // reload
if (0 == srcN) {
break;
}
}
if (0 == (rowN -= minN)) {
row += 2;
rowN = row[0]; // reload
}
SkDEBUGCODE(accumulated += minN;)
SkASSERT(accumulated <= width);
}
dstRuns[0] = 0;
}
void SkAAClipBlitter::blitAntiH(int x, int y, const SkAlpha aa[],
const int16_t runs[]) {
const uint8_t* row = fAAClip->findRow(y);
int initialCount;
row = fAAClip->findX(row, x, &initialCount);
this->ensureRunsAndAA();
merge(row, initialCount, aa, runs, fAA, fRuns, fAAClipBounds.width());
fBlitter->blitAntiH(x, y, fAA, fRuns);
}
void SkAAClipBlitter::blitV(int x, int y, int height, SkAlpha alpha) {
if (fAAClip->quickContains(x, y, x + 1, y + height)) {
fBlitter->blitV(x, y, height, alpha);
return;
}
for (;;) {
int lastY SK_INIT_TO_AVOID_WARNING;
const uint8_t* row = fAAClip->findRow(y, &lastY);
int dy = lastY - y + 1;
if (dy > height) {
dy = height;
}
height -= dy;
row = fAAClip->findX(row, x);
SkAlpha newAlpha = SkMulDiv255Round(alpha, row[1]);
if (newAlpha) {
fBlitter->blitV(x, y, dy, newAlpha);
}
SkASSERT(height >= 0);
if (height <= 0) {
break;
}
y = lastY + 1;
}
}
void SkAAClipBlitter::blitRect(int x, int y, int width, int height) {
if (fAAClip->quickContains(x, y, x + width, y + height)) {
fBlitter->blitRect(x, y, width, height);
return;
}
while (--height >= 0) {
this->blitH(x, y, width);
y += 1;
}
}
typedef void (*MergeAAProc)(const void* src, int width, const uint8_t* row,
int initialRowCount, void* dst);
static void small_memcpy(void* dst, const void* src, size_t n) {
memcpy(dst, src, n);
}
static void small_bzero(void* dst, size_t n) {
sk_bzero(dst, n);
}
static inline uint8_t mergeOne(uint8_t value, unsigned alpha) {
return SkMulDiv255Round(value, alpha);
}
static inline uint16_t mergeOne(uint16_t value, unsigned alpha) {
unsigned r = SkGetPackedR16(value);
unsigned g = SkGetPackedG16(value);
unsigned b = SkGetPackedB16(value);
return SkPackRGB16(SkMulDiv255Round(r, alpha),
SkMulDiv255Round(g, alpha),
SkMulDiv255Round(b, alpha));
}
template <typename T>
void mergeT(const void* inSrc, int srcN, const uint8_t* SK_RESTRICT row, int rowN, void* inDst) {
const T* SK_RESTRICT src = static_cast<const T*>(inSrc);
T* SK_RESTRICT dst = static_cast<T*>(inDst);
for (;;) {
SkASSERT(rowN > 0);
SkASSERT(srcN > 0);
int n = SkMin32(rowN, srcN);
unsigned rowA = row[1];
if (0xFF == rowA) {
small_memcpy(dst, src, n * sizeof(T));
} else if (0 == rowA) {
small_bzero(dst, n * sizeof(T));
} else {
for (int i = 0; i < n; ++i) {
dst[i] = mergeOne(src[i], rowA);
}
}
if (0 == (srcN -= n)) {
break;
}
src += n;
dst += n;
SkASSERT(rowN == n);
row += 2;
rowN = row[0];
}
}
static MergeAAProc find_merge_aa_proc(SkMask::Format format) {
switch (format) {
case SkMask::kBW_Format:
SkDEBUGFAIL("unsupported");
return nullptr;
case SkMask::kA8_Format:
case SkMask::k3D_Format:
return mergeT<uint8_t> ;
case SkMask::kLCD16_Format:
return mergeT<uint16_t>;
default:
SkDEBUGFAIL("unsupported");
return nullptr;
}
}
static U8CPU bit2byte(int bitInAByte) {
SkASSERT(bitInAByte <= 0xFF);
// negation turns any non-zero into 0xFFFFFF??, so we just shift down
// some value >= 8 to get a full FF value
return -bitInAByte >> 8;
}
static void upscaleBW2A8(SkMask* dstMask, const SkMask& srcMask) {
SkASSERT(SkMask::kBW_Format == srcMask.fFormat);
SkASSERT(SkMask::kA8_Format == dstMask->fFormat);
const int width = srcMask.fBounds.width();
const int height = srcMask.fBounds.height();
const uint8_t* SK_RESTRICT src = (const uint8_t*)srcMask.fImage;
const size_t srcRB = srcMask.fRowBytes;
uint8_t* SK_RESTRICT dst = (uint8_t*)dstMask->fImage;
const size_t dstRB = dstMask->fRowBytes;
const int wholeBytes = width >> 3;
const int leftOverBits = width & 7;
for (int y = 0; y < height; ++y) {
uint8_t* SK_RESTRICT d = dst;
for (int i = 0; i < wholeBytes; ++i) {
int srcByte = src[i];
d[0] = bit2byte(srcByte & (1 << 7));
d[1] = bit2byte(srcByte & (1 << 6));
d[2] = bit2byte(srcByte & (1 << 5));
d[3] = bit2byte(srcByte & (1 << 4));
d[4] = bit2byte(srcByte & (1 << 3));
d[5] = bit2byte(srcByte & (1 << 2));
d[6] = bit2byte(srcByte & (1 << 1));
d[7] = bit2byte(srcByte & (1 << 0));
d += 8;
}
if (leftOverBits) {
int srcByte = src[wholeBytes];
for (int x = 0; x < leftOverBits; ++x) {
*d++ = bit2byte(srcByte & 0x80);
srcByte <<= 1;
}
}
src += srcRB;
dst += dstRB;
}
}
void SkAAClipBlitter::blitMask(const SkMask& origMask, const SkIRect& clip) {
SkASSERT(fAAClip->getBounds().contains(clip));
if (fAAClip->quickContains(clip)) {
fBlitter->blitMask(origMask, clip);
return;
}
const SkMask* mask = &origMask;
// if we're BW, we need to upscale to A8 (ugh)
SkMask grayMask;
if (SkMask::kBW_Format == origMask.fFormat) {
grayMask.fFormat = SkMask::kA8_Format;
grayMask.fBounds = origMask.fBounds;
grayMask.fRowBytes = origMask.fBounds.width();
size_t size = grayMask.computeImageSize();
grayMask.fImage = (uint8_t*)fGrayMaskScratch.reset(size,
SkAutoMalloc::kReuse_OnShrink);
upscaleBW2A8(&grayMask, origMask);
mask = &grayMask;
}
this->ensureRunsAndAA();
// HACK -- we are devolving 3D into A8, need to copy the rest of the 3D
// data into a temp block to support it better (ugh)
const void* src = mask->getAddr(clip.fLeft, clip.fTop);
const size_t srcRB = mask->fRowBytes;
const int width = clip.width();
MergeAAProc mergeProc = find_merge_aa_proc(mask->fFormat);
SkMask rowMask;
rowMask.fFormat = SkMask::k3D_Format == mask->fFormat ? SkMask::kA8_Format : mask->fFormat;
rowMask.fBounds.fLeft = clip.fLeft;
rowMask.fBounds.fRight = clip.fRight;
rowMask.fRowBytes = mask->fRowBytes; // doesn't matter, since our height==1
rowMask.fImage = (uint8_t*)fScanlineScratch;
int y = clip.fTop;
const int stopY = y + clip.height();
do {
int localStopY SK_INIT_TO_AVOID_WARNING;
const uint8_t* row = fAAClip->findRow(y, &localStopY);
// findRow returns last Y, not stop, so we add 1
localStopY = SkMin32(localStopY + 1, stopY);
int initialCount;
row = fAAClip->findX(row, clip.fLeft, &initialCount);
do {
mergeProc(src, width, row, initialCount, rowMask.fImage);
rowMask.fBounds.fTop = y;
rowMask.fBounds.fBottom = y + 1;
fBlitter->blitMask(rowMask, rowMask.fBounds);
src = (const void*)((const char*)src + srcRB);
} while (++y < localStopY);
} while (y < stopY);
}
const SkPixmap* SkAAClipBlitter::justAnOpaqueColor(uint32_t* value) {
return nullptr;
}