blob: 9b2a279f2e9abec7b3425050174dcd2e809718e2 [file] [log] [blame]
/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkLatticeIter.h"
#include "SkRect.h"
/**
* Divs must be in increasing order with no duplicates.
*/
static bool valid_divs(const int* divs, int count, int start, int end) {
int prev = start - 1;
for (int i = 0; i < count; i++) {
if (prev >= divs[i] || divs[i] >= end) {
return false;
}
prev = divs[i];
}
return true;
}
bool SkLatticeIter::Valid(int width, int height, const SkCanvas::Lattice& lattice) {
SkIRect totalBounds = SkIRect::MakeWH(width, height);
SkASSERT(lattice.fBounds);
const SkIRect latticeBounds = *lattice.fBounds;
if (!totalBounds.contains(latticeBounds)) {
return false;
}
bool zeroXDivs = lattice.fXCount <= 0 || (1 == lattice.fXCount &&
latticeBounds.fLeft == lattice.fXDivs[0]);
bool zeroYDivs = lattice.fYCount <= 0 || (1 == lattice.fYCount &&
latticeBounds.fTop == lattice.fYDivs[0]);
if (zeroXDivs && zeroYDivs) {
return false;
}
return valid_divs(lattice.fXDivs, lattice.fXCount, latticeBounds.fLeft, latticeBounds.fRight)
&& valid_divs(lattice.fYDivs, lattice.fYCount, latticeBounds.fTop, latticeBounds.fBottom);
}
/**
* Count the number of pixels that are in "scalable" patches.
*/
static int count_scalable_pixels(const int32_t* divs, int numDivs, bool firstIsScalable,
int start, int end) {
if (0 == numDivs) {
return firstIsScalable ? end - start : 0;
}
int i;
int count;
if (firstIsScalable) {
count = divs[0] - start;
i = 1;
} else {
count = 0;
i = 0;
}
for (; i < numDivs; i += 2) {
// Alternatively, we could use |top| and |bottom| as variable names, instead of
// |left| and |right|.
int left = divs[i];
int right = (i + 1 < numDivs) ? divs[i + 1] : end;
count += right - left;
}
return count;
}
/**
* Set points for the src and dst rects on subsequent draw calls.
*/
static void set_points(float* dst, float* src, const int* divs, int divCount, int srcFixed,
int srcScalable, float srcStart, float srcEnd, float dstStart, float dstEnd,
bool isScalable) {
float dstLen = dstEnd - dstStart;
float scale;
if (srcFixed <= dstLen) {
// This is the "normal" case, where we scale the "scalable" patches and leave
// the other patches fixed.
scale = (dstLen - ((float) srcFixed)) / ((float) srcScalable);
} else {
// In this case, we eliminate the "scalable" patches and scale the "fixed" patches.
scale = dstLen / ((float) srcFixed);
}
src[0] = srcStart;
dst[0] = dstStart;
for (int i = 0; i < divCount; i++) {
src[i + 1] = (float) (divs[i]);
float srcDelta = src[i + 1] - src[i];
float dstDelta;
if (srcFixed <= dstLen) {
dstDelta = isScalable ? scale * srcDelta : srcDelta;
} else {
dstDelta = isScalable ? 0.0f : scale * srcDelta;
}
dst[i + 1] = dst[i] + dstDelta;
// Alternate between "scalable" and "fixed" patches.
isScalable = !isScalable;
}
src[divCount + 1] = srcEnd;
dst[divCount + 1] = dstEnd;
}
SkLatticeIter::SkLatticeIter(const SkCanvas::Lattice& lattice, const SkRect& dst) {
const int* xDivs = lattice.fXDivs;
const int origXCount = lattice.fXCount;
const int* yDivs = lattice.fYDivs;
const int origYCount = lattice.fYCount;
SkASSERT(lattice.fBounds);
const SkIRect src = *lattice.fBounds;
// In the x-dimension, the first rectangle always starts at x = 0 and is "scalable".
// If xDiv[0] is 0, it indicates that the first rectangle is degenerate, so the
// first real rectangle "scalable" in the x-direction.
//
// The same interpretation applies to the y-dimension.
//
// As we move left to right across the image, alternating patches will be "fixed" or
// "scalable" in the x-direction. Similarly, as move top to bottom, alternating
// patches will be "fixed" or "scalable" in the y-direction.
int xCount = origXCount;
int yCount = origYCount;
bool xIsScalable = (xCount > 0 && src.fLeft == xDivs[0]);
if (xIsScalable) {
// Once we've decided that the first patch is "scalable", we don't need the
// xDiv. It is always implied that we start at the edge of the bounds.
xDivs++;
xCount--;
}
bool yIsScalable = (yCount > 0 && src.fTop == yDivs[0]);
if (yIsScalable) {
// Once we've decided that the first patch is "scalable", we don't need the
// yDiv. It is always implied that we start at the edge of the bounds.
yDivs++;
yCount--;
}
// Count "scalable" and "fixed" pixels in each dimension.
int xCountScalable = count_scalable_pixels(xDivs, xCount, xIsScalable, src.fLeft, src.fRight);
int xCountFixed = src.width() - xCountScalable;
int yCountScalable = count_scalable_pixels(yDivs, yCount, yIsScalable, src.fTop, src.fBottom);
int yCountFixed = src.height() - yCountScalable;
fSrcX.reset(xCount + 2);
fDstX.reset(xCount + 2);
set_points(fDstX.begin(), fSrcX.begin(), xDivs, xCount, xCountFixed, xCountScalable,
src.fLeft, src.fRight, dst.fLeft, dst.fRight, xIsScalable);
fSrcY.reset(yCount + 2);
fDstY.reset(yCount + 2);
set_points(fDstY.begin(), fSrcY.begin(), yDivs, yCount, yCountFixed, yCountScalable,
src.fTop, src.fBottom, dst.fTop, dst.fBottom, yIsScalable);
fCurrX = fCurrY = 0;
fNumRectsInLattice = (xCount + 1) * (yCount + 1);
fNumRectsToDraw = fNumRectsInLattice;
if (lattice.fFlags) {
fFlags.push_back_n(fNumRectsInLattice);
const SkCanvas::Lattice::Flags* flags = lattice.fFlags;
bool hasPadRow = (yCount != origYCount);
bool hasPadCol = (xCount != origXCount);
if (hasPadRow) {
// The first row of rects are all empty, skip the first row of flags.
flags += origXCount + 1;
}
int i = 0;
for (int y = 0; y < yCount + 1; y++) {
for (int x = 0; x < origXCount + 1; x++) {
if (0 == x && hasPadCol) {
// The first column of rects are all empty. Skip a rect.
flags++;
continue;
}
fFlags[i] = *flags;
flags++;
i++;
}
}
for (int j = 0; j < fFlags.count(); j++) {
if (SkCanvas::Lattice::kTransparent_Flags == fFlags[j]) {
fNumRectsToDraw--;
}
}
}
}
bool SkLatticeIter::Valid(int width, int height, const SkIRect& center) {
return !center.isEmpty() && SkIRect::MakeWH(width, height).contains(center);
}
SkLatticeIter::SkLatticeIter(int w, int h, const SkIRect& c, const SkRect& dst) {
SkASSERT(SkIRect::MakeWH(w, h).contains(c));
fSrcX.reset(4);
fSrcY.reset(4);
fDstX.reset(4);
fDstY.reset(4);
fSrcX[0] = 0;
fSrcX[1] = SkIntToScalar(c.fLeft);
fSrcX[2] = SkIntToScalar(c.fRight);
fSrcX[3] = SkIntToScalar(w);
fSrcY[0] = 0;
fSrcY[1] = SkIntToScalar(c.fTop);
fSrcY[2] = SkIntToScalar(c.fBottom);
fSrcY[3] = SkIntToScalar(h);
fDstX[0] = dst.fLeft;
fDstX[1] = dst.fLeft + SkIntToScalar(c.fLeft);
fDstX[2] = dst.fRight - SkIntToScalar(w - c.fRight);
fDstX[3] = dst.fRight;
fDstY[0] = dst.fTop;
fDstY[1] = dst.fTop + SkIntToScalar(c.fTop);
fDstY[2] = dst.fBottom - SkIntToScalar(h - c.fBottom);
fDstY[3] = dst.fBottom;
if (fDstX[1] > fDstX[2]) {
fDstX[1] = fDstX[0] + (fDstX[3] - fDstX[0]) * c.fLeft / (w - c.width());
fDstX[2] = fDstX[1];
}
if (fDstY[1] > fDstY[2]) {
fDstY[1] = fDstY[0] + (fDstY[3] - fDstY[0]) * c.fTop / (h - c.height());
fDstY[2] = fDstY[1];
}
fCurrX = fCurrY = 0;
fNumRectsInLattice = 9;
fNumRectsToDraw = 9;
}
bool SkLatticeIter::next(SkRect* src, SkRect* dst) {
int currRect = fCurrX + fCurrY * (fSrcX.count() - 1);
if (currRect == fNumRectsInLattice) {
return false;
}
const int x = fCurrX;
const int y = fCurrY;
SkASSERT(x >= 0 && x < fSrcX.count() - 1);
SkASSERT(y >= 0 && y < fSrcY.count() - 1);
if (fSrcX.count() - 1 == ++fCurrX) {
fCurrX = 0;
fCurrY += 1;
}
if (fFlags.count() > 0 && SkToBool(SkCanvas::Lattice::kTransparent_Flags & fFlags[currRect])) {
return this->next(src, dst);
}
src->set(fSrcX[x], fSrcY[y], fSrcX[x + 1], fSrcY[y + 1]);
dst->set(fDstX[x], fDstY[y], fDstX[x + 1], fDstY[y + 1]);
return true;
}
void SkLatticeIter::mapDstScaleTranslate(const SkMatrix& matrix) {
SkASSERT(matrix.isScaleTranslate());
SkScalar tx = matrix.getTranslateX();
SkScalar sx = matrix.getScaleX();
for (int i = 0; i < fDstX.count(); i++) {
fDstX[i] = fDstX[i] * sx + tx;
}
SkScalar ty = matrix.getTranslateY();
SkScalar sy = matrix.getScaleY();
for (int i = 0; i < fDstY.count(); i++) {
fDstY[i] = fDstY[i] * sy + ty;
}
}