/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkRRectPriv.h"
#include "SkBuffer.h"
#include "SkMalloc.h"
#include "SkMatrix.h"
#include "SkScaleToSides.h"
#include <cmath>
#include <utility>
///////////////////////////////////////////////////////////////////////////////
void SkRRect::setRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad) {
if (!this->initializeRect(rect)) {
return;
}
if (!SkScalarsAreFinite(xRad, yRad)) {
xRad = yRad = 0; // devolve into a simple rect
}
if (fRect.width() < xRad+xRad || fRect.height() < yRad+yRad) {
// At most one of these two divides will be by zero, and neither numerator is zero.
SkScalar scale = SkMinScalar(sk_ieee_float_divide(fRect. width(), xRad + xRad),
sk_ieee_float_divide(fRect.height(), yRad + yRad));
SkASSERT(scale < SK_Scalar1);
xRad *= scale;
yRad *= scale;
}
if (xRad <= 0 || yRad <= 0) {
// all corners are square in this case
this->setRect(rect);
return;
}
for (int i = 0; i < 4; ++i) {
fRadii[i].set(xRad, yRad);
}
fType = kSimple_Type;
if (xRad >= SkScalarHalf(fRect.width()) && yRad >= SkScalarHalf(fRect.height())) {
fType = kOval_Type;
// TODO: assert that all the x&y radii are already W/2 & H/2
}
SkASSERT(this->isValid());
}
void SkRRect::setNinePatch(const SkRect& rect, SkScalar leftRad, SkScalar topRad,
SkScalar rightRad, SkScalar bottomRad) {
if (!this->initializeRect(rect)) {
return;
}
const SkScalar array[4] = { leftRad, topRad, rightRad, bottomRad };
if (!SkScalarsAreFinite(array, 4)) {
this->setRect(rect); // devolve into a simple rect
return;
}
leftRad = SkMaxScalar(leftRad, 0);
topRad = SkMaxScalar(topRad, 0);
rightRad = SkMaxScalar(rightRad, 0);
bottomRad = SkMaxScalar(bottomRad, 0);
SkScalar scale = SK_Scalar1;
if (leftRad + rightRad > fRect.width()) {
scale = fRect.width() / (leftRad + rightRad);
}
if (topRad + bottomRad > fRect.height()) {
scale = SkMinScalar(scale, fRect.height() / (topRad + bottomRad));
}
if (scale < SK_Scalar1) {
leftRad *= scale;
topRad *= scale;
rightRad *= scale;
bottomRad *= scale;
}
if (leftRad == rightRad && topRad == bottomRad) {
if (leftRad >= SkScalarHalf(fRect.width()) && topRad >= SkScalarHalf(fRect.height())) {
fType = kOval_Type;
} else if (0 == leftRad || 0 == topRad) {
// If the left and (by equality check above) right radii are zero then it is a rect.
// Same goes for top/bottom.
fType = kRect_Type;
leftRad = 0;
topRad = 0;
rightRad = 0;
bottomRad = 0;
} else {
fType = kSimple_Type;
}
} else {
fType = kNinePatch_Type;
}
fRadii[kUpperLeft_Corner].set(leftRad, topRad);
fRadii[kUpperRight_Corner].set(rightRad, topRad);
fRadii[kLowerRight_Corner].set(rightRad, bottomRad);
fRadii[kLowerLeft_Corner].set(leftRad, bottomRad);
SkASSERT(this->isValid());
}
// These parameters intentionally double. Apropos crbug.com/463920, if one of the
// radii is huge while the other is small, single precision math can completely
// miss the fact that a scale is required.
static double compute_min_scale(double rad1, double rad2, double limit, double curMin) {
if ((rad1 + rad2) > limit) {
return SkTMin(curMin, limit / (rad1 + rad2));
}
return curMin;
}
static bool clamp_to_zero(SkVector radii[4]) {
bool allCornersSquare = true;
// Clamp negative radii to zero
for (int i = 0; i < 4; ++i) {
if (radii[i].fX <= 0 || radii[i].fY <= 0) {
// In this case we are being a little fast & loose. Since one of
// the radii is 0 the corner is square. However, the other radii
// could still be non-zero and play in the global scale factor
// computation.
radii[i].fX = 0;
radii[i].fY = 0;
} else {
allCornersSquare = false;
}
}
return allCornersSquare;
}
void SkRRect::setRectRadii(const SkRect& rect, const SkVector radii[4]) {
if (!this->initializeRect(rect)) {
return;
}
if (!SkScalarsAreFinite(&radii[0].fX, 8)) {
this->setRect(rect); // devolve into a simple rect
return;
}
memcpy(fRadii, radii, sizeof(fRadii));
if (clamp_to_zero(fRadii)) {
this->setRect(rect);
return;
}
this->scaleRadii(rect);
}
bool SkRRect::initializeRect(const SkRect& rect) {
// Check this before sorting because sorting can hide nans.
if (!rect.isFinite()) {
*this = SkRRect();
return false;
}
fRect = rect.makeSorted();
if (fRect.isEmpty()) {
memset(fRadii, 0, sizeof(fRadii));
fType = kEmpty_Type;
return false;
}
return true;
}
// If we can't distinguish one of the radii relative to the other, force it to zero so it
// doesn't confuse us later. See crbug.com/850350
//
static void flush_to_zero(SkScalar& a, SkScalar& b) {
SkASSERT(a >= 0);
SkASSERT(b >= 0);
if (a + b == a) {
b = 0;
} else if (a + b == b) {
a = 0;
}
}
void SkRRect::scaleRadii(const SkRect& rect) {
// Proportionally scale down all radii to fit. Find the minimum ratio
// of a side and the radii on that side (for all four sides) and use
// that to scale down _all_ the radii. This algorithm is from the
// W3 spec (http://www.w3.org/TR/css3-background/) section 5.5 - Overlapping
// Curves:
// "Let f = min(Li/Si), where i is one of { top, right, bottom, left },
// Si is the sum of the two corresponding radii of the corners on side i,
// and Ltop = Lbottom = the width of the box,
// and Lleft = Lright = the height of the box.
// If f < 1, then all corner radii are reduced by multiplying them by f."
double scale = 1.0;
// The sides of the rectangle may be larger than a float.
double width = (double)fRect.fRight - (double)fRect.fLeft;
double height = (double)fRect.fBottom - (double)fRect.fTop;
scale = compute_min_scale(fRadii[0].fX, fRadii[1].fX, width, scale);
scale = compute_min_scale(fRadii[1].fY, fRadii[2].fY, height, scale);
scale = compute_min_scale(fRadii[2].fX, fRadii[3].fX, width, scale);
scale = compute_min_scale(fRadii[3].fY, fRadii[0].fY, height, scale);
flush_to_zero(fRadii[0].fX, fRadii[1].fX);
flush_to_zero(fRadii[1].fY, fRadii[2].fY);
flush_to_zero(fRadii[2].fX, fRadii[3].fX);
flush_to_zero(fRadii[3].fY, fRadii[0].fY);
if (scale < 1.0) {
SkScaleToSides::AdjustRadii(width, scale, &fRadii[0].fX, &fRadii[1].fX);
SkScaleToSides::AdjustRadii(height, scale, &fRadii[1].fY, &fRadii[2].fY);
SkScaleToSides::AdjustRadii(width, scale, &fRadii[2].fX, &fRadii[3].fX);
SkScaleToSides::AdjustRadii(height, scale, &fRadii[3].fY, &fRadii[0].fY);
}
// adjust radii may set x or y to zero; set companion to zero as well
if (clamp_to_zero(fRadii)) {
this->setRect(rect);
return;
}
// At this point we're either oval, simple, or complex (not empty or rect).
this->computeType();
SkASSERT(this->isValid());
}
// This method determines if a point known to be inside the RRect's bounds is
// inside all the corners.
bool SkRRect::checkCornerContainment(SkScalar x, SkScalar y) const {
SkPoint canonicalPt; // (x,y) translated to one of the quadrants
int index;
if (kOval_Type == this->type()) {
canonicalPt.set(x - fRect.centerX(), y - fRect.centerY());
index = kUpperLeft_Corner; // any corner will do in this case
} else {
if (x < fRect.fLeft + fRadii[kUpperLeft_Corner].fX &&
y < fRect.fTop + fRadii[kUpperLeft_Corner].fY) {
// UL corner
index = kUpperLeft_Corner;
canonicalPt.set(x - (fRect.fLeft + fRadii[kUpperLeft_Corner].fX),
y - (fRect.fTop + fRadii[kUpperLeft_Corner].fY));
SkASSERT(canonicalPt.fX < 0 && canonicalPt.fY < 0);
} else if (x < fRect.fLeft + fRadii[kLowerLeft_Corner].fX &&
y > fRect.fBottom - fRadii[kLowerLeft_Corner].fY) {
// LL corner
index = kLowerLeft_Corner;
canonicalPt.set(x - (fRect.fLeft + fRadii[kLowerLeft_Corner].fX),
y - (fRect.fBottom - fRadii[kLowerLeft_Corner].fY));
SkASSERT(canonicalPt.fX < 0 && canonicalPt.fY > 0);
} else if (x > fRect.fRight - fRadii[kUpperRight_Corner].fX &&
y < fRect.fTop + fRadii[kUpperRight_Corner].fY) {
// UR corner
index = kUpperRight_Corner;
canonicalPt.set(x - (fRect.fRight - fRadii[kUpperRight_Corner].fX),
y - (fRect.fTop + fRadii[kUpperRight_Corner].fY));
SkASSERT(canonicalPt.fX > 0 && canonicalPt.fY < 0);
} else if (x > fRect.fRight - fRadii[kLowerRight_Corner].fX &&
y > fRect.fBottom - fRadii[kLowerRight_Corner].fY) {
// LR corner
index = kLowerRight_Corner;
canonicalPt.set(x - (fRect.fRight - fRadii[kLowerRight_Corner].fX),
y - (fRect.fBottom - fRadii[kLowerRight_Corner].fY));
SkASSERT(canonicalPt.fX > 0 && canonicalPt.fY > 0);
} else {
// not in any of the corners
return true;
}
}
// A point is in an ellipse (in standard position) if:
// x^2 y^2
// ----- + ----- <= 1
// a^2 b^2
// or :
// b^2*x^2 + a^2*y^2 <= (ab)^2
SkScalar dist = SkScalarSquare(canonicalPt.fX) * SkScalarSquare(fRadii[index].fY) +
SkScalarSquare(canonicalPt.fY) * SkScalarSquare(fRadii[index].fX);
return dist <= SkScalarSquare(fRadii[index].fX * fRadii[index].fY);
}
bool SkRRectPriv::AllCornersCircular(const SkRRect& rr, SkScalar tolerance) {
return SkScalarNearlyEqual(rr.fRadii[0].fX, rr.fRadii[0].fY, tolerance) &&
SkScalarNearlyEqual(rr.fRadii[1].fX, rr.fRadii[1].fY, tolerance) &&
SkScalarNearlyEqual(rr.fRadii[2].fX, rr.fRadii[2].fY, tolerance) &&
SkScalarNearlyEqual(rr.fRadii[3].fX, rr.fRadii[3].fY, tolerance);
}
bool SkRRect::contains(const SkRect& rect) const {
if (!this->getBounds().contains(rect)) {
// If 'rect' isn't contained by the RR's bounds then the
// RR definitely doesn't contain it
return false;
}
if (this->isRect()) {
// the prior test was sufficient
return true;
}
// At this point we know all four corners of 'rect' are inside the
// bounds of of this RR. Check to make sure all the corners are inside
// all the curves
return this->checkCornerContainment(rect.fLeft, rect.fTop) &&
this->checkCornerContainment(rect.fRight, rect.fTop) &&
this->checkCornerContainment(rect.fRight, rect.fBottom) &&
this->checkCornerContainment(rect.fLeft, rect.fBottom);
}
static bool radii_are_nine_patch(const SkVector radii[4]) {
return radii[SkRRect::kUpperLeft_Corner].fX == radii[SkRRect::kLowerLeft_Corner].fX &&
radii[SkRRect::kUpperLeft_Corner].fY == radii[SkRRect::kUpperRight_Corner].fY &&
radii[SkRRect::kUpperRight_Corner].fX == radii[SkRRect::kLowerRight_Corner].fX &&
radii[SkRRect::kLowerLeft_Corner].fY == radii[SkRRect::kLowerRight_Corner].fY;
}
// There is a simplified version of this method in setRectXY
void SkRRect::computeType() {
if (fRect.isEmpty()) {
SkASSERT(fRect.isSorted());
for (size_t i = 0; i < SK_ARRAY_COUNT(fRadii); ++i) {
SkASSERT((fRadii[i] == SkVector{0, 0}));
}
fType = kEmpty_Type;
SkASSERT(this->isValid());
return;
}
bool allRadiiEqual = true; // are all x radii equal and all y radii?
bool allCornersSquare = 0 == fRadii[0].fX || 0 == fRadii[0].fY;
for (int i = 1; i < 4; ++i) {
if (0 != fRadii[i].fX && 0 != fRadii[i].fY) {
// if either radius is zero the corner is square so both have to
// be non-zero to have a rounded corner
allCornersSquare = false;
}
if (fRadii[i].fX != fRadii[i-1].fX || fRadii[i].fY != fRadii[i-1].fY) {
allRadiiEqual = false;
}
}
if (allCornersSquare) {
fType = kRect_Type;
SkASSERT(this->isValid());
return;
}
if (allRadiiEqual) {
if (fRadii[0].fX >= SkScalarHalf(fRect.width()) &&
fRadii[0].fY >= SkScalarHalf(fRect.height())) {
fType = kOval_Type;
} else {
fType = kSimple_Type;
}
SkASSERT(this->isValid());
return;
}
if (radii_are_nine_patch(fRadii)) {
fType = kNinePatch_Type;
} else {
fType = kComplex_Type;
}
SkASSERT(this->isValid());
}
bool SkRRect::transform(const SkMatrix& matrix, SkRRect* dst) const {
if (nullptr == dst) {
return false;
}
// Assert that the caller is not trying to do this in place, which
// would violate const-ness. Do not return false though, so that
// if they know what they're doing and want to violate it they can.
SkASSERT(dst != this);
if (matrix.isIdentity()) {
*dst = *this;
return true;
}
// If transform supported 90 degree rotations (which it could), we could
// use SkMatrix::rectStaysRect() to check for a valid transformation.
if (!matrix.isScaleTranslate()) {
return false;
}
SkRect newRect;
if (!matrix.mapRect(&newRect, fRect)) {
return false;
}
// The matrix may have scaled us to zero (or due to float madness, we now have collapsed
// some dimension of the rect, so we need to check for that. Note that matrix must be
// scale and translate and mapRect() produces a sorted rect. So an empty rect indicates
// loss of precision.
if (!newRect.isFinite() || newRect.isEmpty()) {
return false;
}
// At this point, this is guaranteed to succeed, so we can modify dst.
dst->fRect = newRect;
// Since the only transforms that were allowed are scale and translate, the type
// remains unchanged.
dst->fType = fType;
if (kRect_Type == fType) {
SkASSERT(dst->isValid());
return true;
}
if (kOval_Type == fType) {
for (int i = 0; i < 4; ++i) {
dst->fRadii[i].fX = SkScalarHalf(newRect.width());
dst->fRadii[i].fY = SkScalarHalf(newRect.height());
}
SkASSERT(dst->isValid());
return true;
}
// Now scale each corner
SkScalar xScale = matrix.getScaleX();
const bool flipX = xScale < 0;
if (flipX) {
xScale = -xScale;
}
SkScalar yScale = matrix.getScaleY();
const bool flipY = yScale < 0;
if (flipY) {
yScale = -yScale;
}
// Scale the radii without respecting the flip.
for (int i = 0; i < 4; ++i) {
dst->fRadii[i].fX = fRadii[i].fX * xScale;
dst->fRadii[i].fY = fRadii[i].fY * yScale;
}
// Now swap as necessary.
using std::swap;
if (flipX) {
if (flipY) {
// Swap with opposite corners
swap(dst->fRadii[kUpperLeft_Corner], dst->fRadii[kLowerRight_Corner]);
swap(dst->fRadii[kUpperRight_Corner], dst->fRadii[kLowerLeft_Corner]);
} else {
// Only swap in x
swap(dst->fRadii[kUpperRight_Corner], dst->fRadii[kUpperLeft_Corner]);
swap(dst->fRadii[kLowerRight_Corner], dst->fRadii[kLowerLeft_Corner]);
}
} else if (flipY) {
// Only swap in y
swap(dst->fRadii[kUpperLeft_Corner], dst->fRadii[kLowerLeft_Corner]);
swap(dst->fRadii[kUpperRight_Corner], dst->fRadii[kLowerRight_Corner]);
}
if (!AreRectAndRadiiValid(dst->fRect, dst->fRadii)) {
return false;
}
dst->scaleRadii(dst->fRect);
dst->isValid();
return true;
}
///////////////////////////////////////////////////////////////////////////////
void SkRRect::inset(SkScalar dx, SkScalar dy, SkRRect* dst) const {
SkRect r = fRect.makeInset(dx, dy);
bool degenerate = false;
if (r.fRight <= r.fLeft) {
degenerate = true;
r.fLeft = r.fRight = SkScalarAve(r.fLeft, r.fRight);
}
if (r.fBottom <= r.fTop) {
degenerate = true;
r.fTop = r.fBottom = SkScalarAve(r.fTop, r.fBottom);
}
if (degenerate) {
dst->fRect = r;
memset(dst->fRadii, 0, sizeof(dst->fRadii));
dst->fType = kEmpty_Type;
return;
}
if (!r.isFinite()) {
*dst = SkRRect();
return;
}
SkVector radii[4];
memcpy(radii, fRadii, sizeof(radii));
for (int i = 0; i < 4; ++i) {
if (radii[i].fX) {
radii[i].fX -= dx;
}
if (radii[i].fY) {
radii[i].fY -= dy;
}
}
dst->setRectRadii(r, radii);
}
///////////////////////////////////////////////////////////////////////////////
size_t SkRRect::writeToMemory(void* buffer) const {
// Serialize only the rect and corners, but not the derived type tag.
memcpy(buffer, this, kSizeInMemory);
return kSizeInMemory;
}
void SkRRectPriv::WriteToBuffer(const SkRRect& rr, SkWBuffer* buffer) {
// Serialize only the rect and corners, but not the derived type tag.
buffer->write(&rr, SkRRect::kSizeInMemory);
}
size_t SkRRect::readFromMemory(const void* buffer, size_t length) {
if (length < kSizeInMemory) {
return 0;
}
SkRRect raw;
memcpy(&raw, buffer, kSizeInMemory);
this->setRectRadii(raw.fRect, raw.fRadii);
return kSizeInMemory;
}
bool SkRRectPriv::ReadFromBuffer(SkRBuffer* buffer, SkRRect* rr) {
if (buffer->available() < SkRRect::kSizeInMemory) {
return false;
}
SkRRect storage;
return buffer->read(&storage, SkRRect::kSizeInMemory) &&
(rr->readFromMemory(&storage, SkRRect::kSizeInMemory) == SkRRect::kSizeInMemory);
}
#include "SkString.h"
#include "SkStringUtils.h"
void SkRRect::dump(bool asHex) const {
SkScalarAsStringType asType = asHex ? kHex_SkScalarAsStringType : kDec_SkScalarAsStringType;
fRect.dump(asHex);
SkString line("const SkPoint corners[] = {\n");
for (int i = 0; i < 4; ++i) {
SkString strX, strY;
SkAppendScalar(&strX, fRadii[i].x(), asType);
SkAppendScalar(&strY, fRadii[i].y(), asType);
line.appendf(" { %s, %s },", strX.c_str(), strY.c_str());
if (asHex) {
line.appendf(" /* %f %f */", fRadii[i].x(), fRadii[i].y());
}
line.append("\n");
}
line.append("};");
SkDebugf("%s\n", line.c_str());
}
///////////////////////////////////////////////////////////////////////////////
/**
* We need all combinations of predicates to be true to have a "safe" radius value.
*/
static bool are_radius_check_predicates_valid(SkScalar rad, SkScalar min, SkScalar max) {
return (min <= max) && (rad <= max - min) && (min + rad <= max) && (max - rad >= min) &&
rad >= 0;
}
bool SkRRect::isValid() const {
if (!AreRectAndRadiiValid(fRect, fRadii)) {
return false;
}
bool allRadiiZero = (0 == fRadii[0].fX && 0 == fRadii[0].fY);
bool allCornersSquare = (0 == fRadii[0].fX || 0 == fRadii[0].fY);
bool allRadiiSame = true;
for (int i = 1; i < 4; ++i) {
if (0 != fRadii[i].fX || 0 != fRadii[i].fY) {
allRadiiZero = false;
}
if (fRadii[i].fX != fRadii[i-1].fX || fRadii[i].fY != fRadii[i-1].fY) {
allRadiiSame = false;
}
if (0 != fRadii[i].fX && 0 != fRadii[i].fY) {
allCornersSquare = false;
}
}
bool patchesOfNine = radii_are_nine_patch(fRadii);
if (fType < 0 || fType > kLastType) {
return false;
}
switch (fType) {
case kEmpty_Type:
if (!fRect.isEmpty() || !allRadiiZero || !allRadiiSame || !allCornersSquare) {
return false;
}
break;
case kRect_Type:
if (fRect.isEmpty() || !allRadiiZero || !allRadiiSame || !allCornersSquare) {
return false;
}
break;
case kOval_Type:
if (fRect.isEmpty() || allRadiiZero || !allRadiiSame || allCornersSquare) {
return false;
}
for (int i = 0; i < 4; ++i) {
if (!SkScalarNearlyEqual(fRadii[i].fX, SkScalarHalf(fRect.width())) ||
!SkScalarNearlyEqual(fRadii[i].fY, SkScalarHalf(fRect.height()))) {
return false;
}
}
break;
case kSimple_Type:
if (fRect.isEmpty() || allRadiiZero || !allRadiiSame || allCornersSquare) {
return false;
}
break;
case kNinePatch_Type:
if (fRect.isEmpty() || allRadiiZero || allRadiiSame || allCornersSquare ||
!patchesOfNine) {
return false;
}
break;
case kComplex_Type:
if (fRect.isEmpty() || allRadiiZero || allRadiiSame || allCornersSquare ||
patchesOfNine) {
return false;
}
break;
}
return true;
}
bool SkRRect::AreRectAndRadiiValid(const SkRect& rect, const SkVector radii[4]) {
if (!rect.isFinite() || !rect.isSorted()) {
return false;
}
for (int i = 0; i < 4; ++i) {
if (!are_radius_check_predicates_valid(radii[i].fX, rect.fLeft, rect.fRight) ||
!are_radius_check_predicates_valid(radii[i].fY, rect.fTop, rect.fBottom)) {
return false;
}
}
return true;
}
///////////////////////////////////////////////////////////////////////////////