/*
* 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 "SkRRect.h"
#include "SkMatrix.h"
///////////////////////////////////////////////////////////////////////////////
void SkRRect::setRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad) {
if (rect.isEmpty()) {
this->setEmpty();
return;
}
if (xRad <= 0 || yRad <= 0) {
// all corners are square in this case
this->setRect(rect);
return;
}
if (rect.width() < xRad+xRad || rect.height() < yRad+yRad) {
SkScalar scale = SkMinScalar(SkScalarDiv(rect.width(), xRad + xRad),
SkScalarDiv(rect.height(), yRad + yRad));
SkASSERT(scale < SK_Scalar1);
xRad = SkScalarMul(xRad, scale);
yRad = SkScalarMul(yRad, scale);
}
fRect = rect;
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
}
SkDEBUGCODE(this->validate();)
}
void SkRRect::setRectRadii(const SkRect& rect, const SkVector radii[4]) {
if (rect.isEmpty()) {
this->setEmpty();
return;
}
fRect = rect;
memcpy(fRadii, radii, sizeof(fRadii));
bool allCornersSquare = true;
// Clamp negative radii to zero
for (int i = 0; i < 4; ++i) {
if (fRadii[i].fX <= 0 || fRadii[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.
fRadii[i].fX = 0;
fRadii[i].fY = 0;
} else {
allCornersSquare = false;
}
}
if (allCornersSquare) {
this->setRect(rect);
return;
}
// 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."
SkScalar scale = SK_Scalar1;
if (fRadii[0].fX + fRadii[1].fX > rect.width()) {
scale = SkMinScalar(scale,
SkScalarDiv(rect.width(), fRadii[0].fX + fRadii[1].fX));
}
if (fRadii[1].fY + fRadii[2].fY > rect.height()) {
scale = SkMinScalar(scale,
SkScalarDiv(rect.height(), fRadii[1].fY + fRadii[2].fY));
}
if (fRadii[2].fX + fRadii[3].fX > rect.width()) {
scale = SkMinScalar(scale,
SkScalarDiv(rect.width(), fRadii[2].fX + fRadii[3].fX));
}
if (fRadii[3].fY + fRadii[0].fY > rect.height()) {
scale = SkMinScalar(scale,
SkScalarDiv(rect.height(), fRadii[3].fY + fRadii[0].fY));
}
if (scale < SK_Scalar1) {
for (int i = 0; i < 4; ++i) {
fRadii[i].fX = SkScalarMul(fRadii[i].fX, scale);
fRadii[i].fY = SkScalarMul(fRadii[i].fY, scale);
}
}
// At this point we're either oval, simple, or complex (not empty or rect)
// but we lazily resolve the type to avoid the work if the information
// isn't required.
fType = (SkRRect::Type) kUnknown_Type;
SkDEBUGCODE(this->validate();)
}
// 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 = SkScalarMul(SkScalarSquare(canonicalPt.fX), SkScalarSquare(fRadii[index].fY)) +
SkScalarMul(SkScalarSquare(canonicalPt.fY), SkScalarSquare(fRadii[index].fX));
return dist <= SkScalarSquare(SkScalarMul(fRadii[index].fX, fRadii[index].fY));
}
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);
}
// There is a simplified version of this method in setRectXY
void SkRRect::computeType() const {
SkDEBUGCODE(this->validate();)
if (fRect.isEmpty()) {
fType = kEmpty_Type;
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;
return;
}
if (allRadiiEqual) {
if (fRadii[0].fX >= SkScalarHalf(fRect.width()) &&
fRadii[0].fY >= SkScalarHalf(fRect.height())) {
fType = kOval_Type;
} else {
fType = kSimple_Type;
}
return;
}
fType = kComplex_Type;
}
static bool matrix_only_scale_and_translate(const SkMatrix& matrix) {
const SkMatrix::TypeMask m = (SkMatrix::TypeMask) (SkMatrix::kAffine_Mask
| SkMatrix::kPerspective_Mask);
return (matrix.getType() & m) == 0;
}
bool SkRRect::transform(const SkMatrix& matrix, SkRRect* dst) const {
if (NULL == 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_only_scale_and_translate(matrix)) {
return false;
}
SkRect newRect;
if (!matrix.mapRect(&newRect, fRect)) {
return false;
}
// At this point, this is guaranteed to succeed, so we can modify dst.
dst->fRect = newRect;
// 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 = SkScalarMul(fRadii[i].fX, xScale);
dst->fRadii[i].fY = SkScalarMul(fRadii[i].fY, yScale);
}
// Now swap as necessary.
if (flipX) {
if (flipY) {
// Swap with opposite corners
SkTSwap(dst->fRadii[kUpperLeft_Corner], dst->fRadii[kLowerRight_Corner]);
SkTSwap(dst->fRadii[kUpperRight_Corner], dst->fRadii[kLowerLeft_Corner]);
} else {
// Only swap in x
SkTSwap(dst->fRadii[kUpperRight_Corner], dst->fRadii[kUpperLeft_Corner]);
SkTSwap(dst->fRadii[kLowerRight_Corner], dst->fRadii[kLowerLeft_Corner]);
}
} else if (flipY) {
// Only swap in y
SkTSwap(dst->fRadii[kUpperLeft_Corner], dst->fRadii[kLowerLeft_Corner]);
SkTSwap(dst->fRadii[kUpperRight_Corner], dst->fRadii[kLowerRight_Corner]);
}
// Since the only transforms that were allowed are scale and translate, the type
// remains unchanged.
dst->fType = fType;
SkDEBUGCODE(dst->validate();)
return true;
}
///////////////////////////////////////////////////////////////////////////////
void SkRRect::inset(SkScalar dx, SkScalar dy, SkRRect* dst) const {
SkRect r = fRect;
r.inset(dx, dy);
if (r.isEmpty()) {
dst->setEmpty();
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 {
SkASSERT(kSizeInMemory == sizeof(SkRect) + sizeof(fRadii));
memcpy(buffer, &fRect, sizeof(SkRect));
memcpy((char*)buffer + sizeof(SkRect), fRadii, sizeof(fRadii));
return kSizeInMemory;
}
size_t SkRRect::readFromMemory(const void* buffer, size_t length) {
if (length < kSizeInMemory) {
return 0;
}
SkScalar storage[12];
SkASSERT(sizeof(storage) == kSizeInMemory);
// we make a local copy, to ensure alignment before we cast
memcpy(storage, buffer, kSizeInMemory);
this->setRectRadii(*(const SkRect*)&storage[0],
(const SkVector*)&storage[4]);
return kSizeInMemory;
}
///////////////////////////////////////////////////////////////////////////////
#ifdef SK_DEBUG
void SkRRect::validate() const {
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;
}
}
switch (fType) {
case kEmpty_Type:
SkASSERT(fRect.isEmpty());
SkASSERT(allRadiiZero && allRadiiSame && allCornersSquare);
SkASSERT(0 == fRect.fLeft && 0 == fRect.fTop &&
0 == fRect.fRight && 0 == fRect.fBottom);
break;
case kRect_Type:
SkASSERT(!fRect.isEmpty());
SkASSERT(allRadiiZero && allRadiiSame && allCornersSquare);
break;
case kOval_Type:
SkASSERT(!fRect.isEmpty());
SkASSERT(!allRadiiZero && allRadiiSame && !allCornersSquare);
for (int i = 0; i < 4; ++i) {
SkASSERT(SkScalarNearlyEqual(fRadii[i].fX, SkScalarHalf(fRect.width())));
SkASSERT(SkScalarNearlyEqual(fRadii[i].fY, SkScalarHalf(fRect.height())));
}
break;
case kSimple_Type:
SkASSERT(!fRect.isEmpty());
SkASSERT(!allRadiiZero && allRadiiSame && !allCornersSquare);
break;
case kComplex_Type:
SkASSERT(!fRect.isEmpty());
SkASSERT(!allRadiiZero && !allRadiiSame && !allCornersSquare);
break;
case kUnknown_Type:
// no limits on this
break;
}
}
#endif // SK_DEBUG
///////////////////////////////////////////////////////////////////////////////