|  | /* | 
|  | * Copyright 2006 The Android Open Source Project | 
|  | * | 
|  | * Use of this source code is governed by a BSD-style license that can be | 
|  | * found in the LICENSE file. | 
|  | */ | 
|  |  | 
|  | #include "SkMatrix.h" | 
|  | #include "SkFloatBits.h" | 
|  | #include "SkString.h" | 
|  |  | 
|  | #include <stddef.h> | 
|  |  | 
|  | // In a few places, we performed the following | 
|  | //      a * b + c * d + e | 
|  | // as | 
|  | //      a * b + (c * d + e) | 
|  | // | 
|  | // sdot and scross are indended to capture these compound operations into a | 
|  | // function, with an eye toward considering upscaling the intermediates to | 
|  | // doubles for more precision (as we do in concat and invert). | 
|  | // | 
|  | // However, these few lines that performed the last add before the "dot", cause | 
|  | // tiny image differences, so we guard that change until we see the impact on | 
|  | // chrome's layouttests. | 
|  | // | 
|  | #define SK_LEGACY_MATRIX_MATH_ORDER | 
|  |  | 
|  | static inline float SkDoubleToFloat(double x) { | 
|  | return static_cast<float>(x); | 
|  | } | 
|  |  | 
|  | /*      [scale-x    skew-x      trans-x]   [X]   [X'] | 
|  | [skew-y     scale-y     trans-y] * [Y] = [Y'] | 
|  | [persp-0    persp-1     persp-2]   [1]   [1 ] | 
|  | */ | 
|  |  | 
|  | void SkMatrix::reset() { | 
|  | fMat[kMScaleX] = fMat[kMScaleY] = fMat[kMPersp2] = 1; | 
|  | fMat[kMSkewX]  = fMat[kMSkewY] = | 
|  | fMat[kMTransX] = fMat[kMTransY] = | 
|  | fMat[kMPersp0] = fMat[kMPersp1] = 0; | 
|  |  | 
|  | this->setTypeMask(kIdentity_Mask | kRectStaysRect_Mask); | 
|  | } | 
|  |  | 
|  | // this guy aligns with the masks, so we can compute a mask from a varaible 0/1 | 
|  | enum { | 
|  | kTranslate_Shift, | 
|  | kScale_Shift, | 
|  | kAffine_Shift, | 
|  | kPerspective_Shift, | 
|  | kRectStaysRect_Shift | 
|  | }; | 
|  |  | 
|  | static const int32_t kScalar1Int = 0x3f800000; | 
|  |  | 
|  | uint8_t SkMatrix::computePerspectiveTypeMask() const { | 
|  | // Benchmarking suggests that replacing this set of SkScalarAs2sCompliment | 
|  | // is a win, but replacing those below is not. We don't yet understand | 
|  | // that result. | 
|  | if (fMat[kMPersp0] != 0 || fMat[kMPersp1] != 0 || fMat[kMPersp2] != 1) { | 
|  | // If this is a perspective transform, we return true for all other | 
|  | // transform flags - this does not disable any optimizations, respects | 
|  | // the rule that the type mask must be conservative, and speeds up | 
|  | // type mask computation. | 
|  | return SkToU8(kORableMasks); | 
|  | } | 
|  |  | 
|  | return SkToU8(kOnlyPerspectiveValid_Mask | kUnknown_Mask); | 
|  | } | 
|  |  | 
|  | uint8_t SkMatrix::computeTypeMask() const { | 
|  | unsigned mask = 0; | 
|  |  | 
|  | if (fMat[kMPersp0] != 0 || fMat[kMPersp1] != 0 || fMat[kMPersp2] != 1) { | 
|  | // Once it is determined that that this is a perspective transform, | 
|  | // all other flags are moot as far as optimizations are concerned. | 
|  | return SkToU8(kORableMasks); | 
|  | } | 
|  |  | 
|  | if (fMat[kMTransX] != 0 || fMat[kMTransY] != 0) { | 
|  | mask |= kTranslate_Mask; | 
|  | } | 
|  |  | 
|  | int m00 = SkScalarAs2sCompliment(fMat[SkMatrix::kMScaleX]); | 
|  | int m01 = SkScalarAs2sCompliment(fMat[SkMatrix::kMSkewX]); | 
|  | int m10 = SkScalarAs2sCompliment(fMat[SkMatrix::kMSkewY]); | 
|  | int m11 = SkScalarAs2sCompliment(fMat[SkMatrix::kMScaleY]); | 
|  |  | 
|  | if (m01 | m10) { | 
|  | // The skew components may be scale-inducing, unless we are dealing | 
|  | // with a pure rotation.  Testing for a pure rotation is expensive, | 
|  | // so we opt for being conservative by always setting the scale bit. | 
|  | // along with affine. | 
|  | // By doing this, we are also ensuring that matrices have the same | 
|  | // type masks as their inverses. | 
|  | mask |= kAffine_Mask | kScale_Mask; | 
|  |  | 
|  | // For rectStaysRect, in the affine case, we only need check that | 
|  | // the primary diagonal is all zeros and that the secondary diagonal | 
|  | // is all non-zero. | 
|  |  | 
|  | // map non-zero to 1 | 
|  | m01 = m01 != 0; | 
|  | m10 = m10 != 0; | 
|  |  | 
|  | int dp0 = 0 == (m00 | m11) ;  // true if both are 0 | 
|  | int ds1 = m01 & m10;        // true if both are 1 | 
|  |  | 
|  | mask |= (dp0 & ds1) << kRectStaysRect_Shift; | 
|  | } else { | 
|  | // Only test for scale explicitly if not affine, since affine sets the | 
|  | // scale bit. | 
|  | if ((m00 - kScalar1Int) | (m11 - kScalar1Int)) { | 
|  | mask |= kScale_Mask; | 
|  | } | 
|  |  | 
|  | // Not affine, therefore we already know secondary diagonal is | 
|  | // all zeros, so we just need to check that primary diagonal is | 
|  | // all non-zero. | 
|  |  | 
|  | // map non-zero to 1 | 
|  | m00 = m00 != 0; | 
|  | m11 = m11 != 0; | 
|  |  | 
|  | // record if the (p)rimary diagonal is all non-zero | 
|  | mask |= (m00 & m11) << kRectStaysRect_Shift; | 
|  | } | 
|  |  | 
|  | return SkToU8(mask); | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | bool operator==(const SkMatrix& a, const SkMatrix& b) { | 
|  | const SkScalar* SK_RESTRICT ma = a.fMat; | 
|  | const SkScalar* SK_RESTRICT mb = b.fMat; | 
|  |  | 
|  | return  ma[0] == mb[0] && ma[1] == mb[1] && ma[2] == mb[2] && | 
|  | ma[3] == mb[3] && ma[4] == mb[4] && ma[5] == mb[5] && | 
|  | ma[6] == mb[6] && ma[7] == mb[7] && ma[8] == mb[8]; | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | // helper function to determine if upper-left 2x2 of matrix is degenerate | 
|  | static inline bool is_degenerate_2x2(SkScalar scaleX, SkScalar skewX, | 
|  | SkScalar skewY,  SkScalar scaleY) { | 
|  | SkScalar perp_dot = scaleX*scaleY - skewX*skewY; | 
|  | return SkScalarNearlyZero(perp_dot, SK_ScalarNearlyZero*SK_ScalarNearlyZero); | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | bool SkMatrix::isSimilarity(SkScalar tol) const { | 
|  | // if identity or translate matrix | 
|  | TypeMask mask = this->getType(); | 
|  | if (mask <= kTranslate_Mask) { | 
|  | return true; | 
|  | } | 
|  | if (mask & kPerspective_Mask) { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | SkScalar mx = fMat[kMScaleX]; | 
|  | SkScalar my = fMat[kMScaleY]; | 
|  | // if no skew, can just compare scale factors | 
|  | if (!(mask & kAffine_Mask)) { | 
|  | return !SkScalarNearlyZero(mx) && SkScalarNearlyEqual(SkScalarAbs(mx), SkScalarAbs(my)); | 
|  | } | 
|  | SkScalar sx = fMat[kMSkewX]; | 
|  | SkScalar sy = fMat[kMSkewY]; | 
|  |  | 
|  | if (is_degenerate_2x2(mx, sx, sy, my)) { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | // it has scales and skews, but it could also be rotation, check it out. | 
|  | SkVector vec[2]; | 
|  | vec[0].set(mx, sx); | 
|  | vec[1].set(sy, my); | 
|  |  | 
|  | return SkScalarNearlyZero(vec[0].dot(vec[1]), SkScalarSquare(tol)) && | 
|  | SkScalarNearlyEqual(vec[0].lengthSqd(), vec[1].lengthSqd(), | 
|  | SkScalarSquare(tol)); | 
|  | } | 
|  |  | 
|  | bool SkMatrix::preservesRightAngles(SkScalar tol) const { | 
|  | TypeMask mask = this->getType(); | 
|  |  | 
|  | if (mask <= (SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask)) { | 
|  | // identity, translate and/or scale | 
|  | return true; | 
|  | } | 
|  | if (mask & kPerspective_Mask) { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | SkASSERT(mask & kAffine_Mask); | 
|  |  | 
|  | SkScalar mx = fMat[kMScaleX]; | 
|  | SkScalar my = fMat[kMScaleY]; | 
|  | SkScalar sx = fMat[kMSkewX]; | 
|  | SkScalar sy = fMat[kMSkewY]; | 
|  |  | 
|  | if (is_degenerate_2x2(mx, sx, sy, my)) { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | // it has scales and skews, but it could also be rotation, check it out. | 
|  | SkVector vec[2]; | 
|  | vec[0].set(mx, sx); | 
|  | vec[1].set(sy, my); | 
|  |  | 
|  | return SkScalarNearlyZero(vec[0].dot(vec[1]), SkScalarSquare(tol)) && | 
|  | SkScalarNearlyEqual(vec[0].lengthSqd(), vec[1].lengthSqd(), | 
|  | SkScalarSquare(tol)); | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | static inline SkScalar sdot(SkScalar a, SkScalar b, SkScalar c, SkScalar d) { | 
|  | return a * b + c * d; | 
|  | } | 
|  |  | 
|  | static inline SkScalar sdot(SkScalar a, SkScalar b, SkScalar c, SkScalar d, | 
|  | SkScalar e, SkScalar f) { | 
|  | return a * b + c * d + e * f; | 
|  | } | 
|  |  | 
|  | static inline SkScalar scross(SkScalar a, SkScalar b, SkScalar c, SkScalar d) { | 
|  | return a * b - c * d; | 
|  | } | 
|  |  | 
|  | void SkMatrix::setTranslate(SkScalar dx, SkScalar dy) { | 
|  | if (dx || dy) { | 
|  | fMat[kMTransX] = dx; | 
|  | fMat[kMTransY] = dy; | 
|  |  | 
|  | fMat[kMScaleX] = fMat[kMScaleY] = fMat[kMPersp2] = 1; | 
|  | fMat[kMSkewX]  = fMat[kMSkewY] = | 
|  | fMat[kMPersp0] = fMat[kMPersp1] = 0; | 
|  |  | 
|  | this->setTypeMask(kTranslate_Mask | kRectStaysRect_Mask); | 
|  | } else { | 
|  | this->reset(); | 
|  | } | 
|  | } | 
|  |  | 
|  | void SkMatrix::preTranslate(SkScalar dx, SkScalar dy) { | 
|  | if (!dx && !dy) { | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (this->hasPerspective()) { | 
|  | SkMatrix    m; | 
|  | m.setTranslate(dx, dy); | 
|  | this->preConcat(m); | 
|  | } else { | 
|  | fMat[kMTransX] += sdot(fMat[kMScaleX], dx, fMat[kMSkewX], dy); | 
|  | fMat[kMTransY] += sdot(fMat[kMSkewY], dx, fMat[kMScaleY], dy); | 
|  | this->setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask); | 
|  | } | 
|  | } | 
|  |  | 
|  | void SkMatrix::postTranslate(SkScalar dx, SkScalar dy) { | 
|  | if (!dx && !dy) { | 
|  | return; | 
|  | } | 
|  |  | 
|  | if (this->hasPerspective()) { | 
|  | SkMatrix    m; | 
|  | m.setTranslate(dx, dy); | 
|  | this->postConcat(m); | 
|  | } else { | 
|  | fMat[kMTransX] += dx; | 
|  | fMat[kMTransY] += dy; | 
|  | this->setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask); | 
|  | } | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | void SkMatrix::setScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) { | 
|  | if (1 == sx && 1 == sy) { | 
|  | this->reset(); | 
|  | } else { | 
|  | fMat[kMScaleX] = sx; | 
|  | fMat[kMScaleY] = sy; | 
|  | fMat[kMTransX] = px - sx * px; | 
|  | fMat[kMTransY] = py - sy * py; | 
|  | fMat[kMPersp2] = 1; | 
|  |  | 
|  | fMat[kMSkewX]  = fMat[kMSkewY] = | 
|  | fMat[kMPersp0] = fMat[kMPersp1] = 0; | 
|  |  | 
|  | this->setTypeMask(kScale_Mask | kTranslate_Mask | kRectStaysRect_Mask); | 
|  | } | 
|  | } | 
|  |  | 
|  | void SkMatrix::setScale(SkScalar sx, SkScalar sy) { | 
|  | if (1 == sx && 1 == sy) { | 
|  | this->reset(); | 
|  | } else { | 
|  | fMat[kMScaleX] = sx; | 
|  | fMat[kMScaleY] = sy; | 
|  | fMat[kMPersp2] = 1; | 
|  |  | 
|  | fMat[kMTransX] = fMat[kMTransY] = | 
|  | fMat[kMSkewX]  = fMat[kMSkewY] = | 
|  | fMat[kMPersp0] = fMat[kMPersp1] = 0; | 
|  |  | 
|  | this->setTypeMask(kScale_Mask | kRectStaysRect_Mask); | 
|  | } | 
|  | } | 
|  |  | 
|  | bool SkMatrix::setIDiv(int divx, int divy) { | 
|  | if (!divx || !divy) { | 
|  | return false; | 
|  | } | 
|  | this->setScale(SkScalarInvert(divx), SkScalarInvert(divy)); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | void SkMatrix::preScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) { | 
|  | if (1 == sx && 1 == sy) { | 
|  | return; | 
|  | } | 
|  |  | 
|  | SkMatrix    m; | 
|  | m.setScale(sx, sy, px, py); | 
|  | this->preConcat(m); | 
|  | } | 
|  |  | 
|  | void SkMatrix::preScale(SkScalar sx, SkScalar sy) { | 
|  | if (1 == sx && 1 == sy) { | 
|  | return; | 
|  | } | 
|  |  | 
|  | // the assumption is that these multiplies are very cheap, and that | 
|  | // a full concat and/or just computing the matrix type is more expensive. | 
|  | // Also, the fixed-point case checks for overflow, but the float doesn't, | 
|  | // so we can get away with these blind multiplies. | 
|  |  | 
|  | fMat[kMScaleX] *= sx; | 
|  | fMat[kMSkewY]  *= sx; | 
|  | fMat[kMPersp0] *= sx; | 
|  |  | 
|  | fMat[kMSkewX]  *= sy; | 
|  | fMat[kMScaleY] *= sy; | 
|  | fMat[kMPersp1] *= sy; | 
|  |  | 
|  | this->orTypeMask(kScale_Mask); | 
|  | } | 
|  |  | 
|  | void SkMatrix::postScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) { | 
|  | if (1 == sx && 1 == sy) { | 
|  | return; | 
|  | } | 
|  | SkMatrix    m; | 
|  | m.setScale(sx, sy, px, py); | 
|  | this->postConcat(m); | 
|  | } | 
|  |  | 
|  | void SkMatrix::postScale(SkScalar sx, SkScalar sy) { | 
|  | if (1 == sx && 1 == sy) { | 
|  | return; | 
|  | } | 
|  | SkMatrix    m; | 
|  | m.setScale(sx, sy); | 
|  | this->postConcat(m); | 
|  | } | 
|  |  | 
|  | // this guy perhaps can go away, if we have a fract/high-precision way to | 
|  | // scale matrices | 
|  | bool SkMatrix::postIDiv(int divx, int divy) { | 
|  | if (divx == 0 || divy == 0) { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | const float invX = 1.f / divx; | 
|  | const float invY = 1.f / divy; | 
|  |  | 
|  | fMat[kMScaleX] *= invX; | 
|  | fMat[kMSkewX]  *= invX; | 
|  | fMat[kMTransX] *= invX; | 
|  |  | 
|  | fMat[kMScaleY] *= invY; | 
|  | fMat[kMSkewY]  *= invY; | 
|  | fMat[kMTransY] *= invY; | 
|  |  | 
|  | this->setTypeMask(kUnknown_Mask); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | //////////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | void SkMatrix::setSinCos(SkScalar sinV, SkScalar cosV, | 
|  | SkScalar px, SkScalar py) { | 
|  | const SkScalar oneMinusCosV = 1 - cosV; | 
|  |  | 
|  | fMat[kMScaleX]  = cosV; | 
|  | fMat[kMSkewX]   = -sinV; | 
|  | fMat[kMTransX]  = sdot(sinV, py, oneMinusCosV, px); | 
|  |  | 
|  | fMat[kMSkewY]   = sinV; | 
|  | fMat[kMScaleY]  = cosV; | 
|  | fMat[kMTransY]  = sdot(-sinV, px, oneMinusCosV, py); | 
|  |  | 
|  | fMat[kMPersp0] = fMat[kMPersp1] = 0; | 
|  | fMat[kMPersp2] = 1; | 
|  |  | 
|  | this->setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask); | 
|  | } | 
|  |  | 
|  | void SkMatrix::setSinCos(SkScalar sinV, SkScalar cosV) { | 
|  | fMat[kMScaleX]  = cosV; | 
|  | fMat[kMSkewX]   = -sinV; | 
|  | fMat[kMTransX]  = 0; | 
|  |  | 
|  | fMat[kMSkewY]   = sinV; | 
|  | fMat[kMScaleY]  = cosV; | 
|  | fMat[kMTransY]  = 0; | 
|  |  | 
|  | fMat[kMPersp0] = fMat[kMPersp1] = 0; | 
|  | fMat[kMPersp2] = 1; | 
|  |  | 
|  | this->setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask); | 
|  | } | 
|  |  | 
|  | void SkMatrix::setRotate(SkScalar degrees, SkScalar px, SkScalar py) { | 
|  | SkScalar sinV, cosV; | 
|  | sinV = SkScalarSinCos(SkDegreesToRadians(degrees), &cosV); | 
|  | this->setSinCos(sinV, cosV, px, py); | 
|  | } | 
|  |  | 
|  | void SkMatrix::setRotate(SkScalar degrees) { | 
|  | SkScalar sinV, cosV; | 
|  | sinV = SkScalarSinCos(SkDegreesToRadians(degrees), &cosV); | 
|  | this->setSinCos(sinV, cosV); | 
|  | } | 
|  |  | 
|  | void SkMatrix::preRotate(SkScalar degrees, SkScalar px, SkScalar py) { | 
|  | SkMatrix    m; | 
|  | m.setRotate(degrees, px, py); | 
|  | this->preConcat(m); | 
|  | } | 
|  |  | 
|  | void SkMatrix::preRotate(SkScalar degrees) { | 
|  | SkMatrix    m; | 
|  | m.setRotate(degrees); | 
|  | this->preConcat(m); | 
|  | } | 
|  |  | 
|  | void SkMatrix::postRotate(SkScalar degrees, SkScalar px, SkScalar py) { | 
|  | SkMatrix    m; | 
|  | m.setRotate(degrees, px, py); | 
|  | this->postConcat(m); | 
|  | } | 
|  |  | 
|  | void SkMatrix::postRotate(SkScalar degrees) { | 
|  | SkMatrix    m; | 
|  | m.setRotate(degrees); | 
|  | this->postConcat(m); | 
|  | } | 
|  |  | 
|  | //////////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | void SkMatrix::setSkew(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) { | 
|  | fMat[kMScaleX]  = 1; | 
|  | fMat[kMSkewX]   = sx; | 
|  | fMat[kMTransX]  = -sx * py; | 
|  |  | 
|  | fMat[kMSkewY]   = sy; | 
|  | fMat[kMScaleY]  = 1; | 
|  | fMat[kMTransY]  = -sy * px; | 
|  |  | 
|  | fMat[kMPersp0] = fMat[kMPersp1] = 0; | 
|  | fMat[kMPersp2] = 1; | 
|  |  | 
|  | this->setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask); | 
|  | } | 
|  |  | 
|  | void SkMatrix::setSkew(SkScalar sx, SkScalar sy) { | 
|  | fMat[kMScaleX]  = 1; | 
|  | fMat[kMSkewX]   = sx; | 
|  | fMat[kMTransX]  = 0; | 
|  |  | 
|  | fMat[kMSkewY]   = sy; | 
|  | fMat[kMScaleY]  = 1; | 
|  | fMat[kMTransY]  = 0; | 
|  |  | 
|  | fMat[kMPersp0] = fMat[kMPersp1] = 0; | 
|  | fMat[kMPersp2] = 1; | 
|  |  | 
|  | this->setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask); | 
|  | } | 
|  |  | 
|  | void SkMatrix::preSkew(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) { | 
|  | SkMatrix    m; | 
|  | m.setSkew(sx, sy, px, py); | 
|  | this->preConcat(m); | 
|  | } | 
|  |  | 
|  | void SkMatrix::preSkew(SkScalar sx, SkScalar sy) { | 
|  | SkMatrix    m; | 
|  | m.setSkew(sx, sy); | 
|  | this->preConcat(m); | 
|  | } | 
|  |  | 
|  | void SkMatrix::postSkew(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) { | 
|  | SkMatrix    m; | 
|  | m.setSkew(sx, sy, px, py); | 
|  | this->postConcat(m); | 
|  | } | 
|  |  | 
|  | void SkMatrix::postSkew(SkScalar sx, SkScalar sy) { | 
|  | SkMatrix    m; | 
|  | m.setSkew(sx, sy); | 
|  | this->postConcat(m); | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | bool SkMatrix::setRectToRect(const SkRect& src, const SkRect& dst, | 
|  | ScaleToFit align) | 
|  | { | 
|  | if (src.isEmpty()) { | 
|  | this->reset(); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | if (dst.isEmpty()) { | 
|  | sk_bzero(fMat, 8 * sizeof(SkScalar)); | 
|  | this->setTypeMask(kScale_Mask | kRectStaysRect_Mask); | 
|  | } else { | 
|  | SkScalar    tx, sx = dst.width() / src.width(); | 
|  | SkScalar    ty, sy = dst.height() / src.height(); | 
|  | bool        xLarger = false; | 
|  |  | 
|  | if (align != kFill_ScaleToFit) { | 
|  | if (sx > sy) { | 
|  | xLarger = true; | 
|  | sx = sy; | 
|  | } else { | 
|  | sy = sx; | 
|  | } | 
|  | } | 
|  |  | 
|  | tx = dst.fLeft - src.fLeft * sx; | 
|  | ty = dst.fTop - src.fTop * sy; | 
|  | if (align == kCenter_ScaleToFit || align == kEnd_ScaleToFit) { | 
|  | SkScalar diff; | 
|  |  | 
|  | if (xLarger) { | 
|  | diff = dst.width() - src.width() * sy; | 
|  | } else { | 
|  | diff = dst.height() - src.height() * sy; | 
|  | } | 
|  |  | 
|  | if (align == kCenter_ScaleToFit) { | 
|  | diff = SkScalarHalf(diff); | 
|  | } | 
|  |  | 
|  | if (xLarger) { | 
|  | tx += diff; | 
|  | } else { | 
|  | ty += diff; | 
|  | } | 
|  | } | 
|  |  | 
|  | fMat[kMScaleX] = sx; | 
|  | fMat[kMScaleY] = sy; | 
|  | fMat[kMTransX] = tx; | 
|  | fMat[kMTransY] = ty; | 
|  | fMat[kMSkewX]  = fMat[kMSkewY] = | 
|  | fMat[kMPersp0] = fMat[kMPersp1] = 0; | 
|  |  | 
|  | unsigned mask = kRectStaysRect_Mask; | 
|  | if (sx != 1 || sy != 1) { | 
|  | mask |= kScale_Mask; | 
|  | } | 
|  | if (tx || ty) { | 
|  | mask |= kTranslate_Mask; | 
|  | } | 
|  | this->setTypeMask(mask); | 
|  | } | 
|  | // shared cleanup | 
|  | fMat[kMPersp2] = 1; | 
|  | return true; | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | static inline float muladdmul(float a, float b, float c, float d) { | 
|  | return SkDoubleToFloat((double)a * b + (double)c * d); | 
|  | } | 
|  |  | 
|  | static inline float rowcol3(const float row[], const float col[]) { | 
|  | return row[0] * col[0] + row[1] * col[3] + row[2] * col[6]; | 
|  | } | 
|  |  | 
|  | static void normalize_perspective(SkScalar mat[9]) { | 
|  | if (SkScalarAbs(mat[SkMatrix::kMPersp2]) > 1) { | 
|  | for (int i = 0; i < 9; i++) | 
|  | mat[i] = SkScalarHalf(mat[i]); | 
|  | } | 
|  | } | 
|  |  | 
|  | void SkMatrix::setConcat(const SkMatrix& a, const SkMatrix& b) { | 
|  | TypeMask aType = a.getPerspectiveTypeMaskOnly(); | 
|  | TypeMask bType = b.getPerspectiveTypeMaskOnly(); | 
|  |  | 
|  | if (a.isTriviallyIdentity()) { | 
|  | *this = b; | 
|  | } else if (b.isTriviallyIdentity()) { | 
|  | *this = a; | 
|  | } else { | 
|  | SkMatrix tmp; | 
|  |  | 
|  | if ((aType | bType) & kPerspective_Mask) { | 
|  | tmp.fMat[kMScaleX] = rowcol3(&a.fMat[0], &b.fMat[0]); | 
|  | tmp.fMat[kMSkewX]  = rowcol3(&a.fMat[0], &b.fMat[1]); | 
|  | tmp.fMat[kMTransX] = rowcol3(&a.fMat[0], &b.fMat[2]); | 
|  | tmp.fMat[kMSkewY]  = rowcol3(&a.fMat[3], &b.fMat[0]); | 
|  | tmp.fMat[kMScaleY] = rowcol3(&a.fMat[3], &b.fMat[1]); | 
|  | tmp.fMat[kMTransY] = rowcol3(&a.fMat[3], &b.fMat[2]); | 
|  | tmp.fMat[kMPersp0] = rowcol3(&a.fMat[6], &b.fMat[0]); | 
|  | tmp.fMat[kMPersp1] = rowcol3(&a.fMat[6], &b.fMat[1]); | 
|  | tmp.fMat[kMPersp2] = rowcol3(&a.fMat[6], &b.fMat[2]); | 
|  |  | 
|  | normalize_perspective(tmp.fMat); | 
|  | tmp.setTypeMask(kUnknown_Mask); | 
|  | } else {    // not perspective | 
|  | tmp.fMat[kMScaleX] = muladdmul(a.fMat[kMScaleX], | 
|  | b.fMat[kMScaleX], | 
|  | a.fMat[kMSkewX], | 
|  | b.fMat[kMSkewY]); | 
|  |  | 
|  | tmp.fMat[kMSkewX]  = muladdmul(a.fMat[kMScaleX], | 
|  | b.fMat[kMSkewX], | 
|  | a.fMat[kMSkewX], | 
|  | b.fMat[kMScaleY]); | 
|  |  | 
|  | tmp.fMat[kMTransX] = muladdmul(a.fMat[kMScaleX], | 
|  | b.fMat[kMTransX], | 
|  | a.fMat[kMSkewX], | 
|  | b.fMat[kMTransY]); | 
|  |  | 
|  | tmp.fMat[kMTransX] += a.fMat[kMTransX]; | 
|  |  | 
|  | tmp.fMat[kMSkewY]  = muladdmul(a.fMat[kMSkewY], | 
|  | b.fMat[kMScaleX], | 
|  | a.fMat[kMScaleY], | 
|  | b.fMat[kMSkewY]); | 
|  |  | 
|  | tmp.fMat[kMScaleY] = muladdmul(a.fMat[kMSkewY], | 
|  | b.fMat[kMSkewX], | 
|  | a.fMat[kMScaleY], | 
|  | b.fMat[kMScaleY]); | 
|  |  | 
|  | tmp.fMat[kMTransY] = muladdmul(a.fMat[kMSkewY], | 
|  | b.fMat[kMTransX], | 
|  | a.fMat[kMScaleY], | 
|  | b.fMat[kMTransY]); | 
|  |  | 
|  | tmp.fMat[kMTransY] += a.fMat[kMTransY]; | 
|  | tmp.fMat[kMPersp0] = tmp.fMat[kMPersp1] = 0; | 
|  | tmp.fMat[kMPersp2] = 1; | 
|  | //SkDebugf("Concat mat non-persp type: %d\n", tmp.getType()); | 
|  | //SkASSERT(!(tmp.getType() & kPerspective_Mask)); | 
|  | tmp.setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask); | 
|  | } | 
|  | *this = tmp; | 
|  | } | 
|  | } | 
|  |  | 
|  | void SkMatrix::preConcat(const SkMatrix& mat) { | 
|  | // check for identity first, so we don't do a needless copy of ourselves | 
|  | // to ourselves inside setConcat() | 
|  | if(!mat.isIdentity()) { | 
|  | this->setConcat(*this, mat); | 
|  | } | 
|  | } | 
|  |  | 
|  | void SkMatrix::postConcat(const SkMatrix& mat) { | 
|  | // check for identity first, so we don't do a needless copy of ourselves | 
|  | // to ourselves inside setConcat() | 
|  | if (!mat.isIdentity()) { | 
|  | this->setConcat(mat, *this); | 
|  | } | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | /*  Matrix inversion is very expensive, but also the place where keeping | 
|  | precision may be most important (here and matrix concat). Hence to avoid | 
|  | bitmap blitting artifacts when walking the inverse, we use doubles for | 
|  | the intermediate math, even though we know that is more expensive. | 
|  | */ | 
|  |  | 
|  | static inline SkScalar scross_dscale(SkScalar a, SkScalar b, | 
|  | SkScalar c, SkScalar d, double scale) { | 
|  | return SkDoubleToScalar(scross(a, b, c, d) * scale); | 
|  | } | 
|  |  | 
|  | static inline double dcross(double a, double b, double c, double d) { | 
|  | return a * b - c * d; | 
|  | } | 
|  |  | 
|  | static inline SkScalar dcross_dscale(double a, double b, | 
|  | double c, double d, double scale) { | 
|  | return SkDoubleToScalar(dcross(a, b, c, d) * scale); | 
|  | } | 
|  |  | 
|  | static double sk_inv_determinant(const float mat[9], int isPerspective) { | 
|  | double det; | 
|  |  | 
|  | if (isPerspective) { | 
|  | det = mat[SkMatrix::kMScaleX] * | 
|  | dcross(mat[SkMatrix::kMScaleY], mat[SkMatrix::kMPersp2], | 
|  | mat[SkMatrix::kMTransY], mat[SkMatrix::kMPersp1]) | 
|  | + | 
|  | mat[SkMatrix::kMSkewX]  * | 
|  | dcross(mat[SkMatrix::kMTransY], mat[SkMatrix::kMPersp0], | 
|  | mat[SkMatrix::kMSkewY],  mat[SkMatrix::kMPersp2]) | 
|  | + | 
|  | mat[SkMatrix::kMTransX] * | 
|  | dcross(mat[SkMatrix::kMSkewY],  mat[SkMatrix::kMPersp1], | 
|  | mat[SkMatrix::kMScaleY], mat[SkMatrix::kMPersp0]); | 
|  | } else { | 
|  | det = dcross(mat[SkMatrix::kMScaleX], mat[SkMatrix::kMScaleY], | 
|  | mat[SkMatrix::kMSkewX], mat[SkMatrix::kMSkewY]); | 
|  | } | 
|  |  | 
|  | // Since the determinant is on the order of the cube of the matrix members, | 
|  | // compare to the cube of the default nearly-zero constant (although an | 
|  | // estimate of the condition number would be better if it wasn't so expensive). | 
|  | if (SkScalarNearlyZero((float)det, SK_ScalarNearlyZero * SK_ScalarNearlyZero * SK_ScalarNearlyZero)) { | 
|  | return 0; | 
|  | } | 
|  | return 1.0 / det; | 
|  | } | 
|  |  | 
|  | void SkMatrix::SetAffineIdentity(SkScalar affine[6]) { | 
|  | affine[kAScaleX] = 1; | 
|  | affine[kASkewY] = 0; | 
|  | affine[kASkewX] = 0; | 
|  | affine[kAScaleY] = 1; | 
|  | affine[kATransX] = 0; | 
|  | affine[kATransY] = 0; | 
|  | } | 
|  |  | 
|  | bool SkMatrix::asAffine(SkScalar affine[6]) const { | 
|  | if (this->hasPerspective()) { | 
|  | return false; | 
|  | } | 
|  | if (affine) { | 
|  | affine[kAScaleX] = this->fMat[kMScaleX]; | 
|  | affine[kASkewY] = this->fMat[kMSkewY]; | 
|  | affine[kASkewX] = this->fMat[kMSkewX]; | 
|  | affine[kAScaleY] = this->fMat[kMScaleY]; | 
|  | affine[kATransX] = this->fMat[kMTransX]; | 
|  | affine[kATransY] = this->fMat[kMTransY]; | 
|  | } | 
|  | return true; | 
|  | } | 
|  |  | 
|  | bool SkMatrix::invertNonIdentity(SkMatrix* inv) const { | 
|  | SkASSERT(!this->isIdentity()); | 
|  |  | 
|  | TypeMask mask = this->getType(); | 
|  |  | 
|  | if (0 == (mask & ~(kScale_Mask | kTranslate_Mask))) { | 
|  | bool invertible = true; | 
|  | if (inv) { | 
|  | if (mask & kScale_Mask) { | 
|  | SkScalar invX = fMat[kMScaleX]; | 
|  | SkScalar invY = fMat[kMScaleY]; | 
|  | if (0 == invX || 0 == invY) { | 
|  | return false; | 
|  | } | 
|  | invX = SkScalarInvert(invX); | 
|  | invY = SkScalarInvert(invY); | 
|  |  | 
|  | // Must be careful when writing to inv, since it may be the | 
|  | // same memory as this. | 
|  |  | 
|  | inv->fMat[kMSkewX] = inv->fMat[kMSkewY] = | 
|  | inv->fMat[kMPersp0] = inv->fMat[kMPersp1] = 0; | 
|  |  | 
|  | inv->fMat[kMScaleX] = invX; | 
|  | inv->fMat[kMScaleY] = invY; | 
|  | inv->fMat[kMPersp2] = 1; | 
|  | inv->fMat[kMTransX] = -fMat[kMTransX] * invX; | 
|  | inv->fMat[kMTransY] = -fMat[kMTransY] * invY; | 
|  |  | 
|  | inv->setTypeMask(mask | kRectStaysRect_Mask); | 
|  | } else { | 
|  | // translate only | 
|  | inv->setTranslate(-fMat[kMTransX], -fMat[kMTransY]); | 
|  | } | 
|  | } else {    // inv is NULL, just check if we're invertible | 
|  | if (!fMat[kMScaleX] || !fMat[kMScaleY]) { | 
|  | invertible = false; | 
|  | } | 
|  | } | 
|  | return invertible; | 
|  | } | 
|  |  | 
|  | int    isPersp = mask & kPerspective_Mask; | 
|  | double scale = sk_inv_determinant(fMat, isPersp); | 
|  |  | 
|  | if (scale == 0) { // underflow | 
|  | return false; | 
|  | } | 
|  |  | 
|  | if (inv) { | 
|  | SkMatrix tmp; | 
|  | if (inv == this) { | 
|  | inv = &tmp; | 
|  | } | 
|  |  | 
|  | if (isPersp) { | 
|  | inv->fMat[kMScaleX] = scross_dscale(fMat[kMScaleY], fMat[kMPersp2], fMat[kMTransY], fMat[kMPersp1], scale); | 
|  | inv->fMat[kMSkewX]  = scross_dscale(fMat[kMTransX], fMat[kMPersp1], fMat[kMSkewX],  fMat[kMPersp2], scale); | 
|  | inv->fMat[kMTransX] = scross_dscale(fMat[kMSkewX],  fMat[kMTransY], fMat[kMTransX], fMat[kMScaleY], scale); | 
|  |  | 
|  | inv->fMat[kMSkewY]  = scross_dscale(fMat[kMTransY], fMat[kMPersp0], fMat[kMSkewY],  fMat[kMPersp2], scale); | 
|  | inv->fMat[kMScaleY] = scross_dscale(fMat[kMScaleX], fMat[kMPersp2], fMat[kMTransX], fMat[kMPersp0], scale); | 
|  | inv->fMat[kMTransY] = scross_dscale(fMat[kMTransX], fMat[kMSkewY],  fMat[kMScaleX], fMat[kMTransY], scale); | 
|  |  | 
|  | inv->fMat[kMPersp0] = scross_dscale(fMat[kMSkewY],  fMat[kMPersp1], fMat[kMScaleY], fMat[kMPersp0], scale); | 
|  | inv->fMat[kMPersp1] = scross_dscale(fMat[kMSkewX],  fMat[kMPersp0], fMat[kMScaleX], fMat[kMPersp1], scale); | 
|  | inv->fMat[kMPersp2] = scross_dscale(fMat[kMScaleX], fMat[kMScaleY], fMat[kMSkewX],  fMat[kMSkewY],  scale); | 
|  | } else {   // not perspective | 
|  | inv->fMat[kMScaleX] = SkDoubleToScalar(fMat[kMScaleY] * scale); | 
|  | inv->fMat[kMSkewX]  = SkDoubleToScalar(-fMat[kMSkewX] * scale); | 
|  | inv->fMat[kMTransX] = dcross_dscale(fMat[kMSkewX], fMat[kMTransY], fMat[kMScaleY], fMat[kMTransX], scale); | 
|  |  | 
|  | inv->fMat[kMSkewY]  = SkDoubleToScalar(-fMat[kMSkewY] * scale); | 
|  | inv->fMat[kMScaleY] = SkDoubleToScalar(fMat[kMScaleX] * scale); | 
|  | inv->fMat[kMTransY] = dcross_dscale(fMat[kMSkewY], fMat[kMTransX], fMat[kMScaleX], fMat[kMTransY], scale); | 
|  |  | 
|  | inv->fMat[kMPersp0] = 0; | 
|  | inv->fMat[kMPersp1] = 0; | 
|  | inv->fMat[kMPersp2] = 1; | 
|  | } | 
|  |  | 
|  | inv->setTypeMask(fTypeMask); | 
|  |  | 
|  | if (inv == &tmp) { | 
|  | *(SkMatrix*)this = tmp; | 
|  | } | 
|  | } | 
|  | return true; | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | void SkMatrix::Identity_pts(const SkMatrix& m, SkPoint dst[], | 
|  | const SkPoint src[], int count) { | 
|  | SkASSERT(m.getType() == 0); | 
|  |  | 
|  | if (dst != src && count > 0) | 
|  | memcpy(dst, src, count * sizeof(SkPoint)); | 
|  | } | 
|  |  | 
|  | void SkMatrix::Trans_pts(const SkMatrix& m, SkPoint dst[], | 
|  | const SkPoint src[], int count) { | 
|  | SkASSERT(m.getType() == kTranslate_Mask); | 
|  |  | 
|  | if (count > 0) { | 
|  | SkScalar tx = m.fMat[kMTransX]; | 
|  | SkScalar ty = m.fMat[kMTransY]; | 
|  | do { | 
|  | dst->fY = src->fY + ty; | 
|  | dst->fX = src->fX + tx; | 
|  | src += 1; | 
|  | dst += 1; | 
|  | } while (--count); | 
|  | } | 
|  | } | 
|  |  | 
|  | void SkMatrix::Scale_pts(const SkMatrix& m, SkPoint dst[], | 
|  | const SkPoint src[], int count) { | 
|  | SkASSERT(m.getType() == kScale_Mask); | 
|  |  | 
|  | if (count > 0) { | 
|  | SkScalar mx = m.fMat[kMScaleX]; | 
|  | SkScalar my = m.fMat[kMScaleY]; | 
|  | do { | 
|  | dst->fY = src->fY * my; | 
|  | dst->fX = src->fX * mx; | 
|  | src += 1; | 
|  | dst += 1; | 
|  | } while (--count); | 
|  | } | 
|  | } | 
|  |  | 
|  | void SkMatrix::ScaleTrans_pts(const SkMatrix& m, SkPoint dst[], | 
|  | const SkPoint src[], int count) { | 
|  | SkASSERT(m.getType() == (kScale_Mask | kTranslate_Mask)); | 
|  |  | 
|  | if (count > 0) { | 
|  | SkScalar mx = m.fMat[kMScaleX]; | 
|  | SkScalar my = m.fMat[kMScaleY]; | 
|  | SkScalar tx = m.fMat[kMTransX]; | 
|  | SkScalar ty = m.fMat[kMTransY]; | 
|  | do { | 
|  | dst->fY = src->fY * my + ty; | 
|  | dst->fX = src->fX * mx + tx; | 
|  | src += 1; | 
|  | dst += 1; | 
|  | } while (--count); | 
|  | } | 
|  | } | 
|  |  | 
|  | void SkMatrix::Rot_pts(const SkMatrix& m, SkPoint dst[], | 
|  | const SkPoint src[], int count) { | 
|  | SkASSERT((m.getType() & (kPerspective_Mask | kTranslate_Mask)) == 0); | 
|  |  | 
|  | if (count > 0) { | 
|  | SkScalar mx = m.fMat[kMScaleX]; | 
|  | SkScalar my = m.fMat[kMScaleY]; | 
|  | SkScalar kx = m.fMat[kMSkewX]; | 
|  | SkScalar ky = m.fMat[kMSkewY]; | 
|  | do { | 
|  | SkScalar sy = src->fY; | 
|  | SkScalar sx = src->fX; | 
|  | src += 1; | 
|  | dst->fY = sdot(sx, ky, sy, my); | 
|  | dst->fX = sdot(sx, mx, sy, kx); | 
|  | dst += 1; | 
|  | } while (--count); | 
|  | } | 
|  | } | 
|  |  | 
|  | void SkMatrix::RotTrans_pts(const SkMatrix& m, SkPoint dst[], | 
|  | const SkPoint src[], int count) { | 
|  | SkASSERT(!m.hasPerspective()); | 
|  |  | 
|  | if (count > 0) { | 
|  | SkScalar mx = m.fMat[kMScaleX]; | 
|  | SkScalar my = m.fMat[kMScaleY]; | 
|  | SkScalar kx = m.fMat[kMSkewX]; | 
|  | SkScalar ky = m.fMat[kMSkewY]; | 
|  | SkScalar tx = m.fMat[kMTransX]; | 
|  | SkScalar ty = m.fMat[kMTransY]; | 
|  | do { | 
|  | SkScalar sy = src->fY; | 
|  | SkScalar sx = src->fX; | 
|  | src += 1; | 
|  | #ifdef SK_LEGACY_MATRIX_MATH_ORDER | 
|  | dst->fY = sx * ky + (sy * my + ty); | 
|  | dst->fX = sx * mx + (sy * kx + tx); | 
|  | #else | 
|  | dst->fY = sdot(sx, ky, sy, my) + ty; | 
|  | dst->fX = sdot(sx, mx, sy, kx) + tx; | 
|  | #endif | 
|  | dst += 1; | 
|  | } while (--count); | 
|  | } | 
|  | } | 
|  |  | 
|  | void SkMatrix::Persp_pts(const SkMatrix& m, SkPoint dst[], | 
|  | const SkPoint src[], int count) { | 
|  | SkASSERT(m.hasPerspective()); | 
|  |  | 
|  | if (count > 0) { | 
|  | do { | 
|  | SkScalar sy = src->fY; | 
|  | SkScalar sx = src->fX; | 
|  | src += 1; | 
|  |  | 
|  | SkScalar x = sdot(sx, m.fMat[kMScaleX], sy, m.fMat[kMSkewX])  + m.fMat[kMTransX]; | 
|  | SkScalar y = sdot(sx, m.fMat[kMSkewY],  sy, m.fMat[kMScaleY]) + m.fMat[kMTransY]; | 
|  | #ifdef SK_LEGACY_MATRIX_MATH_ORDER | 
|  | SkScalar z = sx * m.fMat[kMPersp0] + (sy * m.fMat[kMPersp1] + m.fMat[kMPersp2]); | 
|  | #else | 
|  | SkScalar z = sdot(sx, m.fMat[kMPersp0], sy, m.fMat[kMPersp1]) + m.fMat[kMPersp2]; | 
|  | #endif | 
|  | if (z) { | 
|  | z = SkScalarFastInvert(z); | 
|  | } | 
|  |  | 
|  | dst->fY = y * z; | 
|  | dst->fX = x * z; | 
|  | dst += 1; | 
|  | } while (--count); | 
|  | } | 
|  | } | 
|  |  | 
|  | const SkMatrix::MapPtsProc SkMatrix::gMapPtsProcs[] = { | 
|  | SkMatrix::Identity_pts, SkMatrix::Trans_pts, | 
|  | SkMatrix::Scale_pts,    SkMatrix::ScaleTrans_pts, | 
|  | SkMatrix::Rot_pts,      SkMatrix::RotTrans_pts, | 
|  | SkMatrix::Rot_pts,      SkMatrix::RotTrans_pts, | 
|  | // repeat the persp proc 8 times | 
|  | SkMatrix::Persp_pts,    SkMatrix::Persp_pts, | 
|  | SkMatrix::Persp_pts,    SkMatrix::Persp_pts, | 
|  | SkMatrix::Persp_pts,    SkMatrix::Persp_pts, | 
|  | SkMatrix::Persp_pts,    SkMatrix::Persp_pts | 
|  | }; | 
|  |  | 
|  | void SkMatrix::mapPoints(SkPoint dst[], const SkPoint src[], int count) const { | 
|  | SkASSERT((dst && src && count > 0) || 0 == count); | 
|  | // no partial overlap | 
|  | SkASSERT(src == dst || &dst[count] <= &src[0] || &src[count] <= &dst[0]); | 
|  |  | 
|  | this->getMapPtsProc()(*this, dst, src, count); | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | void SkMatrix::mapHomogeneousPoints(SkScalar dst[], const SkScalar src[], int count) const { | 
|  | SkASSERT((dst && src && count > 0) || 0 == count); | 
|  | // no partial overlap | 
|  | SkASSERT(src == dst || SkAbs32((int32_t)(src - dst)) >= 3*count); | 
|  |  | 
|  | if (count > 0) { | 
|  | if (this->isIdentity()) { | 
|  | memcpy(dst, src, 3*count*sizeof(SkScalar)); | 
|  | return; | 
|  | } | 
|  | do { | 
|  | SkScalar sx = src[0]; | 
|  | SkScalar sy = src[1]; | 
|  | SkScalar sw = src[2]; | 
|  | src += 3; | 
|  |  | 
|  | SkScalar x = sdot(sx, fMat[kMScaleX], sy, fMat[kMSkewX],  sw, fMat[kMTransX]); | 
|  | SkScalar y = sdot(sx, fMat[kMSkewY],  sy, fMat[kMScaleY], sw, fMat[kMTransY]); | 
|  | SkScalar w = sdot(sx, fMat[kMPersp0], sy, fMat[kMPersp1], sw, fMat[kMPersp2]); | 
|  |  | 
|  | dst[0] = x; | 
|  | dst[1] = y; | 
|  | dst[2] = w; | 
|  | dst += 3; | 
|  | } while (--count); | 
|  | } | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | void SkMatrix::mapVectors(SkPoint dst[], const SkPoint src[], int count) const { | 
|  | if (this->hasPerspective()) { | 
|  | SkPoint origin; | 
|  |  | 
|  | MapXYProc proc = this->getMapXYProc(); | 
|  | proc(*this, 0, 0, &origin); | 
|  |  | 
|  | for (int i = count - 1; i >= 0; --i) { | 
|  | SkPoint tmp; | 
|  |  | 
|  | proc(*this, src[i].fX, src[i].fY, &tmp); | 
|  | dst[i].set(tmp.fX - origin.fX, tmp.fY - origin.fY); | 
|  | } | 
|  | } else { | 
|  | SkMatrix tmp = *this; | 
|  |  | 
|  | tmp.fMat[kMTransX] = tmp.fMat[kMTransY] = 0; | 
|  | tmp.clearTypeMask(kTranslate_Mask); | 
|  | tmp.mapPoints(dst, src, count); | 
|  | } | 
|  | } | 
|  |  | 
|  | bool SkMatrix::mapRect(SkRect* dst, const SkRect& src) const { | 
|  | SkASSERT(dst && &src); | 
|  |  | 
|  | if (this->rectStaysRect()) { | 
|  | this->mapPoints((SkPoint*)dst, (const SkPoint*)&src, 2); | 
|  | dst->sort(); | 
|  | return true; | 
|  | } else { | 
|  | SkPoint quad[4]; | 
|  |  | 
|  | src.toQuad(quad); | 
|  | this->mapPoints(quad, quad, 4); | 
|  | dst->set(quad, 4); | 
|  | return false; | 
|  | } | 
|  | } | 
|  |  | 
|  | SkScalar SkMatrix::mapRadius(SkScalar radius) const { | 
|  | SkVector    vec[2]; | 
|  |  | 
|  | vec[0].set(radius, 0); | 
|  | vec[1].set(0, radius); | 
|  | this->mapVectors(vec, 2); | 
|  |  | 
|  | SkScalar d0 = vec[0].length(); | 
|  | SkScalar d1 = vec[1].length(); | 
|  |  | 
|  | // return geometric mean | 
|  | return SkScalarSqrt(d0 * d1); | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | void SkMatrix::Persp_xy(const SkMatrix& m, SkScalar sx, SkScalar sy, | 
|  | SkPoint* pt) { | 
|  | SkASSERT(m.hasPerspective()); | 
|  |  | 
|  | SkScalar x = sdot(sx, m.fMat[kMScaleX], sy, m.fMat[kMSkewX])  + m.fMat[kMTransX]; | 
|  | SkScalar y = sdot(sx, m.fMat[kMSkewY],  sy, m.fMat[kMScaleY]) + m.fMat[kMTransY]; | 
|  | SkScalar z = sdot(sx, m.fMat[kMPersp0], sy, m.fMat[kMPersp1]) + m.fMat[kMPersp2]; | 
|  | if (z) { | 
|  | z = SkScalarFastInvert(z); | 
|  | } | 
|  | pt->fX = x * z; | 
|  | pt->fY = y * z; | 
|  | } | 
|  |  | 
|  | void SkMatrix::RotTrans_xy(const SkMatrix& m, SkScalar sx, SkScalar sy, | 
|  | SkPoint* pt) { | 
|  | SkASSERT((m.getType() & (kAffine_Mask | kPerspective_Mask)) == kAffine_Mask); | 
|  |  | 
|  | #ifdef SK_LEGACY_MATRIX_MATH_ORDER | 
|  | pt->fX = sx * m.fMat[kMScaleX] + (sy * m.fMat[kMSkewX]  +  m.fMat[kMTransX]); | 
|  | pt->fY = sx * m.fMat[kMSkewY]  + (sy * m.fMat[kMScaleY] + m.fMat[kMTransY]); | 
|  | #else | 
|  | pt->fX = sdot(sx, m.fMat[kMScaleX], sy, m.fMat[kMSkewX])  + m.fMat[kMTransX]; | 
|  | pt->fY = sdot(sx, m.fMat[kMSkewY],  sy, m.fMat[kMScaleY]) + m.fMat[kMTransY]; | 
|  | #endif | 
|  | } | 
|  |  | 
|  | void SkMatrix::Rot_xy(const SkMatrix& m, SkScalar sx, SkScalar sy, | 
|  | SkPoint* pt) { | 
|  | SkASSERT((m.getType() & (kAffine_Mask | kPerspective_Mask))== kAffine_Mask); | 
|  | SkASSERT(0 == m.fMat[kMTransX]); | 
|  | SkASSERT(0 == m.fMat[kMTransY]); | 
|  |  | 
|  | #ifdef SK_LEGACY_MATRIX_MATH_ORDER | 
|  | pt->fX = sx * m.fMat[kMScaleX] + (sy * m.fMat[kMSkewX]  + m.fMat[kMTransX]); | 
|  | pt->fY = sx * m.fMat[kMSkewY]  + (sy * m.fMat[kMScaleY] + m.fMat[kMTransY]); | 
|  | #else | 
|  | pt->fX = sdot(sx, m.fMat[kMScaleX], sy, m.fMat[kMSkewX])  + m.fMat[kMTransX]; | 
|  | pt->fY = sdot(sx, m.fMat[kMSkewY],  sy, m.fMat[kMScaleY]) + m.fMat[kMTransY]; | 
|  | #endif | 
|  | } | 
|  |  | 
|  | void SkMatrix::ScaleTrans_xy(const SkMatrix& m, SkScalar sx, SkScalar sy, | 
|  | SkPoint* pt) { | 
|  | SkASSERT((m.getType() & (kScale_Mask | kAffine_Mask | kPerspective_Mask)) | 
|  | == kScale_Mask); | 
|  |  | 
|  | pt->fX = sx * m.fMat[kMScaleX] + m.fMat[kMTransX]; | 
|  | pt->fY = sy * m.fMat[kMScaleY] + m.fMat[kMTransY]; | 
|  | } | 
|  |  | 
|  | void SkMatrix::Scale_xy(const SkMatrix& m, SkScalar sx, SkScalar sy, | 
|  | SkPoint* pt) { | 
|  | SkASSERT((m.getType() & (kScale_Mask | kAffine_Mask | kPerspective_Mask)) | 
|  | == kScale_Mask); | 
|  | SkASSERT(0 == m.fMat[kMTransX]); | 
|  | SkASSERT(0 == m.fMat[kMTransY]); | 
|  |  | 
|  | pt->fX = sx * m.fMat[kMScaleX]; | 
|  | pt->fY = sy * m.fMat[kMScaleY]; | 
|  | } | 
|  |  | 
|  | void SkMatrix::Trans_xy(const SkMatrix& m, SkScalar sx, SkScalar sy, | 
|  | SkPoint* pt) { | 
|  | SkASSERT(m.getType() == kTranslate_Mask); | 
|  |  | 
|  | pt->fX = sx + m.fMat[kMTransX]; | 
|  | pt->fY = sy + m.fMat[kMTransY]; | 
|  | } | 
|  |  | 
|  | void SkMatrix::Identity_xy(const SkMatrix& m, SkScalar sx, SkScalar sy, | 
|  | SkPoint* pt) { | 
|  | SkASSERT(0 == m.getType()); | 
|  |  | 
|  | pt->fX = sx; | 
|  | pt->fY = sy; | 
|  | } | 
|  |  | 
|  | const SkMatrix::MapXYProc SkMatrix::gMapXYProcs[] = { | 
|  | SkMatrix::Identity_xy, SkMatrix::Trans_xy, | 
|  | SkMatrix::Scale_xy,    SkMatrix::ScaleTrans_xy, | 
|  | SkMatrix::Rot_xy,      SkMatrix::RotTrans_xy, | 
|  | SkMatrix::Rot_xy,      SkMatrix::RotTrans_xy, | 
|  | // repeat the persp proc 8 times | 
|  | SkMatrix::Persp_xy,    SkMatrix::Persp_xy, | 
|  | SkMatrix::Persp_xy,    SkMatrix::Persp_xy, | 
|  | SkMatrix::Persp_xy,    SkMatrix::Persp_xy, | 
|  | SkMatrix::Persp_xy,    SkMatrix::Persp_xy | 
|  | }; | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | // if its nearly zero (just made up 26, perhaps it should be bigger or smaller) | 
|  | #define PerspNearlyZero(x)  SkScalarNearlyZero(x, (1.0f / (1 << 26))) | 
|  |  | 
|  | bool SkMatrix::fixedStepInX(SkScalar y, SkFixed* stepX, SkFixed* stepY) const { | 
|  | if (PerspNearlyZero(fMat[kMPersp0])) { | 
|  | if (stepX || stepY) { | 
|  | if (PerspNearlyZero(fMat[kMPersp1]) && | 
|  | PerspNearlyZero(fMat[kMPersp2] - 1)) { | 
|  | if (stepX) { | 
|  | *stepX = SkScalarToFixed(fMat[kMScaleX]); | 
|  | } | 
|  | if (stepY) { | 
|  | *stepY = SkScalarToFixed(fMat[kMSkewY]); | 
|  | } | 
|  | } else { | 
|  | SkScalar z = y * fMat[kMPersp1] + fMat[kMPersp2]; | 
|  | if (stepX) { | 
|  | *stepX = SkScalarToFixed(fMat[kMScaleX] / z); | 
|  | } | 
|  | if (stepY) { | 
|  | *stepY = SkScalarToFixed(fMat[kMSkewY] / z); | 
|  | } | 
|  | } | 
|  | } | 
|  | return true; | 
|  | } | 
|  | return false; | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | #include "SkPerspIter.h" | 
|  |  | 
|  | SkPerspIter::SkPerspIter(const SkMatrix& m, SkScalar x0, SkScalar y0, int count) | 
|  | : fMatrix(m), fSX(x0), fSY(y0), fCount(count) { | 
|  | SkPoint pt; | 
|  |  | 
|  | SkMatrix::Persp_xy(m, x0, y0, &pt); | 
|  | fX = SkScalarToFixed(pt.fX); | 
|  | fY = SkScalarToFixed(pt.fY); | 
|  | } | 
|  |  | 
|  | int SkPerspIter::next() { | 
|  | int n = fCount; | 
|  |  | 
|  | if (0 == n) { | 
|  | return 0; | 
|  | } | 
|  | SkPoint pt; | 
|  | SkFixed x = fX; | 
|  | SkFixed y = fY; | 
|  | SkFixed dx, dy; | 
|  |  | 
|  | if (n >= kCount) { | 
|  | n = kCount; | 
|  | fSX += SkIntToScalar(kCount); | 
|  | SkMatrix::Persp_xy(fMatrix, fSX, fSY, &pt); | 
|  | fX = SkScalarToFixed(pt.fX); | 
|  | fY = SkScalarToFixed(pt.fY); | 
|  | dx = (fX - x) >> kShift; | 
|  | dy = (fY - y) >> kShift; | 
|  | } else { | 
|  | fSX += SkIntToScalar(n); | 
|  | SkMatrix::Persp_xy(fMatrix, fSX, fSY, &pt); | 
|  | fX = SkScalarToFixed(pt.fX); | 
|  | fY = SkScalarToFixed(pt.fY); | 
|  | dx = (fX - x) / n; | 
|  | dy = (fY - y) / n; | 
|  | } | 
|  |  | 
|  | SkFixed* p = fStorage; | 
|  | for (int i = 0; i < n; i++) { | 
|  | *p++ = x; x += dx; | 
|  | *p++ = y; y += dy; | 
|  | } | 
|  |  | 
|  | fCount -= n; | 
|  | return n; | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | static inline bool checkForZero(float x) { | 
|  | return x*x == 0; | 
|  | } | 
|  |  | 
|  | static inline bool poly_to_point(SkPoint* pt, const SkPoint poly[], int count) { | 
|  | float   x = 1, y = 1; | 
|  | SkPoint pt1, pt2; | 
|  |  | 
|  | if (count > 1) { | 
|  | pt1.fX = poly[1].fX - poly[0].fX; | 
|  | pt1.fY = poly[1].fY - poly[0].fY; | 
|  | y = SkPoint::Length(pt1.fX, pt1.fY); | 
|  | if (checkForZero(y)) { | 
|  | return false; | 
|  | } | 
|  | switch (count) { | 
|  | case 2: | 
|  | break; | 
|  | case 3: | 
|  | pt2.fX = poly[0].fY - poly[2].fY; | 
|  | pt2.fY = poly[2].fX - poly[0].fX; | 
|  | goto CALC_X; | 
|  | default: | 
|  | pt2.fX = poly[0].fY - poly[3].fY; | 
|  | pt2.fY = poly[3].fX - poly[0].fX; | 
|  | CALC_X: | 
|  | x = sdot(pt1.fX, pt2.fX, pt1.fY, pt2.fY) / y; | 
|  | break; | 
|  | } | 
|  | } | 
|  | pt->set(x, y); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | bool SkMatrix::Poly2Proc(const SkPoint srcPt[], SkMatrix* dst, | 
|  | const SkPoint& scale) { | 
|  | float invScale = 1 / scale.fY; | 
|  |  | 
|  | dst->fMat[kMScaleX] = (srcPt[1].fY - srcPt[0].fY) * invScale; | 
|  | dst->fMat[kMSkewY] = (srcPt[0].fX - srcPt[1].fX) * invScale; | 
|  | dst->fMat[kMPersp0] = 0; | 
|  | dst->fMat[kMSkewX] = (srcPt[1].fX - srcPt[0].fX) * invScale; | 
|  | dst->fMat[kMScaleY] = (srcPt[1].fY - srcPt[0].fY) * invScale; | 
|  | dst->fMat[kMPersp1] = 0; | 
|  | dst->fMat[kMTransX] = srcPt[0].fX; | 
|  | dst->fMat[kMTransY] = srcPt[0].fY; | 
|  | dst->fMat[kMPersp2] = 1; | 
|  | dst->setTypeMask(kUnknown_Mask); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | bool SkMatrix::Poly3Proc(const SkPoint srcPt[], SkMatrix* dst, | 
|  | const SkPoint& scale) { | 
|  | float invScale = 1 / scale.fX; | 
|  | dst->fMat[kMScaleX] = (srcPt[2].fX - srcPt[0].fX) * invScale; | 
|  | dst->fMat[kMSkewY] = (srcPt[2].fY - srcPt[0].fY) * invScale; | 
|  | dst->fMat[kMPersp0] = 0; | 
|  |  | 
|  | invScale = 1 / scale.fY; | 
|  | dst->fMat[kMSkewX] = (srcPt[1].fX - srcPt[0].fX) * invScale; | 
|  | dst->fMat[kMScaleY] = (srcPt[1].fY - srcPt[0].fY) * invScale; | 
|  | dst->fMat[kMPersp1] = 0; | 
|  |  | 
|  | dst->fMat[kMTransX] = srcPt[0].fX; | 
|  | dst->fMat[kMTransY] = srcPt[0].fY; | 
|  | dst->fMat[kMPersp2] = 1; | 
|  | dst->setTypeMask(kUnknown_Mask); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | bool SkMatrix::Poly4Proc(const SkPoint srcPt[], SkMatrix* dst, | 
|  | const SkPoint& scale) { | 
|  | float   a1, a2; | 
|  | float   x0, y0, x1, y1, x2, y2; | 
|  |  | 
|  | x0 = srcPt[2].fX - srcPt[0].fX; | 
|  | y0 = srcPt[2].fY - srcPt[0].fY; | 
|  | x1 = srcPt[2].fX - srcPt[1].fX; | 
|  | y1 = srcPt[2].fY - srcPt[1].fY; | 
|  | x2 = srcPt[2].fX - srcPt[3].fX; | 
|  | y2 = srcPt[2].fY - srcPt[3].fY; | 
|  |  | 
|  | /* check if abs(x2) > abs(y2) */ | 
|  | if ( x2 > 0 ? y2 > 0 ? x2 > y2 : x2 > -y2 : y2 > 0 ? -x2 > y2 : x2 < y2) { | 
|  | float denom = SkScalarMulDiv(x1, y2, x2) - y1; | 
|  | if (checkForZero(denom)) { | 
|  | return false; | 
|  | } | 
|  | a1 = (SkScalarMulDiv(x0 - x1, y2, x2) - y0 + y1) / denom; | 
|  | } else { | 
|  | float denom = x1 - SkScalarMulDiv(y1, x2, y2); | 
|  | if (checkForZero(denom)) { | 
|  | return false; | 
|  | } | 
|  | a1 = (x0 - x1 - SkScalarMulDiv(y0 - y1, x2, y2)) / denom; | 
|  | } | 
|  |  | 
|  | /* check if abs(x1) > abs(y1) */ | 
|  | if ( x1 > 0 ? y1 > 0 ? x1 > y1 : x1 > -y1 : y1 > 0 ? -x1 > y1 : x1 < y1) { | 
|  | float denom = y2 - SkScalarMulDiv(x2, y1, x1); | 
|  | if (checkForZero(denom)) { | 
|  | return false; | 
|  | } | 
|  | a2 = (y0 - y2 - SkScalarMulDiv(x0 - x2, y1, x1)) / denom; | 
|  | } else { | 
|  | float denom = SkScalarMulDiv(y2, x1, y1) - x2; | 
|  | if (checkForZero(denom)) { | 
|  | return false; | 
|  | } | 
|  | a2 = (SkScalarMulDiv(y0 - y2, x1, y1) - x0 + x2) / denom; | 
|  | } | 
|  |  | 
|  | float invScale = SkScalarInvert(scale.fX); | 
|  | dst->fMat[kMScaleX] = (a2 * srcPt[3].fX + srcPt[3].fX - srcPt[0].fX) * invScale; | 
|  | dst->fMat[kMSkewY]  = (a2 * srcPt[3].fY + srcPt[3].fY - srcPt[0].fY) * invScale; | 
|  | dst->fMat[kMPersp0] = a2 * invScale; | 
|  |  | 
|  | invScale = SkScalarInvert(scale.fY); | 
|  | dst->fMat[kMSkewX]  = (a1 * srcPt[1].fX + srcPt[1].fX - srcPt[0].fX) * invScale; | 
|  | dst->fMat[kMScaleY] = (a1 * srcPt[1].fY + srcPt[1].fY - srcPt[0].fY) * invScale; | 
|  | dst->fMat[kMPersp1] = a1 * invScale; | 
|  |  | 
|  | dst->fMat[kMTransX] = srcPt[0].fX; | 
|  | dst->fMat[kMTransY] = srcPt[0].fY; | 
|  | dst->fMat[kMPersp2] = 1; | 
|  | dst->setTypeMask(kUnknown_Mask); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | typedef bool (*PolyMapProc)(const SkPoint[], SkMatrix*, const SkPoint&); | 
|  |  | 
|  | /*  Taken from Rob Johnson's original sample code in QuickDraw GX | 
|  | */ | 
|  | bool SkMatrix::setPolyToPoly(const SkPoint src[], const SkPoint dst[], | 
|  | int count) { | 
|  | if ((unsigned)count > 4) { | 
|  | SkDebugf("--- SkMatrix::setPolyToPoly count out of range %d\n", count); | 
|  | return false; | 
|  | } | 
|  |  | 
|  | if (0 == count) { | 
|  | this->reset(); | 
|  | return true; | 
|  | } | 
|  | if (1 == count) { | 
|  | this->setTranslate(dst[0].fX - src[0].fX, dst[0].fY - src[0].fY); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | SkPoint scale; | 
|  | if (!poly_to_point(&scale, src, count) || | 
|  | SkScalarNearlyZero(scale.fX) || | 
|  | SkScalarNearlyZero(scale.fY)) { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | static const PolyMapProc gPolyMapProcs[] = { | 
|  | SkMatrix::Poly2Proc, SkMatrix::Poly3Proc, SkMatrix::Poly4Proc | 
|  | }; | 
|  | PolyMapProc proc = gPolyMapProcs[count - 2]; | 
|  |  | 
|  | SkMatrix tempMap, result; | 
|  | tempMap.setTypeMask(kUnknown_Mask); | 
|  |  | 
|  | if (!proc(src, &tempMap, scale)) { | 
|  | return false; | 
|  | } | 
|  | if (!tempMap.invert(&result)) { | 
|  | return false; | 
|  | } | 
|  | if (!proc(dst, &tempMap, scale)) { | 
|  | return false; | 
|  | } | 
|  | this->setConcat(tempMap, result); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | enum MinMaxOrBoth { | 
|  | kMin_MinMaxOrBoth, | 
|  | kMax_MinMaxOrBoth, | 
|  | kBoth_MinMaxOrBoth | 
|  | }; | 
|  |  | 
|  | template <MinMaxOrBoth MIN_MAX_OR_BOTH> bool get_scale_factor(SkMatrix::TypeMask typeMask, | 
|  | const SkScalar m[9], | 
|  | SkScalar results[/*1 or 2*/]) { | 
|  | if (typeMask & SkMatrix::kPerspective_Mask) { | 
|  | return false; | 
|  | } | 
|  | if (SkMatrix::kIdentity_Mask == typeMask) { | 
|  | results[0] = SK_Scalar1; | 
|  | if (kBoth_MinMaxOrBoth == MIN_MAX_OR_BOTH) { | 
|  | results[1] = SK_Scalar1; | 
|  | } | 
|  | return true; | 
|  | } | 
|  | if (!(typeMask & SkMatrix::kAffine_Mask)) { | 
|  | if (kMin_MinMaxOrBoth == MIN_MAX_OR_BOTH) { | 
|  | results[0] = SkMinScalar(SkScalarAbs(m[SkMatrix::kMScaleX]), | 
|  | SkScalarAbs(m[SkMatrix::kMScaleY])); | 
|  | } else if (kMax_MinMaxOrBoth == MIN_MAX_OR_BOTH) { | 
|  | results[0] = SkMaxScalar(SkScalarAbs(m[SkMatrix::kMScaleX]), | 
|  | SkScalarAbs(m[SkMatrix::kMScaleY])); | 
|  | } else { | 
|  | results[0] = SkScalarAbs(m[SkMatrix::kMScaleX]); | 
|  | results[1] = SkScalarAbs(m[SkMatrix::kMScaleY]); | 
|  | if (results[0] > results[1]) { | 
|  | SkTSwap(results[0], results[1]); | 
|  | } | 
|  | } | 
|  | return true; | 
|  | } | 
|  | // ignore the translation part of the matrix, just look at 2x2 portion. | 
|  | // compute singular values, take largest or smallest abs value. | 
|  | // [a b; b c] = A^T*A | 
|  | SkScalar a = sdot(m[SkMatrix::kMScaleX], m[SkMatrix::kMScaleX], | 
|  | m[SkMatrix::kMSkewY],  m[SkMatrix::kMSkewY]); | 
|  | SkScalar b = sdot(m[SkMatrix::kMScaleX], m[SkMatrix::kMSkewX], | 
|  | m[SkMatrix::kMScaleY], m[SkMatrix::kMSkewY]); | 
|  | SkScalar c = sdot(m[SkMatrix::kMSkewX],  m[SkMatrix::kMSkewX], | 
|  | m[SkMatrix::kMScaleY], m[SkMatrix::kMScaleY]); | 
|  | // eigenvalues of A^T*A are the squared singular values of A. | 
|  | // characteristic equation is det((A^T*A) - l*I) = 0 | 
|  | // l^2 - (a + c)l + (ac-b^2) | 
|  | // solve using quadratic equation (divisor is non-zero since l^2 has 1 coeff | 
|  | // and roots are guaranteed to be pos and real). | 
|  | SkScalar bSqd = b * b; | 
|  | // if upper left 2x2 is orthogonal save some math | 
|  | if (bSqd <= SK_ScalarNearlyZero*SK_ScalarNearlyZero) { | 
|  | if (kMin_MinMaxOrBoth == MIN_MAX_OR_BOTH) { | 
|  | results[0] = SkMinScalar(a, c); | 
|  | } else if (kMax_MinMaxOrBoth == MIN_MAX_OR_BOTH) { | 
|  | results[0] = SkMaxScalar(a, c); | 
|  | } else { | 
|  | results[0] = a; | 
|  | results[1] = c; | 
|  | if (results[0] > results[1]) { | 
|  | SkTSwap(results[0], results[1]); | 
|  | } | 
|  | } | 
|  | } else { | 
|  | SkScalar aminusc = a - c; | 
|  | SkScalar apluscdiv2 = SkScalarHalf(a + c); | 
|  | SkScalar x = SkScalarHalf(SkScalarSqrt(aminusc * aminusc + 4 * bSqd)); | 
|  | if (kMin_MinMaxOrBoth == MIN_MAX_OR_BOTH) { | 
|  | results[0] = apluscdiv2 - x; | 
|  | } else if (kMax_MinMaxOrBoth == MIN_MAX_OR_BOTH) { | 
|  | results[0] = apluscdiv2 + x; | 
|  | } else { | 
|  | results[0] = apluscdiv2 - x; | 
|  | results[1] = apluscdiv2 + x; | 
|  | } | 
|  | } | 
|  | SkASSERT(results[0] >= 0); | 
|  | results[0] = SkScalarSqrt(results[0]); | 
|  | if (kBoth_MinMaxOrBoth == MIN_MAX_OR_BOTH) { | 
|  | SkASSERT(results[1] >= 0); | 
|  | results[1] = SkScalarSqrt(results[1]); | 
|  | } | 
|  | return true; | 
|  | } | 
|  |  | 
|  | SkScalar SkMatrix::getMinScale() const { | 
|  | SkScalar factor; | 
|  | if (get_scale_factor<kMin_MinMaxOrBoth>(this->getType(), fMat, &factor)) { | 
|  | return factor; | 
|  | } else { | 
|  | return -1; | 
|  | } | 
|  | } | 
|  |  | 
|  | SkScalar SkMatrix::getMaxScale() const { | 
|  | SkScalar factor; | 
|  | if (get_scale_factor<kMax_MinMaxOrBoth>(this->getType(), fMat, &factor)) { | 
|  | return factor; | 
|  | } else { | 
|  | return -1; | 
|  | } | 
|  | } | 
|  |  | 
|  | bool SkMatrix::getMinMaxScales(SkScalar scaleFactors[2]) const { | 
|  | return get_scale_factor<kBoth_MinMaxOrBoth>(this->getType(), fMat, scaleFactors); | 
|  | } | 
|  |  | 
|  | namespace { | 
|  |  | 
|  | struct PODMatrix { | 
|  | SkScalar matrix[9]; | 
|  | uint32_t typemask; | 
|  |  | 
|  | const SkMatrix& asSkMatrix() const { return *reinterpret_cast<const SkMatrix*>(this); } | 
|  | }; | 
|  | SK_COMPILE_ASSERT(sizeof(PODMatrix) == sizeof(SkMatrix), PODMatrixSizeMismatch); | 
|  |  | 
|  | }  // namespace | 
|  |  | 
|  | const SkMatrix& SkMatrix::I() { | 
|  | SK_COMPILE_ASSERT(offsetof(SkMatrix, fMat)      == offsetof(PODMatrix, matrix),   BadfMat); | 
|  | SK_COMPILE_ASSERT(offsetof(SkMatrix, fTypeMask) == offsetof(PODMatrix, typemask), BadfTypeMask); | 
|  |  | 
|  | static const PODMatrix identity = { {SK_Scalar1, 0, 0, | 
|  | 0, SK_Scalar1, 0, | 
|  | 0, 0, SK_Scalar1 }, | 
|  | kIdentity_Mask | kRectStaysRect_Mask}; | 
|  | SkASSERT(identity.asSkMatrix().isIdentity()); | 
|  | return identity.asSkMatrix(); | 
|  | } | 
|  |  | 
|  | const SkMatrix& SkMatrix::InvalidMatrix() { | 
|  | SK_COMPILE_ASSERT(offsetof(SkMatrix, fMat)      == offsetof(PODMatrix, matrix),   BadfMat); | 
|  | SK_COMPILE_ASSERT(offsetof(SkMatrix, fTypeMask) == offsetof(PODMatrix, typemask), BadfTypeMask); | 
|  |  | 
|  | static const PODMatrix invalid = | 
|  | { {SK_ScalarMax, SK_ScalarMax, SK_ScalarMax, | 
|  | SK_ScalarMax, SK_ScalarMax, SK_ScalarMax, | 
|  | SK_ScalarMax, SK_ScalarMax, SK_ScalarMax }, | 
|  | kTranslate_Mask | kScale_Mask | kAffine_Mask | kPerspective_Mask }; | 
|  | return invalid.asSkMatrix(); | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | size_t SkMatrix::writeToMemory(void* buffer) const { | 
|  | // TODO write less for simple matrices | 
|  | static const size_t sizeInMemory = 9 * sizeof(SkScalar); | 
|  | if (buffer) { | 
|  | memcpy(buffer, fMat, sizeInMemory); | 
|  | } | 
|  | return sizeInMemory; | 
|  | } | 
|  |  | 
|  | size_t SkMatrix::readFromMemory(const void* buffer, size_t length) { | 
|  | static const size_t sizeInMemory = 9 * sizeof(SkScalar); | 
|  | if (length < sizeInMemory) { | 
|  | return 0; | 
|  | } | 
|  | if (buffer) { | 
|  | memcpy(fMat, buffer, sizeInMemory); | 
|  | this->setTypeMask(kUnknown_Mask); | 
|  | } | 
|  | return sizeInMemory; | 
|  | } | 
|  |  | 
|  | #ifdef SK_DEVELOPER | 
|  | void SkMatrix::dump() const { | 
|  | SkString str; | 
|  | this->toString(&str); | 
|  | SkDebugf("%s\n", str.c_str()); | 
|  | } | 
|  | #endif | 
|  |  | 
|  | #ifndef SK_IGNORE_TO_STRING | 
|  | void SkMatrix::toString(SkString* str) const { | 
|  | str->appendf("[%8.4f %8.4f %8.4f][%8.4f %8.4f %8.4f][%8.4f %8.4f %8.4f]", | 
|  | fMat[0], fMat[1], fMat[2], fMat[3], fMat[4], fMat[5], | 
|  | fMat[6], fMat[7], fMat[8]); | 
|  | } | 
|  | #endif | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | #include "SkMatrixUtils.h" | 
|  |  | 
|  | bool SkTreatAsSprite(const SkMatrix& mat, int width, int height, | 
|  | unsigned subpixelBits) { | 
|  | // quick reject on affine or perspective | 
|  | if (mat.getType() & ~(SkMatrix::kScale_Mask | SkMatrix::kTranslate_Mask)) { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | // quick success check | 
|  | if (!subpixelBits && !(mat.getType() & ~SkMatrix::kTranslate_Mask)) { | 
|  | return true; | 
|  | } | 
|  |  | 
|  | // mapRect supports negative scales, so we eliminate those first | 
|  | if (mat.getScaleX() < 0 || mat.getScaleY() < 0) { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | SkRect dst; | 
|  | SkIRect isrc = { 0, 0, width, height }; | 
|  |  | 
|  | { | 
|  | SkRect src; | 
|  | src.set(isrc); | 
|  | mat.mapRect(&dst, src); | 
|  | } | 
|  |  | 
|  | // just apply the translate to isrc | 
|  | isrc.offset(SkScalarRoundToInt(mat.getTranslateX()), | 
|  | SkScalarRoundToInt(mat.getTranslateY())); | 
|  |  | 
|  | if (subpixelBits) { | 
|  | isrc.fLeft <<= subpixelBits; | 
|  | isrc.fTop <<= subpixelBits; | 
|  | isrc.fRight <<= subpixelBits; | 
|  | isrc.fBottom <<= subpixelBits; | 
|  |  | 
|  | const float scale = 1 << subpixelBits; | 
|  | dst.fLeft *= scale; | 
|  | dst.fTop *= scale; | 
|  | dst.fRight *= scale; | 
|  | dst.fBottom *= scale; | 
|  | } | 
|  |  | 
|  | SkIRect idst; | 
|  | dst.round(&idst); | 
|  | return isrc == idst; | 
|  | } | 
|  |  | 
|  | // A square matrix M can be decomposed (via polar decomposition) into two matrices -- | 
|  | // an orthogonal matrix Q and a symmetric matrix S. In turn we can decompose S into U*W*U^T, | 
|  | // where U is another orthogonal matrix and W is a scale matrix. These can be recombined | 
|  | // to give M = (Q*U)*W*U^T, i.e., the product of two orthogonal matrices and a scale matrix. | 
|  | // | 
|  | // The one wrinkle is that traditionally Q may contain a reflection -- the | 
|  | // calculation has been rejiggered to put that reflection into W. | 
|  | bool SkDecomposeUpper2x2(const SkMatrix& matrix, | 
|  | SkPoint* rotation1, | 
|  | SkPoint* scale, | 
|  | SkPoint* rotation2) { | 
|  |  | 
|  | SkScalar A = matrix[SkMatrix::kMScaleX]; | 
|  | SkScalar B = matrix[SkMatrix::kMSkewX]; | 
|  | SkScalar C = matrix[SkMatrix::kMSkewY]; | 
|  | SkScalar D = matrix[SkMatrix::kMScaleY]; | 
|  |  | 
|  | if (is_degenerate_2x2(A, B, C, D)) { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | double w1, w2; | 
|  | SkScalar cos1, sin1; | 
|  | SkScalar cos2, sin2; | 
|  |  | 
|  | // do polar decomposition (M = Q*S) | 
|  | SkScalar cosQ, sinQ; | 
|  | double Sa, Sb, Sd; | 
|  | // if M is already symmetric (i.e., M = I*S) | 
|  | if (SkScalarNearlyEqual(B, C)) { | 
|  | cosQ = 1; | 
|  | sinQ = 0; | 
|  |  | 
|  | Sa = A; | 
|  | Sb = B; | 
|  | Sd = D; | 
|  | } else { | 
|  | cosQ = A + D; | 
|  | sinQ = C - B; | 
|  | SkScalar reciplen = SkScalarInvert(SkScalarSqrt(cosQ*cosQ + sinQ*sinQ)); | 
|  | cosQ *= reciplen; | 
|  | sinQ *= reciplen; | 
|  |  | 
|  | // S = Q^-1*M | 
|  | // we don't calc Sc since it's symmetric | 
|  | Sa = A*cosQ + C*sinQ; | 
|  | Sb = B*cosQ + D*sinQ; | 
|  | Sd = -B*sinQ + D*cosQ; | 
|  | } | 
|  |  | 
|  | // Now we need to compute eigenvalues of S (our scale factors) | 
|  | // and eigenvectors (bases for our rotation) | 
|  | // From this, should be able to reconstruct S as U*W*U^T | 
|  | if (SkScalarNearlyZero(SkDoubleToScalar(Sb))) { | 
|  | // already diagonalized | 
|  | cos1 = 1; | 
|  | sin1 = 0; | 
|  | w1 = Sa; | 
|  | w2 = Sd; | 
|  | cos2 = cosQ; | 
|  | sin2 = sinQ; | 
|  | } else { | 
|  | double diff = Sa - Sd; | 
|  | double discriminant = sqrt(diff*diff + 4.0*Sb*Sb); | 
|  | double trace = Sa + Sd; | 
|  | if (diff > 0) { | 
|  | w1 = 0.5*(trace + discriminant); | 
|  | w2 = 0.5*(trace - discriminant); | 
|  | } else { | 
|  | w1 = 0.5*(trace - discriminant); | 
|  | w2 = 0.5*(trace + discriminant); | 
|  | } | 
|  |  | 
|  | cos1 = SkDoubleToScalar(Sb); sin1 = SkDoubleToScalar(w1 - Sa); | 
|  | SkScalar reciplen = SkScalarInvert(SkScalarSqrt(cos1*cos1 + sin1*sin1)); | 
|  | cos1 *= reciplen; | 
|  | sin1 *= reciplen; | 
|  |  | 
|  | // rotation 2 is composition of Q and U | 
|  | cos2 = cos1*cosQ - sin1*sinQ; | 
|  | sin2 = sin1*cosQ + cos1*sinQ; | 
|  |  | 
|  | // rotation 1 is U^T | 
|  | sin1 = -sin1; | 
|  | } | 
|  |  | 
|  | if (NULL != scale) { | 
|  | scale->fX = SkDoubleToScalar(w1); | 
|  | scale->fY = SkDoubleToScalar(w2); | 
|  | } | 
|  | if (NULL != rotation1) { | 
|  | rotation1->fX = cos1; | 
|  | rotation1->fY = sin1; | 
|  | } | 
|  | if (NULL != rotation2) { | 
|  | rotation2->fX = cos2; | 
|  | rotation2->fY = sin2; | 
|  | } | 
|  |  | 
|  | return true; | 
|  | } |