| /* libs/corecg/SkMatrix.cpp |
| ** |
| ** Copyright 2006, The Android Open Source Project |
| ** |
| ** Licensed under the Apache License, Version 2.0 (the "License"); |
| ** you may not use this file except in compliance with the License. |
| ** You may obtain a copy of the License at |
| ** |
| ** http://www.apache.org/licenses/LICENSE-2.0 |
| ** |
| ** Unless required by applicable law or agreed to in writing, software |
| ** distributed under the License is distributed on an "AS IS" BASIS, |
| ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| ** See the License for the specific language governing permissions and |
| ** limitations under the License. |
| */ |
| |
| #include "SkMatrix.h" |
| #include "Sk64.h" |
| #include "SkFloatBits.h" |
| #include "SkScalarCompare.h" |
| #include "SkString.h" |
| |
| #ifdef SK_SCALAR_IS_FLOAT |
| #define kMatrix22Elem SK_Scalar1 |
| |
| static inline float SkDoubleToFloat(double x) { |
| return static_cast<float>(x); |
| } |
| #else |
| #define kMatrix22Elem SK_Fract1 |
| #endif |
| |
| /* [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] = SK_Scalar1; |
| fMat[kMSkewX] = fMat[kMSkewY] = |
| fMat[kMTransX] = fMat[kMTransY] = |
| fMat[kMPersp0] = fMat[kMPersp1] = 0; |
| fMat[kMPersp2] = kMatrix22Elem; |
| |
| 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 |
| }; |
| |
| #ifdef SK_SCALAR_IS_FLOAT |
| static const int32_t kScalar1Int = 0x3f800000; |
| static const int32_t kPersp1Int = 0x3f800000; |
| #else |
| #define scalarAsInt(x) (x) |
| static const int32_t kScalar1Int = (1 << 16); |
| static const int32_t kPersp1Int = (1 << 30); |
| #endif |
| |
| uint8_t SkMatrix::computeTypeMask() const { |
| unsigned mask = 0; |
| |
| #ifdef SK_SCALAR_SLOW_COMPARES |
| if (SkScalarAs2sCompliment(fMat[kMPersp0]) | |
| SkScalarAs2sCompliment(fMat[kMPersp1]) | |
| (SkScalarAs2sCompliment(fMat[kMPersp2]) - kPersp1Int)) { |
| mask |= kPerspective_Mask; |
| } |
| |
| if (SkScalarAs2sCompliment(fMat[kMTransX]) | |
| SkScalarAs2sCompliment(fMat[kMTransY])) { |
| mask |= kTranslate_Mask; |
| } |
| #else |
| // 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] != kMatrix22Elem) { |
| mask |= kPerspective_Mask; |
| } |
| |
| if (fMat[kMTransX] != 0 || fMat[kMTransY] != 0) { |
| mask |= kTranslate_Mask; |
| } |
| #endif |
| |
| 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) { |
| mask |= kAffine_Mask; |
| } |
| |
| if ((m00 - kScalar1Int) | (m11 - kScalar1Int)) { |
| mask |= kScale_Mask; |
| } |
| |
| if ((mask & kPerspective_Mask) == 0) { |
| // map non-zero to 1 |
| m00 = m00 != 0; |
| m01 = m01 != 0; |
| m10 = m10 != 0; |
| m11 = m11 != 0; |
| |
| // record if the (p)rimary and (s)econdary diagonals are all 0 or |
| // all non-zero (answer is 0 or 1) |
| int dp0 = (m00 | m11) ^ 1; // true if both are 0 |
| int dp1 = m00 & m11; // true if both are 1 |
| int ds0 = (m01 | m10) ^ 1; // true if both are 0 |
| int ds1 = m01 & m10; // true if both are 1 |
| |
| // return 1 if primary is 1 and secondary is 0 or |
| // primary is 0 and secondary is 1 |
| mask |= ((dp0 & ds1) | (dp1 & ds0)) << kRectStaysRect_Shift; |
| } |
| |
| return SkToU8(mask); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| #ifdef SK_SCALAR_IS_FLOAT |
| |
| 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]; |
| } |
| |
| #endif |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| void SkMatrix::setTranslate(SkScalar dx, SkScalar dy) { |
| if (SkScalarToCompareType(dx) || SkScalarToCompareType(dy)) { |
| fMat[kMTransX] = dx; |
| fMat[kMTransY] = dy; |
| |
| fMat[kMScaleX] = fMat[kMScaleY] = SK_Scalar1; |
| fMat[kMSkewX] = fMat[kMSkewY] = |
| fMat[kMPersp0] = fMat[kMPersp1] = 0; |
| fMat[kMPersp2] = kMatrix22Elem; |
| |
| this->setTypeMask(kTranslate_Mask | kRectStaysRect_Mask); |
| } else { |
| this->reset(); |
| } |
| } |
| |
| bool SkMatrix::preTranslate(SkScalar dx, SkScalar dy) { |
| if (this->hasPerspective()) { |
| SkMatrix m; |
| m.setTranslate(dx, dy); |
| return this->preConcat(m); |
| } |
| |
| if (SkScalarToCompareType(dx) || SkScalarToCompareType(dy)) { |
| fMat[kMTransX] += SkScalarMul(fMat[kMScaleX], dx) + |
| SkScalarMul(fMat[kMSkewX], dy); |
| fMat[kMTransY] += SkScalarMul(fMat[kMSkewY], dx) + |
| SkScalarMul(fMat[kMScaleY], dy); |
| |
| this->setTypeMask(kUnknown_Mask); |
| } |
| return true; |
| } |
| |
| bool SkMatrix::postTranslate(SkScalar dx, SkScalar dy) { |
| if (this->hasPerspective()) { |
| SkMatrix m; |
| m.setTranslate(dx, dy); |
| return this->postConcat(m); |
| } |
| |
| if (SkScalarToCompareType(dx) || SkScalarToCompareType(dy)) { |
| fMat[kMTransX] += dx; |
| fMat[kMTransY] += dy; |
| this->setTypeMask(kUnknown_Mask); |
| } |
| return true; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| void SkMatrix::setScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) { |
| fMat[kMScaleX] = sx; |
| fMat[kMScaleY] = sy; |
| fMat[kMTransX] = px - SkScalarMul(sx, px); |
| fMat[kMTransY] = py - SkScalarMul(sy, py); |
| fMat[kMPersp2] = kMatrix22Elem; |
| |
| fMat[kMSkewX] = fMat[kMSkewY] = |
| fMat[kMPersp0] = fMat[kMPersp1] = 0; |
| |
| this->setTypeMask(kScale_Mask | kTranslate_Mask | kRectStaysRect_Mask); |
| } |
| |
| void SkMatrix::setScale(SkScalar sx, SkScalar sy) { |
| fMat[kMScaleX] = sx; |
| fMat[kMScaleY] = sy; |
| fMat[kMPersp2] = kMatrix22Elem; |
| |
| fMat[kMTransX] = fMat[kMTransY] = |
| fMat[kMSkewX] = fMat[kMSkewY] = |
| fMat[kMPersp0] = fMat[kMPersp1] = 0; |
| |
| this->setTypeMask(kScale_Mask | kRectStaysRect_Mask); |
| } |
| |
| bool SkMatrix::preScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) { |
| SkMatrix m; |
| m.setScale(sx, sy, px, py); |
| return this->preConcat(m); |
| } |
| |
| bool SkMatrix::preScale(SkScalar sx, SkScalar sy) { |
| #ifdef SK_SCALAR_IS_FIXED |
| SkMatrix m; |
| m.setScale(sx, sy); |
| return this->preConcat(m); |
| #else |
| // 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] = SkScalarMul(fMat[kMScaleX], sx); |
| fMat[kMSkewY] = SkScalarMul(fMat[kMSkewY], sx); |
| fMat[kMPersp0] = SkScalarMul(fMat[kMPersp0], sx); |
| |
| fMat[kMSkewX] = SkScalarMul(fMat[kMSkewX], sy); |
| fMat[kMScaleY] = SkScalarMul(fMat[kMScaleY], sy); |
| fMat[kMPersp1] = SkScalarMul(fMat[kMPersp1], sy); |
| |
| this->orTypeMask(kScale_Mask); |
| return true; |
| #endif |
| } |
| |
| bool SkMatrix::postScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) { |
| SkMatrix m; |
| m.setScale(sx, sy, px, py); |
| return this->postConcat(m); |
| } |
| |
| bool SkMatrix::postScale(SkScalar sx, SkScalar sy) { |
| SkMatrix m; |
| m.setScale(sx, sy); |
| return this->postConcat(m); |
| } |
| |
| #ifdef SK_SCALAR_IS_FIXED |
| static inline SkFixed roundidiv(SkFixed numer, int denom) { |
| int ns = numer >> 31; |
| int ds = denom >> 31; |
| numer = (numer ^ ns) - ns; |
| denom = (denom ^ ds) - ds; |
| |
| SkFixed answer = (numer + (denom >> 1)) / denom; |
| int as = ns ^ ds; |
| return (answer ^ as) - as; |
| } |
| #endif |
| |
| // 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; |
| } |
| |
| #ifdef SK_SCALAR_IS_FIXED |
| fMat[kMScaleX] = roundidiv(fMat[kMScaleX], divx); |
| fMat[kMSkewX] = roundidiv(fMat[kMSkewX], divx); |
| fMat[kMTransX] = roundidiv(fMat[kMTransX], divx); |
| |
| fMat[kMScaleY] = roundidiv(fMat[kMScaleY], divy); |
| fMat[kMSkewY] = roundidiv(fMat[kMSkewY], divy); |
| fMat[kMTransY] = roundidiv(fMat[kMTransY], divy); |
| #else |
| 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; |
| #endif |
| |
| this->setTypeMask(kUnknown_Mask); |
| return true; |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////////// |
| |
| void SkMatrix::setSinCos(SkScalar sinV, SkScalar cosV, |
| SkScalar px, SkScalar py) { |
| const SkScalar oneMinusCosV = SK_Scalar1 - cosV; |
| |
| fMat[kMScaleX] = cosV; |
| fMat[kMSkewX] = -sinV; |
| fMat[kMTransX] = SkScalarMul(sinV, py) + SkScalarMul(oneMinusCosV, px); |
| |
| fMat[kMSkewY] = sinV; |
| fMat[kMScaleY] = cosV; |
| fMat[kMTransY] = SkScalarMul(-sinV, px) + SkScalarMul(oneMinusCosV, py); |
| |
| fMat[kMPersp0] = fMat[kMPersp1] = 0; |
| fMat[kMPersp2] = kMatrix22Elem; |
| |
| this->setTypeMask(kUnknown_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] = kMatrix22Elem; |
| |
| this->setTypeMask(kUnknown_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); |
| } |
| |
| bool SkMatrix::preRotate(SkScalar degrees, SkScalar px, SkScalar py) { |
| SkMatrix m; |
| m.setRotate(degrees, px, py); |
| return this->preConcat(m); |
| } |
| |
| bool SkMatrix::preRotate(SkScalar degrees) { |
| SkMatrix m; |
| m.setRotate(degrees); |
| return this->preConcat(m); |
| } |
| |
| bool SkMatrix::postRotate(SkScalar degrees, SkScalar px, SkScalar py) { |
| SkMatrix m; |
| m.setRotate(degrees, px, py); |
| return this->postConcat(m); |
| } |
| |
| bool SkMatrix::postRotate(SkScalar degrees) { |
| SkMatrix m; |
| m.setRotate(degrees); |
| return this->postConcat(m); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////////// |
| |
| void SkMatrix::setSkew(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) { |
| fMat[kMScaleX] = SK_Scalar1; |
| fMat[kMSkewX] = sx; |
| fMat[kMTransX] = SkScalarMul(-sx, py); |
| |
| fMat[kMSkewY] = sy; |
| fMat[kMScaleY] = SK_Scalar1; |
| fMat[kMTransY] = SkScalarMul(-sy, px); |
| |
| fMat[kMPersp0] = fMat[kMPersp1] = 0; |
| fMat[kMPersp2] = kMatrix22Elem; |
| |
| this->setTypeMask(kUnknown_Mask); |
| } |
| |
| void SkMatrix::setSkew(SkScalar sx, SkScalar sy) { |
| fMat[kMScaleX] = SK_Scalar1; |
| fMat[kMSkewX] = sx; |
| fMat[kMTransX] = 0; |
| |
| fMat[kMSkewY] = sy; |
| fMat[kMScaleY] = SK_Scalar1; |
| fMat[kMTransY] = 0; |
| |
| fMat[kMPersp0] = fMat[kMPersp1] = 0; |
| fMat[kMPersp2] = kMatrix22Elem; |
| |
| this->setTypeMask(kUnknown_Mask); |
| } |
| |
| bool SkMatrix::preSkew(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) { |
| SkMatrix m; |
| m.setSkew(sx, sy, px, py); |
| return this->preConcat(m); |
| } |
| |
| bool SkMatrix::preSkew(SkScalar sx, SkScalar sy) { |
| SkMatrix m; |
| m.setSkew(sx, sy); |
| return this->preConcat(m); |
| } |
| |
| bool SkMatrix::postSkew(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) { |
| SkMatrix m; |
| m.setSkew(sx, sy, px, py); |
| return this->postConcat(m); |
| } |
| |
| bool SkMatrix::postSkew(SkScalar sx, SkScalar sy) { |
| SkMatrix m; |
| m.setSkew(sx, sy); |
| return 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 = SkScalarDiv(dst.width(), src.width()); |
| SkScalar ty, sy = SkScalarDiv(dst.height(), src.height()); |
| bool xLarger = false; |
| |
| if (align != kFill_ScaleToFit) { |
| if (sx > sy) { |
| xLarger = true; |
| sx = sy; |
| } else { |
| sy = sx; |
| } |
| } |
| |
| tx = dst.fLeft - SkScalarMul(src.fLeft, sx); |
| ty = dst.fTop - SkScalarMul(src.fTop, sy); |
| if (align == kCenter_ScaleToFit || align == kEnd_ScaleToFit) { |
| SkScalar diff; |
| |
| if (xLarger) { |
| diff = dst.width() - SkScalarMul(src.width(), sy); |
| } else { |
| diff = dst.height() - SkScalarMul(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; |
| |
| this->setTypeMask(kScale_Mask | kTranslate_Mask | kRectStaysRect_Mask); |
| } |
| // shared cleanup |
| fMat[kMPersp2] = kMatrix22Elem; |
| return true; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| #ifdef SK_SCALAR_IS_FLOAT |
| static inline int fixmuladdmul(float a, float b, float c, float d, |
| float* result) { |
| *result = SkDoubleToFloat((double)a * b + (double)c * d); |
| return true; |
| } |
| |
| static inline bool rowcol3(const float row[], const float col[], |
| float* result) { |
| *result = row[0] * col[0] + row[1] * col[3] + row[2] * col[6]; |
| return true; |
| } |
| |
| static inline int negifaddoverflows(float& result, float a, float b) { |
| result = a + b; |
| return 0; |
| } |
| #else |
| static inline bool fixmuladdmul(SkFixed a, SkFixed b, SkFixed c, SkFixed d, |
| SkFixed* result) { |
| Sk64 tmp1, tmp2; |
| tmp1.setMul(a, b); |
| tmp2.setMul(c, d); |
| tmp1.add(tmp2); |
| if (tmp1.isFixed()) { |
| *result = tmp1.getFixed(); |
| return true; |
| } |
| return false; |
| } |
| |
| static inline SkFixed fracmuladdmul(SkFixed a, SkFract b, SkFixed c, |
| SkFract d) { |
| Sk64 tmp1, tmp2; |
| tmp1.setMul(a, b); |
| tmp2.setMul(c, d); |
| tmp1.add(tmp2); |
| return tmp1.getFract(); |
| } |
| |
| static inline bool rowcol3(const SkFixed row[], const SkFixed col[], |
| SkFixed* result) { |
| Sk64 tmp1, tmp2; |
| |
| tmp1.setMul(row[0], col[0]); // N * fixed |
| tmp2.setMul(row[1], col[3]); // N * fixed |
| tmp1.add(tmp2); |
| |
| tmp2.setMul(row[2], col[6]); // N * fract |
| tmp2.roundRight(14); // make it fixed |
| tmp1.add(tmp2); |
| |
| if (tmp1.isFixed()) { |
| *result = tmp1.getFixed(); |
| return true; |
| } |
| return false; |
| } |
| |
| static inline int negifaddoverflows(SkFixed& result, SkFixed a, SkFixed b) { |
| SkFixed c = a + b; |
| result = c; |
| return (c ^ a) & (c ^ b); |
| } |
| #endif |
| |
| static void normalize_perspective(SkScalar mat[9]) { |
| if (SkScalarAbs(mat[SkMatrix::kMPersp2]) > kMatrix22Elem) { |
| for (int i = 0; i < 9; i++) |
| mat[i] = SkScalarHalf(mat[i]); |
| } |
| } |
| |
| bool SkMatrix::setConcat(const SkMatrix& a, const SkMatrix& b) { |
| TypeMask aType = a.getType(); |
| TypeMask bType = b.getType(); |
| |
| if (0 == aType) { |
| *this = b; |
| } else if (0 == bType) { |
| *this = a; |
| } else { |
| SkMatrix tmp; |
| |
| if ((aType | bType) & kPerspective_Mask) { |
| if (!rowcol3(&a.fMat[0], &b.fMat[0], &tmp.fMat[kMScaleX])) { |
| return false; |
| } |
| if (!rowcol3(&a.fMat[0], &b.fMat[1], &tmp.fMat[kMSkewX])) { |
| return false; |
| } |
| if (!rowcol3(&a.fMat[0], &b.fMat[2], &tmp.fMat[kMTransX])) { |
| return false; |
| } |
| |
| if (!rowcol3(&a.fMat[3], &b.fMat[0], &tmp.fMat[kMSkewY])) { |
| return false; |
| } |
| if (!rowcol3(&a.fMat[3], &b.fMat[1], &tmp.fMat[kMScaleY])) { |
| return false; |
| } |
| if (!rowcol3(&a.fMat[3], &b.fMat[2], &tmp.fMat[kMTransY])) { |
| return false; |
| } |
| |
| if (!rowcol3(&a.fMat[6], &b.fMat[0], &tmp.fMat[kMPersp0])) { |
| return false; |
| } |
| if (!rowcol3(&a.fMat[6], &b.fMat[1], &tmp.fMat[kMPersp1])) { |
| return false; |
| } |
| if (!rowcol3(&a.fMat[6], &b.fMat[2], &tmp.fMat[kMPersp2])) { |
| return false; |
| } |
| |
| normalize_perspective(tmp.fMat); |
| } else { // not perspective |
| if (!fixmuladdmul(a.fMat[kMScaleX], b.fMat[kMScaleX], |
| a.fMat[kMSkewX], b.fMat[kMSkewY], &tmp.fMat[kMScaleX])) { |
| return false; |
| } |
| if (!fixmuladdmul(a.fMat[kMScaleX], b.fMat[kMSkewX], |
| a.fMat[kMSkewX], b.fMat[kMScaleY], &tmp.fMat[kMSkewX])) { |
| return false; |
| } |
| if (!fixmuladdmul(a.fMat[kMScaleX], b.fMat[kMTransX], |
| a.fMat[kMSkewX], b.fMat[kMTransY], &tmp.fMat[kMTransX])) { |
| return false; |
| } |
| if (negifaddoverflows(tmp.fMat[kMTransX], tmp.fMat[kMTransX], |
| a.fMat[kMTransX]) < 0) { |
| return false; |
| } |
| |
| if (!fixmuladdmul(a.fMat[kMSkewY], b.fMat[kMScaleX], |
| a.fMat[kMScaleY], b.fMat[kMSkewY], &tmp.fMat[kMSkewY])) { |
| return false; |
| } |
| if (!fixmuladdmul(a.fMat[kMSkewY], b.fMat[kMSkewX], |
| a.fMat[kMScaleY], b.fMat[kMScaleY], &tmp.fMat[kMScaleY])) { |
| return false; |
| } |
| if (!fixmuladdmul(a.fMat[kMSkewY], b.fMat[kMTransX], |
| a.fMat[kMScaleY], b.fMat[kMTransY], &tmp.fMat[kMTransY])) { |
| return false; |
| } |
| if (negifaddoverflows(tmp.fMat[kMTransY], tmp.fMat[kMTransY], |
| a.fMat[kMTransY]) < 0) { |
| return false; |
| } |
| |
| tmp.fMat[kMPersp0] = tmp.fMat[kMPersp1] = 0; |
| tmp.fMat[kMPersp2] = kMatrix22Elem; |
| } |
| *this = tmp; |
| } |
| this->setTypeMask(kUnknown_Mask); |
| return true; |
| } |
| |
| bool SkMatrix::preConcat(const SkMatrix& mat) { |
| // check for identity first, so we don't do a needless copy of ourselves |
| // to ourselves inside setConcat() |
| return mat.isIdentity() || this->setConcat(*this, mat); |
| } |
| |
| bool SkMatrix::postConcat(const SkMatrix& mat) { |
| // check for identity first, so we don't do a needless copy of ourselves |
| // to ourselves inside setConcat() |
| return 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. |
| The fixed counter part is us using Sk64 for temp calculations. |
| */ |
| |
| #ifdef SK_SCALAR_IS_FLOAT |
| typedef double SkDetScalar; |
| #define SkPerspMul(a, b) SkScalarMul(a, b) |
| #define SkScalarMulShift(a, b, s) SkDoubleToFloat((a) * (b)) |
| static double sk_inv_determinant(const float mat[9], int isPerspective, |
| int* /* (only used in Fixed case) */) { |
| double det; |
| |
| if (isPerspective) { |
| det = mat[SkMatrix::kMScaleX] * ((double)mat[SkMatrix::kMScaleY] * mat[SkMatrix::kMPersp2] - (double)mat[SkMatrix::kMTransY] * mat[SkMatrix::kMPersp1]) + |
| mat[SkMatrix::kMSkewX] * ((double)mat[SkMatrix::kMTransY] * mat[SkMatrix::kMPersp0] - (double)mat[SkMatrix::kMSkewY] * mat[SkMatrix::kMPersp2]) + |
| mat[SkMatrix::kMTransX] * ((double)mat[SkMatrix::kMSkewY] * mat[SkMatrix::kMPersp1] - (double)mat[SkMatrix::kMScaleY] * mat[SkMatrix::kMPersp0]); |
| } else { |
| det = (double)mat[SkMatrix::kMScaleX] * mat[SkMatrix::kMScaleY] - (double)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; |
| } |
| // we declar a,b,c,d to all be doubles, because we want to perform |
| // double-precision muls and subtract, even though the original values are |
| // from the matrix, which are floats. |
| static float inline mul_diff_scale(double a, double b, double c, double d, |
| double scale) { |
| return SkDoubleToFloat((a * b - c * d) * scale); |
| } |
| #else |
| typedef SkFixed SkDetScalar; |
| #define SkPerspMul(a, b) SkFractMul(a, b) |
| #define SkScalarMulShift(a, b, s) SkMulShift(a, b, s) |
| static void set_muladdmul(Sk64* dst, int32_t a, int32_t b, int32_t c, |
| int32_t d) { |
| Sk64 tmp; |
| dst->setMul(a, b); |
| tmp.setMul(c, d); |
| dst->add(tmp); |
| } |
| |
| static SkFixed sk_inv_determinant(const SkFixed mat[9], int isPerspective, |
| int* shift) { |
| Sk64 tmp1, tmp2; |
| |
| if (isPerspective) { |
| tmp1.setMul(mat[SkMatrix::kMScaleX], fracmuladdmul(mat[SkMatrix::kMScaleY], mat[SkMatrix::kMPersp2], -mat[SkMatrix::kMTransY], mat[SkMatrix::kMPersp1])); |
| tmp2.setMul(mat[SkMatrix::kMSkewX], fracmuladdmul(mat[SkMatrix::kMTransY], mat[SkMatrix::kMPersp0], -mat[SkMatrix::kMSkewY], mat[SkMatrix::kMPersp2])); |
| tmp1.add(tmp2); |
| tmp2.setMul(mat[SkMatrix::kMTransX], fracmuladdmul(mat[SkMatrix::kMSkewY], mat[SkMatrix::kMPersp1], -mat[SkMatrix::kMScaleY], mat[SkMatrix::kMPersp0])); |
| tmp1.add(tmp2); |
| } else { |
| tmp1.setMul(mat[SkMatrix::kMScaleX], mat[SkMatrix::kMScaleY]); |
| tmp2.setMul(mat[SkMatrix::kMSkewX], mat[SkMatrix::kMSkewY]); |
| tmp1.sub(tmp2); |
| } |
| |
| int s = tmp1.getClzAbs(); |
| *shift = s; |
| |
| SkFixed denom; |
| if (s <= 32) { |
| denom = tmp1.getShiftRight(33 - s); |
| } else { |
| denom = (int32_t)tmp1.fLo << (s - 33); |
| } |
| |
| if (denom == 0) { |
| return 0; |
| } |
| /** This could perhaps be a special fractdiv function, since both of its |
| arguments are known to have bit 31 clear and bit 30 set (when they |
| are made positive), thus eliminating the need for calling clz() |
| */ |
| return SkFractDiv(SK_Fract1, denom); |
| } |
| #endif |
| |
| void SkMatrix::SetAffineIdentity(SkScalar affine[6]) { |
| affine[kAScaleX] = SK_Scalar1; |
| affine[kASkewY] = 0; |
| affine[kASkewX] = 0; |
| affine[kAScaleY] = SK_Scalar1; |
| 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::invert(SkMatrix* inv) const { |
| int isPersp = this->hasPerspective(); |
| int shift; |
| SkDetScalar scale = sk_inv_determinant(fMat, isPersp, &shift); |
| |
| if (scale == 0) { // underflow |
| return false; |
| } |
| |
| if (inv) { |
| SkMatrix tmp; |
| if (inv == this) |
| inv = &tmp; |
| |
| if (isPersp) { |
| shift = 61 - shift; |
| inv->fMat[kMScaleX] = SkScalarMulShift(SkPerspMul(fMat[kMScaleY], fMat[kMPersp2]) - SkPerspMul(fMat[kMTransY], fMat[kMPersp1]), scale, shift); |
| inv->fMat[kMSkewX] = SkScalarMulShift(SkPerspMul(fMat[kMTransX], fMat[kMPersp1]) - SkPerspMul(fMat[kMSkewX], fMat[kMPersp2]), scale, shift); |
| inv->fMat[kMTransX] = SkScalarMulShift(SkScalarMul(fMat[kMSkewX], fMat[kMTransY]) - SkScalarMul(fMat[kMTransX], fMat[kMScaleY]), scale, shift); |
| |
| inv->fMat[kMSkewY] = SkScalarMulShift(SkPerspMul(fMat[kMTransY], fMat[kMPersp0]) - SkPerspMul(fMat[kMSkewY], fMat[kMPersp2]), scale, shift); |
| inv->fMat[kMScaleY] = SkScalarMulShift(SkPerspMul(fMat[kMScaleX], fMat[kMPersp2]) - SkPerspMul(fMat[kMTransX], fMat[kMPersp0]), scale, shift); |
| inv->fMat[kMTransY] = SkScalarMulShift(SkScalarMul(fMat[kMTransX], fMat[kMSkewY]) - SkScalarMul(fMat[kMScaleX], fMat[kMTransY]), scale, shift); |
| |
| inv->fMat[kMPersp0] = SkScalarMulShift(SkScalarMul(fMat[kMSkewY], fMat[kMPersp1]) - SkScalarMul(fMat[kMScaleY], fMat[kMPersp0]), scale, shift); |
| inv->fMat[kMPersp1] = SkScalarMulShift(SkScalarMul(fMat[kMSkewX], fMat[kMPersp0]) - SkScalarMul(fMat[kMScaleX], fMat[kMPersp1]), scale, shift); |
| inv->fMat[kMPersp2] = SkScalarMulShift(SkScalarMul(fMat[kMScaleX], fMat[kMScaleY]) - SkScalarMul(fMat[kMSkewX], fMat[kMSkewY]), scale, shift); |
| #ifdef SK_SCALAR_IS_FIXED |
| if (SkAbs32(inv->fMat[kMPersp2]) > SK_Fixed1) { |
| Sk64 tmp; |
| |
| tmp.set(SK_Fract1); |
| tmp.shiftLeft(16); |
| tmp.div(inv->fMat[kMPersp2], Sk64::kRound_DivOption); |
| |
| SkFract scale = tmp.get32(); |
| |
| for (int i = 0; i < 9; i++) { |
| inv->fMat[i] = SkFractMul(inv->fMat[i], scale); |
| } |
| } |
| inv->fMat[kMPersp2] = SkFixedToFract(inv->fMat[kMPersp2]); |
| #endif |
| } else { // not perspective |
| #ifdef SK_SCALAR_IS_FIXED |
| Sk64 tx, ty; |
| int clzNumer; |
| |
| // check the 2x2 for overflow |
| { |
| int32_t value = SkAbs32(fMat[kMScaleY]); |
| value |= SkAbs32(fMat[kMSkewX]); |
| value |= SkAbs32(fMat[kMScaleX]); |
| value |= SkAbs32(fMat[kMSkewY]); |
| clzNumer = SkCLZ(value); |
| if (shift - clzNumer > 31) |
| return false; // overflow |
| } |
| |
| set_muladdmul(&tx, fMat[kMSkewX], fMat[kMTransY], -fMat[kMScaleY], fMat[kMTransX]); |
| set_muladdmul(&ty, fMat[kMSkewY], fMat[kMTransX], -fMat[kMScaleX], fMat[kMTransY]); |
| // check tx,ty for overflow |
| clzNumer = SkCLZ(SkAbs32(tx.fHi) | SkAbs32(ty.fHi)); |
| if (shift - clzNumer > 14) { |
| return false; // overflow |
| } |
| |
| int fixedShift = 61 - shift; |
| int sk64shift = 44 - shift + clzNumer; |
| |
| inv->fMat[kMScaleX] = SkMulShift(fMat[kMScaleY], scale, fixedShift); |
| inv->fMat[kMSkewX] = SkMulShift(-fMat[kMSkewX], scale, fixedShift); |
| inv->fMat[kMTransX] = SkMulShift(tx.getShiftRight(33 - clzNumer), scale, sk64shift); |
| |
| inv->fMat[kMSkewY] = SkMulShift(-fMat[kMSkewY], scale, fixedShift); |
| inv->fMat[kMScaleY] = SkMulShift(fMat[kMScaleX], scale, fixedShift); |
| inv->fMat[kMTransY] = SkMulShift(ty.getShiftRight(33 - clzNumer), scale, sk64shift); |
| #else |
| inv->fMat[kMScaleX] = SkDoubleToFloat(fMat[kMScaleY] * scale); |
| inv->fMat[kMSkewX] = SkDoubleToFloat(-fMat[kMSkewX] * scale); |
| inv->fMat[kMTransX] = mul_diff_scale(fMat[kMSkewX], fMat[kMTransY], |
| fMat[kMScaleY], fMat[kMTransX], scale); |
| |
| inv->fMat[kMSkewY] = SkDoubleToFloat(-fMat[kMSkewY] * scale); |
| inv->fMat[kMScaleY] = SkDoubleToFloat(fMat[kMScaleX] * scale); |
| inv->fMat[kMTransY] = mul_diff_scale(fMat[kMSkewY], fMat[kMTransX], |
| fMat[kMScaleX], fMat[kMTransY], scale); |
| #endif |
| inv->fMat[kMPersp0] = 0; |
| inv->fMat[kMPersp1] = 0; |
| inv->fMat[kMPersp2] = kMatrix22Elem; |
| } |
| |
| if (inv == &tmp) { |
| *(SkMatrix*)this = tmp; |
| } |
| inv->setTypeMask(kUnknown_Mask); |
| } |
| 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 = SkScalarMul(src->fY, my); |
| dst->fX = SkScalarMul(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 = SkScalarMulAdd(src->fY, my, ty); |
| dst->fX = SkScalarMulAdd(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 = SkScalarMul(sx, ky) + SkScalarMul(sy, my); |
| dst->fX = SkScalarMul(sx, mx) + SkScalarMul(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; |
| dst->fY = SkScalarMul(sx, ky) + SkScalarMulAdd(sy, my, ty); |
| dst->fX = SkScalarMul(sx, mx) + SkScalarMulAdd(sy, kx, tx); |
| dst += 1; |
| } while (--count); |
| } |
| } |
| |
| void SkMatrix::Persp_pts(const SkMatrix& m, SkPoint dst[], |
| const SkPoint src[], int count) { |
| SkASSERT(m.hasPerspective()); |
| |
| #ifdef SK_SCALAR_IS_FIXED |
| SkFixed persp2 = SkFractToFixed(m.fMat[kMPersp2]); |
| #endif |
| |
| if (count > 0) { |
| do { |
| SkScalar sy = src->fY; |
| SkScalar sx = src->fX; |
| src += 1; |
| |
| SkScalar x = SkScalarMul(sx, m.fMat[kMScaleX]) + |
| SkScalarMul(sy, m.fMat[kMSkewX]) + m.fMat[kMTransX]; |
| SkScalar y = SkScalarMul(sx, m.fMat[kMSkewY]) + |
| SkScalarMul(sy, m.fMat[kMScaleY]) + m.fMat[kMTransY]; |
| #ifdef SK_SCALAR_IS_FIXED |
| SkFixed z = SkFractMul(sx, m.fMat[kMPersp0]) + |
| SkFractMul(sy, m.fMat[kMPersp1]) + persp2; |
| #else |
| float z = SkScalarMul(sx, m.fMat[kMPersp0]) + |
| SkScalarMulAdd(sy, m.fMat[kMPersp1], m.fMat[kMPersp2]); |
| #endif |
| if (z) { |
| z = SkScalarFastInvert(z); |
| } |
| |
| dst->fY = SkScalarMul(y, z); |
| dst->fX = SkScalarMul(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) || count == 0); |
| // no partial overlap |
| SkASSERT(src == dst || SkAbs32((int32_t)(src - dst)) >= count); |
| |
| this->getMapPtsProc()(*this, dst, src, 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 SkScalarMean(d0, d1); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| void SkMatrix::Persp_xy(const SkMatrix& m, SkScalar sx, SkScalar sy, |
| SkPoint* pt) { |
| SkASSERT(m.hasPerspective()); |
| |
| SkScalar x = SkScalarMul(sx, m.fMat[kMScaleX]) + |
| SkScalarMul(sy, m.fMat[kMSkewX]) + m.fMat[kMTransX]; |
| SkScalar y = SkScalarMul(sx, m.fMat[kMSkewY]) + |
| SkScalarMul(sy, m.fMat[kMScaleY]) + m.fMat[kMTransY]; |
| #ifdef SK_SCALAR_IS_FIXED |
| SkFixed z = SkFractMul(sx, m.fMat[kMPersp0]) + |
| SkFractMul(sy, m.fMat[kMPersp1]) + |
| SkFractToFixed(m.fMat[kMPersp2]); |
| #else |
| float z = SkScalarMul(sx, m.fMat[kMPersp0]) + |
| SkScalarMul(sy, m.fMat[kMPersp1]) + m.fMat[kMPersp2]; |
| #endif |
| if (z) { |
| z = SkScalarFastInvert(z); |
| } |
| pt->fX = SkScalarMul(x, z); |
| pt->fY = SkScalarMul(y, z); |
| } |
| |
| #ifdef SK_SCALAR_IS_FIXED |
| static SkFixed fixmuladdmul(SkFixed a, SkFixed b, SkFixed c, SkFixed d) { |
| Sk64 tmp, tmp1; |
| |
| tmp.setMul(a, b); |
| tmp1.setMul(c, d); |
| return tmp.addGetFixed(tmp1); |
| // tmp.add(tmp1); |
| // return tmp.getFixed(); |
| } |
| #endif |
| |
| void SkMatrix::RotTrans_xy(const SkMatrix& m, SkScalar sx, SkScalar sy, |
| SkPoint* pt) { |
| SkASSERT((m.getType() & (kAffine_Mask | kPerspective_Mask)) == kAffine_Mask); |
| |
| #ifdef SK_SCALAR_IS_FIXED |
| pt->fX = fixmuladdmul(sx, m.fMat[kMScaleX], sy, m.fMat[kMSkewX]) + |
| m.fMat[kMTransX]; |
| pt->fY = fixmuladdmul(sx, m.fMat[kMSkewY], sy, m.fMat[kMScaleY]) + |
| m.fMat[kMTransY]; |
| #else |
| pt->fX = SkScalarMul(sx, m.fMat[kMScaleX]) + |
| SkScalarMulAdd(sy, m.fMat[kMSkewX], m.fMat[kMTransX]); |
| pt->fY = SkScalarMul(sx, m.fMat[kMSkewY]) + |
| SkScalarMulAdd(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_SCALAR_IS_FIXED |
| pt->fX = fixmuladdmul(sx, m.fMat[kMScaleX], sy, m.fMat[kMSkewX]); |
| pt->fY = fixmuladdmul(sx, m.fMat[kMSkewY], sy, m.fMat[kMScaleY]); |
| #else |
| pt->fX = SkScalarMul(sx, m.fMat[kMScaleX]) + |
| SkScalarMulAdd(sy, m.fMat[kMSkewX], m.fMat[kMTransX]); |
| pt->fY = SkScalarMul(sx, m.fMat[kMSkewY]) + |
| SkScalarMulAdd(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 = SkScalarMulAdd(sx, m.fMat[kMScaleX], m.fMat[kMTransX]); |
| pt->fY = SkScalarMulAdd(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 = SkScalarMul(sx, m.fMat[kMScaleX]); |
| pt->fY = SkScalarMul(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) |
| #ifdef SK_SCALAR_IS_FIXED |
| typedef SkFract SkPerspElemType; |
| #define PerspNearlyZero(x) (SkAbs32(x) < (SK_Fract1 >> 26)) |
| #else |
| typedef float SkPerspElemType; |
| #define PerspNearlyZero(x) SkScalarNearlyZero(x, (1.0f / (1 << 26))) |
| #endif |
| |
| bool SkMatrix::fixedStepInX(SkScalar y, SkFixed* stepX, SkFixed* stepY) const { |
| if (PerspNearlyZero(fMat[kMPersp0])) { |
| if (stepX || stepY) { |
| if (PerspNearlyZero(fMat[kMPersp1]) && |
| PerspNearlyZero(fMat[kMPersp2] - kMatrix22Elem)) { |
| if (stepX) { |
| *stepX = SkScalarToFixed(fMat[kMScaleX]); |
| } |
| if (stepY) { |
| *stepY = SkScalarToFixed(fMat[kMSkewY]); |
| } |
| } else { |
| #ifdef SK_SCALAR_IS_FIXED |
| SkFixed z = SkFractMul(y, fMat[kMPersp1]) + |
| SkFractToFixed(fMat[kMPersp2]); |
| #else |
| float z = y * fMat[kMPersp1] + fMat[kMPersp2]; |
| #endif |
| if (stepX) { |
| *stepX = SkScalarToFixed(SkScalarDiv(fMat[kMScaleX], z)); |
| } |
| if (stepY) { |
| *stepY = SkScalarToFixed(SkScalarDiv(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; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| #ifdef SK_SCALAR_IS_FIXED |
| |
| static inline bool poly_to_point(SkPoint* pt, const SkPoint poly[], int count) { |
| SkFixed x = SK_Fixed1, y = SK_Fixed1; |
| SkPoint pt1, pt2; |
| Sk64 w1, w2; |
| |
| 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 (y == 0) { |
| 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: |
| w1.setMul(pt1.fX, pt2.fX); |
| w2.setMul(pt1.fY, pt2.fY); |
| w1.add(w2); |
| w1.div(y, Sk64::kRound_DivOption); |
| if (!w1.is32()) { |
| return false; |
| } |
| x = w1.get32(); |
| break; |
| } |
| } |
| pt->set(x, y); |
| return true; |
| } |
| |
| bool SkMatrix::Poly2Proc(const SkPoint srcPt[], SkMatrix* dst, |
| const SkPoint& scalePt) { |
| // need to check if SkFixedDiv overflows... |
| |
| const SkFixed scale = scalePt.fY; |
| dst->fMat[kMScaleX] = SkFixedDiv(srcPt[1].fY - srcPt[0].fY, scale); |
| dst->fMat[kMSkewY] = SkFixedDiv(srcPt[0].fX - srcPt[1].fX, scale); |
| dst->fMat[kMPersp0] = 0; |
| dst->fMat[kMSkewX] = SkFixedDiv(srcPt[1].fX - srcPt[0].fX, scale); |
| dst->fMat[kMScaleY] = SkFixedDiv(srcPt[1].fY - srcPt[0].fY, scale); |
| dst->fMat[kMPersp1] = 0; |
| dst->fMat[kMTransX] = srcPt[0].fX; |
| dst->fMat[kMTransY] = srcPt[0].fY; |
| dst->fMat[kMPersp2] = SK_Fract1; |
| dst->setTypeMask(kUnknown_Mask); |
| return true; |
| } |
| |
| bool SkMatrix::Poly3Proc(const SkPoint srcPt[], SkMatrix* dst, |
| const SkPoint& scale) { |
| // really, need to check if SkFixedDiv overflow'd |
| |
| dst->fMat[kMScaleX] = SkFixedDiv(srcPt[2].fX - srcPt[0].fX, scale.fX); |
| dst->fMat[kMSkewY] = SkFixedDiv(srcPt[2].fY - srcPt[0].fY, scale.fX); |
| dst->fMat[kMPersp0] = 0; |
| dst->fMat[kMSkewX] = SkFixedDiv(srcPt[1].fX - srcPt[0].fX, scale.fY); |
| dst->fMat[kMScaleY] = SkFixedDiv(srcPt[1].fY - srcPt[0].fY, scale.fY); |
| dst->fMat[kMPersp1] = 0; |
| dst->fMat[kMTransX] = srcPt[0].fX; |
| dst->fMat[kMTransY] = srcPt[0].fY; |
| dst->fMat[kMPersp2] = SK_Fract1; |
| dst->setTypeMask(kUnknown_Mask); |
| return true; |
| } |
| |
| bool SkMatrix::Poly4Proc(const SkPoint srcPt[], SkMatrix* dst, |
| const SkPoint& scale) { |
| SkFract a1, a2; |
| SkFixed 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) { |
| SkFixed denom = SkMulDiv(x1, y2, x2) - y1; |
| if (0 == denom) { |
| return false; |
| } |
| a1 = SkFractDiv(SkMulDiv(x0 - x1, y2, x2) - y0 + y1, denom); |
| } else { |
| SkFixed denom = x1 - SkMulDiv(y1, x2, y2); |
| if (0 == denom) { |
| return false; |
| } |
| a1 = SkFractDiv(x0 - x1 - SkMulDiv(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) { |
| SkFixed denom = y2 - SkMulDiv(x2, y1, x1); |
| if (0 == denom) { |
| return false; |
| } |
| a2 = SkFractDiv(y0 - y2 - SkMulDiv(x0 - x2, y1, x1), denom); |
| } else { |
| SkFixed denom = SkMulDiv(y2, x1, y1) - x2; |
| if (0 == denom) { |
| return false; |
| } |
| a2 = SkFractDiv(SkMulDiv(y0 - y2, x1, y1) - x0 + x2, denom); |
| } |
| |
| // need to check if SkFixedDiv overflows... |
| dst->fMat[kMScaleX] = SkFixedDiv(SkFractMul(a2, srcPt[3].fX) + |
| srcPt[3].fX - srcPt[0].fX, scale.fX); |
| dst->fMat[kMSkewY] = SkFixedDiv(SkFractMul(a2, srcPt[3].fY) + |
| srcPt[3].fY - srcPt[0].fY, scale.fX); |
| dst->fMat[kMPersp0] = SkFixedDiv(a2, scale.fX); |
| dst->fMat[kMSkewX] = SkFixedDiv(SkFractMul(a1, srcPt[1].fX) + |
| srcPt[1].fX - srcPt[0].fX, scale.fY); |
| dst->fMat[kMScaleY] = SkFixedDiv(SkFractMul(a1, srcPt[1].fY) + |
| srcPt[1].fY - srcPt[0].fY, scale.fY); |
| dst->fMat[kMPersp1] = SkFixedDiv(a1, scale.fY); |
| dst->fMat[kMTransX] = srcPt[0].fX; |
| dst->fMat[kMTransY] = srcPt[0].fY; |
| dst->fMat[kMPersp2] = SK_Fract1; |
| dst->setTypeMask(kUnknown_Mask); |
| return true; |
| } |
| |
| #else /* Scalar is float */ |
| |
| 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 = SkScalarDiv(SkScalarMul(pt1.fX, pt2.fX) + |
| SkScalarMul(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 = SkScalarDiv(SkScalarMulDiv(x0 - x1, y2, x2) - y0 + y1, denom); |
| } else { |
| float denom = x1 - SkScalarMulDiv(y1, x2, y2); |
| if (checkForZero(denom)) { |
| return false; |
| } |
| a1 = SkScalarDiv(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 = SkScalarDiv(y0 - y2 - SkScalarMulDiv(x0 - x2, y1, x1), denom); |
| } else { |
| float denom = SkScalarMulDiv(y2, x1, y1) - x2; |
| if (checkForZero(denom)) { |
| return false; |
| } |
| a2 = SkScalarDiv(SkScalarMulDiv(y0 - y2, x1, y1) - x0 + x2, denom); |
| } |
| |
| float invScale = 1 / scale.fX; |
| dst->fMat[kMScaleX] = SkScalarMul(SkScalarMul(a2, srcPt[3].fX) + |
| srcPt[3].fX - srcPt[0].fX, invScale); |
| dst->fMat[kMSkewY] = SkScalarMul(SkScalarMul(a2, srcPt[3].fY) + |
| srcPt[3].fY - srcPt[0].fY, invScale); |
| dst->fMat[kMPersp0] = SkScalarMul(a2, invScale); |
| invScale = 1 / scale.fY; |
| dst->fMat[kMSkewX] = SkScalarMul(SkScalarMul(a1, srcPt[1].fX) + |
| srcPt[1].fX - srcPt[0].fX, invScale); |
| dst->fMat[kMScaleY] = SkScalarMul(SkScalarMul(a1, srcPt[1].fY) + |
| srcPt[1].fY - srcPt[0].fY, invScale); |
| dst->fMat[kMPersp1] = SkScalarMul(a1, invScale); |
| dst->fMat[kMTransX] = srcPt[0].fX; |
| dst->fMat[kMTransY] = srcPt[0].fY; |
| dst->fMat[kMPersp2] = 1; |
| dst->setTypeMask(kUnknown_Mask); |
| return true; |
| } |
| |
| #endif |
| |
| 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; |
| } |
| if (!result.setConcat(tempMap, result)) { |
| return false; |
| } |
| *this = result; |
| return true; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| SkScalar SkMatrix::getMaxStretch() const { |
| TypeMask mask = this->getType(); |
| |
| if (mask & kPerspective_Mask) { |
| return -SK_Scalar1; |
| } |
| |
| SkScalar stretch; |
| |
| if (this->isIdentity()) { |
| stretch = SK_Scalar1; |
| } else if (!(mask & kAffine_Mask)) { |
| stretch = SkMaxScalar(SkScalarAbs(fMat[kMScaleX]), SkScalarAbs(fMat[kMScaleY])); |
| #if 0 // don't have this bit |
| } else if (mask & kZeroScale_TypeBit) { |
| stretch = SkMaxScalar(SkScalarAbs(fM[kSkewX]), SkScalarAbs(fM[kSkewY])); |
| #endif |
| } else { |
| // ignore the translation part of the matrix, just look at 2x2 portion. |
| // compute singular values, take largest abs value. |
| // [a b; b c] = A^T*A |
| SkScalar a = SkScalarMul(fMat[kMScaleX], fMat[kMScaleX]) + SkScalarMul(fMat[kMSkewY], fMat[kMSkewY]); |
| SkScalar b = SkScalarMul(fMat[kMScaleX], fMat[kMSkewX]) + SkScalarMul(fMat[kMScaleY], fMat[kMSkewY]); |
| SkScalar c = SkScalarMul(fMat[kMSkewX], fMat[kMSkewX]) + SkScalarMul(fMat[kMScaleY], fMat[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 guaraunteed to be pos and real). |
| SkScalar largerRoot; |
| SkScalar bSqd = SkScalarMul(b,b); |
| if (bSqd <= SkFloatToScalar(1e-10)) { // will be true if upper left 2x2 is orthogonal, which is common, so save some math |
| largerRoot = SkMaxScalar(a, c); |
| } else { |
| SkScalar aminusc = a - c; |
| SkScalar apluscdiv2 = (a + c) / 2; |
| SkScalar x = SkScalarSqrt(SkScalarMul(aminusc, aminusc) + 4 * bSqd) / 2; |
| largerRoot = apluscdiv2 + x; |
| } |
| |
| stretch = SkScalarSqrt(largerRoot); |
| } |
| #if defined(SK_DEBUG) && 0 |
| // test a bunch of vectors. None should be scaled by more than stretch |
| // (modulo some error) and we should find a vector that is scaled by almost |
| // stretch. |
| SkPoint pt; |
| SkScalar max = 0; |
| for (int i = 0; i < 1000; ++i) { |
| SkScalar x = (float)rand() / RAND_MAX; |
| SkScalar y = sqrtf(1 - (x*x)); |
| pt.fX = fMat[kMScaleX]*x + fMat[kMSkewX]*y; |
| pt.fY = fMat[kMSkewY]*x + fMat[kMScaleY]*y; |
| SkScalar d = pt.distanceToOrigin(); |
| SkASSERT(d <= (1.0001 * stretch)); |
| if (max < pt.distanceToOrigin()) { |
| max = pt.distanceToOrigin(); |
| } |
| } |
| SkASSERT((stretch - max) < .05*stretch); |
| #endif |
| return stretch; |
| } |
| |
| const SkMatrix& SkMatrix::I() { |
| static SkMatrix gIdentity; |
| static bool gOnce; |
| if (!gOnce) { |
| gIdentity.reset(); |
| gOnce = true; |
| } |
| return gIdentity; |
| }; |
| |
| const SkMatrix& SkMatrix::InvalidMatrix() { |
| static SkMatrix gInvalid; |
| static bool gOnce; |
| if (!gOnce) { |
| gInvalid.setAll(SK_ScalarMax, SK_ScalarMax, SK_ScalarMax, |
| SK_ScalarMax, SK_ScalarMax, SK_ScalarMax, |
| SK_ScalarMax, SK_ScalarMax, SK_ScalarMax); |
| gInvalid.getType(); // force the type to be computed |
| gOnce = true; |
| } |
| return gInvalid; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| uint32_t SkMatrix::flatten(void* buffer) const { |
| // TODO write less for simple matrices |
| if (buffer) { |
| memcpy(buffer, fMat, 9 * sizeof(SkScalar)); |
| } |
| return 9 * sizeof(SkScalar); |
| } |
| |
| uint32_t SkMatrix::unflatten(const void* buffer) { |
| if (buffer) { |
| memcpy(fMat, buffer, 9 * sizeof(SkScalar)); |
| this->setTypeMask(kUnknown_Mask); |
| } |
| return 9 * sizeof(SkScalar); |
| } |
| |
| void SkMatrix::dump() const { |
| SkString str; |
| this->toDumpString(&str); |
| SkDebugf("%s\n", str.c_str()); |
| } |
| |
| void SkMatrix::toDumpString(SkString* str) const { |
| #ifdef SK_CAN_USE_FLOAT |
| str->printf("[%8.4f %8.4f %8.4f][%8.4f %8.4f %8.4f][%8.4f %8.4f %8.4f]", |
| #ifdef SK_SCALAR_IS_FLOAT |
| fMat[0], fMat[1], fMat[2], fMat[3], fMat[4], fMat[5], |
| fMat[6], fMat[7], fMat[8]); |
| #else |
| SkFixedToFloat(fMat[0]), SkFixedToFloat(fMat[1]), SkFixedToFloat(fMat[2]), |
| SkFixedToFloat(fMat[3]), SkFixedToFloat(fMat[4]), SkFixedToFloat(fMat[5]), |
| SkFractToFloat(fMat[6]), SkFractToFloat(fMat[7]), SkFractToFloat(fMat[8])); |
| #endif |
| #else // can't use float |
| str->printf("[%x %x %x][%x %x %x][%x %x %x]", |
| fMat[0], fMat[1], fMat[2], fMat[3], fMat[4], fMat[5], |
| fMat[6], fMat[7], fMat[8]); |
| #endif |
| } |