Skia
2DGraphicsLibrary
|
The SkMatrix class holds a 3x3 matrix for transforming coordinates. More...
#include <SkMatrix.h>
Public Types | |
enum | TypeMask { kIdentity_Mask = 0, kTranslate_Mask = 0x01, kScale_Mask = 0x02, kAffine_Mask = 0x04, kPerspective_Mask = 0x08 } |
Enum of bit fields for the mask return by getType(). More... | |
enum | { kMScaleX, kMSkewX, kMTransX, kMSkewY, kMScaleY, kMTransY, kMPersp0, kMPersp1, kMPersp2 } |
enum | { kAScaleX, kASkewY, kASkewX, kAScaleY, kATransX, kATransY } |
Affine arrays are in column major order because that's how PDF and XPS like it. | |
enum | ScaleToFit { kFill_ScaleToFit, kStart_ScaleToFit, kCenter_ScaleToFit, kEnd_ScaleToFit } |
enum | { kMaxFlattenSize = 9 * sizeof(SkScalar) + sizeof(uint32_t) } |
typedef void(* | MapXYProc )(const SkMatrix &mat, SkScalar x, SkScalar y, SkPoint *result) |
typedef void(* | MapPtsProc )(const SkMatrix &mat, SkPoint dst[], const SkPoint src[], int count) |
Public Member Functions | |
TypeMask | getType () const |
Returns a bitfield describing the transformations the matrix may perform. More... | |
bool | isIdentity () const |
Returns true if the matrix is identity. | |
bool | isScaleTranslate () const |
bool | rectStaysRect () const |
Returns true if will map a rectangle to another rectangle. More... | |
bool | preservesAxisAlignment () const |
bool | hasPerspective () const |
Returns true if the matrix contains perspective elements. | |
bool | isSimilarity (SkScalar tol=SK_ScalarNearlyZero) const |
Returns true if the matrix contains only translation, rotation/reflection or uniform scale Returns false if other transformation types are included or is degenerate. | |
bool | preservesRightAngles (SkScalar tol=SK_ScalarNearlyZero) const |
Returns true if the matrix contains only translation, rotation/reflection or scale (non-uniform scale is allowed). More... | |
SkScalar | operator[] (int index) const |
SkScalar | get (int index) const |
SkScalar | getScaleX () const |
SkScalar | getScaleY () const |
SkScalar | getSkewY () const |
SkScalar | getSkewX () const |
SkScalar | getTranslateX () const |
SkScalar | getTranslateY () const |
SkScalar | getPerspX () const |
SkScalar | getPerspY () const |
SkScalar & | operator[] (int index) |
void | set (int index, SkScalar value) |
void | setScaleX (SkScalar v) |
void | setScaleY (SkScalar v) |
void | setSkewY (SkScalar v) |
void | setSkewX (SkScalar v) |
void | setTranslateX (SkScalar v) |
void | setTranslateY (SkScalar v) |
void | setPerspX (SkScalar v) |
void | setPerspY (SkScalar v) |
void | setAll (SkScalar scaleX, SkScalar skewX, SkScalar transX, SkScalar skewY, SkScalar scaleY, SkScalar transY, SkScalar persp0, SkScalar persp1, SkScalar persp2) |
void | get9 (SkScalar buffer[9]) const |
Copy the 9 scalars for this matrix into buffer, in the same order as the kMScaleX enum... More... | |
void | set9 (const SkScalar buffer[9]) |
Set this matrix to the 9 scalars from the buffer, in the same order as the kMScaleX enum... More... | |
void | reset () |
Set the matrix to identity. | |
void | setIdentity () |
void | setTranslate (SkScalar dx, SkScalar dy) |
Set the matrix to translate by (dx, dy). | |
void | setTranslate (const SkVector &v) |
void | setScale (SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) |
Set the matrix to scale by sx and sy, with a pivot point at (px, py). More... | |
void | setScale (SkScalar sx, SkScalar sy) |
Set the matrix to scale by sx and sy. | |
bool | setIDiv (int divx, int divy) |
Set the matrix to scale by 1/divx and 1/divy. More... | |
void | setRotate (SkScalar degrees, SkScalar px, SkScalar py) |
Set the matrix to rotate by the specified number of degrees, with a pivot point at (px, py). More... | |
void | setRotate (SkScalar degrees) |
Set the matrix to rotate about (0,0) by the specified number of degrees. | |
void | setSinCos (SkScalar sinValue, SkScalar cosValue, SkScalar px, SkScalar py) |
Set the matrix to rotate by the specified sine and cosine values, with a pivot point at (px, py). More... | |
void | setSinCos (SkScalar sinValue, SkScalar cosValue) |
Set the matrix to rotate by the specified sine and cosine values. | |
SkMatrix & | setRSXform (const SkRSXform &) |
void | setSkew (SkScalar kx, SkScalar ky, SkScalar px, SkScalar py) |
Set the matrix to skew by sx and sy, with a pivot point at (px, py). More... | |
void | setSkew (SkScalar kx, SkScalar ky) |
Set the matrix to skew by sx and sy. | |
void | setConcat (const SkMatrix &a, const SkMatrix &b) |
Set the matrix to the concatenation of the two specified matrices. More... | |
void | preTranslate (SkScalar dx, SkScalar dy) |
Preconcats the matrix with the specified translation. More... | |
void | preScale (SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) |
Preconcats the matrix with the specified scale. More... | |
void | preScale (SkScalar sx, SkScalar sy) |
Preconcats the matrix with the specified scale. More... | |
void | preRotate (SkScalar degrees, SkScalar px, SkScalar py) |
Preconcats the matrix with the specified rotation. More... | |
void | preRotate (SkScalar degrees) |
Preconcats the matrix with the specified rotation. More... | |
void | preSkew (SkScalar kx, SkScalar ky, SkScalar px, SkScalar py) |
Preconcats the matrix with the specified skew. More... | |
void | preSkew (SkScalar kx, SkScalar ky) |
Preconcats the matrix with the specified skew. More... | |
void | preConcat (const SkMatrix &other) |
Preconcats the matrix with the specified matrix. More... | |
void | postTranslate (SkScalar dx, SkScalar dy) |
Postconcats the matrix with the specified translation. More... | |
void | postScale (SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) |
Postconcats the matrix with the specified scale. More... | |
void | postScale (SkScalar sx, SkScalar sy) |
Postconcats the matrix with the specified scale. More... | |
bool | postIDiv (int divx, int divy) |
Postconcats the matrix by dividing it by the specified integers. More... | |
void | postRotate (SkScalar degrees, SkScalar px, SkScalar py) |
Postconcats the matrix with the specified rotation. More... | |
void | postRotate (SkScalar degrees) |
Postconcats the matrix with the specified rotation. More... | |
void | postSkew (SkScalar kx, SkScalar ky, SkScalar px, SkScalar py) |
Postconcats the matrix with the specified skew. More... | |
void | postSkew (SkScalar kx, SkScalar ky) |
Postconcats the matrix with the specified skew. More... | |
void | postConcat (const SkMatrix &other) |
Postconcats the matrix with the specified matrix. More... | |
bool | setRectToRect (const SkRect &src, const SkRect &dst, ScaleToFit stf) |
Set the matrix to the scale and translate values that map the source rectangle to the destination rectangle, returning true if the the result can be represented. More... | |
bool | setPolyToPoly (const SkPoint src[], const SkPoint dst[], int count) |
Set the matrix such that the specified src points would map to the specified dst points. More... | |
bool SK_WARN_UNUSED_RESULT | invert (SkMatrix *inverse) const |
If this matrix can be inverted, return true and if inverse is not null, set inverse to be the inverse of this matrix. More... | |
bool SK_WARN_UNUSED_RESULT | asAffine (SkScalar affine[6]) const |
Fills the passed array with the affine values in column major order. More... | |
void | setAffine (const SkScalar affine[6]) |
Set the matrix to the specified affine values. More... | |
void | mapPoints (SkPoint dst[], const SkPoint src[], int count) const |
Apply this matrix to the array of points specified by src, and write the transformed points into the array of points specified by dst. More... | |
void | mapPoints (SkPoint pts[], int count) const |
Apply this matrix to the array of points, overwriting it with the transformed values. More... | |
void | mapPointsWithStride (SkPoint pts[], size_t stride, int count) const |
Like mapPoints but with custom byte stride between the points. More... | |
void | mapPointsWithStride (SkPoint dst[], SkPoint src[], size_t stride, int count) const |
Like mapPoints but with custom byte stride between the points. | |
void | mapHomogeneousPoints (SkScalar dst[], const SkScalar src[], int count) const |
Apply this matrix to the array of homogeneous points, specified by src, where a homogeneous point is defined by 3 contiguous scalar values, and write the transformed points into the array of scalars specified by dst. More... | |
void | mapXY (SkScalar x, SkScalar y, SkPoint *result) const |
SkPoint | mapXY (SkScalar x, SkScalar y) const |
void | mapVectors (SkVector dst[], const SkVector src[], int count) const |
Apply this matrix to the array of vectors specified by src, and write the transformed vectors into the array of vectors specified by dst. More... | |
void | mapVectors (SkVector vecs[], int count) const |
Apply this matrix to the array of vectors specified by src, and write the transformed vectors into the array of vectors specified by dst. More... | |
void | mapVector (SkScalar dx, SkScalar dy, SkVector *result) const |
SkVector | mapVector (SkScalar dx, SkScalar dy) const |
bool | mapRect (SkRect *dst, const SkRect &src) const |
Apply this matrix to the src rectangle, and write the transformed rectangle into dst. More... | |
bool | mapRect (SkRect *rect) const |
Apply this matrix to the rectangle, and write the transformed rectangle back into it. More... | |
void | mapRectToQuad (SkPoint dst[4], const SkRect &rect) const |
Apply this matrix to the src rectangle, and write the four transformed points into dst. More... | |
void | mapRectScaleTranslate (SkRect *dst, const SkRect &src) const |
Maps a rect to another rect, asserting (in debug mode) that the matrix only contains scale and translate elements. More... | |
SkScalar | mapRadius (SkScalar radius) const |
Return the mean radius of a circle after it has been mapped by this matrix. More... | |
MapXYProc | getMapXYProc () const |
MapPtsProc | getMapPtsProc () const |
bool | isFixedStepInX () const |
Returns true if the matrix can be stepped in X (not complex perspective). | |
SkVector | fixedStepInX (SkScalar y) const |
If the matrix can be stepped in X (not complex perspective) then return the step value. More... | |
bool | cheapEqualTo (const SkMatrix &m) const |
Efficient comparison of two matrices. More... | |
size_t | writeToMemory (void *buffer) const |
size_t | readFromMemory (const void *buffer, size_t length) |
Reads data from the buffer parameter. More... | |
void | dump () const |
void | toString (SkString *) const |
SkScalar | getMinScale () const |
Calculates the minimum scaling factor of the matrix as computed from the SVD of the upper left 2x2. More... | |
SkScalar | getMaxScale () const |
Calculates the maximum scaling factor of the matrix as computed from the SVD of the upper left 2x2. More... | |
bool SK_WARN_UNUSED_RESULT | getMinMaxScales (SkScalar scaleFactors[2]) const |
Gets both the min and max scale factors. More... | |
bool | decomposeScale (SkSize *scale, SkMatrix *remaining=NULL) const |
Attempt to decompose this matrix into a scale-only component and whatever remains, where the scale component is to be applied first. More... | |
void | dirtyMatrixTypeCache () |
Testing routine; the matrix's type cache should never need to be manually invalidated during normal use. | |
void | setScaleTranslate (SkScalar sx, SkScalar sy, SkScalar tx, SkScalar ty) |
Initialize the matrix to be scale + post-translate. | |
Static Public Member Functions | |
static SkMatrix SK_WARN_UNUSED_RESULT | MakeScale (SkScalar sx, SkScalar sy) |
static SkMatrix SK_WARN_UNUSED_RESULT | MakeScale (SkScalar scale) |
static SkMatrix SK_WARN_UNUSED_RESULT | MakeTrans (SkScalar dx, SkScalar dy) |
static SkMatrix | MakeRectToRect (const SkRect &src, const SkRect &dst, ScaleToFit stf) |
static void | SetAffineIdentity (SkScalar affine[6]) |
Fills the passed array with affine identity values in column major order. More... | |
static MapXYProc | GetMapXYProc (TypeMask mask) |
static MapPtsProc | GetMapPtsProc (TypeMask mask) |
static const SkMatrix & | I () |
Return a reference to a const identity matrix. | |
static const SkMatrix & | InvalidMatrix () |
Return a reference to a const matrix that is "invalid", one that could never be used. | |
static SkMatrix | Concat (const SkMatrix &a, const SkMatrix &b) |
Return the concatenation of two matrices, a * b. | |
Private Types | |
enum | { kRectStaysRect_Mask = 0x10, kOnlyPerspectiveValid_Mask = 0x40, kUnknown_Mask = 0x80, kORableMasks, kAllMasks } |
Private Member Functions | |
bool | isFinite () const |
Are all elements of the matrix finite? | |
uint8_t | computeTypeMask () const |
uint8_t | computePerspectiveTypeMask () const |
void | setTypeMask (int mask) |
void | orTypeMask (int mask) |
void | clearTypeMask (int mask) |
TypeMask | getPerspectiveTypeMaskOnly () const |
bool | isTriviallyIdentity () const |
Returns true if we already know that the matrix is identity; false otherwise. | |
bool SK_WARN_UNUSED_RESULT | invertNonIdentity (SkMatrix *inverse) const |
Static Private Member Functions | |
static void | ComputeInv (SkScalar dst[9], const SkScalar src[9], double invDet, bool isPersp) |
static bool | Poly2Proc (const SkPoint[], SkMatrix *, const SkPoint &scale) |
static bool | Poly3Proc (const SkPoint[], SkMatrix *, const SkPoint &scale) |
static bool | Poly4Proc (const SkPoint[], SkMatrix *, const SkPoint &scale) |
static void | Identity_xy (const SkMatrix &, SkScalar, SkScalar, SkPoint *) |
static void | Trans_xy (const SkMatrix &, SkScalar, SkScalar, SkPoint *) |
static void | Scale_xy (const SkMatrix &, SkScalar, SkScalar, SkPoint *) |
static void | ScaleTrans_xy (const SkMatrix &, SkScalar, SkScalar, SkPoint *) |
static void | Rot_xy (const SkMatrix &, SkScalar, SkScalar, SkPoint *) |
static void | RotTrans_xy (const SkMatrix &, SkScalar, SkScalar, SkPoint *) |
static void | Persp_xy (const SkMatrix &, SkScalar, SkScalar, SkPoint *) |
static void | Identity_pts (const SkMatrix &, SkPoint[], const SkPoint[], int) |
static void | Trans_pts (const SkMatrix &, SkPoint dst[], const SkPoint[], int) |
static void | Scale_pts (const SkMatrix &, SkPoint dst[], const SkPoint[], int) |
static void | ScaleTrans_pts (const SkMatrix &, SkPoint dst[], const SkPoint[], int count) |
static void | Persp_pts (const SkMatrix &, SkPoint dst[], const SkPoint[], int) |
static void | Affine_vpts (const SkMatrix &, SkPoint dst[], const SkPoint[], int) |
Private Attributes | |
SkScalar | fMat [9] |
uint32_t | fTypeMask |
Static Private Attributes | |
static const MapXYProc | gMapXYProcs [] |
static const MapPtsProc | gMapPtsProcs [] |
Friends | |
class | SkPerspIter |
class | SkMatrixPriv |
SK_API bool | operator== (const SkMatrix &a, const SkMatrix &b) |
SK_API bool | operator!= (const SkMatrix &a, const SkMatrix &b) |
The SkMatrix class holds a 3x3 matrix for transforming coordinates.
SkMatrix does not have a constructor, so it must be explicitly initialized using either reset() - to construct an identity matrix, or one of the set functions (e.g. setTranslate, setRotate, etc.).
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enum SkMatrix::ScaleToFit |
enum SkMatrix::TypeMask |
Enum of bit fields for the mask return by getType().
Use this to identify the complexity of the matrix.
bool SK_WARN_UNUSED_RESULT SkMatrix::asAffine | ( | SkScalar | affine[6] | ) | const |
Fills the passed array with the affine values in column major order.
If the matrix is a perspective transform, returns false and does not change the passed array.
affine | The array to fill with affine values. Ignored if NULL. |
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Efficient comparison of two matrices.
It distinguishes between zero and negative zero. It will return false when the sign of zero values is the only difference between the two matrices. It considers NaN values to be equal to themselves. So a matrix full of NaNs is "cheap equal" to another matrix full of NaNs iff the NaN values are bitwise identical while according to strict the strict == test a matrix with a NaN value is equal to nothing, including itself.
Attempt to decompose this matrix into a scale-only component and whatever remains, where the scale component is to be applied first.
M -> Remaining * Scale
On success, return true and assign the scale and remaining components (assuming their respective parameters are not null). On failure return false and ignore the parameters.
Possible reasons to fail: perspective, one or more scale factors are zero.
SkVector SkMatrix::fixedStepInX | ( | SkScalar | y | ) | const |
If the matrix can be stepped in X (not complex perspective) then return the step value.
If it cannot, behavior is undefined.
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Copy the 9 scalars for this matrix into buffer, in the same order as the kMScaleX enum...
scalex, skewx, transx, skewy, scaley, transy, persp0, persp1, persp2
SkScalar SkMatrix::getMaxScale | ( | ) | const |
Calculates the maximum scaling factor of the matrix as computed from the SVD of the upper left 2x2.
If the max scale factor cannot be computed (for example overflow or perspective) -1 is returned.
bool SK_WARN_UNUSED_RESULT SkMatrix::getMinMaxScales | ( | SkScalar | scaleFactors[2] | ) | const |
Gets both the min and max scale factors.
The min scale factor is scaleFactors[0] and the max is scaleFactors[1]. If the min/max scale factors cannot be computed false is returned and the values of scaleFactors[] are undefined.
SkScalar SkMatrix::getMinScale | ( | ) | const |
Calculates the minimum scaling factor of the matrix as computed from the SVD of the upper left 2x2.
If the max scale factor cannot be computed (for example overflow or perspective) -1 is returned.
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Returns a bitfield describing the transformations the matrix may perform.
The bitfield is computed conservatively, so it may include false positives. For example, when kPerspective_Mask is true, all other bits may be set to true even in the case of a pure perspective transform.
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If this matrix can be inverted, return true and if inverse is not null, set inverse to be the inverse of this matrix.
If this matrix cannot be inverted, ignore inverse and return false
void SkMatrix::mapHomogeneousPoints | ( | SkScalar | dst[], |
const SkScalar | src[], | ||
int | count | ||
) | const |
Apply this matrix to the array of homogeneous points, specified by src, where a homogeneous point is defined by 3 contiguous scalar values, and write the transformed points into the array of scalars specified by dst.
dst[] = M * src[]
dst | Where the transformed coordinates are written. It must contain at least 3 * count entries |
src | The original coordinates that are to be transformed. It must contain at least 3 * count entries |
count | The number of triples (homogeneous points) in src to read, and then transform into dst. |
Apply this matrix to the array of points specified by src, and write the transformed points into the array of points specified by dst.
dst[] = M * src[]
dst | Where the transformed coordinates are written. It must contain at least count entries |
src | The original coordinates that are to be transformed. It must contain at least count entries |
count | The number of points in src to read, and then transform into dst. |
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Apply this matrix to the array of points, overwriting it with the transformed values.
dst[] = M * pts[]
pts | The points to be transformed. It must contain at least count entries |
count | The number of points in pts. |
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Like mapPoints but with custom byte stride between the points.
Stride should be a multiple of sizeof(SkScalar).
SkScalar SkMatrix::mapRadius | ( | SkScalar | radius | ) | const |
Return the mean radius of a circle after it has been mapped by this matrix.
NOTE: in perspective this value assumes the circle has its center at the origin.
Apply this matrix to the src rectangle, and write the transformed rectangle into dst.
This is accomplished by transforming the 4 corners of src, and then setting dst to the bounds of those points.
dst | Where the transformed rectangle is written. |
src | The original rectangle to be transformed. |
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Apply this matrix to the rectangle, and write the transformed rectangle back into it.
This is accomplished by transforming the 4 corners of rect, and then setting it to the bounds of those points
rect | The rectangle to transform. |
Maps a rect to another rect, asserting (in debug mode) that the matrix only contains scale and translate elements.
If it contains other elements, the results are undefined.
Apply this matrix to the src rectangle, and write the four transformed points into dst.
The points written to dst will be the original top-left, top-right, bottom-right, and bottom-left points transformed by the matrix.
dst | Where the transformed quad is written. |
rect | The original rectangle to be transformed. |
Apply this matrix to the array of vectors specified by src, and write the transformed vectors into the array of vectors specified by dst.
This is similar to mapPoints, but ignores any translation in the matrix.
dst | Where the transformed coordinates are written. It must contain at least count entries |
src | The original coordinates that are to be transformed. It must contain at least count entries |
count | The number of vectors in src to read, and then transform into dst. |
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Apply this matrix to the array of vectors specified by src, and write the transformed vectors into the array of vectors specified by dst.
This is similar to mapPoints, but ignores any translation in the matrix.
vecs | The vectors to be transformed. It must contain at least count entries |
count | The number of vectors in vecs. |
void SkMatrix::postConcat | ( | const SkMatrix & | other | ) |
Postconcats the matrix with the specified matrix.
M' = other * M
bool SkMatrix::postIDiv | ( | int | divx, |
int | divy | ||
) |
Postconcats the matrix by dividing it by the specified integers.
M' = S(1/divx, 1/divy, 0, 0) * M
void SkMatrix::postRotate | ( | SkScalar | degrees, |
SkScalar | px, | ||
SkScalar | py | ||
) |
Postconcats the matrix with the specified rotation.
M' = R(degrees, px, py) * M
void SkMatrix::postRotate | ( | SkScalar | degrees | ) |
Postconcats the matrix with the specified rotation.
M' = R(degrees) * M
void SkMatrix::postScale | ( | SkScalar | sx, |
SkScalar | sy, | ||
SkScalar | px, | ||
SkScalar | py | ||
) |
Postconcats the matrix with the specified scale.
M' = S(sx, sy, px, py) * M
void SkMatrix::postScale | ( | SkScalar | sx, |
SkScalar | sy | ||
) |
Postconcats the matrix with the specified scale.
M' = S(sx, sy) * M
void SkMatrix::postSkew | ( | SkScalar | kx, |
SkScalar | ky, | ||
SkScalar | px, | ||
SkScalar | py | ||
) |
Postconcats the matrix with the specified skew.
M' = K(kx, ky, px, py) * M
void SkMatrix::postSkew | ( | SkScalar | kx, |
SkScalar | ky | ||
) |
Postconcats the matrix with the specified skew.
M' = K(kx, ky) * M
void SkMatrix::postTranslate | ( | SkScalar | dx, |
SkScalar | dy | ||
) |
Postconcats the matrix with the specified translation.
M' = T(dx, dy) * M
void SkMatrix::preConcat | ( | const SkMatrix & | other | ) |
Preconcats the matrix with the specified matrix.
M' = M * other
void SkMatrix::preRotate | ( | SkScalar | degrees, |
SkScalar | px, | ||
SkScalar | py | ||
) |
Preconcats the matrix with the specified rotation.
M' = M * R(degrees, px, py)
void SkMatrix::preRotate | ( | SkScalar | degrees | ) |
Preconcats the matrix with the specified rotation.
M' = M * R(degrees)
void SkMatrix::preScale | ( | SkScalar | sx, |
SkScalar | sy, | ||
SkScalar | px, | ||
SkScalar | py | ||
) |
Preconcats the matrix with the specified scale.
M' = M * S(sx, sy, px, py)
void SkMatrix::preScale | ( | SkScalar | sx, |
SkScalar | sy | ||
) |
Preconcats the matrix with the specified scale.
M' = M * S(sx, sy)
bool SkMatrix::preservesRightAngles | ( | SkScalar | tol = SK_ScalarNearlyZero | ) | const |
Returns true if the matrix contains only translation, rotation/reflection or scale (non-uniform scale is allowed).
Returns false if other transformation types are included or is degenerate
void SkMatrix::preSkew | ( | SkScalar | kx, |
SkScalar | ky, | ||
SkScalar | px, | ||
SkScalar | py | ||
) |
Preconcats the matrix with the specified skew.
M' = M * K(kx, ky, px, py)
void SkMatrix::preSkew | ( | SkScalar | kx, |
SkScalar | ky | ||
) |
Preconcats the matrix with the specified skew.
M' = M * K(kx, ky)
void SkMatrix::preTranslate | ( | SkScalar | dx, |
SkScalar | dy | ||
) |
Preconcats the matrix with the specified translation.
M' = M * T(dx, dy)
size_t SkMatrix::readFromMemory | ( | const void * | buffer, |
size_t | length | ||
) |
Reads data from the buffer parameter.
buffer | Memory to read from |
length | Amount of memory available in the buffer |
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Returns true if will map a rectangle to another rectangle.
This can be true if the matrix is identity, scale-only, or rotates a multiple of 90 degrees, or mirrors in x or y.
void SkMatrix::set9 | ( | const SkScalar | buffer[9] | ) |
Set this matrix to the 9 scalars from the buffer, in the same order as the kMScaleX enum...
scalex, skewx, transx, skewy, scaley, transy, persp0, persp1, persp2
Note: calling set9 followed by get9 may not return the exact same values. Since the matrix is used to map non-homogeneous coordinates, it is free to rescale the 9 values as needed.
void SkMatrix::setAffine | ( | const SkScalar | affine[6] | ) |
Set the matrix to the specified affine values.
Note: these are passed in column major order.
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Fills the passed array with affine identity values in column major order.
affine | The array to fill with affine identity values. Must not be NULL. |
Set the matrix to the concatenation of the two specified matrices.
Either of the two matrices may also be the target matrix. this = a * b;
bool SkMatrix::setIDiv | ( | int | divx, |
int | divy | ||
) |
Set the matrix to scale by 1/divx and 1/divy.
Returns false and doesn't touch the matrix if either divx or divy is zero.
Set the matrix such that the specified src points would map to the specified dst points.
count must be within [0..4].
src | The array of src points |
dst | The array of dst points |
count | The number of points to use for the transformation |
bool SkMatrix::setRectToRect | ( | const SkRect & | src, |
const SkRect & | dst, | ||
ScaleToFit | stf | ||
) |
Set the matrix to the scale and translate values that map the source rectangle to the destination rectangle, returning true if the the result can be represented.
src | the source rectangle to map from. |
dst | the destination rectangle to map to. |
stf | the ScaleToFit option |
void SkMatrix::setRotate | ( | SkScalar | degrees, |
SkScalar | px, | ||
SkScalar | py | ||
) |
Set the matrix to rotate by the specified number of degrees, with a pivot point at (px, py).
The pivot point is the coordinate that should remain unchanged by the specified transformation.
void SkMatrix::setScale | ( | SkScalar | sx, |
SkScalar | sy, | ||
SkScalar | px, | ||
SkScalar | py | ||
) |
Set the matrix to scale by sx and sy, with a pivot point at (px, py).
The pivot point is the coordinate that should remain unchanged by the specified transformation.
void SkMatrix::setSinCos | ( | SkScalar | sinValue, |
SkScalar | cosValue, | ||
SkScalar | px, | ||
SkScalar | py | ||
) |
Set the matrix to rotate by the specified sine and cosine values, with a pivot point at (px, py).
The pivot point is the coordinate that should remain unchanged by the specified transformation.
void SkMatrix::setSkew | ( | SkScalar | kx, |
SkScalar | ky, | ||
SkScalar | px, | ||
SkScalar | py | ||
) |
Set the matrix to skew by sx and sy, with a pivot point at (px, py).
The pivot point is the coordinate that should remain unchanged by the specified transformation.