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#include <Matrix2D.h>
Public Member Functions | |
Matrix2D (double a=1, double b=0, double c=0, double d=1, double h=0, double v=0) | |
Creates and initializes a Matrix object based on six numbers that define an affine transformation. | |
Matrix2D (const Matrix2D &m) | |
Copy constructor. | |
Matrix2D & | operator= (const Matrix2D &m) |
Assignment operator. | |
void | Set (double a, double b, double c, double d, double h, double v) |
The Set method sets the elements of this matrix. | |
void | Concat (double a, double b, double c, double d, double h, double v) |
The Concat method updates this matrix with the product of itself and another matrix specified through an argument list. | |
Matrix2D & | operator*= (const Matrix2D &m) |
The multiply method updates this matrix with the product of itself and another matrix. | |
Matrix2D | operator* (const Matrix2D &m) const |
Multiplies this matrix with another matrix and return the result in a new matrix. | |
bool | operator== (const Matrix2D &m) const |
The equality operator determines whether the elements of this matrix are equal to the elements of another matrix. | |
bool | operator!= (const Matrix2D &m) const |
The inequality operator determines whether the elements of this matrix are not equal to the elements of another matrix. | |
void | Mult (double &in_out_x, double &in_out_y) const |
Transform/multiply the point (in_out_x, in_out_y) using this matrix. | |
Matrix2D | Inverse () const |
Matrix2D & | Translate (double h, double v) |
The Translate method updates this matrix with the product of itself and a translation matrix (i.e. | |
Matrix2D & | Scale (double h, double v) |
The Scale method updates this matrix with the product of itself and a scaling matrix. | |
Static Public Member Functions | |
static Matrix2D | ZeroMatrix () |
Create zero matrix (0 0 0 0 0 0). | |
static Matrix2D | IdentityMatrix () |
Create identity matrix (1 0 0 1 0 0). | |
static Matrix2D | RotationMatrix (const double angle) |
A Matrix2D object represents a 3x3 matrix that, in turn, represents an affine transformation. A Matrix2D object stores only six of the nine numbers in a 3x3 matrix because all 3x3 matrices that represent affine transformations have the same third column (0, 0, 1).
Affine transformations include rotating, scaling, reflecting, shearing, and translating. In PDFNet, the Matrix2D class provides the foundation for performing affine transformations on vector drawings, images, and text.
A transformation matrix specifies the relationship between two coordinate spaces. By modifying a transformation matrix, objects can be scaled, rotated, translated, or transformed in other ways.
A transformation matrix in PDF is specified by six numbers, usually in the form of an array containing six elements. In its most general form, this array is denoted [a b c d h v]; The following table lists the arrays that specify the most common transformations:
Matrix2D elements are positioned as follows : | m_a m_b 0 | | m_c m_d 0 | | m_h m_v 1 |
A single Matrix2D object can store a single transformation or a sequence of transformations. The latter is called a composite transformation. The matrix of a composite transformation is obtained by multiplying (concatenating) the matrices of the individual transformations. Because matrix multiplication is not commutative-the order in which matrices are multiplied is significant. For example, if you first rotate, then scale, then translate, you get a different result than if you first translate, then rotate, then scale.
For more information on properties of PDF matrices please refer to PDF Reference Manual (Sections 4.2 'Coordinate Systems' and 4.2.3 'Transformation Matrices')
The following sample illustrates how to use Matrix2D in order to position an image on the page. Note that PDFNet uses the same convention of matrix multiplication used in PostScript and OpenGL. Element element = eb.CreateImage(Image(...)); double deg2rad = 3.1415926535 / 180.0; Matrix2D mtx = Matrix2D(1, 0, 0, 1, 0, 200); // Translate mtx *= Matrix2D(300, 0, 0, 200, 0, 0); // Scale mtx *= Matrix2D::RotationMatrix( 90 * deg2rad ); // Rotate element.GetGState().SetTransform(mtx); writer.WritePlacedElement(element);
The following sample sample illustrates how to use Matrix2D in order to calculate absolute positioning for the text on the page. ... Matrix2D text_mtx = text_element.GetTextMatrix(); double x, y; for (CharIterator itr = text_element.GetCharIterator(); itr.HasNext(); itr.Next()) { x = itr.Current().x; // character positioning information y = itr.Current().y; // Get current transformation matrix (CTM) Matrix2D ctm = text_element.GetCTM(); // To get the absolute character positioning information concatenate current // text matrix with CTM and then multiply relative positioning coordinates with // the resulting matrix. Matrix2D mtx = ctm * text_mtx; mtx.Mult(x, y); }
pdftron::Common::Matrix2D::Matrix2D | ( | double | a = 1 , |
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double | b = 0 , |
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double | c = 0 , |
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double | d = 1 , |
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double | h = 0 , |
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double | v = 0 | |||
) |
Creates and initializes a Matrix object based on six numbers that define an affine transformation.
a | the matrix element in the first row, first column. | |
b | the matrix element in the first row, second column. | |
c | the matrix element in the second row, first column. | |
d | the matrix element in the second row, second column. | |
h | the matrix element in the third row, first column. | |
v | the matrix element in the third row, second column. |
pdftron::Common::Matrix2D::Matrix2D | ( | const Matrix2D & | m | ) |
Copy constructor.
void pdftron::Common::Matrix2D::Set | ( | double | a, | |
double | b, | |||
double | c, | |||
double | d, | |||
double | h, | |||
double | v | |||
) |
The Set method sets the elements of this matrix.
a | the matrix element in the first row, first column. | |
b | the matrix element in the first row, second column. | |
c | the matrix element in the second row, first column. | |
d | the matrix element in the second row, second column. | |
h | the matrix element in the third row, first column. | |
v | the matrix element in the third row, second column. |
void pdftron::Common::Matrix2D::Concat | ( | double | a, | |
double | b, | |||
double | c, | |||
double | d, | |||
double | h, | |||
double | v | |||
) |
The Concat method updates this matrix with the product of itself and another matrix specified through an argument list.
a | the matrix element in the first row, first column. | |
b | the matrix element in the first row, second column. | |
c | the matrix element in the second row, first column. | |
d | the matrix element in the second row, second column. | |
h | the matrix element in the third row, first column. | |
v | the matrix element in the third row, second column. |
The multiply method updates this matrix with the product of itself and another matrix.
m | A matrix used to update this matrix |
Multiplies this matrix with another matrix and return the result in a new matrix.
bool pdftron::Common::Matrix2D::operator== | ( | const Matrix2D & | m | ) | const |
The equality operator determines whether the elements of this matrix are equal to the elements of another matrix.
A | Matrix object that is compared with this Matrix object. |
Referenced by operator!=().
bool pdftron::Common::Matrix2D::operator!= | ( | const Matrix2D & | m | ) | const [inline] |
The inequality operator determines whether the elements of this matrix are not equal to the elements of another matrix.
A | Matrix object that is compared with this Matrix object. |
References operator==().
void pdftron::Common::Matrix2D::Mult | ( | double & | in_out_x, | |
double & | in_out_y | |||
) | const |
Transform/multiply the point (in_out_x, in_out_y) using this matrix.
Matrix2D pdftron::Common::Matrix2D::Inverse | ( | ) | const |
Matrix2D& pdftron::Common::Matrix2D::Translate | ( | double | h, | |
double | v | |||
) |
The Translate method updates this matrix with the product of itself and a translation matrix (i.e.
it is equivalent to this.m_h += h; this.m_v += v).
h | the horizontal component of the translation. | |
v | the vertical component of the translation. |
Matrix2D& pdftron::Common::Matrix2D::Scale | ( | double | h, | |
double | v | |||
) |
The Scale method updates this matrix with the product of itself and a scaling matrix.
(i.e. it is equivalent to this.m_a *= h; this.m_d *= v).
h | the horizontal scale factor. | |
v | the vertical scale factor |
static Matrix2D pdftron::Common::Matrix2D::ZeroMatrix | ( | ) | [static] |
Create zero matrix (0 0 0 0 0 0).
static Matrix2D pdftron::Common::Matrix2D::IdentityMatrix | ( | ) | [static] |
Create identity matrix (1 0 0 1 0 0).
static Matrix2D pdftron::Common::Matrix2D::RotationMatrix | ( | const double | angle | ) | [static] |
angle | the angle of rotation in radians. Positive values specify clockwise rotation. |