2D Transformation Matrix More...

#include <mat2d.h>

Inheritance diagram for cMat2Df:

Collaboration diagram for cMat2Df:

Public Member Functions
void	PrepDrawImg (int ws, int hs, int x0, int y0, int wd, int hd, float shearx, float sheary, float r, float tx, float ty)
	Prepare transformation matrix (for DrawImgMat() function) More...

void	ExportInt (int *mat) const
	Export matrix to int array[6]. More...

float	GetX (float x, float y) const
	Transform X.

float	GetY (float x, float y) const
	Transform Y.

void	Unit ()
	Set unit matrix.

void	Copy (const cMat2D *m)
	Copy matrix.

void	TransX (float tx)
	Translate in X direction. More...

void	TransY (float ty)
	Translate in Y direction. More...

void	ScaleX (float sx)
	Scale in X direction. More...

void	ScaleY (float sy)
	Scale in Y direction. More...

void	RotSC (float sina, float cosa)
	Rotate, using sin and cos. More...

void	Rot (float a)
	Rotate, using angle.

void	Rot90 ()
	Rotate by 90 deg (sina=1, cosa=0)

void	Rot180 ()
	Rotate by 180 deg (=flipX and flipY) (sina=0, cosa=-1)

void	Rot270 ()
	Rotate by 270 deg (sina=-1, cosa=0)

void	ShearX (float dx)
	Shear in X direction. More...

void	ShearY (float dy)
	Shear in Y direction. More...

void	FlipY ()
	Flip in Y direction. More...

void	FlipX ()
	Flip in X direction. More...

Data Fields
float	m11

float	m12

float	m13

float	m21

float	m22

float	m23

Detailed Description

2D Transformation Matrix

Some rendering functions use the cMat2Df transformation matrix to define image transformation. The matrix has 6 numeric elements of float type. The transformation is prepared by setting the initial state with the Unit function and then entering the transformations one by one. Using the matrix, operations are performed on the image as if the operations were entered sequentially.

Member Function Documentation

◆ PrepDrawImg()

void cMat2Df::PrepDrawImg	(	int	ws,
		int	hs,
		int	x0,
		int	y0,
		int	wd,
		int	hd,
		float	shearx,
		float	sheary,
		float	r,
		float	tx,
		float	ty
	)

Prepare transformation matrix (for DrawImgMat() function)

The order of operations is chosen as if the image is first moved to the point tx and ty, scaled, skewed, then rotated and finally moved to the target coordinates.

Parameters

ws	Source image width
hs	Source image height
x0	Reference point X on source image
y0	Reference point Y on source image
wd	Destination image width (negative = flip image in X direction)
hd	Destination image height (negative = flip image in Y direction)
shearx	Shear image in X direction
sheary	Shear image in Y direction
r	Rotate image (angle in radians)
tx	Shift in X direction (ws = whole image width)
ty	Shift in Y direction (hs = whole image height)

◆ ExportInt()

void cMat2Df::ExportInt ( int * mat ) const

Export matrix to int array[6].

After transformation, the lower 12 bits of the number contain the decimal part of the number, the upper 20 bits contain the integer part of the number. Rendering functions require this integer form of the transformation matrix.

◆ TransX()

void cMat2D< float >::TransX ( float tx )

inlineinherited

Translate in X direction.

 1  0 tx   m11 m12 m13   m11 m12 m13+tx
 0  1  0 * m21 m22 m23 = m21 m22 m23
 0  0  1     0   0   1    0   0   1

◆ TransY()

void cMat2D< float >::TransY ( float ty )

inlineinherited

Translate in Y direction.

 1  0  0   m11 m12 m13   m11 m12 m13
 0  1 ty * m21 m22 m23 = m21 m22 m23+ty
 0  0  1     0   0   1    0   0   1

◆ ScaleX()

void cMat2D< float >::ScaleX ( float sx )

inlineinherited

Scale in X direction.

 sx 0  0   m11 m12 m13    m11*sx m12*sx m13*sx
 0  1  0 * m21 m22 m23  = m21    m22    m23
 0  0  1     0   0   1      0      0      1

◆ ScaleY()

void cMat2D< float >::ScaleY ( float sy )

inlineinherited

Scale in Y direction.

 1  0  0   m11 m12 m13    m11    m12    m13
 0  sy 0 * m21 m22 m23  = m21*sy m22*sy m23*sy
 0  0  1     0   0   1      0      0      1

◆ RotSC()

void cMat2D< float >::RotSC	(	float	sina,
		float	cosa
	)

inlineinherited

Rotate, using sin and cos.

 cosa -sina  0   m11 m12 m13   m11*cosa-m21*sina  m12*cosa-m22*sina  m13*cosa-m23*sina
 sina  cosa  0 * m21 m22 m23 = m11*sina+m21*cosa  m12*sina+m22*cosa  m13*sina+m23*cosa
  0      0   1     0   0   1           0                    0                 1

◆ ShearX()

void cMat2D< float >::ShearX ( float dx )

inlineinherited

Shear in X direction.

 1  dx 0   m11 m12 m13   m11+m21*dx m12+m22*dx m13+m23*dx
 0  1  0 * m21 m22 m23 = m21        m22        m23
 0  0  1     0   0   1     0          0          1

◆ ShearY()

void cMat2D< float >::ShearY ( float dy )

inlineinherited

Shear in Y direction.

 1  0  0   m11 m12 m13   m11        m12        m13
 dy 1  0 * m21 m22 m23 = m21+m11*dy m22+m12*dy m23+m13*dy
 0  0  1     0   0   1     0          0          1

◆ FlipY()

void cMat2D< float >::FlipY ( )

inlineinherited

Flip in Y direction.

 1  0  0   m11 m12 m13     m11   m12    m13
 0 -1  0 * m21 m22 m23  = -m21  -m22   -m23
 0  0  1     0   0   1      0     0      1

◆ FlipX()

void cMat2D< float >::FlipX ( )

inlineinherited

Flip in X direction.

 -1 0  0   m11 m12 m13    -m11  -m12   -m13
 0  1  0 * m21 m22 m23  = m21    m22    m23
 0  0  1     0   0   1      0      0      1

The documentation for this class was generated from the following files:

src/util/mat2d.h
src/util/mat2d.cpp

Public Member Functions

Data Fields

Detailed Description

Member Function Documentation

◆ PrepDrawImg()

◆ ExportInt()

◆ TransX()

◆ TransY()

◆ ScaleX()

◆ ScaleY()

◆ RotSC()

◆ ShearX()

◆ ShearY()

◆ FlipY()

◆ FlipX()