Package org.tinfour.utils.rendering

Class RenderingTransformAid

java.lang.Object

org.tinfour.utils.rendering.RenderingTransformAid

public class RenderingTransformAid
extends Object

Provides an aid for establishing a Cartesian coordinate system for rendering 2D drawings as well as utilities for initializing a graphics surface.

Constructor Summary

Constructors

Constructor	Description
RenderingTransformAid(int width, int height, int pad, double x0, double y0, double x1, double y1)	Constructs resources for a coordinate system appropriate for the presentation of a rectangular region defined by the specified coordinates.

Method Summary

Modifier and Type	Method	Description
AffineTransform	getCartesianToPixelTransform()	Gets the affine transform for mapping Cartesian coordinates to pixel coordinates.
Rectangle2D	getDomainRectangle()	Gets the rectangle for the drawing area corresponding to the coordinate domain that was specified for the constructor.
double	getPixelsPerUnit()	Gets the distance in pixels across one unit of distance in the Cartesian coordinate system.
AffineTransform	getPixelToCartesianTransform()	Gets the affine transform for mapping pixel coordinates to Cartesian coordinates.
double	getUnitsPerPixel()	Gets the distance across a pixel in the corresponding Cartesian coordinate system.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RenderingTransformAid

public RenderingTransformAid(int width,
                             int height,
                             int pad,
                             double x0,
                             double y0,
                             double x1,
                             double y1)

Constructs resources for a coordinate system appropriate for the presentation of a rectangular region defined by the specified coordinates. The transforms created by this class will be appropriate for drawing graphs within the coordinate domain as large as possible within the bounds of the specified size of the graphics surface based on width, height, and padding allowance.

Parameters:

width - the width of the drawing surface, in pixels

height - the height of the drawing surface, in pixels

pad - an arbitrary padding to be added to each side of the rectangle, in pixels

x0 - Cartesian x coordinate for the lower-left corner of the domain

y0 - Cartesian y coordinate for the lower-left corner of the domain

x1 - Cartesian x coordinate for the upper-right corner of the domain

y1 - Cartesian y coordinate for the upper-right corner of the domain

Method Detail

getCartesianToPixelTransform

public AffineTransform getCartesianToPixelTransform()

Gets the affine transform for mapping Cartesian coordinates to pixel coordinates. The transform was established by the constructor for this class.

Returns:

a valid instance of an affine transform

getPixelToCartesianTransform

public AffineTransform getPixelToCartesianTransform()

Gets the affine transform for mapping pixel coordinates to Cartesian coordinates. The transform was established by the constructor for this class.

Returns:

a valid instance of an affine transform

getDomainRectangle

public Rectangle2D getDomainRectangle()

Gets the rectangle for the drawing area corresponding to the coordinate domain that was specified for the constructor. This rectangle is suitable for use as a clipping rectangle when creating images.

Returns:

a valid instance of a rectangle, in pixel coordinates.

getUnitsPerPixel

public double getUnitsPerPixel()

Gets the distance across a pixel in the corresponding Cartesian coordinate system.

Returns:

a non-zero floating point value

getPixelsPerUnit

public double getPixelsPerUnit()

Gets the distance in pixels across one unit of distance in the Cartesian coordinate system.

Returns:

a non-zero floating point value