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Diffstat (limited to 'bundles/org.eclipse.swt/Eclipse SWT/cairo/org/eclipse/swt/graphics/Transform.java')
| -rw-r--r-- | bundles/org.eclipse.swt/Eclipse SWT/cairo/org/eclipse/swt/graphics/Transform.java | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/cairo/org/eclipse/swt/graphics/Transform.java b/bundles/org.eclipse.swt/Eclipse SWT/cairo/org/eclipse/swt/graphics/Transform.java new file mode 100644 index 0000000000..b755f16571 --- /dev/null +++ b/bundles/org.eclipse.swt/Eclipse SWT/cairo/org/eclipse/swt/graphics/Transform.java @@ -0,0 +1,387 @@ +/******************************************************************************* + * Copyright (c) 2000, 2008 IBM Corporation and others. + * All rights reserved. This program and the accompanying materials + * are made available under the terms of the Eclipse Public License v1.0 + * which accompanies this distribution, and is available at + * http://www.eclipse.org/legal/epl-v10.html + * + * Contributors: + * IBM Corporation - initial API and implementation + *******************************************************************************/ +package org.eclipse.swt.graphics; + +import org.eclipse.swt.*; +import org.eclipse.swt.internal.*; +import org.eclipse.swt.internal.cairo.*; + +/** + * Instances of this class represent transformation matrices for + * points expressed as (x, y) pairs of floating point numbers. + * <p> + * Application code must explicitly invoke the <code>Transform.dispose()</code> + * method to release the operating system resources managed by each instance + * when those instances are no longer required. + * </p> + * <p> + * This class requires the operating system's advanced graphics subsystem + * which may not be available on some platforms. + * </p> + * + * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: GraphicsExample</a> + * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a> + * + * @since 3.1 + */ +public class Transform extends Resource { + /** + * the OS resource for the Transform + * (Warning: This field is platform dependent) + * <p> + * <b>IMPORTANT:</b> This field is <em>not</em> part of the SWT + * public API. It is marked public only so that it can be shared + * within the packages provided by SWT. It is not available on all + * platforms and should never be accessed from application code. + * </p> + */ + public double[] handle; + +/** + * Constructs a new identity Transform. + * <p> + * This operation requires the operating system's advanced + * graphics subsystem which may not be available on some + * platforms. + * </p> + * + * @param device the device on which to allocate the Transform + * + * @exception IllegalArgumentException <ul> + * <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li> + * </ul> + * @exception SWTException <ul> + * <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li> + * </ul> + * @exception SWTError <ul> + * <li>ERROR_NO_HANDLES if a handle for the Transform could not be obtained</li> + * </ul> + * + * @see #dispose() + */ +public Transform (Device device) { + this(device, 1, 0, 0, 1, 0, 0); +} + +/** + * Constructs a new Transform given an array of elements that represent the + * matrix that describes the transformation. + * <p> + * This operation requires the operating system's advanced + * graphics subsystem which may not be available on some + * platforms. + * </p> + * + * @param device the device on which to allocate the Transform + * @param elements an array of floats that describe the transformation matrix + * + * @exception IllegalArgumentException <ul> + * <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device, or the elements array is null</li> + * <li>ERROR_INVALID_ARGUMENT - if the elements array is too small to hold the matrix values</li> + * </ul> + * @exception SWTException <ul> + * <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li> + * </ul> + * @exception SWTError <ul> + * <li>ERROR_NO_HANDLES if a handle for the Transform could not be obtained</li> + * </ul> + * + * @see #dispose() + */ +public Transform(Device device, float[] elements) { + this (device, checkTransform(elements)[0], elements[1], elements[2], elements[3], elements[4], elements[5]); +} + +/** + * Constructs a new Transform given all of the elements that represent the + * matrix that describes the transformation. + * <p> + * This operation requires the operating system's advanced + * graphics subsystem which may not be available on some + * platforms. + * </p> + * + * @param device the device on which to allocate the Transform + * @param m11 the first element of the first row of the matrix + * @param m12 the second element of the first row of the matrix + * @param m21 the first element of the second row of the matrix + * @param m22 the second element of the second row of the matrix + * @param dx the third element of the first row of the matrix + * @param dy the third element of the second row of the matrix + * + * @exception IllegalArgumentException <ul> + * <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li> + * </ul> + * @exception SWTException <ul> + * <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li> + * </ul> + * @exception SWTError <ul> + * <li>ERROR_NO_HANDLES if a handle for the Transform could not be obtained</li> + * </ul> + * + * @see #dispose() + */ +public Transform (Device device, float m11, float m12, float m21, float m22, float dx, float dy) { + super(device); + this.device.checkCairo(); + handle = new double[6]; + if (handle == null) SWT.error(SWT.ERROR_NO_HANDLES); + Cairo.cairo_matrix_init(handle, m11, m12, m21, m22, dx, dy); + init(); +} + +static float[] checkTransform(float[] elements) { + if (elements == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); + if (elements.length < 6) SWT.error(SWT.ERROR_INVALID_ARGUMENT); + return elements; +} + +void destroy() { + handle = null; +} + +/** + * Fills the parameter with the values of the transformation matrix + * that the receiver represents, in the order {m11, m12, m21, m22, dx, dy}. + * + * @param elements array to hold the matrix values + * + * @exception SWTException <ul> + * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> + * </ul> + * @exception IllegalArgumentException <ul> + * <li>ERROR_NULL_ARGUMENT - if the parameter is null</li> + * <li>ERROR_INVALID_ARGUMENT - if the parameter is too small to hold the matrix values</li> + * </ul> + */ +public void getElements(float[] elements) { + if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); + if (elements == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); + if (elements.length < 6) SWT.error(SWT.ERROR_INVALID_ARGUMENT); + elements[0] = (float)handle[0]; + elements[1] = (float)handle[1]; + elements[2] = (float)handle[2]; + elements[3] = (float)handle[3]; + elements[4] = (float)handle[4]; + elements[5] = (float)handle[5]; +} + +/** + * Modifies the receiver such that the matrix it represents becomes the + * identity matrix. + * + * @exception SWTException <ul> + * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> + * </ul> + * + * @since 3.4 + */ +public void identity() { + if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); + Cairo.cairo_matrix_init(handle, 1, 0, 0, 1, 0, 0); +} + +/** + * Modifies the receiver such that the matrix it represents becomes + * the mathematical inverse of the matrix it previously represented. + * + * @exception SWTException <ul> + * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> + * <li>ERROR_CANNOT_INVERT_MATRIX - if the matrix is not invertible</li> + * </ul> + */ +public void invert() { + if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); + if (Cairo.cairo_matrix_invert(handle) != 0) { + SWT.error(SWT.ERROR_CANNOT_INVERT_MATRIX); + } +} + +/** + * Returns <code>true</code> if the Transform has been disposed, + * and <code>false</code> otherwise. + * <p> + * This method gets the dispose state for the Transform. + * When a Transform has been disposed, it is an error to + * invoke any other method using the Transform. + * + * @return <code>true</code> when the Transform is disposed, and <code>false</code> otherwise + */ +public boolean isDisposed() { + return handle == null; +} + +/** + * Returns <code>true</code> if the Transform represents the identity matrix + * and false otherwise. + * + * @return <code>true</code> if the receiver is an identity Transform, and <code>false</code> otherwise + */ +public boolean isIdentity() { + if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); + float[] m = new float[6]; + getElements(m); + return m[0] == 1 && m[1] == 0 && m[2] == 0 && m[3] == 1 && m[4] == 0 && m[5] == 0; +} + +/** + * Modifies the receiver such that the matrix it represents becomes the + * the result of multiplying the matrix it previously represented by the + * argument. + * + * @param matrix the matrix to multiply the receiver by + * + * @exception SWTException <ul> + * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> + * </ul> + * @exception IllegalArgumentException <ul> + * <li>ERROR_NULL_ARGUMENT - if the parameter is null</li> + * <li>ERROR_INVALID_ARGUMENT - if the parameter has been disposed</li> + * </ul> + */ +public void multiply(Transform matrix) { + if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); + if (matrix == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); + if (matrix.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT); + Cairo.cairo_matrix_multiply(handle, matrix.handle, handle); +} + +/** + * Modifies the receiver so that it represents a transformation that is + * equivalent to its previous transformation rotated by the specified angle. + * The angle is specified in degrees and for the identity transform 0 degrees + * is at the 3 o'clock position. A positive value indicates a clockwise rotation + * while a negative value indicates a counter-clockwise rotation. + * + * @param angle the angle to rotate the transformation by + * + * @exception SWTException <ul> + * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> + * </ul> + */ +public void rotate(float angle) { + if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); + Cairo.cairo_matrix_rotate(handle, angle * (float)Compatibility.PI / 180); +} + +/** + * Modifies the receiver so that it represents a transformation that is + * equivalent to its previous transformation scaled by (scaleX, scaleY). + * + * @param scaleX the amount to scale in the X direction + * @param scaleY the amount to scale in the Y direction + * + * @exception SWTException <ul> + * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> + * </ul> + */ +public void scale(float scaleX, float scaleY) { + if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); + Cairo.cairo_matrix_scale(handle, scaleX, scaleY); +} + +/** + * Modifies the receiver to represent a new transformation given all of + * the elements that represent the matrix that describes that transformation. + * + * @param m11 the first element of the first row of the matrix + * @param m12 the second element of the first row of the matrix + * @param m21 the first element of the second row of the matrix + * @param m22 the second element of the second row of the matrix + * @param dx the third element of the first row of the matrix + * @param dy the third element of the second row of the matrix + * + * @exception SWTException <ul> + * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> + * </ul> + */ +public void setElements(float m11, float m12, float m21, float m22, float dx, float dy) { + if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); + Cairo.cairo_matrix_init(handle, m11, m12, m21, m22, dx, dy); +} + +/** + * Modifies the receiver so that it represents a transformation that is + * equivalent to its previous transformation sheared by (shearX, shearY). + * + * @param shearX the shear factor in the X direction + * @param shearY the shear factor in the Y direction + * + * @exception SWTException <ul> + * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> + * </ul> + * + * @since 3.4 + */ +public void shear(float shearX, float shearY) { + if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); + double[] matrix = {1, shearX, shearY, 1, 0, 0}; + Cairo.cairo_matrix_multiply(handle, matrix, handle); +} + +/** + * Given an array containing points described by alternating x and y values, + * modify that array such that each point has been replaced with the result of + * applying the transformation represented by the receiver to that point. + * + * @param pointArray an array of alternating x and y values to be transformed + * + * @exception IllegalArgumentException <ul> + * <li>ERROR_NULL_ARGUMENT - if the point array is null</li> + * </ul> + * @exception SWTException <ul> + * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> + * </ul> + */ +public void transform(float[] pointArray) { + if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); + if (pointArray == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); + double[] dx = new double[1], dy = new double[1]; + int length = pointArray.length / 2; + for (int i = 0, j = 0; i < length; i++, j += 2) { + dx[0] = pointArray[j]; + dy[0] = pointArray[j + 1]; + Cairo.cairo_matrix_transform_point(handle, dx, dy); + pointArray[j] = (float)dx[0]; + pointArray[j + 1] = (float)dy[0]; + } +} + +/** + * Modifies the receiver so that it represents a transformation that is + * equivalent to its previous transformation translated by (offsetX, offsetY). + * + * @param offsetX the distance to translate in the X direction + * @param offsetY the distance to translate in the Y direction + * + * @exception SWTException <ul> + * <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> + * </ul> + */ +public void translate(float offsetX, float offsetY) { + if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED); + Cairo.cairo_matrix_translate(handle, offsetX, offsetY); +} + +/** + * Returns a string containing a concise, human-readable + * description of the receiver. + * + * @return a string representation of the receiver + */ +public String toString() { + if (isDisposed()) return "Transform {*DISPOSED*}"; + float[] elements = new float[6]; + getElements(elements); + return "Transform {" + elements [0] + "," + elements [1] + "," +elements [2] + "," +elements [3] + "," +elements [4] + "," +elements [5] + "}"; +} + +} |