/* * Copyright 1999-2004 The Apache Software Foundation. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* $Id$ */ package org.apache.fop.area; import java.awt.Rectangle; import java.awt.geom.Rectangle2D; import java.io.Serializable; import org.apache.fop.datatypes.FODimension; import org.apache.fop.fo.Constants; /** * Describe a PDF or PostScript style coordinate transformation matrix (CTM). * The matrix encodes translations, scaling and rotations of the coordinate * system used to render pages. */ public class CTM implements Serializable { private double a, b, c, d, e, f; private static final CTM CTM_LRTB = new CTM(1, 0, 0, 1, 0, 0); private static final CTM CTM_RLTB = new CTM(-1, 0, 0, 1, 0, 0); private static final CTM CTM_TBRL = new CTM(0, 1, -1, 0, 0, 0); /** * Create the identity matrix */ public CTM() { a = 1; b = 0; c = 0; d = 1; e = 0; f = 0; } /** * Initialize a CTM from the passed arguments. * * @param a the x scale * @param b the x shear * @param c the y shear * @param d the y scale * @param e the x shift * @param f the y shift */ public CTM(double a, double b, double c, double d, double e, double f) { this.a = a; this.b = b; this.c = c; this.d = d; this.e = e; this.f = f; } /** * Initialize a CTM to the identity matrix with a translation * specified by x and y * * @param x the x shift * @param y the y shift. */ public CTM(double x, double y) { this.a = 1; this.b = 0; this.c = 0; this.d = 1; this.e = x; this.f = y; } /** * Initialize a CTM with the values of another CTM. * * @param ctm another CTM */ protected CTM(CTM ctm) { this.a = ctm.a; this.b = ctm.b; this.c = ctm.c; this.d = ctm.d; this.e = ctm.e; this.f = ctm.f; } /** * Return a CTM which will transform coordinates for a particular writing-mode * into normalized first quandrant coordinates. * @param wm A writing mode constant from fo.properties.WritingMode, ie. * one of LR_TB, RL_TB, TB_RL. * @param ipd The inline-progression dimension of the reference area whose * CTM is being set.. * @param bpd The block-progression dimension of the reference area whose * CTM is being set. * @return a new CTM with the required transform */ public static CTM getWMctm(int wm, int ipd, int bpd) { CTM wmctm; switch (wm) { case Constants.EN_LR_TB: return new CTM(CTM_LRTB); case Constants.EN_RL_TB: { wmctm = new CTM(CTM_RLTB); wmctm.e = ipd; return wmctm; } //return CTM_RLTB.translate(ipd, 0); case Constants.EN_TB_RL: { // CJK wmctm = new CTM(CTM_TBRL); wmctm.e = bpd; return wmctm; } //return CTM_TBRL.translate(0, ipd); default: return null; } } /** * Multiply new passed CTM with this one and generate a new result CTM. * @param premult The CTM to multiply with this one. The new one will be * the first multiplicand. * @return CTM The result of multiplying premult * this. */ public CTM multiply(CTM premult) { CTM rslt = new CTM ((premult.a * a) + (premult.b * c), (premult.a * b) + (premult.b * d), (premult.c * a) + (premult.d * c), (premult.c * b) + (premult.d * d), (premult.e * a) + (premult.f * c) + e, (premult.e * b) + (premult.f * d) + f); return rslt; } /** * Rotate this CTM by "angle" radians and return a new result CTM. * This is used to account for reference-orientation. * @param angle The angle in radians. Positive angles are measured counter- * clockwise. * @return CTM The result of rotating this CTM. */ public CTM rotate(double angle) { double cos, sin; if (angle == 90.0) { cos = 0.0; sin = 1.0; } else if (angle == 270.0) { cos = 0.0; sin = -1.0; } else if (angle == 180.0) { cos = -1.0; sin = 0.0; } else { double rad = Math.toRadians(angle); cos = Math.cos(rad); sin = Math.sin(rad); } CTM rotate = new CTM(cos, -sin, sin, cos, 0, 0); return multiply(rotate); } /** * Translate this CTM by the passed x and y values and return a new result CTM. * @param x The amount to translate along the x axis. * @param y The amount to translate along the y axis. * @return CTM The result of translating this CTM. */ public CTM translate(double x, double y) { CTM translate = new CTM(1, 0, 0, 1, x, y); return multiply(translate); } /** * Scale this CTM by the passed x and y values and return a new result CTM. * @param x The amount to scale along the x axis. * @param y The amount to scale along the y axis. * @return CTM The result of scaling this CTM. */ public CTM scale(double x, double y) { CTM scale = new CTM(x, 0, 0, y, 0, 0); return multiply(scale); } /** * Transform a rectangle by the CTM to produce a rectangle in the transformed * coordinate system. * @param inRect The rectangle in the original coordinate system * @return Rectangle2D The rectangle in the transformed coordinate system. */ public Rectangle2D transform(Rectangle2D inRect) { // Store as 2 sets of 2 points and transform those, then // recalculate the width and height int x1t = (int)(inRect.getX() * a + inRect.getY() * c + e); int y1t = (int)(inRect.getX() * b + inRect.getY() * d + f); int x2t = (int)((inRect.getX() + inRect.getWidth()) * a + (inRect.getY() + inRect.getHeight()) * c + e); int y2t = (int)((inRect.getX() + inRect.getWidth()) * b + (inRect.getY() + inRect.getHeight()) * d + f); // Normalize with x1 < x2 if (x1t > x2t) { int tmp = x2t; x2t = x1t; x1t = tmp; } if (y1t > y2t) { int tmp = y2t; y2t = y1t; y1t = tmp; } return new Rectangle(x1t, y1t, x2t - x1t, y2t - y1t); } /** * Get string for this transform. * * @return a string with the transform values */ public String toString() { return "[" + a + " " + b + " " + c + " " + d + " " + e + " " + f + "]"; } /** * Get an array containing the values of this transform. * This creates and returns a new transform with the values in it. * * @return an array containing the transform values */ public double[] toArray() { return new double[]{a, b, c, d, e, f}; } /** * Construct a coordinate transformation matrix (CTM). * @param absVPrect absolute viewpoint rectangle * @param reldims relative dimensions * @return CTM the coordinate transformation matrix (CTM) */ public static CTM getCTMandRelDims(int absRefOrient, int writingMode, Rectangle2D absVPrect, FODimension reldims) { int width, height; // We will use the absolute reference-orientation to set up the CTM. // The value here is relative to its ancestor reference area. if (absRefOrient % 180 == 0) { width = (int) absVPrect.getWidth(); height = (int) absVPrect.getHeight(); } else { // invert width and height since top left are rotated by 90 (cl or ccl) height = (int) absVPrect.getWidth(); width = (int) absVPrect.getHeight(); } /* Set up the CTM for the content of this reference area. * This will transform region content coordinates in * writing-mode relative into absolute page-relative * which will then be translated based on the position of * the region viewport. * (Note: scrolling between region vp and ref area when * doing online content!) */ CTM ctm = new CTM(absVPrect.getX(), absVPrect.getY()); // First transform for rotation if (absRefOrient != 0) { // Rotation implies translation to keep the drawing area in the // first quadrant. Note: rotation is counter-clockwise switch (absRefOrient) { case 90: ctm = ctm.translate(0, width); // width = absVPrect.height break; case 180: ctm = ctm.translate(width, height); break; case 270: ctm = ctm.translate(height, 0); // height = absVPrect.width break; } ctm = ctm.rotate(absRefOrient); } /* Since we've already put adjusted width and height values for the * top and left positions implied by the reference-orientation, we * can set ipd and bpd appropriately based on the writing mode. */ if (writingMode == Constants.EN_LR_TB || writingMode == Constants.EN_RL_TB) { reldims.ipd = width; reldims.bpd = height; } else { reldims.ipd = height; reldims.bpd = width; } // Set a rectangle to be the writing-mode relative version??? // Now transform for writing mode return ctm.multiply(CTM.getWMctm(writingMode, reldims.ipd, reldims.bpd)); } }