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File: polyExample.php

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File: polyExample.php
Role: Example script
Content type: text/plain
Description: Example - See screen shots for output
Class: Polygon
Perform geometric operations on polygons
Author: By
Last change: Added new examples for scale & translate methods and new examples showing the degenerate vertex issue
Date: 13 years ago
Size: 35,722 bytes
 

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<?php /*------------------------------------------------------------------------------ ** File: polyExample.php ** Description: Demo's the capability of the polygon class. ** Version: 1.6 ** Author: Brenor Brophy ** Email: brenor dot brophy at gmail dot com ** Homepage: www.brenorbrophy.com **------------------------------------------------------------------------------ ** COPYRIGHT (c) 2005-2010 BRENOR BROPHY ** ** The source code included in this package is free software; you can ** redistribute it and/or modify it under the terms of the GNU General Public ** License as published by the Free Software Foundation. This license can be ** read at: ** ** http://www.opensource.org/licenses/gpl-license.php ** ** This program is distributed in the hope that it will be useful, but WITHOUT ** ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS ** FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. **------------------------------------------------------------------------------ ** ** Based on the paper "Efficient Clipping of Arbitary Polygons" by Gunther ** Greiner (greiner at informatik dot uni-erlangen dot de) and Kai Hormann ** (hormann at informatik dot tu-clausthal dot de), ACM Transactions on Graphics ** 1998;17(2):71-83. ** ** Available at: ** ** http://www2.in.tu-clausthal.de/~hormann/papers/Greiner.1998.ECO.pdf ** ** Another useful site describing the algorithm and with some example ** C code by Ionel Daniel Stroe is at: ** ** http://davis.wpi.edu/~matt/courses/clipping/ ** ** The algorithm is extended by Brenor Brophy to allow polygons with ** arcs between vertices. ** ** Rev History ** ----------------------------------------------------------------------------- ** 1.0 08/25/2005 Initial Release. ** 1.1 09/04/2005 Removed old html documentation from file. ** Added software license language to header comments. ** Added example code for new methods Move(),Rotate(),bRect() ** and isPolyInside(). ** Added newImage() function to make the code a bit neater. ** 1.2 09/07/2005 Minor fix to v1p2/../v1p6%20unreleased/polygon.php - no change to this file ** 1.3 04/16/2006 Minor fix to v1p3/../v1p6%20unreleased/polygon.php ** Added example 6 - a test for the degenerate case where ** a vertex falls exactly on a line of the other polygon. ** 1.4 03/19/2009 Added example 7 - show how the new isPolyInside, ** isPolyOutside & isPolyIntersect methods are used. ** 1.5 07/11/2009 Added example 8 - show how the isPolySelfIntersect ** method is used. ** 1.6 15/05/2010 Added some round statements in the drawPolyAt() method ** to cleanup how perturbed vertices were drawn. ** Added new examples for scale & translate methods and ** new examples showing the degenerate vertex issue */ require('polygon.php'); // Where all the good stuff is /* ** A simple function that draws the polygons onto an image to demo the class ** ** $x,$y .. are an offset that will be added to all coordinates of the polygon ** $i .. an image created with the imagecreate function ** $p .. A polygon Object to be drawn (could be a list of polygons) ** $col .. An array of allocated colors for the image ** $c .. Index to the colors array - i.e. the draw color ** ** Real Angle 0 45 90 135 180 225 270 315 360 ** imgarc Angle 360 315 270 225 180 135 90 45 0 (To draw real angle) ** Thus imagearc Angle = 360 - Real Angle ** ** If d == -1 the arc is Anti-Clockwise, d == 1 the arc is clockwise ** ** imagearc only draws clockwise arcs, so if we have an Anti-Clockwise arc we ** must reverse the order of start-angle and end-angle. ** ** images have their origin point (0,0) at the top left corner. However in ** real world math the origin is at the bottom left. This really only matters ** for arcs (determining clockwise or anti-clockwise). Thus the points in ** the polygon are assumed to exist in real world coordinates. Thus they ** are 'inverted' in the y-axis to plot them on the image. */ function drawPolyAt($x, $y, &$i, &$p, &$col, $c) { if ($i) $sy = imagesy($i); // Determine the height of the image in pixels // All $y coords will be subtracted from this if ($p) // If a polygon exists do // For all polygons in the list { $v =& $p->getFirst(); // get the first vertex of the first polygon do // For all vertices in this polygon { $n =& $v->Next(); // Get the next vertex if ($v->d() == 0) // Check is this is an ARc segment { // It is a line imageLine ($i,round($x+$v->X()),round($sy-($y+$v->Y())),round($x+$n->X()),round($sy-($y+$n->Y())),$col[$c]); // Draw a line vertex to vertex } else { // It is an Arc $s = 360 - rad2deg ($p->angle($v->Xc(), $v->Yc(), $v->X(), $v->Y())); // Calc start angle $e = 360 - rad2deg ($p->angle($v->Xc(), $v->Yc(), $n->X(), $n->Y())); // Calc end angle $dia = round(2*$p->dist($v->X(), $v->Y(), $v->Xc(), $v->Yc())); if ($v->d() == -1) // Clockwise imagearc($i, round($x+$v->Xc()), round($sy-($y+$v->Yc())),$dia,$dia,$s,$e,$col[$c]); else // Anti-Clockwise imagearc($i, round($x+$v->Xc()), round($sy-($y+$v->Yc())),$dia,$dia,$e,$s,$col[$c]); } $v =& $n; // Move to next vertex } while ($v->id() != $p->first->id()); // Keep drawing until the last vertex $p =& $p->NextPoly(); // Get the next polygon in the list } while ($p); // Keep drawing polygons as long as they exist } /* ** Function to create an image and allocate a color table to it */ function newImage($width, $height, &$i, &$col) { if($i) imagedestroy($i); // Delete any old image $i = imagecreate ($width,$height); // New image to draw our polygons $col["wht"] = imagecolorallocate ($i, 255, 255, 255); // Allocate some colors $col["blk"] = imagecolorallocate ($i, 0, 0, 0); $col["red"] = imagecolorallocate ($i, 255,0,0); $col["blu"] = imagecolorallocate ($i, 0,0,255); $col["grn"] = imagecolorallocate ($i, 0,192,0); $col["pur"] = imagecolorallocate ($i, 255,0,255); } //------------------------------------------------------------------------------ // First example re-creates the example in Figure 5 of the paper // $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv( 16,131); $polyA->addv( 71,166); $polyA->addv(105,138); $polyA->addv( 25, 63); $polyA->addv(118, 75); $polyB =& new polygon; // Create a second polygon with some more points $polyB->addv( 9,155); $polyB->addv( 88,134); $polyB->addv( 80, 16); $polyB->addv( 26, 92); $polyB->addv( 42,129); // // THIS IS THE IMPORTANT BIT // $poly3 =& $polyA->boolean($polyB, "A&B");// A&B .. A AND B .. (A intersection B) $poly4 =& $polyA->boolean($polyB, "A|B");// A|B .. A OR B .. (A union B) $poly5 =& $polyA->boolean($polyB, "A\B");// A\B .. A - B $poly6 =& $polyA->boolean($polyB, "B\A");// B\A .. B - A // // Output the results // newImage (600,200, $im, $colors); // Create a new image to draw our polygons drawPolyAt(0, 0, $im, $polyA, $colors, "red"); drawPolyAt(0, 0, $im, $polyB, $colors, "grn"); drawPolyAt(120, 0, $im, $poly3, $colors, "blu"); drawPolyAt(240, 0, $im, $poly4, $colors, "blu"); drawPolyAt(360, 0, $im, $poly5, $colors,"blu"); drawPolyAt(480, 0, $im, $poly6, $colors, "blu"); imagestring ($im, 1, 55, 190, "A", $colors["red"]); imagestring ($im, 1, 65, 190, "B", $colors["grn"]); imagestring ($im, 1, 185, 190, "A&B", $colors["blu"]); imagestring ($im, 1, 305, 190, "A|B", $colors["blu"]); imagestring ($im, 1, 425, 190, "A\B", $colors["blu"]); imagestring ($im, 1, 545, 190, "B\A", $colors["blu"]); imageGif($im,"poly_ex1.gif"); // Save the image to a file //------------------------------------------------------------------------------ // Second example shows how to handle more than two polygons // $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv( 40, 40); $polyA->addv( 80, 40); $polyA->addv( 68,100); $polyA->addv( 80,160); $polyA->addv( 40,160); $polyB =& new polygon; // Create a second polygon with some more points $polyB->addv( 60, 60); $polyB->addv(100, 60); $polyB->addv(100,140); $polyB->addv( 60,140); $polyB->addv( 48,100); $polyC =& new polygon; // Create a third polygon with some more points $polyC->addv( 20,100); $polyC->addv(120, 80); $polyC->addv(110,100); $polyC->addv(120,120); // // THIS IS THE IMPORTANT BIT // $poly3 =& $polyA->boolean($polyB, "A&B"); // All the magic happens here $poly4 =& $poly3->boolean($polyC, "A|B"); // Now OR polyC with the result // // Output the results // newImage (400,200, $im, $colors); // Create a new image to draw our polygons drawPolyAt(0, 0, $im, $polyA, $colors, "red"); drawPolyAt(0, 0, $im, $polyB, $colors, "grn"); drawPolyAt(120, 0, $im, $poly3, $colors, "blu"); drawPolyAt(120, 0, $im, $polyC, $colors, "pur"); drawPolyAt(240, 0, $im, $poly4, $colors, "blu"); imagestring ($im, 1, 55, 190, "A", $colors["red"]); imagestring ($im, 1, 65, 190, "B", $colors["grn"]); imagestring ($im, 1, 185, 190, "(A&B)", $colors["blu"]); imagestring ($im, 1, 215, 190, "C", $colors["pur"]); imagestring ($im, 1, 305, 190, "(A&B)|C", $colors["blu"]); imageGif($im,"poly_ex2.gif"); //------------------------------------------------------------------------------ // Third example shows how arc segments work // $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv( 60,110,60,60,-1); // Arc with center 60,90 Clockwise $polyA->addv( 60, 10,60,60,-1); $polyB =& new polygon(); // Create a new polygon and add some vertices to it $polyB->addv(100, 60,110,60,-1);// Arc with center 100,140 Clockwise $polyB->addv(120, 60,110,60,-1); // // THIS IS THE IMPORTANT BIT // $poly3 =& $polyA->boolean($polyB, "A&B"); $poly4 =& $polyA->boolean($polyB, "A|B"); $poly5 =& $polyA->boolean($polyB, "A\B"); $poly6 =& $polyA->boolean($polyB, "B\A"); // // Output the results // newImage (600,140, $im, $colors); // Create a new image to draw our polygons drawPolyAt(0, 20, $im, $polyA, $colors, "red"); drawPolyAt(0, 20, $im, $polyB, $colors, "grn"); drawPolyAt(120, 20, $im, $poly3, $colors, "blu"); drawPolyAt(240, 20, $im, $poly4, $colors, "blu"); drawPolyAt(360, 20, $im, $poly5, $colors, "blu"); drawPolyAt(480, 20, $im, $poly6, $colors, "blu"); imagestring ($im, 1, 55, 130, "A", $colors["red"]); imagestring ($im, 1, 65, 130, "B", $colors["grn"]); imagestring ($im, 1, 185, 130, "A&B", $colors["blu"]); imagestring ($im, 1, 305, 130, "A|B", $colors["blu"]); imagestring ($im, 1, 425, 130, "A\B", $colors["blu"]); imagestring ($im, 1, 545, 130, "B\A", $colors["blu"]); imageGif($im,"poly_ex3.gif"); //------------------------------------------------------------------------------ // This example shows how polygon the move, rotate and bRect methods work // $poly1 =& new polygon(); $poly1->addv(25,35); $poly1->addv(12,47); $poly1->addv(12,93,50,60,-1); $poly1->addv(100,60); $poly1->addv(75,35,50,35,-1); newImage (600,120, $im, $colors); // Create a new image to draw our polygons drawPolyAt(0, 0, $im, $poly1, $colors, "red"); // The starting polygon // Polygon center is at 50,60 for ($i=0; $i<5; $i++) { $poly1->move(100,0); // Move it 100 right $poly1->rotate(150+($i*100),60,deg2rad(-30)); // Rotate 30 degrees clockwise around its center drawPolyAt(0, 0, $im, $poly1, $colors, "blu"); // Draw it again $br = NULL; // Dont waste memory $br =& $poly1->bRect(); // Get the Bounding Rectangle drawPolyAt(0, 0, $im, $br, $colors, "grn"); // And draw that as well } imageGif($im,"poly_ex4.gif"); //------------------------------------------------------------------------------ // This example shows how the isPolyInside method works // // poly1 & poly2 show that arc segments are treated correctly. The function will // return false even when all vertices are inside, but when part of the polygon // is still outside (because it is and arc or intersects with an arc) // poly3 & poly4 show the simpler case where the function returns false because // a vertex of the polygon is outside. // $poly1 =& new polygon(); $poly1->addv(0,0); $poly1->addv(0,25,0,50,1); $poly1->addv(0,75); $poly1->addv(0,100); $poly1->addv(100,100); $poly1->addv(100,0); $poly1->move(10,10); $poly2 =& new polygon(); // poly2 does fit inside poly1 $poly2->addv(10,10); $poly2->addv(10,20,0,50,1); $poly2->addv(10,80); $poly2->addv(10,90); $poly2->addv(90,90); $poly2->addv(90,10); $poly2->move(10,10); $poly3 =& new polygon(); $poly3->addv(0,0); $poly3->addv(0,100); $poly3->addv(100,100); $poly3->addv(100,0); $poly3->move(300,10); $poly4 =& new polygon(); $poly4->addv(10,50); $poly4->addv(10,90); $poly4->addv(50,90); $poly4->addv(50,50); $poly4->move(300,10); newImage (600,120, $im, $colors); // Create a new image to draw our polygons drawPolyAt(0, 0, $im, $poly1, $colors, "blu"); // Draw the initial outer polygons drawPolyAt(0, 0, $im, $poly3, $colors, "blu"); // // Depending on result of isPolyInside(0 method draw the polygon in green (inside) or // in red (NOT inside) // if ($poly1->isPolyInside($poly2)) // example 1 drawPolyAt(0, 0, $im, $poly2, $colors, "grn"); else drawPolyAt(0, 0, $im, $poly2, $colors, "red"); if ($poly3->isPolyInside($poly4)) // example 2 drawPolyAt(0, 0, $im, $poly4, $colors, "grn"); // The starting polygon else drawPolyAt(0, 0, $im, $poly4, $colors, "red"); // The starting polygon // // Now move the 4 polygons and rotate the inner ones to cause them to fail // the isPolyInside test // $poly1->move(150,0); $poly2->move(150,0); $poly2->rotate(210,60,deg2rad(90)); $poly3->move(150,0); $poly4->move(150,0); $poly4->rotate(500,60,deg2rad(45)); // // Draw the polygons again. This time the inner polygons will be red because they fail // isPolyInside test. // drawPolyAt(0, 0, $im, $poly1, $colors, "blu"); // Draw the initial outer polygons drawPolyAt(0, 0, $im, $poly3, $colors, "blu"); if ($poly1->isPolyInside($poly2)) drawPolyAt(0, 0, $im, $poly2, $colors, "grn"); else drawPolyAt(0, 0, $im, $poly2, $colors, "red"); if ($poly3->isPolyInside($poly4)) drawPolyAt(0, 0, $im, $poly4, $colors, "grn"); else drawPolyAt(0, 0, $im, $poly4, $colors, "red"); imageGif($im,"poly_ex5.gif"); //------------------------------------------------------------------------------ // This example shows how the isPolyOutside and isPolyIntersect methods work // // poly1 & poly2 show that arc segments are treated correctly. The function will // return false even when all vertices are inside, but when part of the polygon // is still outside (because it is and arc or intersects with an arc) // poly3 & poly4 show the simpler case where the function returns false because // a vertex of the polygon is outside. // $poly1 =& new polygon(); $poly1->addv(0,0); $poly1->addv(0,80); $poly1->addv(80,80); $poly1->addv(80,0); $poly1->move(10,40); $poly2 =& new polygon(); $poly2->addv(0,0); $poly2->addv(0,40); $poly2->addv(40,40); $poly2->addv(40,0); $poly2->move(30,60); newImage (600,160, $im, $colors); // Create a new image to draw our polygons drawPolyAt(0, 0, $im, $poly1, $colors, "blu"); // Draw the initial outer polygons drawPolyAt(0, 0, $im, $poly2, $colors, "blu"); // // Display the results of isPolyInside, isPolyOutside & isPolyIntersect methods // if ($poly1->isPolyInside($poly2)) imagestring ($im, 1, 10, 130, "isPolyInside =T", $colors["grn"]); else imagestring ($im, 1, 10, 130, "isPolyInside =F", $colors["red"]); if ($poly1->isPolyOutside($poly2)) imagestring ($im, 1, 10, 140, "isPolyOutside =T", $colors["grn"]); else imagestring ($im, 1, 10, 140, "isPolyOutside =F", $colors["red"]); if ($poly1->isPolyIntersect($poly2)) imagestring ($im, 1, 10, 150, "isPolyIntersect=T", $colors["grn"]); else imagestring ($im, 1, 10, 150, "isPolyIntersect=F", $colors["red"]); // // Now move the 2 polygons and repeat // $poly1->move(150,0); $poly2->move(190,0); drawPolyAt(0, 0, $im, $poly1, $colors, "blu"); // Draw the initial outer polygons drawPolyAt(0, 0, $im, $poly2, $colors, "blu"); // // Display the results of isPolyInside, isPolyOutside & isPolyIntersect methods // if ($poly1->isPolyInside($poly2)) imagestring ($im, 1, 160, 130, "isPolyInside =T", $colors["grn"]); else imagestring ($im, 1, 160, 130, "isPolyInside =F", $colors["red"]); if ($poly1->isPolyOutside($poly2)) imagestring ($im, 1, 160, 140, "isPolyOutside =T", $colors["grn"]); else imagestring ($im, 1, 160, 140, "isPolyOutside =F", $colors["red"]); if ($poly1->isPolyIntersect($poly2)) imagestring ($im, 1, 160, 150, "isPolyIntersect=T", $colors["grn"]); else imagestring ($im, 1, 160, 150, "isPolyIntersect=F", $colors["red"]); // // Now move the 2 polygons and repeat // $poly1->move(150,0); $poly2->move(160,50); $poly2->rotate(400,130,deg2rad(45)); drawPolyAt(0, 0, $im, $poly1, $colors, "blu"); // Draw the initial outer polygons drawPolyAt(0, 0, $im, $poly2, $colors, "blu"); // // Display the results of isPolyInside, isPolyOutside & isPolyIntersect methods // if ($poly1->isPolyInside($poly2)) imagestring ($im, 1, 310, 130, "isPolyInside =T", $colors["grn"]); else imagestring ($im, 1, 310, 130, "isPolyInside =F", $colors["red"]); if ($poly1->isPolyOutside($poly2)) imagestring ($im, 1, 310, 140, "isPolyOutside =T", $colors["grn"]); else imagestring ($im, 1, 310, 140, "isPolyOutside =F", $colors["red"]); if ($poly1->isPolyIntersect($poly2)) imagestring ($im, 1, 310, 150, "isPolyIntersect=T", $colors["grn"]); else imagestring ($im, 1, 310, 150, "isPolyIntersect=F", $colors["red"]); // // Now move the 2 polygons and repeat // $poly1->move(150,0); $poly2->move(165,0); drawPolyAt(0, 0, $im, $poly1, $colors, "blu"); // Draw the initial outer polygons drawPolyAt(0, 0, $im, $poly2, $colors, "blu"); // // Display the results of isPolyInside, isPolyOutside & isPolyIntersect methods // if ($poly1->isPolyInside($poly2)) imagestring ($im, 1, 460, 130, "isPolyInside =T", $colors["grn"]); else imagestring ($im, 1, 460, 130, "isPolyInside =F", $colors["red"]); if ($poly1->isPolyOutside($poly2)) imagestring ($im, 1, 460, 140, "isPolyOutside =T", $colors["grn"]); else imagestring ($im, 1, 460, 140, "isPolyOutside =F", $colors["red"]); if ($poly1->isPolyIntersect($poly2)) imagestring ($im, 1, 460, 150, "isPolyIntersect=T", $colors["grn"]); else imagestring ($im, 1, 460, 150, "isPolyIntersect=F", $colors["red"]); imageGif($im,"poly_ex6.gif"); //------------------------------------------------------------------------------ // This example shows how the isPolySelfIntersect method works // // A number of different test cases of the isPolySelfIntersect method. Checks // arc/arc, arc/line & line/line intersections. Also checks when the very last // segment intersects with the first segment - in this case the last segment has // to be an arc. // newImage (600,110, $im, $colors); // Create a new image to draw our polygons $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv(0,0); $polyA->addv(0,20,0,40,1); $polyA->addv(0,60); $polyA->addv(0,80); $polyA->addv(45,80); $polyA->addv(45,60,45,40,1); $polyA->addv(45,20); $polyA->addv(45,0); if ($polyA->isPolySelfIntersect()) drawPolyAt(0, 20, $im, $polyA, $colors, "grn"); else drawPolyAt(0, 20, $im, $polyA, $colors, "red"); $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv(0,0); $polyA->addv(0,20,0,40,1); $polyA->addv(0,60); $polyA->addv(0,80); $polyA->addv(35,80); $polyA->addv(35,60,35,40,1); $polyA->addv(35,20); $polyA->addv(35,0); if ($polyA->isPolySelfIntersect()) drawPolyAt(75, 20, $im, $polyA, $colors, "grn"); else drawPolyAt(75, 20, $im, $polyA, $colors, "red"); $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv(0,0); $polyA->addv(0,20,0,40,1); $polyA->addv(0,60); $polyA->addv(0,80); $polyA->addv(25,80); $polyA->addv(25,0); if ($polyA->isPolySelfIntersect()) drawPolyAt(150, 20, $im, $polyA, $colors, "grn"); else drawPolyAt(150, 20, $im, $polyA, $colors, "red"); $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv(0,0); $polyA->addv(0,20,0,40,1); $polyA->addv(0,60); $polyA->addv(0,80); $polyA->addv(10,80); $polyA->addv(25,0); if ($polyA->isPolySelfIntersect()) drawPolyAt(225, 20, $im, $polyA, $colors, "grn"); else drawPolyAt(225, 20, $im, $polyA, $colors, "red"); $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv(0,0); $polyA->addv(0,80); $polyA->addv(40,0); $polyA->addv(40,80); if ($polyA->isPolySelfIntersect()) drawPolyAt(300, 20, $im, $polyA, $colors, "grn"); else drawPolyAt(300, 20, $im, $polyA, $colors, "red"); $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv(0,0,0,20,1); $polyA->addv(0,40,20,40,1); $polyA->addv(40,40,40,20,1); $polyA->addv(40,0,20,0,1); if ($polyA->isPolySelfIntersect()) drawPolyAt(375, 20, $im, $polyA, $colors, "grn"); else drawPolyAt(375, 20, $im, $polyA, $colors, "red"); $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv(0,0,0,20,-1); $polyA->addv(0,40,20,40,-1); $polyA->addv(40,40,40,20,-1); $polyA->addv(40,0,20,0,-1); if ($polyA->isPolySelfIntersect()) drawPolyAt(440, 40, $im, $polyA, $colors, "grn"); else drawPolyAt(440, 40, $im, $polyA, $colors, "red"); $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv(0,0); $polyA->addv(0,80); $polyA->addv(40,80); $polyA->addv(40,0); $polyA->addv(10,0,0,20,1); if ($polyA->isPolySelfIntersect()) drawPolyAt(525, 20, $im, $polyA, $colors, "grn"); else drawPolyAt(525, 20, $im, $polyA, $colors, "red"); imagestring ($im, 1, 100, 95, "isPolySelfIntersect = F", $colors["red"]); imagestring ($im, 1, 300, 95, "isPolySelfIntersect = T", $colors["grn"]); imageGif($im,"poly_ex7.gif"); //------------------------------------------------------------------------------ // This example shows how the scale & translate methods work // newImage (400,150, $im, $colors); // Create a new image to draw our polygons $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv(0,50); $polyA->addv(50,100); $polyA->addv(65,65); $polyA->addv(100,50); $polyA->addv(50,0); drawPolyAt(0, 20, $im, $polyA, $colors, "red"); $polyA->scale(1.2,1.2); // Increase size by 20% drawPolyAt(0, 20, $im, $polyA, $colors, "blu"); $polyA->translate(150,0,250,50); drawPolyAt(0, 20, $im, $polyA, $colors, "blu"); $polyA->translate(300,50,350,100); drawPolyAt(0, 20, $im, $polyA, $colors, "blu"); imageGif($im,"poly_ex8.gif"); //------------------------------------------------------------------------------ // This example checks the degenerate case when the vertex of one polygon lies // exactly one the edge of the other polygon. // $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv(0,0); $polyA->addv(0,80); $polyA->addv(80,80); $polyA->addv(80,0); $polyB =& new polygon; // Create a second polygon with some more points $polyB->addv(40,80); $polyB->addv(80,40,80,80,1); $polyB->addv(120,80); $polyB->addv(80,80); $polyB->addv(80,120); // // THIS IS THE IMPORTANT BIT // $poly3 =& $polyA->boolean($polyB, "A&B");// A&B .. A AND B .. (A intersection B) $poly4 =& $polyA->boolean($polyB, "A|B");// A|B .. A OR B .. (A union B) $poly5 =& $polyA->boolean($polyB, "A\B"); $poly6 =& $polyA->boolean($polyB, "B\A"); // // Output the results // newImage (600,150, $im, $colors); // Create a new image to draw our polygons drawPolyAt(0, 20, $im, $polyA, $colors, "red"); drawPolyAt(0, 20, $im, $polyB, $colors, "grn"); drawPolyAt(120, 20, $im, $poly3, $colors, "blu"); drawPolyAt(240, 20, $im, $poly4, $colors, "blu"); drawPolyAt(360, 20, $im, $poly5, $colors,"blu"); drawPolyAt(480, 20, $im, $poly6, $colors, "blu"); imagestring ($im, 1, 35, 140, "A", $colors["red"]); imagestring ($im, 1, 45, 140, "B", $colors["grn"]); imagestring ($im, 1, 155, 140, "A&B", $colors["blu"]); imagestring ($im, 1, 275, 140, "A|B", $colors["blu"]); imagestring ($im, 1, 395, 140, "A\B", $colors["blu"]); imagestring ($im, 1, 515, 140, "B\A", $colors["blu"]); imageGif($im,"poly_ex9.gif"); //------------------------------------------------------------------------------ // A second example that checks the degenerate case when the vertex of one // polygon lies exactly one the edge of the other polygon. This is the diamond // inside a square from the Kim Kim paper // $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv(0,0); $polyA->addv(0,80); $polyA->addv(80,80); $polyA->addv(80,0); $polyB =& new polygon; // Create a second polygon with some more points $polyB->addv(0,40); $polyB->addv(40,80); $polyB->addv(80,40); $polyB->addv(40,0); // // THIS IS THE IMPORTANT BIT // $poly3 =& $polyA->boolean($polyB, "A&B");// A&B .. A AND B .. (A intersection B) $poly4 =& $polyA->boolean($polyB, "A|B");// A|B .. A OR B .. (A union B) $poly5 =& $polyA->boolean($polyB, "A\B"); $poly6 =& $polyA->boolean($polyB, "B\A"); // // Output the results // newImage (600,120, $im, $colors); // Create a new image to draw our polygons drawPolyAt(1, 20, $im, $polyA, $colors, "red"); drawPolyAt(1, 20, $im, $polyB, $colors, "grn"); drawPolyAt(120, 20, $im, $poly3, $colors, "blu"); drawPolyAt(240, 20, $im, $poly4, $colors, "blu"); drawPolyAt(360, 20, $im, $poly5, $colors,"blu"); drawPolyAt(480, 20, $im, $poly6, $colors, "blu"); imagestring ($im, 1, 35, 110, "A", $colors["red"]); imagestring ($im, 1, 45, 110, "B", $colors["grn"]); imagestring ($im, 1, 155, 110, "A&B", $colors["blu"]); imagestring ($im, 1, 275, 110, "A|B", $colors["blu"]); imagestring ($im, 1, 395, 110, "A\B", $colors["blu"]); imagestring ($im, 1, 515, 110, "B\A", $colors["blu"]); imageGif($im,"poly_ex10.gif"); //------------------------------------------------------------------------------ // A third degenerate vertex example re-creates the example in Figure 15 of the // pre-published Kim Kim paper // $polyA =& new polygon(); // Create a new polygon and add some vertices to it $polyA->addv( 0, 26); $polyA->addv( 0, 74); $polyA->addv( 84,116); // int $polyA->addv( 84, 26); $polyB =& new polygon; // Create a second polygon with some more points $polyB->addv( 26,116); $polyB->addv( 84,116); // int $polyB->addv(124, 54); $polyB->addv( 68, 54); $polyB->addv( 68, 0); $polyB->addv( 50, 26); // int $polyB->addv( 26, 26); // int $polyB->addv( 26, 42); $polyB->addv( 0, 52); // int $polyB->addv( 26, 64); $polyB->addv( 26, 87); // int $polyB->addv( 58,103); // int // // THIS IS THE IMPORTANT BIT // $poly1 =& $polyA->boolean($polyB, "A&B");// A|B .. A OR B .. (A union B) $poly2 =& $polyA->boolean($polyB, "A|B");// A|B .. A OR B .. (A union B) $poly3 =& $polyA->boolean($polyB, "A\B"); $poly4 =& $polyA->boolean($polyB, "B\A"); // $polyA->print_poly(); // $polyB->print_poly(); // $poly1->print_poly(); // // Output the results // newImage (750,150, $im, $colors); // Create a new image to draw our polygons drawPolyAt(1, 20, $im, $polyA, $colors, "red"); drawPolyAt(1, 20, $im, $polyB, $colors, "grn"); drawPolyAt(151, 20, $im, $poly1, $colors, "blu"); drawPolyAt(301, 20, $im, $poly2, $colors, "blu"); drawPolyAt(451, 20, $im, $poly3, $colors,"blu"); drawPolyAt(601, 20, $im, $poly4, $colors, "blu"); imagestring ($im, 1, 60, 140, "A", $colors["red"]); imagestring ($im, 1, 70, 140, "B", $colors["grn"]); imagestring ($im, 1, 215, 140, "A&B", $colors["blu"]); imagestring ($im, 1, 365, 140, "A|B", $colors["blu"]); imagestring ($im, 1, 515, 140, "A\B", $colors["blu"]); imagestring ($im, 1, 665, 140, "B\A", $colors["blu"]); imageGif($im,"poly_ex11.gif"); // Save the image to a file //------------------------------------------------------------------------------ // This example checks the isPolySelfIntersect method // // // Some links to display the created images // echo '<p><div align="center"><strong>EXAMPLE 1 - Boolean Operations</strong><br><img src="poly_ex1.gif" width="600" height="200"><br></div></p>'; echo '<p><div align="center"><strong>EXAMPLE 2 - Sequential Boolean Operations</strong><br><img src="poly_ex2.gif" width="400" height="200"><br></div></p>'; echo '<p><div align="center"><strong>EXAMPLE 3 - Arc Segments</strong><br><img src="poly_ex3.gif" width="600" height="140"><br></div></p>'; echo '<p><div align="center"><strong>EXAMPLE 4 - Move, Rotate & bRect Methods</strong><br><img src="poly_ex4.gif" width="600" height="120"><br></div></p>'; echo '<p><div align="center"><strong>EXAMPLE 5 - isPolyInside Method</strong><br><img src="poly_ex5.gif" width="600" height="120"><br></div></p>'; echo '<p><div align="center"><strong>EXAMPLE 6 - isPolyOutside and isPolyIntersect Methods</strong><br><img src="poly_ex6.gif" width="600" height="160"><br></div></p>'; echo '<p><div align="center"><strong>EXAMPLE 7 - isPolySelfIntersect Method</strong><br><img src="poly_ex7.gif" width="600" height="110"><br></div></p>'; echo '<p><div align="center"><strong>EXAMPLE 8 - Scale and Translate Methods</strong><br><img src="poly_ex8.gif" width="400" height="150"><br></div></p>'; echo '<p><div align="center"><strong>EXAMPLE 9 - Degenerate Vertices</strong><br><img src="poly_ex9.gif" width="600" height="150"><br></div></p>'; echo '<p><div align="center"><strong>EXAMPLE 10 - Degenerate Vertices</strong><br><img src="poly_ex10.gif" width="600" height="120"><br></div></p>'; echo '<p><div align="center"><strong>EXAMPLE 11 - Degenerate Vertices</strong><br><img src="poly_ex11.gif" width="750" height="150"><br></div></p>'; ?>