lib/MECON/Graph/external/jpgraph/src/jpgraph_gradient.php

   1 <?php
   2 /*=======================================================================
   3 // File:        JPGRAPH_GRADIENT.PHP
   4 // Description: Create a color gradient
   5 // Created:     2003-02-01
   6 // Author:      Johan Persson (johanp@aditus.nu)
   7 // Ver:         $Id: jpgraph_gradient.php,v 1.1.2.5 2003/08/23 23:15:06 aditus Exp $
   8 //
   9 // License:     This code is released under QPL
  10 // Copyright (C) 2003 Johan Persson
  11 //========================================================================
  12 */
  13
  14
  15 //===================================================
  16 // CLASS Gradient
  17 // Description: Handles gradient fills. This is to be
  18 // considered a "friend" class of Class Image.
  19 //===================================================
  20 class Gradient {
  21     var $img=null;
  22     var $numcolors=100;
  23 //---------------
  24 // CONSTRUCTOR
  25     function Gradient(&$img) {
  26         $this->img = $img;
  27     }
  28
  29
  30     function SetNumColors($aNum) {
  31         $this->numcolors=$aNum;
  32     }
  33 //---------------
  34 // PUBLIC METHODS
  35     // Produce a gradient filled rectangle with a smooth transition between
  36     // two colors.
  37     // ($xl,$yt)        Top left corner
  38     // ($xr,$yb)        Bottom right
  39     // $from_color      Starting color in gradient
  40     // $to_color        End color in the gradient
  41     // $style           Which way is the gradient oriented?
  42     function FilledRectangle($xl,$yt,$xr,$yb,$from_color,$to_color,$style=1) {
  43         switch( $style ) {
  44             case 1:  // HORIZONTAL
  45                 $steps = abs($xr-$xl);
  46                 $delta = $xr>=$xl ? 1 : -1;
  47                 $this->GetColArray($from_color,$to_color,$steps,$colors,$this->numcolors);
  48                 for( $i=0, $x=$xl; $i < $steps; ++$i ) {
  49                     $this->img->current_color = $colors[$i];
  50                     $this->img->Line($x,$yt,$x,$yb);
  51                     $x += $delta;
  52                 }
  53                 break;
  54
  55             case 2: // VERTICAL
  56                 $steps = abs($yb-$yt);
  57                 $delta = $yb>=$yt ? 1 : -1;
  58                 $this->GetColArray($from_color,$to_color,$steps,$colors,$this->numcolors);
  59                 for($i=0,$y=$yt; $i < $steps; ++$i) {
  60                     $this->img->current_color = $colors[$i];
  61                     $this->img->Line($xl,$y,$xr,$y);
  62                     $y += $delta;
  63                 }
  64                 break;
  65
  66             case 3: // VERTICAL FROM MIDDLE
  67                 $steps = abs($yb-$yt)/2;
  68                 $delta = $yb >= $yt ? 1 : -1;
  69                 $this->GetColArray($from_color,$to_color,$steps,$colors,$this->numcolors);
  70                 for($y=$yt, $i=0; $i < $steps;  ++$i) {
  71                     $this->img->current_color = $colors[$i];
  72                     $this->img->Line($xl,$y,$xr,$y);
  73                     $y += $delta;
  74                 }
  75                 --$i;
  76                 for($j=0; $j < $steps; ++$j, --$i) {
  77                     $this->img->current_color = $colors[$i];
  78                     $this->img->Line($xl,$y,$xr,$y);
  79                     $y += $delta;
  80                 }
  81                 $this->img->Line($xl,$y,$xr,$y);
  82                 break;
  83
  84             case 4: // HORIZONTAL FROM MIDDLE
  85                 $steps = abs($xr-$xl)/2;
  86                 $delta = $xr>=$xl ? 1 : -1;
  87                 $this->GetColArray($from_color,$to_color,$steps,$colors,$this->numcolors);
  88                 for($x=$xl, $i=0; $i < $steps; ++$i) {
  89                     $this->img->current_color = $colors[$i];
  90                     $this->img->Line($x,$yb,$x,$yt);
  91                     $x += $delta;
  92                 }
  93                 --$i;
  94                 for($j=0; $j < $steps; ++$j, --$i) {
  95                     $this->img->current_color = $colors[$i];
  96                     $this->img->Line($x,$yb,$x,$yt);
  97                     $x += $delta;
  98                 }
  99                 $this->img->Line($x,$yb,$x,$yt);
 100                 break;
 101
 102             case 6: // HORIZONTAL WIDER MIDDLE
 103                 $diff = round(abs($xr-$xl));
 104                 $steps = floor(abs($diff)/3);
 105                 $firststep = $diff - 2*$steps ;
 106                 // $steps = abs($xr-$xl)/3;
 107                 $delta = $xr >= $xl ? 1 : -1;
 108                 $this->GetColArray($from_color,$to_color,$firststep,$colors,$this->numcolors);
 109                 for($x=$xl, $i=0; $i < $firststep; ++$i) {
 110                     $this->img->current_color = $colors[$i];
 111                     $this->img->Line($x,$yb,$x,$yt);
 112                     $x += $delta;
 113                 }
 114                 --$i;
 115                 $this->img->current_color = $colors[$i];
 116                 for($j=0; $j< $steps; ++$j) {
 117                     $this->img->Line($x,$yb,$x,$yt);
 118                     $x += $delta;
 119                 }
 120
 121                 for($j=0; $j < $steps; ++$j, --$i) {
 122                     $this->img->current_color = $colors[$i];
 123                     $this->img->Line($x,$yb,$x,$yt);
 124                     $x += $delta;
 125                 }
 126                 break;
 127
 128             case 7: // VERTICAL WIDER MIDDLE
 129                 $diff = round(abs($yb-$yt));
 130                 $steps = floor(abs($diff)/3);
 131                 $firststep = $diff - 2*$steps ;
 132                 $delta = $yb >= $yt? 1 : -1;
 133                 $this->GetColArray($from_color,$to_color,$firststep,$colors,$this->numcolors);
 134                 for($y=$yt, $i=0; $i < $firststep;  ++$i) {
 135                     $this->img->current_color = $colors[$i];
 136                     $this->img->Line($xl,$y,$xr,$y);
 137                     $y += $delta;
 138                 }
 139                 --$i;
 140                 $this->img->current_color = $colors[$i];
 141                 for($j=0; $j < $steps; ++$j) {
 142                     $this->img->Line($xl,$y,$xr,$y);
 143                     $y += $delta;
 144                 }
 145                 for($j=0; $j < $steps; ++$j, --$i) {
 146                     $this->img->current_color = $colors[$i];
 147                     $this->img->Line($xl,$y,$xr,$y);
 148                     $y += $delta;
 149                 }
 150                 break;
 151
 152             case 8:  // LEFT REFLECTION
 153                 $steps1 = round(0.3*abs($xr-$xl));
 154                 $delta = $xr>=$xl ? 1 : -1;
 155
 156                 $this->GetColArray($from_color.':1.3',$to_color,$steps1,$colors,$this->numcolors);
 157                 for($x=$xl, $i=0; $i < $steps1; ++$i) {
 158                     $this->img->current_color = $colors[$i];
 159                     $this->img->Line($x,$yb,$x,$yt);
 160                     $x += $delta;
 161                 }
 162                 $steps2 = max(1,round(0.08*abs($xr-$xl)));
 163                 $this->img->SetColor($to_color);
 164                 for($j=0; $j< $steps2; ++$j) {
 165                     $this->img->Line($x,$yb,$x,$yt);
 166                     $x += $delta;
 167                 }
 168                 $steps = abs($xr-$xl)-$steps1-$steps2;
 169                 $this->GetColArray($to_color,$from_color,$steps,$colors,$this->numcolors);
 170                 for($i=0; $i < $steps; ++$i) {
 171                     $this->img->current_color = $colors[$i];
 172                     $this->img->Line($x,$yb,$x,$yt);
 173                     $x += $delta;
 174                 }
 175                 break;
 176
 177             case 9:  // RIGHT REFLECTION
 178                 $steps1 = round(0.7*abs($xr-$xl));
 179                 $delta = $xr>=$xl ? 1 : -1;
 180
 181                 $this->GetColArray($from_color,$to_color,$steps1,$colors,$this->numcolors);
 182                 for($x=$xl, $i=0; $i < $steps1; ++$i) {
 183                     $this->img->current_color = $colors[$i];
 184                     $this->img->Line($x,$yb,$x,$yt);
 185                     $x += $delta;
 186                 }
 187                 $steps2 = max(1,round(0.08*abs($xr-$xl)));
 188                 $this->img->SetColor($to_color);
 189                 for($j=0; $j< $steps2; ++$j) {
 190                     $this->img->Line($x,$yb,$x,$yt);
 191                     $x += $delta;
 192                 }
 193                 $steps = abs($xr-$xl)-$steps1-$steps2;
 194                 $this->GetColArray($to_color,$from_color.':1.3',$steps,$colors,$this->numcolors);
 195                 for($i=0; $i < $steps; ++$i) {
 196                     $this->img->current_color = $colors[$i];
 197                     $this->img->Line($x,$yb,$x,$yt);
 198                     $x += $delta;
 199                 }
 200                 break;
 201
 202
 203             case 5: // Rectangle
 204                 $steps = floor(min(($yb-$yt)+1,($xr-$xl)+1)/2);
 205                 $this->GetColArray($from_color,$to_color,$steps,$colors,$this->numcolors);
 206                 $dx = ($xr-$xl)/2;
 207                 $dy = ($yb-$yt)/2;
 208                 $x=$xl;$y=$yt;$x2=$xr;$y2=$yb;
 209                 for($x=$xl, $i=0; $x < $xl+$dx && $y < $yt+$dy ; ++$x, ++$y, --$x2, --$y2, ++$i) {
 210                     assert( $i < count($colors));
 211                     $this->img->current_color = $colors[$i];
 212                     $this->img->Rectangle($x,$y,$x2,$y2);
 213                 }
 214                 $this->img->Line($x,$y,$x2,$y2);
 215                 break;
 216
 217             default:
 218                 die("JpGraph Error: Unknown gradient style (=$style).");
 219                 break;
 220         }
 221     }
 222
 223     // Fill a special case of a polygon with a flat bottom
 224     // with a gradient. Can be used for filled line plots.
 225     // Please note that this is NOT a generic gradient polygon fill
 226     // routine. It assumes that the bottom is flat (like a drawing
 227     // of a mountain)
 228     function FilledFlatPolygon($pts,$from_color,$to_color) {
 229         if( count($pts) == 0 ) return;
 230
 231         $maxy=$pts[1];
 232         $miny=$pts[1];
 233         $n = count($pts) ;
 234         for( $i=0, $idx=0; $i < $n; $i += 2) {
 235             $x = round($pts[$i]);
 236             $y = round($pts[$i+1]);
 237             $miny = min($miny,$y);
 238             $maxy = max($maxy,$y);
 239         }
 240
 241         $colors = array();
 242         $this->GetColArray($from_color,$to_color,abs($maxy-$miny)+1,$colors,$this->numcolors);
 243         for($i=$miny, $idx=0; $i <= $maxy; ++$i ) {
 244             $colmap[$i] = $colors[$idx++];
 245         }
 246
 247         $n = count($pts)/2 ;
 248         $idx = 0 ;
 249         while( $idx < $n-1 ) {
 250             $p1 = array(round($pts[$idx*2]),round($pts[$idx*2+1]));
 251             $p2 = array(round($pts[++$idx*2]),round($pts[$idx*2+1]));
 252
 253             // Find the largest rectangle we can fill
 254             $y = max($p1[1],$p2[1]) ;
 255             for($yy=$maxy; $yy >= $y; --$yy) {
 256                 $this->img->current_color = $colmap[$yy];
 257                 $this->img->Line($p1[0],$yy,$p2[0],$yy);
 258             }
 259
 260             if( $p1[1] == $p2[1] ) continue;
 261
 262             // Fill the rest using lines (slow...)
 263             $slope = ($p2[0]-$p1[0])/($p1[1]-$p2[1]);
 264             $x1 = $p1[0];
 265             $x2 = $p2[0];
 266             $start = $y;
 267             if( $p1[1] > $p2[1] ) {
 268                 while( $y >= $p2[1] ) {
 269                     $x1=$slope*($start-$y)+$p1[0];
 270                     $this->img->current_color = $colmap[$y];
 271                     $this->img->Line($x1,$y,$x2,$y);
 272                     --$y;
 273                 }
 274             }
 275             else {
 276                 while( $y >= $p1[1] ) {
 277                     $x2=$p2[0]+$slope*($start-$y);
 278                     $this->img->current_color = $colmap[$y];
 279                     $this->img->Line($x1,$y,$x2,$y);
 280                     --$y;
 281                 }
 282             }
 283         }
 284     }
 285
 286 //---------------
 287 // PRIVATE METHODS
 288     // Add to the image color map the necessary colors to do the transition
 289     // between the two colors using $numcolors intermediate colors
 290     function GetColArray($from_color,$to_color,$arr_size,&$colors,$numcols=100) {
 291         if( $arr_size==0 ) return;
 292         // If color is given as text get it's corresponding r,g,b values
 293         $from_color = $this->img->rgb->Color($from_color);
 294         $to_color = $this->img->rgb->Color($to_color);
 295
 296         $rdelta=($to_color[0]-$from_color[0])/$numcols;
 297         $gdelta=($to_color[1]-$from_color[1])/$numcols;
 298         $bdelta=($to_color[2]-$from_color[2])/$numcols;
 299         $colorsperstep  = $numcols/$arr_size;
 300         $prevcolnum     = -1;
 301         for ($i=0; $i < $arr_size; ++$i) {
 302             $colnum = floor($colorsperstep*$i);
 303             if ( $colnum == $prevcolnum )
 304                 $colors[$i]     = $colidx;
 305             else {
 306                 $r = floor($from_color[0] + $colnum*$rdelta);
 307                 $g = floor($from_color[1] + $colnum*$gdelta);
 308                 $b = floor($from_color[2] + $colnum*$bdelta);
 309                 $colidx = $this->img->rgb->Allocate(sprintf("#%02x%02x%02x",$r,$g,$b));
 310                 $colors[$i] = $colidx;
 311             }
 312             $prevcolnum = $colnum;
 313         }
 314     }
 315 } // Class
 316
 317 ?>