<?php
/*=======================================================================
// File: JPGRAPH_GRADIENT.PHP
// Description: Create a color gradient
// Created: 2003-02-01
// Author: Johan Persson (hide@address.com)
// Ver: $Id: jpgraph_gradient.php,v 1.1.2.5 2003/08/23 23:15:06 aditus Exp $
//
// License: This code is released under QPL
// Copyright (C) 2003 Johan Persson
//========================================================================
*/
//===================================================
// CLASS Gradient
// Description: Handles gradient fills. This is to be
// considered a "friend" class of Class Image.
//===================================================
class Gradient {
var $img=null;
var $numcolors=100;
//---------------
// CONSTRUCTOR
function Gradient(&$img) {
$this->img = $img;
}
function SetNumColors($aNum) {
$this->numcolors=$aNum;
}
//---------------
// PUBLIC METHODS
// Produce a gradient filled rectangle with a smooth transition between
// two colors.
// ($xl,$yt) Top left corner
// ($xr,$yb) Bottom right
// $from_color Starting color in gradient
// $to_color End color in the gradient
// $style Which way is the gradient oriented?
function FilledRectangle($xl,$yt,$xr,$yb,$from_color,$to_color,$style=1) {
switch( $style ) {
case 1: // HORIZONTAL
$steps = abs($xr-$xl);
$delta = $xr>=$xl ? 1 : -1;
$this->GetColArray($from_color,$to_color,$steps,$colors,$this->numcolors);
for( $i=0, $x=$xl; $i < $steps; ++$i ) {
$this->img->current_color = $colors[$i];
$this->img->Line($x,$yt,$x,$yb);
$x += $delta;
}
break;
case 2: // VERTICAL
$steps = abs($yb-$yt);
$delta = $yb>=$yt ? 1 : -1;
$this->GetColArray($from_color,$to_color,$steps,$colors,$this->numcolors);
for($i=0,$y=$yt; $i < $steps; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($xl,$y,$xr,$y);
$y += $delta;
}
break;
case 3: // VERTICAL FROM MIDDLE
$steps = abs($yb-$yt)/2;
$delta = $yb >= $yt ? 1 : -1;
$this->GetColArray($from_color,$to_color,$steps,$colors,$this->numcolors);
for($y=$yt, $i=0; $i < $steps; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($xl,$y,$xr,$y);
$y += $delta;
}
--$i;
for($j=0; $j < $steps; ++$j, --$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($xl,$y,$xr,$y);
$y += $delta;
}
$this->img->Line($xl,$y,$xr,$y);
break;
case 4: // HORIZONTAL FROM MIDDLE
$steps = abs($xr-$xl)/2;
$delta = $xr>=$xl ? 1 : -1;
$this->GetColArray($from_color,$to_color,$steps,$colors,$this->numcolors);
for($x=$xl, $i=0; $i < $steps; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x,$yb,$x,$yt);
$x += $delta;
}
--$i;
for($j=0; $j < $steps; ++$j, --$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x,$yb,$x,$yt);
$x += $delta;
}
$this->img->Line($x,$yb,$x,$yt);
break;
case 6: // HORIZONTAL WIDER MIDDLE
$diff = round(abs($xr-$xl));
$steps = floor(abs($diff)/3);
$firststep = $diff - 2*$steps ;
// $steps = abs($xr-$xl)/3;
$delta = $xr >= $xl ? 1 : -1;
$this->GetColArray($from_color,$to_color,$firststep,$colors,$this->numcolors);
for($x=$xl, $i=0; $i < $firststep; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x,$yb,$x,$yt);
$x += $delta;
}
--$i;
$this->img->current_color = $colors[$i];
for($j=0; $j< $steps; ++$j) {
$this->img->Line($x,$yb,$x,$yt);
$x += $delta;
}
for($j=0; $j < $steps; ++$j, --$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x,$yb,$x,$yt);
$x += $delta;
}
break;
case 7: // VERTICAL WIDER MIDDLE
$diff = round(abs($yb-$yt));
$steps = floor(abs($diff)/3);
$firststep = $diff - 2*$steps ;
$delta = $yb >= $yt? 1 : -1;
$this->GetColArray($from_color,$to_color,$firststep,$colors,$this->numcolors);
for($y=$yt, $i=0; $i < $firststep; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($xl,$y,$xr,$y);
$y += $delta;
}
--$i;
$this->img->current_color = $colors[$i];
for($j=0; $j < $steps; ++$j) {
$this->img->Line($xl,$y,$xr,$y);
$y += $delta;
}
for($j=0; $j < $steps; ++$j, --$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($xl,$y,$xr,$y);
$y += $delta;
}
break;
case 8: // LEFT REFLECTION
$steps1 = round(0.3*abs($xr-$xl));
$delta = $xr>=$xl ? 1 : -1;
$this->GetColArray($from_color.':1.3',$to_color,$steps1,$colors,$this->numcolors);
for($x=$xl, $i=0; $i < $steps1; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x,$yb,$x,$yt);
$x += $delta;
}
$steps2 = max(1,round(0.08*abs($xr-$xl)));
$this->img->SetColor($to_color);
for($j=0; $j< $steps2; ++$j) {
$this->img->Line($x,$yb,$x,$yt);
$x += $delta;
}
$steps = abs($xr-$xl)-$steps1-$steps2;
$this->GetColArray($to_color,$from_color,$steps,$colors,$this->numcolors);
for($i=0; $i < $steps; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x,$yb,$x,$yt);
$x += $delta;
}
break;
case 9: // RIGHT REFLECTION
$steps1 = round(0.7*abs($xr-$xl));
$delta = $xr>=$xl ? 1 : -1;
$this->GetColArray($from_color,$to_color,$steps1,$colors,$this->numcolors);
for($x=$xl, $i=0; $i < $steps1; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x,$yb,$x,$yt);
$x += $delta;
}
$steps2 = max(1,round(0.08*abs($xr-$xl)));
$this->img->SetColor($to_color);
for($j=0; $j< $steps2; ++$j) {
$this->img->Line($x,$yb,$x,$yt);
$x += $delta;
}
$steps = abs($xr-$xl)-$steps1-$steps2;
$this->GetColArray($to_color,$from_color.':1.3',$steps,$colors,$this->numcolors);
for($i=0; $i < $steps; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x,$yb,$x,$yt);
$x += $delta;
}
break;
case 5: // Rectangle
$steps = floor(min(($yb-$yt)+1,($xr-$xl)+1)/2);
$this->GetColArray($from_color,$to_color,$steps,$colors,$this->numcolors);
$dx = ($xr-$xl)/2;
$dy = ($yb-$yt)/2;
$x=$xl;$y=$yt;$x2=$xr;$y2=$yb;
for($x=$xl, $i=0; $x < $xl+$dx && $y < $yt+$dy ; ++$x, ++$y, --$x2, --$y2, ++$i) {
assert( $i < count($colors));
$this->img->current_color = $colors[$i];
$this->img->Rectangle($x,$y,$x2,$y2);
}
$this->img->Line($x,$y,$x2,$y2);
break;
default:
die("JpGraph Error: Unknown gradient style (=$style).");
break;
}
}
// Fill a special case of a polygon with a flat bottom
// with a gradient. Can be used for filled line plots.
// Please note that this is NOT a generic gradient polygon fill
// routine. It assumes that the bottom is flat (like a drawing
// of a mountain)
function FilledFlatPolygon($pts,$from_color,$to_color) {
if( count($pts) == 0 ) return;
$maxy=$pts[1];
$miny=$pts[1];
$n = count($pts) ;
for( $i=0, $idx=0; $i < $n; $i += 2) {
$x = round($pts[$i]);
$y = round($pts[$i+1]);
$miny = min($miny,$y);
$maxy = max($maxy,$y);
}
$colors = array();
$this->GetColArray($from_color,$to_color,abs($maxy-$miny)+1,$colors,$this->numcolors);
for($i=$miny, $idx=0; $i <= $maxy; ++$i ) {
$colmap[$i] = $colors[$idx++];
}
$n = count($pts)/2 ;
$idx = 0 ;
while( $idx < $n-1 ) {
$p1 = array(round($pts[$idx*2]),round($pts[$idx*2+1]));
$p2 = array(round($pts[++$idx*2]),round($pts[$idx*2+1]));
// Find the largest rectangle we can fill
$y = max($p1[1],$p2[1]) ;
for($yy=$maxy; $yy >= $y; --$yy) {
$this->img->current_color = $colmap[$yy];
$this->img->Line($p1[0],$yy,$p2[0],$yy);
}
if( $p1[1] == $p2[1] ) continue;
// Fill the rest using lines (slow...)
$slope = ($p2[0]-$p1[0])/($p1[1]-$p2[1]);
$x1 = $p1[0];
$x2 = $p2[0];
$start = $y;
if( $p1[1] > $p2[1] ) {
while( $y >= $p2[1] ) {
$x1=$slope*($start-$y)+$p1[0];
$this->img->current_color = $colmap[$y];
$this->img->Line($x1,$y,$x2,$y);
--$y;
}
}
else {
while( $y >= $p1[1] ) {
$x2=$p2[0]+$slope*($start-$y);
$this->img->current_color = $colmap[$y];
$this->img->Line($x1,$y,$x2,$y);
--$y;
}
}
}
}
//---------------
// PRIVATE METHODS
// Add to the image color map the necessary colors to do the transition
// between the two colors using $numcolors intermediate colors
function GetColArray($from_color,$to_color,$arr_size,&$colors,$numcols=100) {
if( $arr_size==0 ) return;
// If color is given as text get it's corresponding r,g,b values
$from_color = $this->img->rgb->Color($from_color);
$to_color = $this->img->rgb->Color($to_color);
$rdelta=($to_color[0]-$from_color[0])/$numcols;
$gdelta=($to_color[1]-$from_color[1])/$numcols;
$bdelta=($to_color[2]-$from_color[2])/$numcols;
$colorsperstep = $numcols/$arr_size;
$prevcolnum = -1;
for ($i=0; $i < $arr_size; ++$i) {
$colnum = floor($colorsperstep*$i);
if ( $colnum == $prevcolnum )
$colors[$i] = $colidx;
else {
$r = floor($from_color[0] + $colnum*$rdelta);
$g = floor($from_color[1] + $colnum*$gdelta);
$b = floor($from_color[2] + $colnum*$bdelta);
$colidx = $this->img->rgb->Allocate(sprintf("#%02x%02x%02x",$r,$g,$b));
$colors[$i] = $colidx;
}
$prevcolnum = $colnum;
}
}
} // Class
?>