src/plot/Gradient.php
<?php
/**
* JPGraph v4.0.3
*/
namespace Amenadiel\JpGraph\Plot;
/*
* File: JPGRAPH_GRADIENT.PHP
* // Description: Create a color gradient
* // Created: 2003-02-01
* // Ver: $Id: jpgraph_gradient.php 1761 2009-08-01 08:31:28Z ljp $
* //
* // Copyright (c) Asial Corporation. All rights reserved.
*/
use Amenadiel\JpGraph\Util;
/**
* @class Gradient
* // Description: Handles gradient fills. This is to be
* // considered a "friend" class of Class Image.
*/
class Gradient
{
private $img;
private $numcolors = 100;
/**
* CONSTRUCTOR.
*
* @param mixed $img
*/
public function __construct(&$img)
{
$this->img = $img;
}
public function SetNumColors($aNum)
{
$this->numcolors = $aNum;
}
/**
* PUBLIC METHODS.
*
* @param mixed $xl
* @param mixed $yt
* @param mixed $xr
* @param mixed $yb
* @param mixed $from_color
* @param mixed $to_color
* @param mixed $style
*/
// Produce a gradient filled rectangle with a smooth transition between
// two colors.
// ($xl,$yt) Top left corner
// ($xr,$yb) Bottom right
// $from_color Starting color in gradient
// $to_color End color in the gradient
// $style Which way is the gradient oriented?
public function FilledRectangle($xl, $yt, $xr, $yb, $from_color, $to_color, $style = 1)
{
$this->img->SetLineWeight(1);
switch ($style) {
case GRAD_VER:
$steps = ceil(abs($xr - $xl) + 1);
$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 GRAD_HOR:
$steps = ceil(abs($yb - $yt) + 1);
$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 GRAD_MIDHOR:
$steps = ceil(abs($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;
if (abs($yb - $yt) % 2 == 1) {
--$steps;
}
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 GRAD_MIDVER:
$steps = ceil(abs($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;
if (abs($xr - $xl) % 2 == 1) {
--$steps;
}
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 GRAD_WIDE_MIDVER:
$diff = ceil(abs($xr - $xl));
$steps = floor(abs($diff) / 3);
$firststep = $diff - 2 * $steps;
$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 GRAD_WIDE_MIDHOR:
$diff = ceil(abs($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 GRAD_LEFT_REFLECTION:
$steps1 = ceil(0.3 * abs($xr - $xl));
$delta = $xr >= $xl ? 1 : -1;
$from_color = $this->img->rgb->Color($from_color);
$adj = 1.4;
$m = ($adj - 1.0) * (255 - min(255, min($from_color[0], min($from_color[1], $from_color[2]))));
$from_color2 = [min(255, $from_color[0] + $m),
min(255, $from_color[1] + $m), min(255, $from_color[2] + $m), ];
$this->GetColArray($from_color2, $to_color, $steps1, $colors, $this->numcolors);
$n = safe_count($colors);
for ($x = $xl, $i = 0; $i < $steps1 && $i < $n; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x, $yb, $x, $yt);
$x += $delta;
}
$steps2 = max(1, ceil(0.08 * abs($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);
$n = safe_count($colors);
for ($i = 0; $i < $steps && $i < $n; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x, $yb, $x, $yt);
$x += $delta;
}
break;
case GRAD_RIGHT_REFLECTION:
$steps1 = ceil(0.7 * abs($xr - $xl));
$delta = $xr >= $xl ? 1 : -1;
$this->GetColArray($from_color, $to_color, $steps1, $colors, $this->numcolors);
$n = safe_count($colors);
for ($x = $xl, $i = 0; $i < $steps1 && $i < $n; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x, $yb, $x, $yt);
$x += $delta;
}
$steps2 = max(1, ceil(0.08 * abs($xr - $xl)));
$this->img->SetColor($to_color);
for ($j = 0; $j < $steps2; ++$j) {
$this->img->Line($x, $yb, $x, $yt);
$x += $delta;
}
$from_color = $this->img->rgb->Color($from_color);
$adj = 1.4;
$m = ($adj - 1.0) * (255 - min(255, min($from_color[0], min($from_color[1], $from_color[2]))));
$from_color = [min(255, $from_color[0] + $m),
min(255, $from_color[1] + $m), min(255, $from_color[2] + $m), ];
$steps = abs($xr - $xl) - $steps1 - $steps2;
$this->GetColArray($to_color, $from_color, $steps, $colors, $this->numcolors);
$n = safe_count($colors);
for ($i = 0; $i < $steps && $i < $n; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x, $yb, $x, $yt);
$x += $delta;
}
break;
case GRAD_CENTER:
$steps = ceil(min(($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;
$n = safe_count($colors);
for ($x = $xl, $i = 0; $x < $xl + $dx && $y < $yt + $dy && $i < $n; ++$x, ++$y, --$x2, --$y2, ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Rectangle($x, $y, $x2, $y2);
}
$this->img->Line($x, $y, $x2, $y2);
break;
case GRAD_RAISED_PANEL:
// right to left
$steps1 = $xr - $xl;
$delta = $xr >= $xl ? 1 : -1;
$this->GetColArray($to_color, $from_color, $steps1, $colors, $this->numcolors);
$n = safe_count($colors);
for ($x = $xl, $i = 0; $i < $steps1 && $i < $n; ++$i) {
$this->img->current_color = $colors[$i];
$this->img->Line($x, $yb, $x, $yt);
$x += $delta;
}
// left to right
$xr -= 3;
$xl += 3;
$yb -= 3;
$yt += 3;
$steps2 = $xr - $xl;
$delta = $xr >= $xl ? 1 : -1;
for ($x = $xl, $j = $steps2; $j >= 0; --$j) {
$this->img->current_color = $colors[$j];
$this->img->Line($x, $yb, $x, $yt);
$x += $delta;
}
break;
case GRAD_DIAGONAL:
// use the longer dimension to determine the required number of steps.
// first loop draws from one corner to the mid-diagonal and the second
// loop draws from the mid-diagonal to the opposing corner.
if ($xr - $xl > $yb - $yt) {
// width is greater than height -> use x-dimension for steps
$steps = $xr - $xl;
$delta = $xr >= $xl ? 1 : -1;
$this->GetColArray($from_color, $to_color, $steps * 2, $colors, $this->numcolors);
$n = safe_count($colors);
for ($x = $xl, $i = 0; $i < $steps && $i < $n; ++$i) {
$this->img->current_color = $colors[$i];
$y = $yt + ($i / $steps) * ($yb - $yt) * $delta;
$this->img->Line($x, $yt, $xl, $y);
$x += $delta;
}
for ($x = $xl, $i = 0; $i < $steps && $i < $n; ++$i) {
$this->img->current_color = $colors[$steps + $i];
$y = $yt + ($i / $steps) * ($yb - $yt) * $delta;
$this->img->Line($x, $yb, $xr, $y);
$x += $delta;
}
} else {
// height is greater than width -> use y-dimension for steps
$steps = $yb - $yt;
$delta = $yb >= $yt ? 1 : -1;
$this->GetColArray($from_color, $to_color, $steps * 2, $colors, $this->numcolors);
$n = safe_count($colors);
for ($y = $yt, $i = 0; $i < $steps && $i < $n; ++$i) {
$this->img->current_color = $colors[$i];
$x = $xl + ($i / $steps) * ($xr - $xl) * $delta;
$this->img->Line($x, $yt, $xl, $y);
$y += $delta;
}
for ($y = $yt, $i = 0; $i < $steps && $i < $n; ++$i) {
$this->img->current_color = $colors[$steps + $i];
$x = $xl + ($i / $steps) * ($xr - $xl) * $delta;
$this->img->Line($x, $yb, $xr, $y);
$x += $delta;
}
}
break;
default:
Util\JpGraphError::RaiseL(7001, $style);
//("Unknown gradient style (=$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)
public function FilledFlatPolygon($pts, $from_color, $to_color)
{
if (safe_count($pts) == 0) {
return;
}
$maxy = $pts[1];
$miny = $pts[1];
$n = safe_count($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 = [];
$this->GetColArray($from_color, $to_color, abs($maxy - $miny) + 1, $colors, $this->numcolors);
for ($i = $miny, $idx = 0; $i <= $maxy; ++$i) {
$colmap[$i] = $colors[$idx++];
}
$n = safe_count($pts) / 2;
$idx = 0;
while ($idx < $n - 1) {
$p1 = [round($pts[$idx * 2]), round($pts[$idx * 2 + 1])];
$p2 = [round($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] - 1, $yy);
}
if ($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] - 1;
$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.
*
* @param mixed $from_color
* @param mixed $to_color
* @param mixed $arr_size
* @param mixed $numcols
* @param mixed $colors
*/
// Add to the image color map the necessary colors to do the transition
// between the two colors using $numcolors intermediate colors
public function GetColArray($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;
$from_alpha = $from_color[3];
$to_alpha = $to_color[3];
$adelta = ($to_alpha - $from_alpha) / $numcols;
for ($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);
$alpha = $from_alpha + $colnum * $adelta;
$colidx = $this->img->rgb->Allocate(sprintf('#%02x%02x%02x', $r, $g, $b), $alpha);
$colors[$i] = $colidx;
}
$prevcolnum = $colnum;
}
}
} // @class