//RBGtoHSL、HuetoRGB、HSLtoRGBはphp公式の http://www.php.net/manual/ja/ref.image.php#79996 より
function RBGtoHSL( $R, $G, $B ){
$var_R = ( $R / 255 );
$var_G = ( $G / 255 );
$var_B = ( $B / 255 );
$var_Min = min( $var_R, $var_G, $var_B );
$var_Max = max( $var_R, $var_G, $var_B );
$del_Max = $var_Max - $var_Min;
$L = ( $var_Max + $var_Min ) / 2;
if ( $del_Max == 0 ) {
$H = 0;
$S = 0;
} else {
if ( $L < 0.5 ) {
$S = $del_Max / ( $var_Max + $var_Min );
} else {
$S = $del_Max / ( 2 - $var_Max - $var_Min );
}
$del_R = ( ( ( $var_Max - $var_R ) / 6 ) + ( $del_Max / 2 ) ) / $del_Max;
$del_G = ( ( ( $var_Max - $var_G ) / 6 ) + ( $del_Max / 2 ) ) / $del_Max;
$del_B = ( ( ( $var_Max - $var_B ) / 6 ) + ( $del_Max / 2 ) ) / $del_Max;
if ( $var_R == $var_Max ){
$H = $del_B - $del_G;
} else if ( $var_G == $var_Max ){
$H = ( 1 / 3 ) + $del_R - $del_B;
}else if ( $var_B == $var_Max ){
$H = ( 2 / 3 ) + $del_G - $del_R;
}
if ( $H < 0 ){
$H += 1;
}
if ( $H > 1 ){
$H -= 1;
}
}
return array( $H, $S, $L );
}
function HuetoRGB( $v1, $v2, $vH ) {
if ( $vH < 0 ) {
$vH += 1;
}
if ( $vH > 1 ) {
$vH -= 1;
}
if ( ( 6 * $vH ) < 1 ) {
return ( $v1 + ( $v2 - $v1 ) * 6 * $vH );
}
if ( ( 2 * $vH ) < 1 ) {
return ( $v2 );
}
if ( ( 3 * $vH ) < 2 ) {
return ( $v1 + ( $v2 - $v1 ) * ( ( 2 / 3 ) - $vH ) * 6 );
}
return ( $v1 );
}
function HSLtoRGB( $H, $S, $L ){
if ( $S == 0 ) {
$R = $L * 255;
$G = $L * 255;
$B = $L * 255;
} else {
if ( $L < 0.5 ) {
$var_2 = $L * ( 1 + $S );
} else {
$var_2 = ( $L + $S ) - ( $S * $L );
}
$var_1 = 2 * $L - $var_2;
$R = 255 * $this->HuetoRGB( $var_1, $var_2, $H + ( 1 / 3 ) );
$G = 255 * $this->HuetoRGB( $var_1, $var_2, $H );
$B = 255 * $this->HuetoRGB( $var_1, $var_2, $H - ( 1 / 3 ) );
}
return array( $R, $G, $B );
}
/**
* Draw random curvy lines over the image<br />
* Modified code from HKCaptcha
*
* @since 2.0
* @access private
*
*/
function drawLines(){
for ($line = 0; $line < $this->num_lines; ++$line) {
//元々の $this->line_color は一色しか入ってないから、テキスト用の色配列を使う
shuffle($this->multi_text_color);
$nowColor=$this->multi_text_color[0];
$nowColor=$this->RBGtoHSL($nowColor[0],$nowColor[1],$nowColor[2]);
$nowColor[2]=0.5;
$nowColor=$this->HSLtoRGB($nowColor[0],$nowColor[1],$nowColor[2]);
$linecolor = imagecolorallocatealpha($this->im,$nowColor[0],$nowColor[1],$nowColor[2],126);
//追加ここまで
$x = $this->image_width * (1 + $line) / ($this->num_lines + 1);
$x += (0.5 - $this->frand()) * $this->image_width / $this->num_lines;
$y = rand($this->image_height * 0.1, $this->image_height * 0.9);
$theta = ($this->frand()-0.5) * M_PI * 0.7;
$w = $this->image_width;
$len = rand($w * 0.4, $w * 0.7);
$lwid = rand(0, 15);//おまけで線を太めにする。
$k = $this->frand() * 0.6 + 0.2;
$k = $k * $k * 0.5;
$phi = $this->frand() * 6.28;
$step = 0.5;
$dx = $step * cos($theta);
$dy = $step * sin($theta);
$n = $len / $step;
$amp = 1.5 * $this->frand() / ($k + 5.0 / $len);
$x0 = $x - 0.5 * $len * cos($theta);
$y0 = $y - 0.5 * $len * sin($theta);
$ldx = round(-$dy * $lwid);
$ldy = round($dx * $lwid);
for ($i = 0; $i < $n; ++$i) {
$x = $x0 + $i * $dx + $amp * $dy * sin($k * $i * $step + $phi);
$y = $y0 + $i * $dy - $amp * $dx * sin($k * $i * $step + $phi);
imagefilledrectangle($this->im, $x, $y, $x + $lwid, $y + $lwid, $linecolor);
}
}
}
