CairoContext::arcNegative

(PECL cairo >= 0.1.0)

Adds a negative arc

public void CairoContext::arcNegative ( float $x, float $y, float $radius, float $angle1, float $angle2 )

Object oriented style (method):

Procedural style:

void cairo_arc_negative ( CairoContext $context , float $x , float $y , float $radius , float $angle1 , float $angle2 )

Adds a circular arc of the given radius to the current path. The arc is centered at (x, y), begins at angle1 and proceeds in the direction of decreasing angles to end at angle2. If angle2 is greater than angle1 it will be progressively decreased by 2*M_PI until it is less than angle1. See CairoContext::arc() or cairo_arc() for more details. This function differs only in the direction of the arc between the two angles.

Parameters:

context

A valid CairoContext object

double x position

double y position

radius

The radius of the desired negative arc

angle1

Start angle of the arc

angle2

End angle of the arc

Returns:

No value is returned.

Examples:

Object oriented style

<?php
 
$s = new CairoImageSurface(CairoFormat::ARGB32, 100, 100);
$c = new CairoContext($s);
 
$c->setSourceRgb(0, 0, 0);
$c->paint();
 
$c->setLineWidth(1);
$c->setSourceRgb(1, 1, 1);
 
for ($r = 50; $r > 0; $r -= 10) {
 $c->arcNegative(50, 50, $r, 2 * M_PI, 0);
 $c->stroke();
 $c->fill();
}
 
$s->writeToPng(dirname(__FILE__) . '/CairoContext__arcNegative.png');
?>

Procedural style

<?php
 
$s = cairo_image_surface_create(CAIRO_SURFACE_TYPE_IMAGE, 100, 100);
$c = cairo_create($s);
 
cairo_set_source_rgb($c, 0, 0, 0);
cairo_paint($c);
 
cairo_set_source_rgb($c, 1, 1, 1);
cairo_set_line_width($c, 1);
 
for ($r = 50; $r > 0; $r -= 10) {
 cairo_arc_negative($c, 50, 50, $r, 2 * M_PI, 0);
 cairo_stroke($c);
 cairo_fill($c);
}
 
cairo_surface_write_to_png($s, dirname(__FILE__) . '/cairo_arc_negative.png');
?>