CAIRO_ARC_NEGATIVE(3) 1 CAIRO_ARC_NEGATIVE(3)
CairoContext::arcNegative - Adds a negative arc
Object oriented style (method):
SYNOPSIS
public void CairoContext::arcNegative (float $x, float $y, float $radius, float $angle1, float $angle2)
DESCRIPTION
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(3) for more details. This function differs only in the direction of the arc
between the two angles.
PARAMETERS
o $context
- A valid CairoContext object
o $x
- double x position
o $y
- double y position
o $radius
- The radius of the desired negative arc
o $angle1
- Start angle of the arc
o $angle2
- End angle of the arc
RETURN VALUES
No value is returned.
EXAMPLES
Example #1
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');
?>
Example #2
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');
?>
SEE ALSO
CairoContext::arc.
PHP Documentation Group CAIRO_ARC_NEGATIVE(3)