# cairo_arc_negative

(PECL cairo >= 0.1.0)

CairoContext::arcNegative -- cairo_arc_negativeAdds a negative arc

### 説明

オブジェクト指向型 (method):

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

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

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.

### パラメータ

`context`

A valid CairoContext object

`x`

double x position

`y`

double y position

`radius`

The radius of the desired negative arc

`angle1`

Start angle of the arc

`angle2`

End angle of the arc

### 例

``` <?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');?> ```

``` <?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');?> ```