Programming Web Graphics with Perl and GNU Softwar

Name

Shade( ) — shade the image with light source

Synopsis

$image->Shade(geometry=>geometry,


azimuth=>integer,


elevation=>float,

             color=>{1, 0})

Shade( ), as shown in Figure 5.12, creates an effect similar to that of Emboss( ) in that it gives the edges of the image a three-dimensional look and lights it with a distant light source (in fact, Emboss( ) is a special enhanced case of the Shade( ) function). You may control the light source with the azimuth and elevation parameters; azimuth is measured in degrees off the x axis and elevation is measured in “virtual pixels” on the (also virtual) z axis. The geometry parameter may be specified as a shortcut for azimuth× elevation .

Figure 5-12. $image->Shade(azimuth => 60, elevation => 50, color => 0)