PHP/MapScript layer mask test
SelectOutputFormat("PNG");
////////
// Draw the base layers into an imageObj
$img1 = $map->prepareimage();
$layer = $map->getLayerByName("bathymetry");
$layer->set("status", 1);
$layer->draw($img1);
//$img = $map->draw();
$url = $img1->saveWebImage();
echo "
Draw the base layers into an image...
\n";
printf("
\n", $url, $map->width, $map->height);
//////////////
// Use the parks layer as a mask... we only want to see the base layers
// through the area of the park polygons and the rest should be light grey.
// Start by creating a new image ...
$img2 = $map->prepareimage();
// ... and we'll use a rectObj to draw the opaque mask background
$rect = ms_newRectObj();
$rect->setExtent(0, 0, $map->width, $map->height);
// We need to create a temporary layer and class to use in drawing the
// filled rectangle that will be the opaque part of the mask.
$tmplayer = ms_newLayerObj($map);
$tmplayer->set("type", MS_LAYER_POLYGON);
$tmplayer->set("status", 1);
$tmplayer->set("transform", MS_FALSE);
$tmpclass = ms_newClassObj($tmplayer);
$tmpstyle = ms_newStyleObj($tmpclass);
$tmpstyle->color->setRGB(222,222,222);
$rect->draw($map, $tmplayer, $img2, 0, ""); // Draw rect with class 0
// Now fetch the park layer and change its only class to use color index 0
// which is the transparent background color... so the parks polygons will
// create transparent holes in the mask
$layer = $map->getLayerByName("park");
$layer->set("status", 1);
$class = $layer->getClass(0);
$style = $class->getStyle(0);
$style->color->setRGB(12,12,12);
$style->outlinecolor->setRGB(12,12,12);
$layer->draw($img2);
$url = $img2->saveWebImage();
echo "
Draw the mask into another image...
\n";
printf("\n", $url, $map->width, $map->height);
////////
// Last step... combine the two images using pasteImage()
//
echo "
And combine the two with pasteImage()... you see the base layer through the holes in the mask...
\n";
$img1->pasteImage($img2, 0x0c0c0c);
$url = $img1->saveWebImage();
printf("\n", $url, $map->width, $map->height);
?>