NAME
wml::des::imgdot - 1pt Dot-Images for Webdesign
SYNOPSIS
#use wml::des::imgdot
<: $file = &imgdot($base, $x, $y, $c, $r, $g, $b, $transp, $format); :>
<imgdot [attributes]>
DESCRIPTION
Currently (as of HTML 3.2 and 1997 ;_) webdesigners use two commonly
known tricks for creating their layout on webpages: HTML tables and so-
called 1pt Dot-Images. The first one is nicely supported by the WML
tag "<grid>" (see wml::des::grid(3) for details), the latter is
supported by this "<imgdot>" tag.
The usual purpose of this tag is to create a transparent PNG or GIF
image with a physical size of 1x1 points and a corresponding "<img>"
tag which includes this image with appropriate "width" and "height"
attributes. The visual result is a invisible reserved space of size
"width"X"height". Alternatively this tag can create the image with the
requested size instead of scaling the 1pt image (see the "noscale"
attribute below). This approach is more safe (all browsers support
this) but wastes bandwith and increases page load time.
ATTRIBUTES
base
Usually the created images are named imgdot-XxY-rrggbb.png where
"XxY" is the dimension of the image and "rrggbb" the used color (or
‘"transp"’ for transparent). When you use a "base=foo" attribute,
then the resulting files are named foo.imgdot-XxY-rrggbb.gif.
Actually you can even use a complete filename including a directory
prefix, i.e. when you use "base=../../common/foo" attribute, then
the PNG images are created as
../../common/foo.imgdot-XxY-rrggbb.png.
And for most flexibility when no base is specified and the variable
"IMGDOT_BASE" is defined (usually from within a .wmlrc file via
"-DIMGDOT_BASE~path/to/imgdot/dir/base") it is used. Use this
feature to redirect the created images to a particular directory.
You may also use the variable "IMAGE_BASE" which defines in a
single line all base names for images generated by WML.
format
By default, GIF images are generated. This attribute lets you use
an alternate image format (actually only PNG and GIF are
recognized). You may also change the default format with the
variable "IMAGE_FORMAT".
width
Specifies the width (x-dimension) of the reserved space in pixel.
Default is 1 pixel.
height
Specifies the height (y-dimension) of the reserved space in pixel.
Default is 1 pixel.
color
Sets the color of the image. Default is transparent, i.e. no color.
In fact, this is not true, transparency is rendered by choosing a
color which is made transparent, which is white by default.
Prepending an hyphen to the "color" attribute sets the color of the
transparent color.
align
Sets the alignment of the image. Default is ‘"bottom"’. This
alignment is used for the "align" attribute of the inserted "<img>"
tag.
noscale
Indicates if the image should be created with 1pt in size and
scaled online by the browser (default) or should be created with
the correct physical size (this option).
:img:ATTR=STR
The ‘‘ATTR=STR’’ pairs are passed along to the "<img>" HTML tag.
AUTHOR
Ralf S. Engelschall
rse@engelschall.com
www.engelschall.com
Denis Barbier
barbier@engelschall.com
REQUIRES
Internal: P1, P2, P3
SEE ALSO
HTML <"img"> tag.