History of map

For Filter Factory compatibility only

== Syntax ==

int map(int i, int n)

== Arguments ==

:i

::The index number, divided by two, of the first of two consecutive slider controls

:n

::The value to map between the range.

== Return ==

The pixel value mapped to the narrower range of values.

== Description ==

The map function takes two consecutive STANDARD values and maps the given pixel value between them. Lowering the Map 1 slider value causes the image to brighten, while raising the Map 2 slider value causes it to darken, if applied to an entire image.

Internally, the map function works like this:

<code>

(n < MAP2) ? 0 : (n > MAP1) ? 255 : (MAP1 == MAP2) ? 255 : (n-MAP2)*255/(MAP1-MAP2);

</code>

== Example ==

<code>

%ffp

ctl[2]: "Map 1", Range=(0,255), Val=255

ctl[3]: "Map 2", Range=(0,255), Val=0

ForEveryTile: {

for (y = y_start; y &lt; y_end; y++) {

for (x = x_start; x &lt; x_end; x++) {

for (z=0; z &lt; 3; z++) {

pset(x,y,z, map(1, src(x,y,z)) );

}

}

}

return true;

</code>