// gradient — chrome
//
// Hand-written, unlike contrib/shaders: those are generated from
// contrib/shadertoy.html, and the toy previews a pane's *contents*. A frame is
// a different rect and the toy has no frame to show.
//
// Drop this into ~/.config/slosh/config.kdl (a running session picks it up
// when you save), or point $SLOSH_CONFIG at this file. To hang it off a pane
// state instead of every pane, put the same pass inside one:
//
//     states { bell { ... } }
//
// Not animated: the border is simply brightest at the top-left corner and falls
// away round both sides, so the frame reads as lit from somewhere rather than
// drawn in one flat colour. Costs nothing per frame -- it does not read the
// clock, so the whole pass is computed once into a map and reused.

shaders {
    tint where="chrome" channel="fg" color="#ffffff" amount="235 - min((y == 0 ? x : x == cols - 1 ? cols - 1 + y : y == rows - 1 ? 2 * cols + rows - 3 - x : 2 * cols + 2 * rows - 4 - y), (2 * cols + 2 * rows - 4) - (y == 0 ? x : x == cols - 1 ? cols - 1 + y : y == rows - 1 ? 2 * cols + rows - 3 - x : 2 * cols + 2 * rows - 4 - y)) * 255 / (cols + rows - 2)"
}