contrib: the shadertoy presets, usable in sl0ppty

They only existed in a browser, which is a strange place for a terminal
multiplexer's shaders to live. Now each one is a file you can paste.

contrib/shaders/ holds all thirty-two, one per file, *generated* from the
presets in shadertoy.html by contrib/gen-shaders. The page stays the source:
it is where they are written, previewed and conformance-tested against the
compiler, and a hand-kept second copy would drift the day after it was
written. `gen-shaders --check` says whether the files are current, which is a
test, so the drift is a failing build rather than a stale example.

contrib/shader-tour cycles a session through them, in the shape theme-tour
already established — write the config the session watches and let the
watcher do the rest. It takes one shader, one group, or nothing for all of
them, and it resolves a short name (`torch`) as well as the whole slug
(`guides-torch`), because nobody remembers which group a shader is in. The
tour writes the theme alongside the shader: shaders resolve default-coloured
text through theme's default_fg/default_bg, so a preset judged without one is
being judged against a guess.

The new test is the one that matters. Every shipped file is loaded into a
real session and has to *change the cells of a pane* -- an example that
previews beautifully and does nothing when pasted is worse than no example,
and neither the toy's conformance test nor a config parse would notice. Three
of them are then checked for the specific thing they claim: scanlines
alternate row by row, indent guides land on every fourth column, a flat dim
is flat. One session, reloaded per preset, which is both quick and a fair
exercise of the path anyone will actually use.

Renamed the "the built-ins, as expressions" group to drop the qualifier from
its filenames; it was generating built-ins-as-expressions-scanlines.kdl,
which is a sentence rather than a name.

32 files changed, 458 insertions, 0 deletions

diff --git a/contrib/shaders/built-ins-checker.kdl b/contrib/shaders/built-ins-checker.kdl
new file mode 100644
index 0000000..e689305
--- /dev/null
+++ b/contrib/shaders/built-ins-checker.kdl
@@ -0,0 +1,14 @@
+// checker — built-ins, as expressions
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="((x / 8 + y / 4) % 2) * 45"
+}
diff --git a/contrib/shaders/built-ins-gradient.kdl b/contrib/shaders/built-ins-gradient.kdl
new file mode 100644
index 0000000..69f977f
--- /dev/null
+++ b/contrib/shaders/built-ins-gradient.kdl
@@ -0,0 +1,14 @@
+// gradient — built-ins, as expressions
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="y * 200 / rows"
+}
diff --git a/contrib/shaders/built-ins-ruler.kdl b/contrib/shaders/built-ins-ruler.kdl
new file mode 100644
index 0000000..e4643aa
--- /dev/null
+++ b/contrib/shaders/built-ins-ruler.kdl
@@ -0,0 +1,14 @@
+// ruler — built-ins, as expressions
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    tint color="#ff5fd7" amount="(x == 40) * 220"
+}
diff --git a/contrib/shaders/built-ins-scanlines.kdl b/contrib/shaders/built-ins-scanlines.kdl
new file mode 100644
index 0000000..6d25c05
--- /dev/null
+++ b/contrib/shaders/built-ins-scanlines.kdl
@@ -0,0 +1,14 @@
+// scanlines — built-ins, as expressions
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="(y % 2) * 40"
+}
diff --git a/contrib/shaders/built-ins-spotlight.kdl b/contrib/shaders/built-ins-spotlight.kdl
new file mode 100644
index 0000000..2635871
--- /dev/null
+++ b/contrib/shaders/built-ins-spotlight.kdl
@@ -0,0 +1,14 @@
+// spotlight — built-ins, as expressions
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="clamp(dist(x, y, curx, cury) * 9, 0, 200)"
+}
diff --git a/contrib/shaders/built-ins-vignette.kdl b/contrib/shaders/built-ins-vignette.kdl
new file mode 100644
index 0000000..138bd84
--- /dev/null
+++ b/contrib/shaders/built-ins-vignette.kdl
@@ -0,0 +1,14 @@
+// vignette — built-ins, as expressions
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="clamp(dist(x, y, cols / 2, rows / 2) * 4, 0, 190)"
+}
diff --git a/contrib/shaders/built-ins-zebra.kdl b/contrib/shaders/built-ins-zebra.kdl
new file mode 100644
index 0000000..852e66a
--- /dev/null
+++ b/contrib/shaders/built-ins-zebra.kdl
@@ -0,0 +1,14 @@
+// zebra — built-ins, as expressions
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="(y / 3 % 2) * 60"
+}
diff --git a/contrib/shaders/crt-amber.kdl b/contrib/shaders/crt-amber.kdl
new file mode 100644
index 0000000..746aa4e
--- /dev/null
+++ b/contrib/shaders/crt-amber.kdl
@@ -0,0 +1,16 @@
+// amber — crt
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    grayscale amount="255"
+    tint color="#ffb000" amount="95"
+    dim amount="(y % 2) * 40"
+}
diff --git a/contrib/shaders/crt-film.kdl b/contrib/shaders/crt-film.kdl
new file mode 100644
index 0000000..19b295f
--- /dev/null
+++ b/contrib/shaders/crt-film.kdl
@@ -0,0 +1,16 @@
+// film — crt
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    grayscale amount="255"
+    dim amount="((x * 7 + y * 13 + t / 40) % 17 < 2) * 70"
+    dim amount="clamp(dist(x, y, cols / 2, rows / 2) * 5, 0, 165)"
+}
diff --git a/contrib/shaders/crt-interlace.kdl b/contrib/shaders/crt-interlace.kdl
new file mode 100644
index 0000000..18bd1c5
--- /dev/null
+++ b/contrib/shaders/crt-interlace.kdl
@@ -0,0 +1,14 @@
+// interlace — crt
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="((y + t / 80) % 2) * 45"
+}
diff --git a/contrib/shaders/crt-phosphor.kdl b/contrib/shaders/crt-phosphor.kdl
new file mode 100644
index 0000000..7cdb397
--- /dev/null
+++ b/contrib/shaders/crt-phosphor.kdl
@@ -0,0 +1,17 @@
+// phosphor — crt
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    grayscale amount="255"
+    tint color="#33ff66" amount="80"
+    dim amount="(y % 3 == 0) * 55"
+    dim amount="clamp(dist(x, y, cols / 2, rows / 2) * 4, 0, 150)"
+}
diff --git a/contrib/shaders/crt-rolling-bar.kdl b/contrib/shaders/crt-rolling-bar.kdl
new file mode 100644
index 0000000..b9ce7ef
--- /dev/null
+++ b/contrib/shaders/crt-rolling-bar.kdl
@@ -0,0 +1,14 @@
+// rolling bar — crt
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="(abs(y - (t / 90) % rows) < 2) * 70"
+}
diff --git a/contrib/shaders/guides-crosshair.kdl b/contrib/shaders/guides-crosshair.kdl
new file mode 100644
index 0000000..7c8ab09
--- /dev/null
+++ b/contrib/shaders/guides-crosshair.kdl
@@ -0,0 +1,14 @@
+// crosshair — guides
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="((y == cury) || (x == curx)) * 55"
+}
diff --git a/contrib/shaders/guides-cursor-line.kdl b/contrib/shaders/guides-cursor-line.kdl
new file mode 100644
index 0000000..b3cb744
--- /dev/null
+++ b/contrib/shaders/guides-cursor-line.kdl
@@ -0,0 +1,14 @@
+// cursor line — guides
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    tint color="#ff5fd7" amount="(y == cury) * 45"
+}
diff --git a/contrib/shaders/guides-edge-falloff.kdl b/contrib/shaders/guides-edge-falloff.kdl
new file mode 100644
index 0000000..865a8f5
--- /dev/null
+++ b/contrib/shaders/guides-edge-falloff.kdl
@@ -0,0 +1,14 @@
+// edge falloff — guides
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="clamp((5 - min(x, cols - 1 - x)) * 34, 0, 170)"
+}
diff --git a/contrib/shaders/guides-focus-mode.kdl b/contrib/shaders/guides-focus-mode.kdl
new file mode 100644
index 0000000..2acf5ac
--- /dev/null
+++ b/contrib/shaders/guides-focus-mode.kdl
@@ -0,0 +1,14 @@
+// focus mode — guides
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="clamp(abs(y - cury) * 26, 0, 190)"
+}
diff --git a/contrib/shaders/guides-indent-guides.kdl b/contrib/shaders/guides-indent-guides.kdl
new file mode 100644
index 0000000..210b495
--- /dev/null
+++ b/contrib/shaders/guides-indent-guides.kdl
@@ -0,0 +1,14 @@
+// indent guides — guides
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    tint color="#7aa2f7" amount="(x % 4 == 0) * 38"
+}
diff --git a/contrib/shaders/guides-right-margin.kdl b/contrib/shaders/guides-right-margin.kdl
new file mode 100644
index 0000000..3d6a96d
--- /dev/null
+++ b/contrib/shaders/guides-right-margin.kdl
@@ -0,0 +1,14 @@
+// right margin — guides
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="clamp((x - cols * 3 / 4) * 30, 0, 170)"
+}
diff --git a/contrib/shaders/guides-thirds.kdl b/contrib/shaders/guides-thirds.kdl
new file mode 100644
index 0000000..4c099cd
--- /dev/null
+++ b/contrib/shaders/guides-thirds.kdl
@@ -0,0 +1,14 @@
+// thirds — guides
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    tint color="#ff5fd7" amount="(x == cols / 3 || x == cols * 2 / 3) * 140"
+}
diff --git a/contrib/shaders/guides-torch.kdl b/contrib/shaders/guides-torch.kdl
new file mode 100644
index 0000000..41e1f3c
--- /dev/null
+++ b/contrib/shaders/guides-torch.kdl
@@ -0,0 +1,14 @@
+// torch — guides
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="clamp((dist(x, y, curx, cury) - 8) * 22, 0, 215)"
+}
diff --git a/contrib/shaders/motion-barber-pole.kdl b/contrib/shaders/motion-barber-pole.kdl
new file mode 100644
index 0000000..21c01ba
--- /dev/null
+++ b/contrib/shaders/motion-barber-pole.kdl
@@ -0,0 +1,14 @@
+// barber pole — motion
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="((x + y + t / 50) / 3 % 2) * 50"
+}
diff --git a/contrib/shaders/motion-matrix-rain.kdl b/contrib/shaders/motion-matrix-rain.kdl
new file mode 100644
index 0000000..cb46843
--- /dev/null
+++ b/contrib/shaders/motion-matrix-rain.kdl
@@ -0,0 +1,15 @@
+// matrix rain — motion
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    grayscale amount="220"
+    tint color="#33ff66" amount="clamp(240 - (((t / 70 + (x * 11) % 23 * 3) % rows - y + rows) % rows) * 45, 0, 240)"
+}
diff --git a/contrib/shaders/motion-plasma.kdl b/contrib/shaders/motion-plasma.kdl
new file mode 100644
index 0000000..6689753
--- /dev/null
+++ b/contrib/shaders/motion-plasma.kdl
@@ -0,0 +1,14 @@
+// plasma — motion
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="clamp(abs((x * 2 + t / 40) % 34 - 17) * 7 + abs((y * 3 - t / 55) % 26 - 13) * 6 - 40, 0, 170)"
+}
diff --git a/contrib/shaders/motion-pulse.kdl b/contrib/shaders/motion-pulse.kdl
new file mode 100644
index 0000000..1646fe5
--- /dev/null
+++ b/contrib/shaders/motion-pulse.kdl
@@ -0,0 +1,14 @@
+// pulse — motion
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    tint color="#ff5fd7" amount="clamp((t / 6) % 300 - 45, 0, 160)"
+}
diff --git a/contrib/shaders/motion-ripples.kdl b/contrib/shaders/motion-ripples.kdl
new file mode 100644
index 0000000..551a888
--- /dev/null
+++ b/contrib/shaders/motion-ripples.kdl
@@ -0,0 +1,14 @@
+// ripples — motion
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    tint color="#7aa2f7" amount="((dist(x, y, curx, cury) + t / 30) % 10 < 5) * 50"
+}
diff --git a/contrib/shaders/motion-sonar.kdl b/contrib/shaders/motion-sonar.kdl
new file mode 100644
index 0000000..d62ef09
--- /dev/null
+++ b/contrib/shaders/motion-sonar.kdl
@@ -0,0 +1,14 @@
+// sonar — motion
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    tint color="#33ff66" amount="(abs(dist(x, y, curx, cury) - (t / 22) % 80) < 3) * 220"
+}
diff --git a/contrib/shaders/motion-sweep.kdl b/contrib/shaders/motion-sweep.kdl
new file mode 100644
index 0000000..bb6eef3
--- /dev/null
+++ b/contrib/shaders/motion-sweep.kdl
@@ -0,0 +1,14 @@
+// sweep — motion
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="clamp(abs(x - (t / 24) % cols) * 22, 0, 200)"
+}
diff --git a/contrib/shaders/motion-typewriter.kdl b/contrib/shaders/motion-typewriter.kdl
new file mode 100644
index 0000000..e8ce5c0
--- /dev/null
+++ b/contrib/shaders/motion-typewriter.kdl
@@ -0,0 +1,14 @@
+// typewriter — motion
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="(y > (t / 400) % rows) * 200"
+}
diff --git a/contrib/shaders/pane-states-dead.kdl b/contrib/shaders/pane-states-dead.kdl
new file mode 100644
index 0000000..d2ab61c
--- /dev/null
+++ b/contrib/shaders/pane-states-dead.kdl
@@ -0,0 +1,15 @@
+// dead — pane states
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    grayscale amount="200"
+    dim amount="90"
+}
diff --git a/contrib/shaders/pane-states-scrolled.kdl b/contrib/shaders/pane-states-scrolled.kdl
new file mode 100644
index 0000000..6c8699f
--- /dev/null
+++ b/contrib/shaders/pane-states-scrolled.kdl
@@ -0,0 +1,14 @@
+// scrolled — pane states
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    tint color="#ffcc88" amount="30"
+}
diff --git a/contrib/shaders/pane-states-suspended.kdl b/contrib/shaders/pane-states-suspended.kdl
new file mode 100644
index 0000000..9cc6cb3
--- /dev/null
+++ b/contrib/shaders/pane-states-suspended.kdl
@@ -0,0 +1,15 @@
+// suspended — pane states
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    grayscale amount="180"
+    dim amount="90"
+}
diff --git a/contrib/shaders/pane-states-unfocused.kdl b/contrib/shaders/pane-states-unfocused.kdl
new file mode 100644
index 0000000..746ac08
--- /dev/null
+++ b/contrib/shaders/pane-states-unfocused.kdl
@@ -0,0 +1,14 @@
+// unfocused — pane states
+//
+// Generated from contrib/shadertoy.html by contrib/gen-shaders; edit the
+// preset there, where you can see what it does, and run that again.
+//
+// Drop this into ~/.config/sl0ppty/config.kdl (a running session picks it up
+// when you save), or point $SL0PPTY_CONFIG at this file. To hang it off a
+// pane state instead of every pane, put the same passes inside one:
+//
+//     states { unfocused { ... } }
+
+shaders {
+    dim amount="90"
+}