Add video/gif generation + add wavey example

7 files changed, 144 insertions, 23 deletions

diff --git a/README.md b/README.md
index 368a2ff..95b047c 100644
--- a/README.md
+++ b/README.md
@@ -2,18 +2,7 @@
 
 Generating some visuals with SQL because nobody stopped me. With the magic of [recursive CTE](https://sqlite.org/lang_with.html).
 
-### Dependencies
-- sqlite3
-- imagemagick
-
-### Setup
-- Using justfile: `just setup`
-- Directly: `sqlite3 fun.db < setup.sql`
-
-### Generate image
-- Using justfile: `just image src/mandelbrot.sql`
-- Directly: `sqlite3 fun.db < src/mandelbrot.sql && ./image.sh mandelbrot fun.db`
-
+[How it works](https://ediblemonad.dev/coding4fun/2026-06-03-creative-coding-in-sqlite.html)
 
 <table>
   <tr>
@@ -36,5 +25,32 @@ Generating some visuals with SQL because nobody stopped me. With the magic of [r
       <img src="media/voronoi.png" />
     </td>
   </tr>
+  <tr>
+    <td width="50%" valign="top">
+      <h3><a href="./src/wavey.sql">Wavey</a></h3>
+      <img src="media/wavey.gif" />
+    </td>
+    <td width="50%" valign="top"></td>
+  </tr>
 </table>
 
+---
+
+## Setup and run
+
+### Dependencies
+- sqlite3
+- imagemagick
+
+### Setup
+- Using justfile: `just setup`
+- Directly: `sqlite3 fun.db < setup.sql`
+
+### Generate image
+- Using justfile: `just image src/mandelbrot.sql`
+- Directly: `sqlite3 fun.db < src/mandelbrot.sql && ./image.sh mandelbrot fun.db`
+
+### Generate video
+- Using justfile: `just video src/wavey.sql`
+- Directly: `sqlite3 fun.db < src/wavey.sql && ./video.sh wavey fun.db`
+
diff --git a/image.sh b/image.sh
index 69da148..9cc7e19 100755
--- a/image.sh
+++ b/image.sh
@@ -2,10 +2,14 @@
 
 set -eu
 
+[ $# -lt 1 ] && echo "Fuck" && exit 1;
+IMAGE_ID="$1"
+DB="${2:-fun.db}"
+
 db() { sqlite3 -tabs -noheader "$DB" "$@"; }
 
 ppm() {
-  image_id="$1"
+  local image_id="$1"
   echo "P3"
   db "SELECT width, height FROM images WHERE id='$image_id'"
   echo "255"
@@ -16,9 +20,4 @@ save_png() { magick ppm:- "media/$1.png"; }
 
 display() { magick display ppm:-; }
 
-
-[ $# -lt 1 ] && echo "Fuck" && exit 1;
-image_id="$1"
-DB="${2:-fun.db}"
-
-ppm "$image_id" | tee >(save_png "$image_id") | display
+ppm "$IMAGE_ID" | tee >(save_png "$IMAGE_ID") | display
diff --git a/justfile b/justfile
index 9eefddf..69420b7 100644
--- a/justfile
+++ b/justfile
@@ -9,12 +9,22 @@ image file *args:
   #!/usr/bin/env sh
   set -eu
   image_id=$(just run "{{file}}" {{args}})
-  just show-image "$image_id"
+  just gen-image "$image_id"
 
-show-image image_id:
+gen-image image_id:
   echo "Displaying {{image_id}}" 1>&2
   ./image.sh "{{image_id}}"
 
+video file *args:
+  #!/usr/bin/env sh
+  set -eu
+  video_id=$(just run "{{file}}" {{args}})
+  just gen-video "$video_id"
+
+gen-video video_id:
+  echo "Displaying {{video_id}}" 1>&2
+  ./video.sh "{{video_id}}"
+
 repl *args:
   rlwrap sqlite3 "{{DB}}" {{args}}
 
diff --git a/media/wavey.gif b/media/wavey.gif
new file mode 100644
index 0000000..d5015ca
--- /dev/null
+++ b/media/wavey.gif
diff --git a/setup.sql b/setup.sql
index 3a80a8c..0a56f55 100644
--- a/setup.sql
+++ b/setup.sql
@@ -4,7 +4,17 @@ PRAGMA temp_store = MEMORY;
 CREATE TABLE images (
   id TEXT PRIMARY KEY,
   width INTEGER NOT NULL,
-  height INTEGER NOT NULL
+  height INTEGER NOT NULL,
+  video_id TEXT,
+  frame INTEGER DEFAULT 0,
+  FOREIGN KEY(video_id) REFERENCES videos(id) ON DELETE CASCADE
+);
+
+CREATE TABLE videos (
+  id TEXT PRIMARY KEY,
+  width INTEGER NOT NULL,
+  height INTEGER NOT NULL,
+  fps INTEGER NOT NULL
 );
 
 CREATE TABLE pixels (
@@ -15,7 +25,7 @@ CREATE TABLE pixels (
   r INTEGER NOT NULL CHECK(r >= 0 AND r <= 255),
   g INTEGER NOT NULL CHECK(g >= 0 AND g <= 255),
   b INTEGER NOT NULL CHECK(b >= 0 AND b <= 255),
-  -- FOREIGN KEY(image_id) REFERENCES images(id) ON DELETE CASCADE,
+  FOREIGN KEY(image_id) REFERENCES images(id) ON DELETE CASCADE,
   UNIQUE(image_id, x, y)
 );
 
@@ -24,3 +34,9 @@ BEFORE INSERT ON images
 BEGIN
   DELETE FROM pixels WHERE image_id = NEW.id;
 END;
+
+CREATE TRIGGER delete_frames_when_video_reinserted_because_i_said_so_and_to_make_rerunning_easier
+BEFORE INSERT ON videos
+BEGIN
+  DELETE FROM images WHERE video_id = NEW.id;
+END;
diff --git a/src/wavey.sql b/src/wavey.sql
new file mode 100644
index 0000000..70da417
--- /dev/null
+++ b/src/wavey.sql
@@ -0,0 +1,33 @@
+INSERT OR REPLACE INTO videos (id, width, height, fps) VALUES ('wavey', 400, 400, 10) RETURNING id;
+
+WITH RECURSIVE
+  video AS (SELECT * FROM videos WHERE id = 'wavey'),
+  _frames(frame) AS (
+    SELECT 1 UNION ALL
+    SELECT frame + 1 FROM _frames, video WHERE frame < 50
+  )
+INSERT INTO images (id, width, height, frame, video_id) SELECT CONCAT('wavey/', frame), width, height, frame, 'wavey' FROM _frames, video;
+
+WITH RECURSIVE
+  video AS (SELECT * FROM videos WHERE id = 'wavey'),
+  horizontal(x) AS (SELECT width FROM video UNION ALL SELECT x - 1 FROM horizontal WHERE x > 1),
+  vertical(y) AS (SELECT height FROM video UNION ALL SELECT y - 1 FROM vertical WHERE y > 1),
+  _frames(id, frame) AS (SELECT id, frame FROM images WHERE video_id = (SELECT id FROM video)),
+  _pixels(frame_id, x, y, r, g, b) AS
+    (SELECT
+      frames_id,
+      x, y,
+      ROUND(100 * value),
+      ROUND(240 * value*value),
+      ROUND(255 * value)
+    FROM (SELECT *,
+        (CASE
+          WHEN SIN((x - 4.0*frame) / 20.0)*10.0 > y - 150 THEN 1.0
+          WHEN SIN((x - 0.5*frame) / 20.0)*10.0 > y - 200 THEN 0.75
+          WHEN SIN((x + 8.0*frame) / 20.0)*10.0 > y - 280 THEN 0.5
+          ELSE 0.3
+        END) AS value,
+        _frames.id AS frames_id
+      FROM vertical, horizontal, _frames)
+  )
+INSERT INTO pixels (image_id, x, y, r, g, b) SELECT frame_id, x, y, r, g, b FROM _pixels;
diff --git a/video.sh b/video.sh
new file mode 100755
index 0000000..59c5d28
--- /dev/null
+++ b/video.sh
@@ -0,0 +1,47 @@
+#!/usr/bin/env sh
+
+set -eu
+
+[ $# -lt 1 ] && echo "Fuck" && exit 1;
+VIDEO_ID="$1"
+DB="${2:-fun.db}"
+
+db() { sqlite3 -tabs -noheader "$DB" "$@"; }
+
+frame_ppm() {
+  local image_id="$1"
+  echo "P3"
+  db "SELECT width, height FROM images WHERE id='$image_id'"
+  echo "255"
+  db "SELECT r,g,b FROM pixels WHERE image_id='$image_id' ORDER BY y ASC, x ASC"
+}
+
+video_info() {
+  local video_id="$1"
+  db "SELECT fps FROM videos WHERE id='$video_id'"
+}
+
+video_frames() {
+  local video_id="$1"
+  db "SELECT id FROM images WHERE video_id='$video_id' ORDER BY frame ASC" | while IFS= read image_id; do
+    frame_ppm "$image_id";
+  done;
+}
+
+save_video() {
+  local id="$1"
+  local fps="$2"
+  ffmpeg -y -f image2pipe -framerate "$fps" -i pipe:0 "media/$id.gif"
+}
+
+display() {
+  local fps="$1";
+  ffplay - -framerate "$fps" -autoexit;
+}
+
+## Main stuff
+
+data="$(video_info "$VIDEO_ID")"
+fps="$data"
+
+video_frames "$VIDEO_ID" | tee >(save_video "$VIDEO_ID" "$fps") | display "$fps"