diff options
Diffstat (limited to 'examples')
| -rw-r--r-- | examples/mandelbrot.sql | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/examples/mandelbrot.sql b/examples/mandelbrot.sql new file mode 100644 index 0000000..1c25461 --- /dev/null +++ b/examples/mandelbrot.sql @@ -0,0 +1,31 @@ +DELETE FROM images WHERE id = 'mandelbrot'; +INSERT INTO images (id, width, height) VALUES ('mandelbrot', 400, 400) RETURNING id; + +WITH RECURSIVE + image AS (SELECT *, 0.008 AS scale, (width * 5)/7 AS ox, (height / 2) AS oy FROM images WHERE id = 'mandelbrot'), + horizontal(x) AS + (SELECT width FROM image UNION ALL SELECT x - 1 FROM horizontal WHERE x > 1), + vertical(y) AS + (SELECT height FROM image UNION ALL SELECT y - 1 FROM vertical WHERE y > 1), + mando(i, px, py, cx, cy, x, y) AS ( + SELECT 0, 0.0, 0.0, + (SELECT (horizontal.x - ox)*scale FROM image), (SELECT (vertical.y - oy)*scale FROM image), + horizontal.x, vertical.y + FROM vertical, horizontal + UNION ALL + SELECT i + 1, px*px - py*py + cx, 2.0*px*py + cy, cx, cy, x, y FROM mando + WHERE (px*px + py*py) < 4.0 AND i < 20 + ), + mandogrouped(x, y, i) AS (SELECT x, y, max(i) FROM mando GROUP BY x, y), + colors(i, r, g, b) AS ( + SELECT 19, 255, 150, 150 UNION ALL + SELECT 10, 150, 120, 120 UNION ALL + SELECT 7, 50, 100, 100 UNION ALL + SELECT 0 , 0, 50, 50 + ), + _pixels(x, y, r, g, b) AS ( + SELECT x, y, c.r, c.g, c.b + FROM mandogrouped g + JOIN colors c ON c.i = (SELECT max(i) FROM colors WHERE i <= g.i) + ) +INSERT INTO pixels (image_id, x, y, r, g, b) SELECT 'mandelbrot', x, y, r, g, b FROM _pixels; |
