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-rw-r--r--src/circle.image.sql17
1 files changed, 17 insertions, 0 deletions
diff --git a/src/circle.image.sql b/src/circle.image.sql
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+++ b/src/circle.image.sql
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+INSERT OR REPLACE INTO images (id, width, height) VALUES ('circle', 400, 400) RETURNING id;
+
+WITH RECURSIVE
+ image AS (SELECT * FROM images WHERE id = 'circle'),
+ circle AS (SELECT width/2 AS cx, height/2 AS cy, 160 AS radius FROM image),
+ 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),
+ _pixels(x, y, r, g, b) AS (SELECT
+ x, y,
+ 150,
+ 255 * MAX(0, MIN(1, (SELECT (x - cx)*(x - cx) + (y - cy)*(y - cy) - radius*radius FROM circle))),
+ 150
+ FROM vertical, horizontal
+ )
+INSERT INTO pixels (image_id, x, y, r, g, b) SELECT 'circle', x, y, r, g, b FROM _pixels;