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-rw-r--r--chickadee/graphics/path.scm32
1 files changed, 32 insertions, 0 deletions
diff --git a/chickadee/graphics/path.scm b/chickadee/graphics/path.scm
index 48e80d9..3b29b19 100644
--- a/chickadee/graphics/path.scm
+++ b/chickadee/graphics/path.scm
@@ -83,6 +83,9 @@
pad
beside
below
+ right-split
+ up-split
+ corner-split
painter?
painter-bounding-box
make-empty-canvas
@@ -1463,6 +1466,35 @@
(let ((r (painter-bounding-box painter)))
(loop rest (max width (rect-width r)) (+ height (rect-height r)))))))))
+;; Adapted from Structure and Interpretation of Computer Programs,
+;; section 2.2.4.
+(define (right-split painter n)
+ (if (<= n 0)
+ painter
+ (let ((smaller (right-split (scale 0.5 painter) (- n 1))))
+ (beside (scale (vec2 0.5 1.0) painter)
+ (below smaller smaller)))))
+
+(define (up-split painter n)
+ (if (<= n 0)
+ painter
+ (let ((smaller (up-split (scale 0.5 painter) (- n 1))))
+ (below (scale (vec2 1.0 0.5) painter)
+ (beside smaller smaller)))))
+
+(define (corner-split painter n)
+ (if (<= n 0)
+ painter
+ (let* ((smaller (scale (vec2 0.5 0.5) painter))
+ (up (up-split smaller (- n 1)))
+ (right (right-split smaller (- n 1)))
+ (up-small (scale (vec2 0.5 1.0) up))
+ (right-small (scale (vec2 1.0 0.5) right)))
+ (beside (below smaller
+ (beside up-small up-small))
+ (below (below right-small right-small)
+ (corner-split smaller (- n 1)))))))
+
(define-record-type <canvas>
(%make-canvas matrix compiled-path filled-path-pool stroked-path-pool
tesselated-paths)