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-rw-r--r--pict.scm111
1 files changed, 110 insertions, 1 deletions
diff --git a/pict.scm b/pict.scm
index b853c47..54f0ce0 100644
--- a/pict.scm
+++ b/pict.scm
@@ -59,6 +59,12 @@
frame
;; graphics primitives
+ move-to
+ close-path
+ curve
+ line-to
+ path
+
line
polyline
polygon
@@ -360,7 +366,7 @@ strings that are built from the list of attributes LST."
(make-pict
(foldt (lambda (thing)
(let ((tag (car thing)))
- (if (member tag '(rect polygon polyline circle ellipse text))
+ (if (member tag '(path rect polygon polyline circle ellipse text))
(proc thing) thing)))
identity
(pict-sxml pict))))
@@ -547,6 +553,109 @@ full transparency) and 1 (for full opacity)."
;;; Each shape is wrapped in an SVG tag that records the width,
;;; height, and the coordinates.
+;; This is a record for path draw instruction
+(define-record-type <instruction>
+ (make-instruction type absolute? points compile)
+ instruction?
+ (type instruction-type)
+ (absolute? instruction-absolute?)
+ (points instruction-points)
+ (compile instruction-compile))
+
+(define* (move-to point #:key absolute?)
+ (make-instruction
+ 'move absolute?
+ (list point)
+ (lambda ()
+ (format #false "~a ~a,~a"
+ (if absolute? "M" "m")
+ (car point) (cdr point)))))
+
+(define (close-path)
+ (make-instruction
+ 'close #false
+ (list)
+ (const "z")))
+
+(define* (line-to point #:key absolute?)
+ (make-instruction
+ 'line-to absolute?
+ (list point)
+ (lambda ()
+ (format #false "~a ~a,~a"
+ (if absolute? "L" "l")
+ (car point) (cdr point)))))
+
+;; The last point is the target
+(define* (curve points #:key absolute?)
+ (call-with-values
+ (lambda ()
+ (match points
+ ((one)
+ (values "s" (list one one)))
+ ((one two)
+ (values "s" (list one two)))
+ ((and (one two . more) points)
+ (values "c" points))))
+ (lambda (command points)
+ (make-instruction
+ 'curveto absolute?
+ points
+ (lambda ()
+ (format #false "~a ~{~a~^ ~}"
+ (if absolute? (string-upcase command) command)
+ (map (lambda (point)
+ (format #false "~a,~a"
+ (car point) (cdr point)))
+ points)))))))
+
+(define* (path instructions
+ #:key
+ (color "black")
+ (stroke-width 1))
+ "TODO"
+ (match (fold
+ (lambda (instruction acc)
+ (match (instruction-points instruction)
+ (() acc)
+ (lst
+ (let ((point (last lst)))
+ (match acc
+ ((cursor-x cursor-y min-x max-x min-y max-y)
+ (match point
+ ((x . y)
+ (if (instruction-absolute? instruction)
+ (list x y
+ (min x min-x)
+ (max x max-x)
+ (min y min-y)
+ (max y max-y))
+ (list (+ x cursor-x)
+ (+ y cursor-y)
+ (min (+ cursor-x x) min-x)
+ (max (+ cursor-x x) max-x)
+ (min (+ cursor-y y) min-y)
+ (max (+ cursor-y y) max-y)))))))))))
+ (list 0 0 0 0 0 0)
+ instructions)
+ ((cursor-x cursor-y min-x max-x min-y max-y)
+ (make-pict
+ `(svg (@ (width ,(+ (abs min-x)
+ (abs max-x)))
+ (height ,(+ (abs min-y)
+ (abs max-y)))
+ (x 0)
+ (y 0))
+ (path (@ (d ,(string-join
+ (map (lambda (instruction)
+ ((instruction-compile instruction)))
+ instructions)))
+ (style ,(style-list->string
+ `(("fill" "none")
+ ("stroke" ,color)
+ ("stroke-width"
+ ,(number->string stroke-width))))))))))))
+
(define* (line x1 y1 x2 y2
#:optional (maxw 0) (maxh 0)
#:key