check for cyclic dependencies in pure Y-offset stuff

[lilypond.git] / scm / layout-page-layout.scm

diff --git a/scm/layout-page-layout.scm b/scm/layout-page-layout.scm
index c5721b325a98711b2d89c4ff7195705ea89e50fd..91742ef315f98319e9d017aa4a1021af2ed79539 100644 (file)
--- a/scm/layout-page-layout.scm
+++ b/scm/layout-page-layout.scm
@@ -15,6 +15,7 @@
   #:use-module (lily)
   #:export (post-process-pages optimal-page-breaks make-page-from-systems
            page-breaking-wrapper
+           stretchable-line? ; delete me
            ;; utilities for writing custom page breaking functions
             line-height line-next-space line-next-padding
            line-minimum-distance line-ideal-distance
@@ -23,10 +24,23 @@
             line-minimum-position-on-page
            page-maximum-space-to-fill page-maximum-space-left space-systems))
 
+; this is for 2-pass spacing. Delete me.
+(define (stretchable-line? line)
+  "Say whether a system can be stretched."
+  (not (or (ly:prob-property? line 'is-title)
+          (let ((system-extent (paper-system-staff-extents line)))
+            (= (interval-start system-extent)
+               (interval-end   system-extent))))))
+
 (define (stretch-and-draw-page paper-book systems page-number ragged last)
+  (define (max-stretch sys)
+    (if (ly:grob? sys)
+       (ly:grob-property sys 'max-stretch)
+       0.0))
+
   (define (stretchable? sys)
     (and (ly:grob? sys)
-        (ly:grob-property sys 'stretchable)))
+        (> (max-stretch sys) 0.0)))
 
   (define (height-estimate sys)
     (interval-length
@@ -34,11 +48,6 @@
         (ly:grob-property sys 'pure-Y-extent)
         (paper-system-extent sys Y))))
 
-  (define (max-stretch sys)
-    (if (stretchable? sys)
-       (ly:grob-property sys 'max-stretch)
-       0.0))
-
   (define (print-system sys)
     (if (ly:grob? sys)
        (ly:system-print sys)
@@ -60,6 +69,14 @@
                                 rest-height)
                             (- space-left stretch)))))
 
+  (define (total-padding systems)
+    (let ((layout (ly:paper-book-paper paper-book)))
+      (if (or (null? systems)
+             (null? (cdr systems)))
+         0.0
+         (+ (line-next-padding (car systems) (cadr systems) layout)
+            (total-padding (cdr systems))))))
+
   (let* ((page (make-page paper-book
                          'page-number page-number
                          'is-last last))
@@ -70,18 +87,20 @@
         ; yet, etc. If we overstretch because of underestimation, the result
         ; is very bad. So we stick in some extra space, just to be sure.
         (buffer (/ height 10.0))
-        (total-system-height (apply + (map height-estimate systems)))
+        (total-system-height (+ (apply + (map height-estimate systems))
+                                (total-padding systems)))
         (height-left (- height total-system-height buffer)))
 
-    (if (not ragged)
+    (if (and
+        (not ragged)
+        (> height-left 0))
        (set-line-stretch! (sort systems
                                 (lambda (s1 s2)
                                   (< (height-estimate s1)
                                      (height-estimate s2))))
                           (apply + (map height-estimate
                                         (filter stretchable? systems)))
-                          (- (page-printable-height page)
-                             total-system-height)))
+                          height-left))
 
     (let* ((lines (map print-system systems))
           (posns (if (null? lines)
@@ -137,23 +156,25 @@
   `next-line' can be #f, meaning that `line' is the last line."
   (let* ((title (paper-system-title? line))
         (next-title (and next-line (paper-system-title? next-line))))
-    (cond ((and title next-title)
-          (ly:output-def-lookup layout 'between-title-space))
-         (title
-          (ly:output-def-lookup layout 'after-title-space))
-         (next-title
-          (ly:output-def-lookup layout 'before-title-space))
-         (else
-          (ly:prob-property
-           line 'next-space
-           (ly:output-def-lookup layout 'between-system-space))))))
+    (ly:prob-property
+     line 'next-space
+     (ly:output-def-lookup layout 
+                          (cond ((and title next-title) 'between-title-space)
+                                (title 'after-title-space)
+                                (next-title 'before-title-space)
+                                (else 'between-system-space))))))
 
 (define (line-next-padding line next-line layout)
   "Return padding to use between `line' and `next-line'.
   `next-line' can be #f, meaning that `line' is the last line."
-  (ly:prob-property
-   line 'next-padding
-   (ly:output-def-lookup layout 'between-system-padding)))
+  (let ((default (ly:output-def-lookup layout 'between-system-padding)))
+    (if (ly:grob? line)
+       (let* ((details (ly:grob-property line 'line-break-system-details))
+              (padding (assq 'next-padding details)))
+         (if padding
+             (cdr padding)
+             default))
+       (ly:prob-property line 'next-padding default))))
 
 
 (define (line-minimum-distance line next-line layout ignore-padding)
@@ -174,10 +195,11 @@
   "Ideal distance between `line' reference position and `next-line'
  reference position. If next-line is #f, return #f."
   (and next-line
-       (+ (max 0 (- (+ (interval-end (paper-system-staff-extents next-line))
-                      (if ignore-padding 0 (line-next-padding line next-line layout)))
-                   (interval-start (paper-system-staff-extents line))))
-         (line-next-space line next-line layout))))
+       (max (+ (max 0 (- (+ (interval-end (paper-system-staff-extents next-line))
+                           (if ignore-padding 0 (line-next-padding line next-line layout)))
+                        (interval-start (paper-system-staff-extents line))))
+              (line-next-space line next-line layout))
+           (line-minimum-distance line next-line layout ignore-padding))))
 
 (define (first-line-position line layout)
   "Position of the first line on page"
@@ -263,7 +285,7 @@
                                '())))
         (springs (map (lambda (prev-line line)
                         (list (line-ideal-distance prev-line line paper ignore-padding)
-                              (/ 1.0 (line-next-space prev-line line paper))))
+                              (line-next-space prev-line line paper)))
                       lines
                       cdr-lines))
         (rods (map (let ((i -1))