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authorNorbert Preining <norbert@preining.info>2019-09-02 13:46:59 +0900
committerNorbert Preining <norbert@preining.info>2019-09-02 13:46:59 +0900
commite0c6872cf40896c7be36b11dcc744620f10adf1d (patch)
tree60335e10d2f4354b0674ec22d7b53f0f8abee672 /macros/luatex/generic/lua-visual-debug/lua-visual-debug.lua
Initial commit
Diffstat (limited to 'macros/luatex/generic/lua-visual-debug/lua-visual-debug.lua')
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diff --git a/macros/luatex/generic/lua-visual-debug/lua-visual-debug.lua b/macros/luatex/generic/lua-visual-debug/lua-visual-debug.lua
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+-- Copyright 2012-2019 Patrick Gundlach, patrick@gundla.ch
+-- Public repository: https://github.com/pgundlach/lvdebug (issues/pull requests,...)
+-- Version: 0.7
+
+-- Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the
+-- "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge,
+-- publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do
+-- so, subject to the following conditions:
+--
+-- The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+-- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+-- FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+-- WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+
+
+module(...,package.seeall)
+
+-- There are 65782 scaled points in a PDF point
+-- Therefore we need to divide all TeX lengths by
+-- this amount to get the PDF points.
+local number_sp_in_a_pdf_point = 65782
+
+
+-- The idea is the following: at page shipout, all elements on a page are fixed.
+-- TeX creates an intermediate data structure before putting that into the PDF
+-- We can "intercept" that data structure and add pdf_literal (whatist) nodes,
+-- that makes glues, kerns and other items visible by drawing a rule, rectangle or
+-- other visual aids.
+-- This has no influence on typeset material, because these pdf_literal instructions
+-- are only visible to the PDF file (PDF renderer) and have no size themselves.
+
+-- We recursively loop through the contents of boxes and look at the (linear) list of
+-- items in that box. We start at the "shipout box".
+
+-- The "algorithm" goes like this:
+--
+-- head = pointer_to_beginning_of_box_material
+-- while head is not nil
+-- if this_item_is_a_box
+-- recurse_into_contents
+-- draw a rectangle around the contents
+-- elseif this_item_is_a_glue
+-- draw a rule that has the length of that glue
+-- elseif this_item_is_a_kern
+-- draw a rectangle with width of that kern
+-- ...
+-- end
+-- move pointer to the next item in the list
+-- -- the pointer is "nil" if there is no next item
+-- end
+
+local HLIST = node.id("hlist")
+local VLIST = node.id("vlist")
+local RULE = node.id("rule")
+local DISC = node.id("disc")
+local GLUE = node.id("glue")
+local KERN = node.id("kern")
+local PENALTY = node.id("penalty")
+
+function math.round(num, idp)
+ if idp and idp>0 then
+ local mult = 10^idp
+ return math.floor(num * mult + 0.5) / mult
+ end
+ return math.floor(num + 0.5)
+end
+
+
+function show_page_elements(parent)
+ local head = parent.list
+ while head do
+ if head.id == HLIST or head.id == VLIST then
+
+ local rule_width = 0.1
+ local wd = math.round(head.width / number_sp_in_a_pdf_point - rule_width ,2)
+ local ht = math.round((head.height + head.depth) / number_sp_in_a_pdf_point - rule_width ,2)
+ local dp = math.round(head.depth / number_sp_in_a_pdf_point - rule_width / 2 ,2)
+
+ -- recurse into the contents of the box
+ show_page_elements(head)
+ local rectangle = node.new("whatsit","pdf_literal")
+ if head.id == HLIST then -- hbox
+ rectangle.data = string.format("q 0.5 G %g w %g %g %g %g re s Q", rule_width, -rule_width / 2, -dp, wd, ht)
+ else
+ rectangle.data = string.format("q 0.1 G %g w %g %g %g %g re s Q", rule_width, -rule_width / 2, 0, wd, -ht)
+ end
+ head.list = node.insert_before(head.list,head.list,rectangle)
+
+
+ elseif head.id == RULE then
+ local show_rule = node.new("whatsit","pdf_literal")
+ if head.width == -1073741824 or head.height == -1073741824 or head.depth == -1073741824 then
+ -- ignore for now -- these rules are stretchable
+ else
+ local dp = math.round( head.depth / number_sp_in_a_pdf_point ,2)
+ local ht = math.round( head.height / number_sp_in_a_pdf_point ,2)
+ show_rule.data = string.format("q 1 0 0 RG 1 0 0 rg 0.4 w 0 %g m 0 %g l S Q",-dp,ht)
+ end
+ parent.list = node.insert_before(parent.list,head,show_rule)
+
+
+ elseif head.id == DISC then
+ local hyphen_marker = node.new("whatsit","pdf_literal")
+ hyphen_marker.data = "q 0 0 1 RG 0.3 w 0 -1 m 0 0 l S Q"
+ parent.list = node.insert_before(parent.list,head,hyphen_marker)
+
+
+ elseif head.id == GLUE then
+ local head_spec = head.spec
+ if not head_spec then
+ head_spec = head
+ end
+ local wd = head_spec.width
+ local color = "0.5 G"
+ if parent.glue_sign == 1 and parent.glue_order == head_spec.stretch_order then
+ wd = wd + parent.glue_set * head_spec.stretch
+ color = "0 0 1 RG"
+ elseif parent.glue_sign == 2 and parent.glue_order == head_spec.shrink_order then
+ wd = wd - parent.glue_set * head_spec.shrink
+ color = "1 0 1 RG"
+ end
+ local pdfstring = node.new("whatsit","pdf_literal")
+ local wd_bp = math.round(wd / number_sp_in_a_pdf_point,2)
+ if parent.id == HLIST then
+ pdfstring.data = string.format("q %s [0.2] 0 d 0.5 w 0 0 m %g 0 l s Q",color,wd_bp)
+ else -- vlist
+ pdfstring.data = string.format("q 0.1 G 0.1 w -0.5 0 m 0.5 0 l -0.5 %g m 0.5 %g l s [0.2] 0 d 0.5 w 0.25 0 m 0.25 %g l s Q",-wd_bp,-wd_bp,-wd_bp)
+ end
+ parent.list = node.insert_before(parent.list,head,pdfstring)
+
+
+ elseif head.id == KERN then
+ local rectangle = node.new("whatsit","pdf_literal")
+ local color = "1 1 0 rg"
+ if head.kern < 0 then color = "1 0 0 rg" end
+ local k = math.round(head.kern / number_sp_in_a_pdf_point,2)
+ if parent.id == HLIST then
+ rectangle.data = string.format("q %s 0 w 0 0 %g 1 re B Q",color, k )
+ else
+ rectangle.data = string.format("q %s 0 w 0 0 1 %g re B Q",color, -k )
+ end
+ parent.list = node.insert_before(parent.list,head,rectangle)
+
+
+ elseif head.id == PENALTY then
+ local color = "1 g"
+ local rectangle = node.new("whatsit","pdf_literal")
+ if head.penalty < 10000 then
+ color = string.format("%d g", 1 - math.floor(head.penalty / 10000))
+ end
+ rectangle.data = string.format("q %s 0 w 0 0 1 1 re B Q",color)
+ parent.list = node.insert_before(parent.list,head,rectangle)
+ end
+ head = head.next
+ end
+ return true
+end