[latex3-commits] [git/LaTeX3-latex3-luaotfload] dev: Semisplit color and transparency handling (e823c6e)
Marcel Fabian Krüger
tex at 2krueger.de
Fri Feb 21 17:32:23 CET 2020
Repository : https://github.com/latex3/luaotfload
On branch : dev
Link : https://github.com/latex3/luaotfload/commit/e823c6eaeac6ced09feb48886200cad0886c3ac9
>---------------------------------------------------------------
commit e823c6eaeac6ced09feb48886200cad0886c3ac9
Author: Marcel Fabian Krüger <tex at 2krueger.de>
Date: Fri Feb 21 17:32:03 2020 +0100
Semisplit color and transparency handling
First step toward compatibility with luacolor and maybe at some point
also transparency
>---------------------------------------------------------------
e823c6eaeac6ced09feb48886200cad0886c3ac9
src/luaotfload-colors.lua | 242 ++++++++++++++++++----------------------------
1 file changed, 92 insertions(+), 150 deletions(-)
diff --git a/src/luaotfload-colors.lua b/src/luaotfload-colors.lua
index b8091b2..e39dc64 100644
--- a/src/luaotfload-colors.lua
+++ b/src/luaotfload-colors.lua
@@ -59,22 +59,7 @@ local identifiers = fonts.hashes.identifiers
local add_color_callback --[[ this used to be a global‽ ]]
--[[doc--
-This converts a single octet into a decimal with three digits of
-precision. The optional second argument limits precision to a single
-digit.
---doc]]--
-
---- string -> bool? -> string
-local function hex_to_dec (hex,one)
- if one then
- return stringformat("%.1g", tonumber(hex, 16)/255)
- else
- return stringformat("%.3g", tonumber(hex, 16)/255)
- end
-end
-
---[[doc--
-Color string validator / parser.
+Color string parser.
--doc]]--
local lpeg = require"lpeg"
@@ -83,31 +68,14 @@ local C, Cg, Ct, P, R, S = lpeg.C, lpeg.Cg, lpeg.Ct, lpeg.P, lpeg.R, lpeg.S
local digit16 = R("09", "af", "AF")
local opaque = S("fF") * S("fF")
-local octet = C(digit16 * digit16)
-
-local p_rgb = octet * octet * octet
-local p_rgba = p_rgb * (octet - opaque)
-local valid_digits = C(p_rgba + p_rgb) -- matches eight or six hex digits
-
-local p_Crgb = Cg(octet/hex_to_dec, "red") --- for captures
- * Cg(octet/hex_to_dec, "green")
- * Cg(octet/hex_to_dec, "blue")
-local p_Crgba = p_Crgb * Cg(octet/hex_to_dec, "alpha")
-local extract_color = Ct(p_Crgba + p_Crgb)
-
---- string -> (string | nil)
-local function sanitize_color_expression (digits)
- digits = tostring(digits)
- local sanitized = lpegmatch(valid_digits, digits)
- if not sanitized then
- logreport("both", 0, "color",
- "%q is not a valid rgb[a] color expression",
- digits)
- return nil
- end
- return sanitized
+local octet = digit16 * digit16 / function(s)
+ return tonumber(s, 16) / 255
end
+local extract_color = octet * octet * octet / function(r,g,b)
+ return stringformat("%.3g %.3g %.3g rg", r, g, b)
+ end * (octet - opaque + opaque)^-1 * -1
+
--- something is carried around in ``res``
--- for later use by color_handler() --- but what?
@@ -116,47 +84,37 @@ local res = nil
--- float -> unit
local function pageresources(alpha)
res = res or {}
- res[alpha] = true
+ local f = res[alpha]
+ or stringformat("/TransGs%.3g gs", alpha, alpha)
+ res[alpha] = f
+ return f
end
---- we store results of below color handler as tuples of
---- push/pop strings
-local color_cache = { } --- (string, (string * string)) hash_t
-
---- string -> (string * string)
-local function hex_to_rgba (digits)
- if not digits then
+--- string -> (string | nil)
+local function sanitize_color_expression (digits)
+ digits = tostring(digits)
+ local rgb, a = lpegmatch(extract_color, digits)
+ if not rgb then
+ logreport("both", 0, "color",
+ "%q is not a valid rgb[a] color expression",
+ digits)
return
end
+ return rgb, (a and pageresources(a))
+end
- --- this is called like a thousand times, so some
- --- memoizing is in order.
- local cached = color_cache[digits]
- if not cached then
- local push, pop
- local rgb = lpegmatch(extract_color, digits)
- if rgb.alpha then
- pageresources(rgb.alpha)
- push = stringformat(
- "/TransGs%g gs %s %s %s rg",
- rgb.alpha,
- rgb.red,
- rgb.green,
- rgb.blue)
- pop = "0 g /TransGs1 gs"
- else
- push = stringformat(
- "%s %s %s rg",
- rgb.red,
- rgb.green,
- rgb.blue)
- pop = "0 g"
- end
- color_cache[digits] = { push, pop }
- return push, pop
- end
-
- return cached[1], cached[2]
+local color_stack = 0
+-- Beside maybe allowing {transpareny} package compatibility at some
+-- point, this ensures that the stack is only created if it is actually
+-- needed. Especially important because it adds /TransGs1 gs to every page
+local function transparent_stack()
+ -- if token.is_defined'TRP at colorstack' then -- transparency
+ -- transparent_stack = tonumber(token.get_macro'TRP at colorstack')
+ -- else
+ res[1] = true
+ transparent_stack = pdf.newcolorstack("/TransGs1 gs","direct",true)
+ -- end
+ return transparent_stack
end
--- Luatex internal types
@@ -167,49 +125,43 @@ local hlist_t = nodetype("hlist")
local vlist_t = nodetype("vlist")
local whatsit_t = nodetype("whatsit")
local disc_t = nodetype("disc")
-local pdfliteral_t = node.subtype("pdf_literal")
local colorstack_t = node.subtype("pdf_colorstack")
local mlist_to_hlist = node.mlist_to_hlist
local color_callback
local color_attr = luatexbase.new_attribute("luaotfload_color_attribute")
--- (node * node * string * bool * (bool | nil)) -> (node * node * (string | nil))
-local function color_whatsit (head, curr, color, push, tail)
- local pushdata = hex_to_rgba(color)
+-- Pass nil for new_color or old_color to indicate no color
+-- If color is nil, pass tail to decide where to add whatsit
+local function color_whatsit (head, curr, stack, old_color, new_color, tail)
+ if new_color == old_color then
+ return head, curr, old_color
+ end
local colornode = newnode(whatsit_t, colorstack_t)
- setfield(colornode, "stack", 0)
- setfield(colornode, "command", push and 1 or 2) -- 1: push, 2: pop
- setfield(colornode, "data", push and pushdata or nil)
+ setfield(colornode, "stack", tonumber(stack) or stack())
+ setfield(colornode, "command", new_color and (old_color and 0 or 1) or 2) -- 1: push, 2: pop
+ setfield(colornode, "data", new_color) -- Is nil for pop
if tail then
head, curr = insert_node_after (head, curr, colornode)
else
head = insert_node_before(head, curr, colornode)
end
- if not push and color:len() > 6 then
- local colornode = newnode(whatsit_t, pdfliteral_t)
- setfield(colornode, "mode", 2)
- setfield(colornode, "data", "/TransGs1 gs")
- if tail then
- head, curr = insert_node_after (head, curr, colornode)
- else
- head = insert_node_before(head, curr, colornode)
- end
- end
- color = push and color or nil
- return head, curr, color
+ return head, curr, new_color
end
-- number -> string | nil
local function get_glyph_color (font_id, char)
local tfmdata = identifiers[font_id]
- local font_color = tfmdata and tfmdata.properties and tfmdata.properties.color
- if type(font_color) == "table" then
+ local properties = tfmdata and tfmdata.properties
+ local font_color = properties and properties.color_rgb
+ local font_transparent = properties and properties.color_a
+ if type(font_color) == "table" and type(font_transparent) == "table" then
local char_tbl = tfmdata.characters[char]
char = char_tbl and (char_tbl.index or char)
- return char and font_color[char] or font_color.default
+ font_color = char and font_color[char] or font_color.default
+ font_transparent = char and font_transparent[char] or font_transparent.default
end
- return font_color
+ return font_color, font_transparent
end
--[[doc--
@@ -219,7 +171,7 @@ values during the node list traversal.
--doc]]--
--- (node * (string | nil)) -> (node * (string | nil))
-local function node_colorize (head, toplevel, current_color)
+local function node_colorize (head, toplevel, current_color, current_transparent)
local n = head
while n do
local n_id = getid(n)
@@ -227,70 +179,52 @@ local function node_colorize (head, toplevel, current_color)
if n_id == hlist_t or n_id == vlist_t then
local n_list = getlist(n)
if getattribute(n_list, color_attr) then
- if current_color then
- head, n, current_color = color_whatsit(head, n, current_color, false)
- end
+ head, n, current_color = color_whatsit(head, n, color_stack, current_color, nil)
+ head, n, current_transparent = color_whatsit(head, n, transparent_stack, current_transparent, nil)
else
- n_list, current_color = node_colorize(n_list, false, current_color)
- if current_color and getsubtype(n) == 1 then -- created by linebreak
- n_list, _, current_color = color_whatsit(n_list, nodetail(n_list), current_color, false, true)
+ n_list, current_color, current_transparent = node_colorize(n_list, false, current_color, current_transparent)
+ if getsubtype(n) == 1 then -- created by linebreak
+ local nn = nodetail(n_list)
+ n_list, nn, current_color = color_whatsit(n_list, nn, color_stack, current_color, nil, true)
+ n_list, nn, current_transparent = color_whatsit(n_list, nn, transparent_stack, current_transparent, nil, true)
end
setfield(n, "head", n_list)
end
elseif n_id == disc_t then
local n_pre, n_post, n_replace = getdisc(n)
- n_replace, current_color = node_colorize(n_replace, false, current_color)
+ n_replace, current_color, current_transparent = node_colorize(n_replace, false, current_color, current_transparent)
setdisc(n, n_pre, n_post, n_replace)
elseif n_id == glyph_t then
--- colorization is restricted to those fonts
--- that received the “color” property upon
--- loading (see ``setcolor()`` above)
- local glyph_color = get_glyph_color(getfont(n), getchar(n))
- if glyph_color ~= current_color then
- if current_color then
- head, n, current_color = color_whatsit(head, n, current_color, false)
- end
- if glyph_color then
- head, n, current_color = color_whatsit(head, n, glyph_color, true)
- end
- end
-
- if current_color and color_callback == "pre_linebreak_filter" then
- local nn = getnext(n)
- while nn and getid(nn) == glyph_t do
- local glyph_color = get_glyph_color(getfont(nn), getchar(nn))
- if glyph_color == current_color then
- n = nn
- else
- break
- end
- nn = getnext(nn)
- end
- if getid(nn) == disc_t then
- head, n, current_color = color_whatsit(head, nn, current_color, false, true)
- else
- head, n, current_color = color_whatsit(head, n, current_color, false, true)
- end
- end
+ local glyph_color, glyph_transparent = get_glyph_color(getfont(n), getchar(n))
+ head, n, current_color = color_whatsit(head, n, color_stack, current_color, glyph_color)
+ head, n, current_transparent = color_whatsit(head, n, transparent_stack, current_transparent, glyph_transparent)
elseif n_id == whatsit_t then
- if current_color then
- head, n, current_color = color_whatsit(head, n, current_color, false)
- end
+ head, n, current_color = color_whatsit(head, n, color_stack, current_color, nil)
+ head, n, current_transparent = color_whatsit(head, n, transparent_stack, current_transparent, nil)
end
n = getnext(n)
end
- if toplevel and current_color then
- head, _, current_color = color_whatsit(head, nodetail(head), current_color, false, true)
+ if toplevel then
+ local nn = nodetail(n_list)
+ if current_color then
+ head, nn, current_color = color_whatsit(head, nn, color_stack, false, true)
+ end
+ if current_transparent then
+ head, nn, current_transparent = color_whatsit(head, nn, transparent_stack, false, true)
+ end
end
setattribute(head, color_attr, 1)
- return head, current_color
+ return head, current_color, current_transparent
end
local getpageres = pdf.getpageresources or function() return pdf.pageresources end
@@ -307,16 +241,16 @@ local function color_handler (head)
-- now append our page resources
if res then
- res["1"] = true
- if scantoks and pgf.bye and not pgf.loaded then
+ if scantoks and nil == pgf.loaded then
pgf.loaded = token.create(pgf.bye).cmdname == "assign_toks"
- pgf.bye = pgf.loaded and pgf.bye
end
- local tpr = pgf.loaded and gettoks(pgf.bye) or getpageres() or ""
+ local tpr = pgf.loaded and gettoks(pgf.bye) or -- PGF
+ -- token.is_defined'TRP at list' and token.get_macro'TRP at list' or -- transparency
+ getpageres() or ""
local t = ""
for k in pairs(res) do
- local str = stringformat("/TransGs%s<</ca %s>>", k, k) -- don't touch stroking elements
+ local str = stringformat("/TransGs%.3g<</ca %.3g>>", k, k) -- don't touch stroking elements
if not tpr:find(str) then
t = t .. str
end
@@ -324,6 +258,8 @@ local function color_handler (head)
if t ~= "" then
if pgf.loaded then
scantoks("global", pgf.bye, catat11, stringformat("%s{%s}%s", pgf.extgs, t, tpr))
+ -- elseif token.is_defined'TRP at list' then
+ -- token.set_macro('TRP at list', t .. tpr, 'global')
else
local tpr, n = tpr:gsub("/ExtGState<<", "%1"..t)
if n == 0 then
@@ -401,10 +337,10 @@ local glyph_color_tables = { }
-- and node and difficulties with getting the mapped unicode value for
-- a GID.
local function setcolor (tfmdata, value)
- local sanitized
+ local sanitized_rgb, sanitized_a
local color_table = glyph_color_tables[tonumber(value) or value]
if color_table then
- sanitized = {}
+ sanitized_rgb = {}
local unicodes = tfmdata.resources.unicodes
local gid_mapping = {}
local descriptions = tfmdata.descriptions or tfmdata.characters
@@ -417,7 +353,13 @@ local function setcolor (tfmdata, value)
gid = desc and (desc.index or unicode)
end
if gid then
- sanitized[gid] = sanitize_color_expression(color)
+ local a
+ sanitized_rgb[gid], a
+ = sanitize_color_expression(color)
+ if a then
+ sanitized_a = sanitized_a or {}
+ sanitized_a[gid] = a
+ end
else
-- TODO: ??? Error out, warn or just ignore? Ignore
-- makes sense because we have to ignore for GIDs
@@ -426,12 +368,12 @@ local function setcolor (tfmdata, value)
end
end
else
- sanitized = sanitize_color_expression(value)
+ sanitized_rgb, sanitized_a = sanitize_color_expression(value)
end
local properties = tfmdata.properties
- if sanitized then
- properties.color = sanitized
+ if sanitized_rgb then
+ properties.color_rgb, properties.color_a = sanitized_rgb, sanitized_a
add_color_callback()
end
end
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