From d47088e6cf3a95ddb33808b373b2320013ae6741 Mon Sep 17 00:00:00 2001
From: Caleb Maclennan <caleb@alerque.com>
Date: Thu, 20 Aug 2020 16:50:36 +0300
Subject: [PATCH 1/8] refactor(backends): Move current font tracking from
 module to class

This is work towards being able to instantiate multiple outputters at
the same time. Tracking this in a module-local variable means only one
could be run without interference.
---
 core/libtexpdf-output.lua | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/core/libtexpdf-output.lua b/core/libtexpdf-output.lua
index 35003732d..39ecb340a 100644
--- a/core/libtexpdf-output.lua
+++ b/core/libtexpdf-output.lua
@@ -5,7 +5,6 @@ if (not SILE.outputters) then SILE.outputters = {} end
 local cursorX = 0
 local cursorY = 0
 
-local font = 0
 local started = false
 local lastkey
 
@@ -120,7 +119,7 @@ SILE.outputters.libtexpdf = {
       for i = 1, #(value.items) do
         local glyph = value.items[i].gid
         local buf = string.char(math.floor(glyph % 2^32 / 2^8)) .. string.char(glyph % 0x100)
-        pdf.setstring(cursorX + (value.items[i].x_offset or 0), cursorY + (value.items[i].y_offset or 0), buf, string.len(buf), font, value.items[i].glyphAdvance)
+        pdf.setstring(cursorX + (value.items[i].x_offset or 0), cursorY + (value.items[i].y_offset or 0), buf, string.len(buf), self._font, value.items[i].glyphAdvance)
         cursorX = cursorX + value.items[i].width
       end
       return
@@ -132,15 +131,17 @@ SILE.outputters.libtexpdf = {
       buf[#buf+1] = string.char(glyph % 0x100)
     end
     buf = table.concat(buf, "")
-    pdf.setstring(cursorX, cursorY, buf, string.len(buf), font, width)
+    pdf.setstring(cursorX, cursorY, buf, string.len(buf), self._font, width)
   end,
 
+  _font = nil,
+
   setFont = function (self, options)
     _deprecationCheck(self)
     ensureInit()
     if SILE.font._key(options) == lastkey then return end
     lastkey = SILE.font._key(options)
-    font = SILE.font.cache(options, SILE.shaper.getFace)
+    local font = SILE.font.cache(options, SILE.shaper.getFace)
     if options.direction == "TTB" then
       font.layout_dir = 1
     end
@@ -149,9 +150,9 @@ SILE.outputters.libtexpdf = {
     else
       pdf.setdirmode(0)
     end
-    local pdffont = pdf.loadfont(font)
-    if pdffont < 0 then SU.error("Font loading error for "..options) end
-    font = pdffont
+    self._font = pdf.loadfont(font)
+    if self._font < 0 then SU.error("Font loading error for "..options) end
+    return self._font
   end,
 
   drawImage = function (self, src, x, y, width, height)
@@ -228,12 +229,12 @@ SILE.outputters.libtexpdf = {
       buf[#buf+1] = string.char(glyph % 0x100)
     end
     buf = table.concat(buf, "")
-    local oldfont = font
+    local oldfont = self._font
     self:setFont(gentium)
-    pdf.setstring(frame:left():tonumber() - _dl/2, (SILE.documentState.paperSize[2] - frame:top()):tonumber() + _dl/2, buf, string.len(buf), font, 0)
+    pdf.setstring(frame:left():tonumber() - _dl/2, (SILE.documentState.paperSize[2] - frame:top()):tonumber() + _dl/2, buf, string.len(buf), self._font, 0)
     if oldfont then
       pdf.loadfont(oldfont)
-      font = oldfont
+      self._font = oldfont
     end
     self:popColor()
   end,

From 1ffe51acd1870c0860df9a8b6ced6e1bd878d262 Mon Sep 17 00:00:00 2001
From: Caleb Maclennan <caleb@alerque.com>
Date: Thu, 20 Aug 2020 16:58:26 +0300
Subject: [PATCH 2/8] refactor(backends): Use function for repeated crazy math

---
 core/libtexpdf-output.lua | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/core/libtexpdf-output.lua b/core/libtexpdf-output.lua
index 39ecb340a..14ddf3ca7 100644
--- a/core/libtexpdf-output.lua
+++ b/core/libtexpdf-output.lua
@@ -22,6 +22,10 @@ local _deprecationCheck = function (caller)
   end
 end
 
+local glyph2string = function (glyph)
+  return string.char(math.floor(glyph % 2^32 / 2^8)) .. string.char(glyph % 0x100)
+end
+
 local _dl = 0.5
 
 SILE.outputters.libtexpdf = {
@@ -117,8 +121,7 @@ SILE.outputters.libtexpdf = {
     -- is actually the shaped x_advance).
     if value.complex then
       for i = 1, #(value.items) do
-        local glyph = value.items[i].gid
-        local buf = string.char(math.floor(glyph % 2^32 / 2^8)) .. string.char(glyph % 0x100)
+        local buf = glyph2string(value.items[i].gid)
         pdf.setstring(cursorX + (value.items[i].x_offset or 0), cursorY + (value.items[i].y_offset or 0), buf, string.len(buf), self._font, value.items[i].glyphAdvance)
         cursorX = cursorX + value.items[i].width
       end
@@ -126,9 +129,7 @@ SILE.outputters.libtexpdf = {
     end
     local buf = {}
     for i = 1, #(value.glyphString) do
-      local glyph = value.glyphString[i]
-      buf[#buf+1] = string.char(math.floor(glyph % 2^32 / 2^8))
-      buf[#buf+1] = string.char(glyph % 0x100)
+      buf[i] = glyph2string(value.glyphString[i])
     end
     buf = table.concat(buf, "")
     pdf.setstring(cursorX, cursorY, buf, string.len(buf), self._font, width)
@@ -224,9 +225,7 @@ SILE.outputters.libtexpdf = {
     stuff = stuff[1].nodes[1].value.glyphString -- Horrible hack
     local buf = {}
     for i = 1, #stuff do
-      local glyph = stuff[i]
-      buf[#buf+1] = string.char(math.floor(glyph % 2^32 / 2^8))
-      buf[#buf+1] = string.char(glyph % 0x100)
+      buf[i] = glyph2string(stuff[i])
     end
     buf = table.concat(buf, "")
     local oldfont = self._font

From 02cce408c209fd59fbd531d2e8bdd4625964c4ee Mon Sep 17 00:00:00 2001
From: Caleb Maclennan <caleb@alerque.com>
Date: Thu, 20 Aug 2020 17:11:28 +0300
Subject: [PATCH 3/8] perf(backends): Reuse variables instead of recalculating
 values

---
 core/libtexpdf-output.lua | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/core/libtexpdf-output.lua b/core/libtexpdf-output.lua
index 14ddf3ca7..3442ad4b6 100644
--- a/core/libtexpdf-output.lua
+++ b/core/libtexpdf-output.lua
@@ -120,19 +120,19 @@ SILE.outputters.libtexpdf = {
     -- position (cursorX + width - remember that the box's "width"
     -- is actually the shaped x_advance).
     if value.complex then
-      for i = 1, #(value.items) do
+      for i = 1, #value.items do
         local buf = glyph2string(value.items[i].gid)
         pdf.setstring(cursorX + (value.items[i].x_offset or 0), cursorY + (value.items[i].y_offset or 0), buf, string.len(buf), self._font, value.items[i].glyphAdvance)
         cursorX = cursorX + value.items[i].width
       end
-      return
-    end
-    local buf = {}
-    for i = 1, #(value.glyphString) do
-      buf[i] = glyph2string(value.glyphString[i])
+    else
+      local buf = {}
+      for i = 1, #value.glyphString do
+        buf[i] = glyph2string(value.glyphString[i])
+      end
+      buf = table.concat(buf, "")
+      pdf.setstring(cursorX, cursorY, buf, string.len(buf), self._font, width)
     end
-    buf = table.concat(buf, "")
-    pdf.setstring(cursorX, cursorY, buf, string.len(buf), self._font, width)
   end,
 
   _font = nil,
@@ -140,8 +140,8 @@ SILE.outputters.libtexpdf = {
   setFont = function (self, options)
     _deprecationCheck(self)
     ensureInit()
-    if SILE.font._key(options) == lastkey then return end
-    lastkey = SILE.font._key(options)
+    local key = SILE.font._key(options)
+    if key == lastkey then return end
     local font = SILE.font.cache(options, SILE.shaper.getFace)
     if options.direction == "TTB" then
       font.layout_dir = 1
@@ -153,6 +153,7 @@ SILE.outputters.libtexpdf = {
     end
     self._font = pdf.loadfont(font)
     if self._font < 0 then SU.error("Font loading error for "..options) end
+    lastkey = key
     return self._font
   end,
 

From 7caa9c82bbf0bd021e316893ffb2b2693ceeac55 Mon Sep 17 00:00:00 2001
From: Caleb Maclennan <caleb@alerque.com>
Date: Thu, 20 Aug 2020 17:22:22 +0300
Subject: [PATCH 4/8] feat(backends): Modify setCursor() to handle relative
 movements

---
 core/cairo-output.lua     |  7 +++++--
 core/debug-output.lua     | 10 +++++++---
 core/libtexpdf-output.lua |  7 ++++---
 core/podofo-output.lua    |  7 ++++---
 core/text-output.lua      | 18 ++++++++++--------
 5 files changed, 30 insertions(+), 19 deletions(-)

diff --git a/core/cairo-output.lua b/core/cairo-output.lua
index c54c570f1..7401373ee 100644
--- a/core/cairo-output.lua
+++ b/core/cairo-output.lua
@@ -59,9 +59,12 @@ SILE.outputters.cairo = {
     return self:setCursor(x, y)
   end,
 
-  setCursor = function (self, x, y)
+  setCursor = function (self, x, y, relative)
     _deprecationCheck(self)
-    move(cr, x, y)
+    local offset = relative and { x = cursorX, y = cursorY } or { x = 0, y = 0 }
+    cursorX = offset.x + x
+    cursorY = offset.y - y
+    move(cr, cursorX, cursorY)
   end,
 
   setColor = function (self, color)
diff --git a/core/debug-output.lua b/core/debug-output.lua
index 1e4b6275b..39b7f4775 100644
--- a/core/debug-output.lua
+++ b/core/debug-output.lua
@@ -60,12 +60,16 @@ SILE.outputters.debug = {
     return self:setCursor(x, y)
   end,
 
-  setCursor = function (self, x, y)
+  setCursor = function (self, x, y, relative)
     _deprecationCheck(self)
     x = SU.cast("number", x)
     y = SU.cast("number", y)
-    if string.format("%.4f", x) ~= string.format("%.4f", cursorX) then writeline("Mx ", string.format("%.4f", x)); cursorX = x end
-    if string.format("%.4f", y) ~= string.format("%.4f", cursorY) then writeline("My ", string.format("%.4f", y)); cursorY = y end
+    local oldx, oldy = self:getCursor()
+    local offset = relative and { x = cursorX, y = cursorY } or { x = 0, y = 0 }
+    cursorX = offset.x + x
+    cursorY = offset.y - y
+    if string.format("%.4f", oldx) ~= string.format("%.4f", cursorX) then writeline("Mx ", string.format("%.4f", x)) end
+    if string.format("%.4f", oldy) ~= string.format("%.4f", cursorY) then writeline("My ", string.format("%.4f", y)) end
   end,
 
   setColor = function (self, color)
diff --git a/core/libtexpdf-output.lua b/core/libtexpdf-output.lua
index 3442ad4b6..4eb76fe6f 100644
--- a/core/libtexpdf-output.lua
+++ b/core/libtexpdf-output.lua
@@ -70,12 +70,13 @@ SILE.outputters.libtexpdf = {
     return self:setCursor(x, y)
   end,
 
-  setCursor = function (self, x, y)
+  setCursor = function (self, x, y, relative)
     _deprecationCheck(self)
     x = SU.cast("number", x)
     y = SU.cast("number", y)
-    cursorX = x
-    cursorY = SILE.documentState.paperSize[2] - y
+    local offset = relative and { x = cursorX, y = cursorY } or { x = 0, y = 0 }
+    cursorX = offset.x + x
+    cursorY = offset.y + (relative and 0 or SILE.documentState.paperSize[2]) - y
   end,
 
   setColor = function (self, color)
diff --git a/core/podofo-output.lua b/core/podofo-output.lua
index be1764b26..51b178d6e 100644
--- a/core/podofo-output.lua
+++ b/core/podofo-output.lua
@@ -65,10 +65,11 @@ SILE.outputters.podofo = {
     return self:setCursor(x, y)
   end,
 
-  setCursor = function (self, x, y)
+  setCursor = function (self, x, y, relative)
     _deprecationCheck(self)
-    cursorX = x
-    cursorY = SILE.documentState.paperSize[2] - y
+    local offset = relative and { x = cursorX, y = cursorY } or { x = 0, y = 0 }
+    cursorX = offset.x + x
+    cursorY = offset.y + SILE.documentState.paperSize[2] - y
   end,
 
   setColor = function (self, color)
diff --git a/core/text-output.lua b/core/text-output.lua
index 6255fd9d7..d95902a7e 100644
--- a/core/text-output.lua
+++ b/core/text-output.lua
@@ -53,29 +53,31 @@ cursor = function (self)
     return self:setCursor(x, y)
   end,
 
-  setCursor = function (self, x, y)
+  setCursor = function (self, x, y, relative)
     _deprecationCheck(self)
     local bs = SILE.measurement("0.8bs"):tonumber()
     local spc = SILE.measurement("0.8spc"):tonumber()
+    local offset = relative and { x = cursorX, y = cursorY } or { x = 0, y = 0 }
+    local newx, newy = offset.x + x, offset.y - y
     if started then
-      if x < cursorX then
+      if newx < cursorX then
           outfile:write("\n")
-      elseif y > cursorY then
-        if y - cursorY > bs then
+      elseif newy > cursorY then
+        if newy - cursorY > bs then
           outfile:write("\n")
         else
           outfile:write("‫")
         end
-      elseif x > cursorX then
-        if x - cursorX > spc then
+      elseif newx > cursorX then
+        if newx - cursorX > spc then
           outfile:write(" ")
         else
           outfile:write("‫")
         end
       end
     end
-    cursorY = y
-    cursorX = x
+    cursorY = newy
+    cursorX = newx
   end,
 
   setColor = function(self)

From 095e4ac5a35a3d94f6b3c3a23bf79ee079dbd5ed Mon Sep 17 00:00:00 2001
From: Caleb Maclennan <caleb@alerque.com>
Date: Thu, 20 Aug 2020 17:26:55 +0300
Subject: [PATCH 5/8] refactor(backends): Re-use methods for easier extension
 and debugging

---
 core/libtexpdf-output.lua | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/core/libtexpdf-output.lua b/core/libtexpdf-output.lua
index 4eb76fe6f..fbe21af92 100644
--- a/core/libtexpdf-output.lua
+++ b/core/libtexpdf-output.lua
@@ -107,6 +107,11 @@ SILE.outputters.libtexpdf = {
     return self:drawHbox(value, width)
   end,
 
+  _drawString = function(self, str, width)
+    local x, y = self:getCursor()
+    pdf.setstring(x, y, str, string.len(str), self._font, width)
+  end,
+
   drawHbox = function (self, value, width)
     _deprecationCheck(self)
     width = SU.cast("number", width)
@@ -123,8 +128,9 @@ SILE.outputters.libtexpdf = {
     if value.complex then
       for i = 1, #value.items do
         local buf = glyph2string(value.items[i].gid)
-        pdf.setstring(cursorX + (value.items[i].x_offset or 0), cursorY + (value.items[i].y_offset or 0), buf, string.len(buf), self._font, value.items[i].glyphAdvance)
-        cursorX = cursorX + value.items[i].width
+        self:setCursor(value.items[i].x_offset or 0, value.items[i].y_offset or 0, true)
+        self:_drawString(buf, value.items[i].glyphAdvance)
+        self:setCursor(value.items[i].width, 0, true)
       end
     else
       local buf = {}
@@ -132,7 +138,7 @@ SILE.outputters.libtexpdf = {
         buf[i] = glyph2string(value.glyphString[i])
       end
       buf = table.concat(buf, "")
-      pdf.setstring(cursorX, cursorY, buf, string.len(buf), self._font, width)
+      self:_drawString(buf, width)
     end
   end,
 
@@ -232,7 +238,8 @@ SILE.outputters.libtexpdf = {
     buf = table.concat(buf, "")
     local oldfont = self._font
     self:setFont(gentium)
-    pdf.setstring(frame:left():tonumber() - _dl/2, (SILE.documentState.paperSize[2] - frame:top()):tonumber() + _dl/2, buf, string.len(buf), self._font, 0)
+    self:setCursor(frame:left():tonumber() - _dl/2, frame:top():tonumber() + _dl/2)
+    self:_drawString(buf, 0)
     if oldfont then
       pdf.loadfont(oldfont)
       self._font = oldfont

From b53896e1fea42f639074f0bba40504ba85eda19c Mon Sep 17 00:00:00 2001
From: Caleb Maclennan <caleb@alerque.com>
Date: Thu, 20 Aug 2020 17:30:11 +0300
Subject: [PATCH 6/8] fix(backends): Properly switch between normal and debug
 fonts

---
 core/libtexpdf-output.lua | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/core/libtexpdf-output.lua b/core/libtexpdf-output.lua
index fbe21af92..32cb98797 100644
--- a/core/libtexpdf-output.lua
+++ b/core/libtexpdf-output.lua
@@ -8,6 +8,8 @@ local cursorY = 0
 local started = false
 local lastkey
 
+local debugfont = SILE.font.loadDefaults({ family = "Gentium Plus", language = "en", size = 10 })
+
 local function ensureInit ()
   if not started then
     pdf.init(SILE.outputFilename, SILE.documentState.paperSize[1], SILE.documentState.paperSize[2], SILE.full_version)
@@ -142,6 +144,18 @@ SILE.outputters.libtexpdf = {
     end
   end,
 
+  _debugfont = nil,
+
+  _withDebugFont = function (self, callback)
+    if not self._debugfont then
+      self._debugfont = self:setFont(debugfont)
+    end
+    local oldfont = self._font
+    self._font = self._debugfont
+    callback()
+    self._font = oldfont
+  end,
+
   _font = nil,
 
   setFont = function (self, options)
@@ -228,22 +242,17 @@ SILE.outputters.libtexpdf = {
     self:drawRule(frame:right()-_dl/2, frame:top()-_dl/2, _dl, frame:height()+_dl)
     self:drawRule(frame:left()-_dl/2, frame:bottom()-_dl/2, frame:width()+_dl, _dl)
     -- self:drawRule(frame:left() + frame:width()/2 - 5, (frame:top() + frame:bottom())/2+5, 10, 10)
-    local gentium = SILE.font.loadDefaults({family="Gentium Plus", language="en"})
-    local stuff = SILE.shaper:createNnodes(frame.id, gentium)
+    local stuff = SILE.shaper:createNnodes(frame.id, debugfont)
     stuff = stuff[1].nodes[1].value.glyphString -- Horrible hack
     local buf = {}
     for i = 1, #stuff do
       buf[i] = glyph2string(stuff[i])
     end
     buf = table.concat(buf, "")
-    local oldfont = self._font
-    self:setFont(gentium)
-    self:setCursor(frame:left():tonumber() - _dl/2, frame:top():tonumber() + _dl/2)
-    self:_drawString(buf, 0)
-    if oldfont then
-      pdf.loadfont(oldfont)
-      self._font = oldfont
-    end
+    self:_withDebugFont(function ()
+      self:setCursor(frame:left():tonumber() - _dl/2, frame:top():tonumber() + _dl/2)
+      self:_drawString(buf, 0)
+    end)
     self:popColor()
   end,
 

From 774b0447d8bd0f954444f332dcbfac9018b8321d Mon Sep 17 00:00:00 2001
From: Caleb Maclennan <caleb@alerque.com>
Date: Tue, 25 Aug 2020 14:05:25 +0300
Subject: [PATCH 7/8] test(backends): Check output of complex hboxes in
 libtexpdf

---
 tests/bug-1044.expected | 10 ++++++++++
 tests/bug-1044.sil      |  8 ++++++++
 2 files changed, 18 insertions(+)
 create mode 100644 tests/bug-1044.expected
 create mode 100644 tests/bug-1044.sil

diff --git a/tests/bug-1044.expected b/tests/bug-1044.expected
new file mode 100644
index 000000000..93f3b363e
--- /dev/null
+++ b/tests/bug-1044.expected
@@ -0,0 +1,10 @@
+Set paper size 	297.6377985	419.5275636
+Begin page
+Mx 	14.8819
+My 	27.9564
+Set font 	Libertinus Serif;10;400;;normal;;LTR
+T	53 66	(Ta)
+Mx 	27.9627
+T	80 71	(of)
+End page
+Finish
diff --git a/tests/bug-1044.sil b/tests/bug-1044.sil
new file mode 100644
index 000000000..26d156816
--- /dev/null
+++ b/tests/bug-1044.sil
@@ -0,0 +1,8 @@
+\begin[papersize=a6]{document}
+\nofolios
+\neverindent
+\font[family=Libertinus Serif]{Ta of}
+% If complex shaping is skipped and glyphAdvance ignored when outputting
+% a series of hboxes, the "Ta" kerning above will cause "of" to be positioned
+% too far forward.
+\end{document}

From 88ac88805c138397d7cf94f8b7864d65956a7e13 Mon Sep 17 00:00:00 2001
From: Caleb Maclennan <caleb@alerque.com>
Date: Tue, 25 Aug 2020 14:18:49 +0300
Subject: [PATCH 8/8] fix(tooling): Expand variables so fonts are known
 dependencies of tests

---
 Makefile.am | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index f563ac877..0e1c5278c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -184,9 +184,9 @@ define runsile =
 endef
 
 _FORCED = $(and $(SILE_COVERAGE)$(CLEAN),force)
-_TEST_DEPS = $(and $(filter tests/%,$@),$(addprefix .fonts/,$(TESTFONTFILES)))
-_DOCS_DEPS = $(and $(filter documentation/%,$@),$(addprefix .fonts/,$(DOCSFONTFILES)))
-_EXAM_DEPS = $(and $(filter examples/%,$@),$(addprefix .fonts/,$(EXAMFONTFILES)))
+_TEST_DEPS = $(and $$(filter tests/%,$@),$(addprefix .fonts/,$(TESTFONTFILES)))
+_DOCS_DEPS = $(and $$(filter documentation/%,$@),$(addprefix .fonts/,$(DOCSFONTFILES)))
+_EXAM_DEPS = $(and $$(filter examples/%,$@),$(addprefix .fonts/,$(EXAMFONTFILES)))
 
 # TODO: remove _BUILT_SUBDIRS hack and replace it with something sensible when
 # these subdirs don't do crazy things like copying files outside of their own trees!