Fix optical size matching

With the previous commit, if we don't found a font with the requested
optical size, we return nothing, though we might have a matching font
name.

Now we store all matching names with no matching optical size and return
the first one, then we return the closest match (i.e. if the requested
size is 15pt and we have 10pt and 5pt match, we return the 10pt one).

1 files changed, 37 insertions, 15 deletions

diff --git a/otfl-font-nms.lua b/otfl-font-nms.lua
index 51db3bd..bb5628c 100644
--- a/otfl-font-nms.lua
+++ b/otfl-font-nms.lua
@@ -63,6 +63,7 @@ local synonyms  = {
 function names.resolve(specification)
     local name  = sanitize(specification.name)
     local style = sanitize(specification.style) or "regular"
+    local size  = tonumber(specification.optsize) or specification.size and specification.size / 65536
     if not loaded then
         names.data   = names.load()
         loaded = true
@@ -70,17 +71,16 @@ function names.resolve(specification)
     local data  = names.data
     if type(data) == "table" and data.version == names.version then
         if data.mappings then
-            local found
+            local found = { }
             for _,face in ipairs(data.mappings) do
                 local family    = sanitize(face.names.family)
                 local subfamily = sanitize(face.names.subfamily)
                 local fullname  = sanitize(face.names.fullname)
                 local psname    = sanitize(face.names.psname)
                 local filename  = face.filename
-                local optsize, rqssize, dsnsize, maxsize, minsize
+                local optsize, dsnsize, maxsize, minsize
                 if #face.size > 0 then
                     optsize = face.size
-                    rqssize = tonumber(specification.optsize) or specification.size and specification.size / 65536
                     dsnsize = optsize[1] and optsize[1] / 10
                     maxsize = optsize[2] and optsize[2] / 10 or dsnsize -- can be nil
                     minsize = optsize[3] and optsize[3] / 10 or dsnsize -- can be nil
@@ -88,12 +88,14 @@ function names.resolve(specification)
                 if name == family and subfamily then
                     if subfamily == style then
                         if optsize then
-                            if dsnsize == rqssize or (rqssize > minsize and rqssize <= maxsize) then
-                                found = filename
+                            if dsnsize == size or (size > minsize and size <= maxsize) then
+                                found[1] = face
                                 break
+                            else
+                                found[#found+1] = face
                             end
                         else
-                            found = filename
+                            found[1] = face
                             break
                         end
                     else
@@ -101,12 +103,14 @@ function names.resolve(specification)
                             for _,v in ipairs(synonyms[style]) do
                                 if subfamily == v then
                                     if optsize then
-                                        if dsnsize == rqssize or (rqssize > minsize and rqssize <= maxsize) then
-                                            found = filename
+                                        if dsnsize == size or (size > minsize and size <= maxsize) then
+                                            found[1] = face
                                             break
+                                        else
+                                            found[#found+1] = face
                                         end
                                     else
-                                        found = filename
+                                        found[1] = face
                                         break
                                     end
                                 end
@@ -116,20 +120,38 @@ function names.resolve(specification)
                 else
                     if name == family or name == fullname or name == psname then
                         if optsize then
-                            if dsnsize == rqssize or (rqssize > minsize and rqssize <= maxsize) then
-                                found = filename
+                            if dsnsize == size or (size > minsize and size <= maxsize) then
+                                found[1] = face
                                 break
+                            else
+                                found[#found+1] = face
                             end
                         else
-                            found = filename
+                            found[1] = face
                             break
                         end
                     end
                 end
             end
-            if found then
-                logs.report("load font", "font family='%s', subfamily='%s' found: %s", name, style, found)
-                return found, false
+            if #found == 1 then
+                logs.report("load font", "font family='%s', subfamily='%s' found: %s", name, style, found[1].filename)
+                return found[1].filename, false
+            elseif #found > 1 then
+                -- we found matching font(s) but not in the requested optical
+                -- sizes, so we loop through the matches to find the one with
+                -- least difference from the requested size.
+                local closest
+                local least = math.huge -- initial value is infinity
+                for i,face in ipairs(found) do
+                    local dsnsize    = face.size[1]/10
+                    local difference = math.abs(dsnsize-size)
+                    if difference < least then
+                        closest = face
+                        least   = difference
+                    end
+                end
+                logs.report("load font", "font family='%s', subfamily='%s' found: %s", name, style, closest.filename)
+                return closest.filename, false
             else
                 return name, false -- fallback to filename
             end