LCDs: Rework line breaking algorithm, include spaces, show unknown symbols as spaces (#64)

Typeset the lines according to these rules (in order of subjective significance):

 * words that fit on the screen but would let the current line overflow are placed on a new line instead
 *  " | " always forces a linebreak
 *  spaces are included, except when there is a linebreak anyway
 * words with more characters than fit on screen are just chopped up, filling the lines as full as possible
 * don't bother typesetting more lines than fit on screen
 * if we are on the last line that will fit on screen
This commit is contained in:
Peter Nerlich 2020-12-09 17:48:18 +01:00 committed by GitHub
parent 021c521c65
commit ab2eb4af43
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115
lcd.lua

@ -5,7 +5,6 @@
-- load characters map -- load characters map
local chars_file = io.open(minetest.get_modpath("digilines").."/characters", "r") local chars_file = io.open(minetest.get_modpath("digilines").."/characters", "r")
local charmap = {} local charmap = {}
local max_chars = 12
if not chars_file then if not chars_file then
print("[digilines] E: LCD: character map file not found") print("[digilines] E: LCD: character map file not found")
else else
@ -21,7 +20,7 @@ else
end end
-- CONSTANTS -- CONSTANTS
local LCD_WITH = 100 local LCD_WIDTH = 100
local LCD_PADDING = 8 local LCD_PADDING = 8
local LINE_LENGTH = 12 local LINE_LENGTH = 12
@ -30,31 +29,96 @@ local NUMBER_OF_LINES = 5
local LINE_HEIGHT = 14 local LINE_HEIGHT = 14
local CHAR_WIDTH = 5 local CHAR_WIDTH = 5
assert((CHAR_WIDTH+1) * LINE_LENGTH <= LCD_WIDTH - LCD_PADDING*2, "LCD: Lines set too long!")
assert((LINE_HEIGHT+1) * NUMBER_OF_LINES <= LCD_WIDTH - LCD_PADDING*2, "LCD: Too many lines!")
local split = function(s, pat)
-- adapted from https://stackoverflow.com/a/1647577/4067384
-- simplified for our only usecase
local st, g = 1, s:gmatch("()("..pat..")")
local function getter()
if st then
local segs, seps, sep = st, g()
st = sep and seps + #sep
return s:sub(segs, (seps or 0) - 1)
end
end
return getter
end
local create_lines = function(text) local create_lines = function(text)
--[[
Typeset the lines according to these rules (in order of subjective significance):
- words that fit on the screen but would let the current line overflow are placed on a new line instead
- " | " always forces a linebreak
- spaces are included, except when there is a linebreak anyway
- words with more characters than fit on screen are just chopped up, filling the lines as full as possible
- don't bother typesetting more lines than fit on screen
- if we are on the last line that will fit on screen
]]--
local line = "" local line = ""
local line_num = 1 local line_num = 1
local tab = {} local tab = {}
for word in string.gmatch(text, "%S+") do local flush_line_and_check_for_return = function()
if string.len(line)+string.len(word) < LINE_LENGTH and word ~= "|" then table.insert(tab, line)
if line ~= "" then line_num = line_num+1
line = line.." "..word if line_num > NUMBER_OF_LINES then
return true
end
line = ""
end
for par in split(text, " | ") do
for word in split(par, "%s") do
if string.len(word) <= LINE_LENGTH and line_num < NUMBER_OF_LINES then
local line_len = string.len(line)
if line_len > 0 then
-- remember the space
line_len = line_len + 1
end
if line_len + string.len(word) <= LINE_LENGTH then
if line_len > 0 then
line = line.." "..word
else
line = word
end
else
if word == " " then
-- don't add the space since we have a line break
else
if line_len > 0 then
-- ok, we need the new line
if flush_line_and_check_for_return() then return tab end
end
line = word
end
end
else else
line = word -- chop up word to make it fit
end local remaining
else while true do
table.insert(tab, line) remaining = LINE_LENGTH - string.len(line)
if word ~= "|" then if remaining < LINE_LENGTH then
line = word line = line .. " "
else remaining = remaining - 1
line = "" end
end if remaining < string.len(word) then
line_num = line_num+1 line = line .. string.sub(word, 1, remaining)
if line_num > NUMBER_OF_LINES then word = string.sub(word, remaining+1)
return tab if flush_line_and_check_for_return() then return tab end
else
-- used up the word
line = line .. word
break
end
end
end end
end end
-- end of paragraph
if flush_line_and_check_for_return() then return tab end
line = ""
end end
table.insert(tab, line)
return tab return tab
end end
@ -63,7 +127,7 @@ local generate_line = function(s, ypos)
local parsed = {} local parsed = {}
local width = 0 local width = 0
local chars = 0 local chars = 0
while chars < max_chars and i <= #s do while chars < LINE_LENGTH and i <= #s do
local file = nil local file = nil
if charmap[s:sub(i, i)] ~= nil then if charmap[s:sub(i, i)] ~= nil then
file = charmap[s:sub(i, i)] file = charmap[s:sub(i, i)]
@ -73,10 +137,13 @@ local generate_line = function(s, ypos)
i = i + 2 i = i + 2
else else
print("[digilines] W: LCD: unknown symbol in '"..s.."' at "..i) print("[digilines] W: LCD: unknown symbol in '"..s.."' at "..i)
if charmap[" "] ~= nil then
file = charmap[" "]
end
i = i + 1 i = i + 1
end end
if file ~= nil then if file ~= nil then
width = width + CHAR_WIDTH width = width + CHAR_WIDTH + 1
table.insert(parsed, file) table.insert(parsed, file)
chars = chars + 1 chars = chars + 1
end end
@ -84,7 +151,7 @@ local generate_line = function(s, ypos)
width = width - 1 width = width - 1
local texture = "" local texture = ""
local xpos = math.floor((LCD_WITH - 2 * LCD_PADDING - width) / 2 + LCD_PADDING) local xpos = math.floor((LCD_WIDTH - width) / 2)
for ii = 1, #parsed do for ii = 1, #parsed do
texture = texture..":"..xpos..","..ypos.."="..parsed[ii]..".png" texture = texture..":"..xpos..","..ypos.."="..parsed[ii]..".png"
xpos = xpos + CHAR_WIDTH + 1 xpos = xpos + CHAR_WIDTH + 1
@ -93,8 +160,8 @@ local generate_line = function(s, ypos)
end end
local generate_texture = function(lines) local generate_texture = function(lines)
local texture = "[combine:"..LCD_WITH.."x"..LCD_WITH local texture = "[combine:"..LCD_WIDTH.."x"..LCD_WIDTH
local ypos = 16 local ypos = math.floor((LCD_WIDTH - LINE_HEIGHT*NUMBER_OF_LINES) / 2)
for i = 1, #lines do for i = 1, #lines do
texture = texture..generate_line(lines[i], ypos) texture = texture..generate_line(lines[i], ypos)
ypos = ypos + LINE_HEIGHT ypos = ypos + LINE_HEIGHT