TPTLua Font Generator

--[[

    USAGE:

    Start a new font:

    makeFont(Font width (number), Font height (number), Font name (string))

    -Makes a new file usable by the texter

    -Sets up the font data used throughout the program



    Make all the letters in a font:

    autoGen()



    GUI Usage:

    Click a pixel to toggle it

    Click outside of the GUI to move to the next character

    At the top-right corner of the GUI, there is:

        a) A display telling you which character you are on, and
        b) A pixel preview of your letter at a 1:1 scale.



    To exit the GUI before you have completed your font:

    Type 'done()' into the console. It will exit the GUI, finish your font, and write it to a file.

]]

-- Make a matrix of all the characters
local charchart = {}

-- Make the file opened wit makeFont visible to other functions that need it
local f

-- Set up the info needed to make a font file
function makeFont(w, h, name)
    -- Globally visible metrics data
    ftf_w = w
    ftf_h = h
    -- Globally visible font name
    ftf_name = name
    -- Generic character header - 'char' will be replaced by the character name,
    -- and '_KERN' with the kerning data. 'texter_font' is replaced by the font
    -- name.
    charStr = ({string.gsub([[
texter_font[char] = {
    ['descender'] = -2,
    ['kerning'] = _KERN,
    ['pixels']  = {
]], 'texter_font', name)})[1]
    f = io.open(name .. '.txt', 'w')
    -- Write the font header - '_NAME' is replaced by the font name, '_W is
    -- replaced by the default character width (when kerning is set to 0), and
    -- '_H' is replaced with the font height.
    f:write(tostring(({string.gsub(string.gsub(string.gsub([[
_NAME = {}
_NAME['width'] = _W
_NAME['height'] = _H
    ]], '_NAME', name), '_W', w), '_H', h)})[1]))
end

-- Takes a table returned by the GUI and converts it to readable character data
local function makeLetterFromGui(char, currentfont_pixels)
    -- Kerning data
    local kern, doBreak
    -- Calculate the kerning for the character
    for x = 0, ftf_w - 1 do
        for y = 1, ftf_h do
            if currentfont_pixels[y][ftf_w - x - 1] == 1 then
                kern = -x
                doBreak = true -- Break out of for loops?
                break
            end
            if doBreak == true then
                break
            end
        end
        if doBreak == true then
            break
        end
    end
    -- Default kerning to 0
    if not kern then kern = 0 end
    -- Replace  the '_KERN' in the character header with real kerning data
    local charStr = ({string.gsub(charStr, '_KERN', kern)})[1]
    -- Replace the 'char' in the character header with the character name and write it
    f:write(({string.gsub(charStr, 'char', string.format('%q', char))})[1])
    for y = 1, ftf_h + 2 do
        for x = 1, ftf_w do
            -- Writing font data to the file
            if x == 1 then
                -- First pixel in a row
                f:write('\t\t{', currentfont_pixels[y][x] and tostring(currentfont_pixels[y][x]) or '0', ', ')
            elseif x == ftf_w then
                -- Last pixel
                if y == ftf_h + 2 then
                    f:write('\n')
                -- Other edge pixels
                else
                    f:write(',\n')
                end
            else
                -- All the other pixels
                f:write(currentfont_pixels[y][x] and tostring(currentfont_pixels[y][x]) or '0', ', ')
            end
        end
    end
    -- Close off the character data
    f:write('\t}\n}\n')
end

-- Autopilot Character Set
local charstr = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789~`!@#$%^&*()-_=+[{]}\\|;:\'",<.>/?'
-- Current character in the autopilot
local n = 0
-- GUI Stopper
local endMatGet
-- Weird bugfix, if you delete this, it breaks, but I have no idea why.
local getmcoords, rectSetGui, rectDrawGui, testForEnd
-- The GUI!
function autoGen()
    n = n + 1
    -- Current character
    local char = string.sub(charstr, n, n)
    -- Width and height data
    local w, h = ftf_w, ftf_h + 2
    -- Distance between rectangles
    local rstep = 340 / h
    -- Size of rectangles
    local wsize = w * rstep
    -- Character data table
    local mat = {}
    -- Make the character data table 2-D
    for k = 1, h + 2 do
        mat[k] = {}
    end
    -- Predefine the mouse coords - I don't know why, but sometimes they don't get defined
    local rectInMX, rectInMY = 1, 1
    -- Calculate which box the cursor is on
    function getmcoords()
        rectInMX = math.floor((tpt.mousex + rstep) / rstep) - 1
        rectInMY = math.floor((tpt.mousey + rstep) / rstep) - 1
    end
    tpt.register_step(getmcoords)
    -- Variable, not important
    -- Modify the table as you click!
    function rectSetGui(x, y, button, event)
        if event == 2 then
            if mat[rectInMY][rectInMX] ~= 1 then
                mat[rectInMY][rectInMX] = 1
            else
                mat[rectInMY][rectInMX] = 0
            end
            -- Stop the GUI if you click outside the character map
            if rectInMX > w or rectInMY > h then endMatGet = true end
        end
        return false
    end
    tpt.register_mouseclick(rectSetGui)
    -- Draw the GUI itself
    function rectDrawGui()
        for y = 1, h do
            for x = 1, w do
                -- Drawing rectangles, boring stuff
                tpt.drawrect(x * rstep, y * rstep, rstep - 2, rstep - 2, 255, 255, 255, 255)
                tpt.fillrect(rectInMX * rstep, rectInMY * rstep, rstep - 2, rstep - 2, 75, 75, 75)
                -- Draw the current character
                if mat[y][x] == 1 then
                    tpt.fillrect(x * rstep, y * rstep, rstep - 2, rstep - 2, 125, 125, 125)
                    -- Pixel Preview
                    tpt.drawpixel(w * rstep + rstep + 2 + x, 46 + y, 255, 255, 255, 255)
                end
            end
        end
        -- Tell the user which character they are drawing
        tpt.drawtext(w * rstep + rstep + 2, 38, 'Current character: ' .. char, 255, 255, 0, 255)
    end
    tpt.register_step(rectDrawGui)
    -- Check whether the program should be stopping
    function testForEnd()
        if endMatGet then
            -- Stop all the GUI stuff
            tpt.unregister_step(getmcoords)
            tpt.unregister_step(rectDrawGui)
            tpt.unregister_mouseclick(rectSetGui)
            -- Save the current character unless done() has closed the file
            if endMatGet ~= 'DONE' then
                makeLetterFromGui(string.sub(charstr, n, n), mat)
            end
            -- Recurse until it reaches the end of the character list or until done() is called
            if n <= #charstr and endMatGet ~= 'DONE' then
                autoGen()
                endMatGet = nil
            end
        end
    end
    tpt.register_step(testForEnd)
end

-- Finish up the font and write it
function done()
    -- Write the NULL character, it can break without it
    f:write('\n' .. ftf_name .. [[['NULL'] = {
    ['descender'] = 0,
    ['kerning'] = 0,
    ['pixels']  = {
        {1, 1, 1, 1, 1},
        {1, 0, 0, 1, 1},
        {1, 1, 1, 0, 1},
        {1, 1, 0, 1, 1},
        {1, 1, 1, 1, 1},
        {1, 1, 0, 1, 1},
        {1, 1, 1, 1, 1},
        {0, 0, 0, 0, 0},
        {0, 0, 0, 0, 0}
    }
}]])
    -- Stop the GUI
    endMatGet = 'DONE'
    tpt.unregister_step(testForEnd)
    -- Close the file
    f:close()
end