billy API

billy = {}
billy.time = 0

billy.keys = {}
billy.keys.used = {}
billy.keys.used[29] = true
billy.keys.quit = 29

--[[
    miscellaneous functions and values.
]]
local misc = {}
misc.flipTable = function(table)
    local ntable = {}
    for i=1,#table do
        ntable[i] = table[#table - i + 1]
    end
    return ntable
end
misc.split = function(str, pat)
    local t = {}  -- NOTE: use {n = 0} in Lua-5.0
    if str ~= nil then
       local fpat = "(.-)" .. pat
       local last_end = 1
       local s, e, cap = str:find(fpat, 1)
       while s do
          if s ~= 1 or cap ~= "" then
         table.insert(t,cap)
          end
          last_end = e+1
          s, e, cap = str:find(fpat, last_end)
       end
       if last_end <= #str then
          cap = str:sub(last_end)
          table.insert(t, cap)
       end
    else
        print("##ERROR failed to split ["..str.."] by:"..pat)
    end
    return t
end
billy.misc = misc

--[[
    Dump table;
    not used inside billy - basically just an alternative to using the _G table if you don't want
    to clutter in it, as cluttering the _G table is more of a problem in CC than it is in LOVE
]]
billy.dump = {}

--[[
    All the standard override functions,
    override these and they get called at the appropriate time.
]]
billy.load = function() end --called when the program starts
billy.update = function() end --called every 0.05 seconds
billy.draw = function() return false end --called every time the game is drawn, after update, every 0.05 seconds, return true/false depending on if changes have/haven't been made
billy.event = function() end --called every time an event is called
billy.quit = function() end --called when the game is quit using the quit button

--[[
    graphics table for billy;
    contains all the graphics functions
]]
local graphics = {}

--[[
    data to be set in graphics functions for the graphics functions,
    It's safer to ignore this table, but you don't have to.
]]
graphics.LOCAL_DATA = {}
graphics.LOCAL_DATA.background = colors.black
graphics.LOCAL_DATA.text = colors.white
graphics.LOCAL_DATA.size = 1
graphics.LOCAL_DATA.char = " "

--[[
    Function to set the background colour in LOCAL_DATA, can be called by both:
        setBackgroundColor(colour)
        setBackgroundColour(colour)
    returns:
        old, colour
    where:
        old is the old background colour that was used
        colour is the new background colour being used
]]
graphics.setBackgroundColor = function(color)
    local old = graphics.LOCAL_DATA.background
    graphics.LOCAL_DATA.background = color
    return old, color
end
graphics.setBackgroundColour = function(color) return graphics.setBackgroundColor(color) end

--[[
    Function to set the text colour in LOCAL_DATA, can be called by both:
        setTextColor(colour)
        setTextColour(colour)
    returns:
        old, colour
    where:
        old is the old text colour that was used
        colour is the new text colour being used
]]
graphics.setTextColor = function(color)
    local old = graphics.LOCAL_DATA.background
    graphics.LOCAL_DATA.text = color
    return old, color
end
graphics.setTextColour = function(color) return graphics.setTextColor(color) end

--[[
    Function to set the size value in LOCAL_DATA,
    returns:
        old, size
    where:
        old is the old size value that was used
        size is the new size value being used
]]
graphics.setSize = function(size)
    local old = graphics.LOCAL_DATA.size
    graphics.LOCAL_DATA.size = size
    return old, size
end

--[[
    Function to set the char value in LOCAL_DATA,
    returns:
        old, char
    where:
        old is the old char value that was used
        char is the new char value being used
]]
graphics.setChar = function(char)
    local old = graphics.LOCAL_DATA.char
    graphics.LOCAL_DATA.char = char
    return old, char
end

--[[
    Function to draw a line between to points;
        x1,y1 are the x,y co-ordinates of the first point on the line
        x2,y2 are the x,y co-ordinates of the last point on the line
    returns:
        a table containing all positions of the line in the format:
            table[i] = {x, y}
        where:
            i = index of table, a number
            x,y are the x,y positions of the point on the line
    note:
        the table returned always has the first point as x1,y2 and the last point as x2,y2;
        so it keeps it's order.
]]
graphics.drawLine = function(x1, y1, x2, y2)
    local pixs = {}

    x1 = math.floor(x1)
    y1 = math.floor(y1)
    x2 = math.floor(x2)
    y2 = math.floor(y2)

    if x1 == x2 and y1 == y2 then
        pixs[#pixs + 1] = {x1, y1}
        return pixs
    end

    local minX = math.min( x1, x2 )
    if minX == x1 then
            minY = y1
            maxX = x2
            maxY = y2
    else
            minY = y2
            maxX = x1
            maxY = y1
    end

    local xDiff = maxX - minX
    local yDiff = maxY - minY

    if xDiff > math.abs(yDiff) then
            local y = minY
            local dy = yDiff / xDiff
            for x=minX,maxX do
                    if #pixs > 0 then
                        if pixs[#pixs][1] == x and pixs[#pixs][2] == math.floor(y + 0.5) then else
                            pixs[#pixs + 1] = {x, math.floor(y + 0.5)}
                        end
                    else
                        pixs[#pixs + 1] = {x, math.floor(y + 0.5)}
                    end
                    y = y + dy
            end
    else
            local x = minX
            local dx = xDiff / yDiff
            if maxY >= minY then
                    for y=minY,maxY do
                            if #pixs > 0 then
                                if pixs[#pixs][1] == math.floor(x+0.5) and pixs[#pixs][2] == y then else
                                    pixs[#pixs + 1] = {math.floor(x+0.5), y}
                                end
                            else
                                pixs[#pixs + 1] = {math.floor(x+0.5), y}
                            end
                            x = x + dx
                    end
            else
                    for y=minY,maxY,-1 do
                            if #pixs > 0 then
                                if pixs[#pixs][1] == math.floor(x+0.5) and pixs[#pixs][2] == y then else
                                    pixs[#pixs + 1] = {math.floor(x+0.5), y}
                                end
                            else
                                pixs[#pixs + 1] = {math.floor(x+0.5), y}
                            end
                            x = x - dx
                    end
            end
    end
    if pixs[1][1] == x2 and pixs[1][2] == y2 then pixs = billy.misc.flipTable(pixs) end
    return pixs
end

--[[
    Creates a polygon,
        poly is a table in the format:
            table[i] = {x,y}
        where:
            i = index of table, a number
            x,y = x,y co-ordinates of one of the corners of the polygon
    returns:
        shape
    where:
        shape is a table containing the following values and functions:
            shape.det = a string containing all the points of the corners of the polygon on it
            shape.poly = the table you used to create the shape
            shape.back = background colour of the shape
            shape.text = text colour of the shape
            shape.char = character used to draw the shape
            shape:draw = function that draws the polygon, no parameters or returns.
]]
graphics.createShape = function(poly)
    local shape = {}
    local l = ""
    for i=1,#poly do
        local p1 = poly[i]
        local p2 = poly[i+1]
        if i == #poly then p2 = poly[1] end
        local line = drawLine(p1[1], p1[2], p2[1], p2[2])
        for j=1,#line do
            shape[#shape + 1] = line[j]
        end
        l = l..p1[1]..","..p1[2].." "
    end
    shape.det = l
    shape.poly = poly
    shape.back = billy.graphics.LOCAL_DATA.background
    shape.text = billy.graphics.LOCAL_DATA.text
    shape.char = billy.graphics.LOCAL_DATA.char
    shape.draw = function(self)
        for i=1,#self do
            local p = self[i]
            billy.buffer.setCursorPos(p[1], p[2])
            billy.buffer.setBackgroundColor(self.back)
            billy.buffer.setTextColor(self.text)
            billy.buffer.write(self.char)
        end
        --[[
        for i=1,#self.poly do
            local p = self.poly[i]
            billy.buffer.setCursorPos(p[1], p[2])
            billy.buffer.setBackgroundColor(self.back)
            billy.buffer.setTextColor(self.text)
            billy.buffer.write(tostring(i))
        end
        ]]
        --billy.buffer.setCursorPos(1, sh-1)
        --billy.buffer.write(self.det)
    end
    return shape
end

--[[
    Function that draws a shape with the current LOCAL_DATA,
    exactly the same as shape:draw but uses LOCAL_DATA for colours instead of the shape's colours.

    can be used to draw Triangles and Squares (Filled in ones)
]]
graphics.drawShape = function(shape)
    for i=1,#shape do
        local p = shape[i]
        billy.buffer.setCursorPos(p[1], p[2])
        billy.buffer.setBackgroundColor(graphics.LOCAL_DATA.background)
        billy.buffer.setTextColor(graphics.LOCAL_DATA.text)
        billy.buffer.write(graphics.LOCAL_DATA.char)
    end
end

--[[
    Creates a Triangle, for use with fillTriangle
        p1,p2,p3 - the 3 co-ordinates of the triangle
    returns:
        table in format:
            table[x][y] = true
]]
graphics.createTriangle = function(p1, p2, p3)
    local tab1 = billy.graphics.drawLine(p1[1], p1[2], p2[1], p2[2])
    local tab2 = billy.graphics.drawLine(p1[1], p1[2], p3[1], p3[2])
    local tab3 = billy.graphics.drawLine(p2[1], p2[2], p3[1], p3[2])
    local tabs = {tab1, tab2, tab3}
    local triangle = {}
    for i=1,#tabs do
        local tab = tabs[i]
        for i=1,#tab do
            local pos = tab[i]
            if triangle[x] == nil then triangle[x] = {} end
            triangle[pos[1]][pos[2]] = true
        end
    end
    return triangle
end

--[[
    Fills in a triangle, must be a triangle returned from createTriangle, NOT createShape
        tri - a triangle returned from createTriangle
    returns:
        table containing all the points in the triangle in format:
            table[i] = {x,y}
        where:
            i = index of table, a number
            x,y = the x,y coordinates of the point on the triangle
]]
graphics.fillTriangle = function(tri)
    local minX, maxX = nil
    local minys = {}
    for x,v in pairs(tri) do
        if minX == nil then
            minX = x
        elseif x < minX then
            minX = x
        end

        if maxX == nil then
            maxX = x
        elseif x > maxX then
            maxX = x
        end

        if v ~= nil then
            local minY = nil
            for y,r in pairs(v) do
                if minY == nil then
                    minY = y
                elseif y < minY then
                    minY = y
                end
            end
            if minY ~= nil then
                if minys[x] == nil then minys[x] = {} end
                minys[x] = minY
            end
        end
    end

    local ntri = {}
    for x,v in pairs(tri) do
        if v ~= nil then
            for y,r in pairs(v) do
                ntri[#ntri + 1] = {x,y}
            end
        end
    end
    if minX ~= nil and maxX ~= nil then
        for x=minX, maxX do
            if minys[x] ~= nil then
                local y = minys[x]
                if tri[x] ~= nil then
                    if getSize(tri[x]) > 1 then
                        local check = false
                        while check == false do
                            y = y + 1

                            if tri[x] ~= nil then
                                if tri[x][y] ~= nil then check = true end
                            end
                            if y >= h then check = true end

                            --term.setCursorPos(1, h-2)
                            --print("y = "..y.."; x = "..x)

                            --if check then
                                ntri[#ntri + 1] = {x,y}
                            --end
                        end
                    end
                end
            end
        end
    end
    return ntri
end

--[[
    function that creates a quadrilateral,
        p1,p2,p3,p4 = the 4 points of the quadrilateral
    returns:
        table containing all the points of the square in format:
            table[i] = {x,y}
        where:
            i = index of table, a number
            x,y = the x,y coordinates of the point on the square
]]
graphics.fillQuad = function(p1, p2, p3, p4)
    local tri1 = billy.graphics.fillTriangle(getTriangle(p1, p2, p3))
    local tri2 = billy.graphics.fillTriangle(getTriangle(p1, p4, p3))
    local tris = {tri1, tri2}
    local square = {}
    for i=1,#tris do
        local tri = tris[i]
        for i=1,#tri do
            local pos = tri[i]
            local x = pos[1]
            local y = pos[2]
            square[#square + 1] = {x,y}
        end
    end
    return square
end

--[[
    Creates a circle;
        center = table containing {x,y} coordinates of the centre point
        radius = the radius of the circle
        fill = boolean as to whether or not the circle is filled in
    returns:
        table containing all the points in the circle on it, format:
            table[i] = {x,y}
        where:
            i = index of table, a number
            x,y = the x,y coordinates of the point
]]
graphics.createCircle = function(center, radius, fill)
        -- (x-a)^2 + (y-B)^2 = r^2 (formula, where r is radius, x and y are coordinates and a and b is center)
        local pixs = {}
        local rads = radius^2
        local topright = {center[1]-radius, center[2]-radius}
        local bottomleft = {center[1]+radius, center[2]+radius}
        for cx=topright[1],bottomleft[1],1 do
                for cy=topright[2],bottomleft[2],1 do
                        local xb = (cx-center[1])^2
                        local yb = (cy-center[2])^2
                        if (xb+yb) == rads then
                                pixs[#pixs + 1] = {cx, cy}
                        elseif fill and (xb+yb) <= rads then
                                pixs[#pixs + 1] = {cx, cy}
                        end
                end
        end
        return pixs
end

billy.graphics = graphics

local IO = {}
--[[
    gets all of the lines out of a file
        dir - the directory of the file
    returns:
        a table containing all the lines, in format:
            table[i] = line
        where:
            i = index of the table, a number
            line = the line of the file
]]
IO.getLines = function(dir)
    local lines = {}
    if fs.exists(dir) then
        local file = fs.open(dir, "r")
        local line = file.readLine()
        while line ~= nil do
            lines[#lines + 1] = line
            line = file.readLine()
        end
        file.close()
    end
    return lines
end
--[[
    re-writes a file (or creates a new one) with the lines in it
        dir - the directory of the file
        lines - a table containing all the lines to write in the format:
            table[i] = line
        where:
            i = index of the table, a number
            line = the line of the file
    no returns.
]]
IO.writeLines = function(dir, lines)
    local file = fs.open("w")
    for i=1,#lines do
        local line = lines[i]
        file.writeLine(line)
    end
    file.close()
end
--[[
    adds lines to a file at certain index, adds them before the line at that index
        dir - the directory of the file
        lines - a table containing all of the lines and their indexes, in the format:
            table[i] = {index, line}
        where:
            i = index of the table, a number
            index = index of the file to put the line in
            line = line to add to the file
    no returns.
]]
IO.addLines = function(dir, lines)
    local lns = billy.IO.getLines(dir)
    local nlines = {}
    for i=1,#lns do
        local line = lines[i]
        for i=1,#lines do
            if lines[i][1] == i then nlines[#nlines + 1] = lines[i][2] end
        end
        nlines[#nlines + 1] = line
    end
    billy.IO.writeLines(nlines)
end

billy.IO = IO

local image = {}
--[[
    creates a table in image-table format from a file
        dir - the directory of the file
    returns:
        a table containing all of the characters in the file in the following format:
            table[x][y] = character
        where:
            x = the x position of the character
            y = the y position of the character
            character = the character
        the table also contains another table called "data", this contains significant data
        about the images and formating of the image-table.
]]
image.createImageTable = function(dir)
    local lines = billy.IO.getLines(file)
    local imgtab = {}
    for y=1,#lines do
        local line = lines[y]
        if line:sub(1, 5) ~= "DAT::" then
            for x=1,string.len(line) do
                local char = line:sub(x, y)
                if imgtab[x] == nil then imgtab[x] = {} end
                imgtab[x][y] = char
            end
        else
            imgtab.data[#imgtab.data] = billy.misc.split(string.lower(line:sub(6, -1)), "::")
        end
    end
    return imgtab
end
--[[
    creates an image table out of a imgtab table using the appropriate name
        imgtab - the image-table
        name - the name of the image in the image-table
    returns:
        a table containing all of the characters in the image in the following format:
            table[x][y] = character
        where:
            x = the x position of the character
            y = the y position of the character
            character = the character
        the table also contains the following values:
            table.x = the x coordinate of the image
            table.y = the y coordinate of the image
            table.width = the width of the image
            table.height = the height of the image
    NOTE:
        if you want to get the true coordinate of one of the image coordinates it can be done via:
            c+image.c-1
        where:
            c = the x or y coordinate inside the image from 1 to width
            image = the image table
            image.c = image.x/y depending on what c is
        the -1 must be there as the inner-image co-ords start at 1, not 0.
]]
image.getImage = function(imgtab, name)
    local data = imgtab.data
    for i=1,#data do
        local tab = data[i]
        if tab[1] == "image" then
            if tab[2] == name then
                local x1 = tonumber(tab[3])
                local y1 = tonumber(tab[4])
                local x2 = tonumber(tab[5])
                local y2 = tonumber(tab[6])
                local img = {}
                img.x = x1
                img.y = y1
                img.width = x2-x1+1
                img.height = y2-y1+1
                for x=x1,x2 do
                    for y=y1,y2 do
                        if imgtab[x] ~= nil then
                            local char = imgtab[x][y]
                            if char ~= nil then
                                img[x-x1+1][y-y1+1] = char
                            end
                        end
                    end
                end
                return img
            end
        end
    end
    return nil
end

billy.image = image

local bufferAPI = {}
bufferAPI.curCols = {} --almost useless, saves presents of "colour" combinations when they are used - character, background and text colour.

bufferAPI.buffer_details = {1, 1, colors.black, colors.white, nil}
local sw,sh = term.getSize()

bufferAPI.getColorTab = function(char, background, text)
        if billy.bufferAPI.curCols[char] ~= nil then
                if billy.bufferAPI.curCols[char][background] ~= nil then
                        if billy.bufferAPI.curCols[char][background][text] ~= nil then
                                return billy.bufferAPI.curCols[char][background][text]
                        end
                end
        end
        return nil
end

bufferAPI.addColorTab = function(col)
        local char = col.char
        local background = col.background
        local text = col.text
        if billy.bufferAPI.getColorTab(char, background, text) == nil then
                if billy.bufferAPI.curCols[char] == nil then billy.bufferAPI.curCols[char] = {} end
                if billy.bufferAPI.curCols[char][background] == nil then billy.bufferAPI.curCols[char][background] = {} end
                billy.bufferAPI.curCols[char][background][text] = col
                return true
        end
        return false
end

bufferAPI.createColor = function(char, background, text)
        --sleep(0)
        local col = billy.bufferAPI.getColorTab(char, background, text)
        if col == nil then
                col = {}
                col.char = char
                col.background = background
                col.text = text
                billy.bufferAPI.addColorTab(col)
        end
        return col
end

bufferAPI.createPixel = function(x, y, col)
        local pixel = {}
        pixel.x = x
        pixel.y = y
        pixel.col = col
        pixel.compare = function(self, col)
                return self.col == col
        end
        return pixel
end


bufferAPI.createBuffer = function()
        local buffer = {}
        buffer.width = sw
        buffer.height = height
        buffer.changes = {}
        buffer.changed = {}
        buffer.term = term

        billy.bufferAPI.buffer_details[5] = buffer
        for x=1,sw do
                buffer[x] = {}
                buffer.changes[x] = {}
                for y=1,sh do
                        --print("x="..x..", y="..y)
                        buffer[x][y] = billy.bufferAPI.createPixel(x, y, billy.bufferAPI.createColor(" ", colors.black, colors.white))
                        buffer.changes[x][y] = false
                end
        end

        buffer.get = function(self, x, y)
                if self[x] ~= nil then
                        if self[x][y] ~= nil then
                                return self[x][y]
                        end
                end
                return nil
        end

        buffer.check = function(self, x, y)
                if self.changes[x] ~= nil then
                        if self.changes[x][y] ~= nil then
                                return self.changes[x][y]
                        end
                end
                return false
        end

        buffer.set = function(self, x, y, col)
                local pixel = self:get(x,y)
                if pixel ~= nil then
                        if not pixel:compare(col) then
                                pixel.col = col
                                if not self:check(x,y) then
                                        self.changed[#self.changed + 1] = {x,y}
                                        if self.changes[x] == nil then self.changes[x] = {} end
                                        self.changes[x][y] = true
                                end
                        end
                end
        end

        buffer.render = function(self)
                for i=1,#self.changed do
                        local pos = self.changed[i]
                        self.changes[pos[1]][pos[2]] = false
                        local pixel = self[pos[1]][pos[2]]
                        self.term.setCursorPos(pixel.x, pixel.y)
                        self.term.setBackgroundColor(pixel.col.background)
                        self.term.setTextColor(pixel.col.text)
                        self.term.write(pixel.col.char)
                end
                term.setCursorPos(1, 13)
                term.setBackgroundColor(colors.black)
                term.setTextColor(colors.white)
                print(#self.changed.." pixels changed")
                self.changed = {}
        end

        buffer.setBuffer = function(self)
                buffer_detials[5] = self
        end

        buffer.setCursorPos = function(x, y)
                billy.bufferAPI.buffer_details[1] = x
                billy.bufferAPI.buffer_details[2] = y
        end

        buffer.setBackgroundColor = function(col)
                billy.bufferAPI.buffer_details[3] = col
        end

        buffer.setTextColor = function(col)
                billy.bufferAPI.buffer_details[4] = col
        end

        buffer.getSize = function()
                local buffer = billy.bufferAPI.buffer_details[5]
                if buffer == nil then print("NIL_BUFFER") end
                return billy.bufferAPI.buffer_details[5].width, billy.bufferAPI.buffer_details[5].height
        end

        buffer.write = function(char)
                char = char:sub(1,1)
                local col = billy.bufferAPI.createColor(char, billy.bufferAPI.buffer_details[3], billy.bufferAPI.buffer_details[4])
                local buffer = billy.bufferAPI.buffer_details[5]
                if buffer ~= nil then
                        buffer:set(billy.bufferAPI.buffer_details[1], billy.bufferAPI.buffer_details[2], col)
                end
        end

        buffer.clear = function()
                billy.bufferAPI.buffer_details[5]:reset()
        end

        buffer.reset = function(self)
                local buffer = self
                for x=1,self.width do
                        buffer[x] = {}
                        buffer.changes[x] = {}
                        for y=1,sh do
                                --print("x="..x..", y="..y)
                                local pixel = billy.bufferAPI.createPixel(x, y, billy.bufferAPI.createColor(" ", billy.bufferAPI.buffer_details[3], colors.white))
                                term.setCursorPos(x, y)
                                term.setBackgroundColor(pixel.col.background)
                                term.setTextColor(pixel.col.text)
                                term.write(pixel.col.char)
                                buffer[x][y] = pixel

                                buffer.changes[x][y] = false
                        end
                end
                buffer.changes = {}
                buffer.changed = {}
        end

        return buffer
end

billy.bufferAPI = bufferAPI
billy.buffer = billy.bufferAPI.createBuffer()

local args = {...}
if #args > 0 then

    shell.run(unpack(args))
    billy.load()

    local pause = 0.05
    local on = true
    local timer = os.startTimer(pause)
    while on do
        local event,p1,p2,p3 = os.pullEvent()
        if event == "timer" and p1 == timer then
            billy.time = billy.time + 1
            billy.update()
            if billy.draw() then
                billy.buffer:render()
            end
        elseif event == "key" and billy.keys.used[p1] == true then
            if billy.keys.quit == p1 then
                billy.quit()
                on = false
            end
        else
            billy.event(event, p1, p2, p3)
        end
        if on then
            timer = os.startTimer(pause)
        end
    end
else
    print("Error: No program entered")
end