CraftOS-PC Graphics Mode terminal (requires readBDFFont)

gfxterm.lua

-- WARNING: Render crashes are lethal and will 100% kill the computer
local loadBDF = require "readBDFFont" -- get from https://gist.github.com/MCJack123/3cbce89640923b3c42d4d0a0b8eaa7b2

if term.setGraphicsMode == nil then error("This requires CraftOS-PC v1.2 or later.") end

local font, oldterm, gfxMode
local nativeTerm = term.native()
local oldSetGfx, oldGetGfx = term.setGraphicsMode, term.getGraphicsMode
local nativeWidth, nativeHeight = term.getSize()
nativeWidth = nativeWidth * 6
nativeHeight = nativeHeight * 9

local function log2(num) return math.floor(math.log10(num) / math.log10(2)) end

local function drawChar(x, y, ch, fg, bg, transparent)
    x=x-1
    y=y-1
    if x * font.bounds.width > nativeWidth or y * font.bounds.height > nativeHeight or x < 0 or y < 0 then return end
    local fch = font.chars[ch]
    if fch == nil then fch = font.chars[' '] end
    if transparent then
        local heightDiff = (font.bounds.height + font.bounds.y) - fch.bounds.height + font.bounds.y - fch.bounds.y
        for i,t in pairs(fch.bitmap) do if i <= font.bounds.height then for j,a in pairs(t) do if j <= font.bounds.width and a then 
            nativeTerm.setPixel(x*font.bounds.width+j-1, y*font.bounds.height+i+heightDiff-1, gfxMode == 2 and fg or log2(fg))
        end end end end
    else
        local pixelTable = {}
        for i = 1, font.bounds.height do pixelTable[i] = string.char(bg):rep(font.bounds.width) end
        local starty = (font.bounds.height - fch.bounds.height) - fch.bounds.y + font.bounds.y
        for i = 1, fch.bounds.height do
            if fch.bitmap[i] then
                pixelTable[i+starty] = string.char(bg):rep(fch.bounds.x)
                for j = 1, font.bounds.width-fch.bounds.x do
                    pixelTable[i+starty] = pixelTable[i+starty] .. string.char(fch.bitmap[i][j] and fg or bg)
                end
            end
        end
        local ypos = y*font.bounds.height+font.bounds.y
        while ypos < 0 do
            table.remove(pixelTable, 1)
            ypos=ypos+1
        end
        nativeTerm.drawPixels(x*font.bounds.width, ypos, pixelTable)
    end
end

local file
if #({...}) > 0 then file = fs.open(shell.resolve(({...})[1]), "r")
else file = fs.open(shell.resolve("font.bdf"), "r") end
if file == nil then error("Could not find font!") end
font = loadBDF(file.readAll())
file.close()

local backgroundColor = 15
local textColor = 0
local cursorX = 1
local cursorY = 1
local cursorBlink = true -- soon(tm)
local cursorShouldBlink = true
local cursorTimer = os.startTimer(0.5)
local width = math.floor(nativeWidth / font.bounds.width)
local height = math.floor(nativeHeight / font.bounds.height)
gfxMode = 0

local termBuffer = {}
local colorBuffer = {}
for i = 1, height do 
    termBuffer[i] = {}
    colorBuffer[i] = {}
    for j = 1, width do
        termBuffer[i][j] = " "
        colorBuffer[i][j] = {textColor, backgroundColor}
    end
end

local lastcx, lastcy = 1, 1
local function redrawCursor()
    if lastcx <= width and lastcy <= height then drawChar(lastcx, lastcy, termBuffer[lastcy][lastcx], colorBuffer[lastcy][lastcx][1], colorBuffer[lastcy][lastcx][2], false) end
    if cursorX <= width and cursorY <= height and cursorBlink and cursorShouldBlink then drawChar(cursorX, cursorY, '_', 0, 15, true) end
    lastcx, lastcy = cursorX, cursorY
end

local termObject = {
    write = function(text)
        if cursorY > height or cursorX > width then return end
        for c in text:gmatch(".") do
            termBuffer[cursorY][cursorX] = c
            colorBuffer[cursorY][cursorX] = {textColor, backgroundColor}
            drawChar(cursorX, cursorY, c, textColor, backgroundColor, false)
            cursorX = cursorX + 1
            if cursorX > width then break end
        end
        redrawCursor()
    end,
    blit = function(text, fg, bg)
        if #text ~= #fg or #fg ~= #bg then error("Arguments must be same length", 2) end
        if cursorY > height or cursorX > width then return end
        for i = 1, #text do
            textColor = (("0123456789abcdef"):find(fg:sub(i, i)) or (textColor + 1)) - 1
            backgroundColor = (("0123456789abcdef"):find(bg:sub(i, i)) or (backgroundColor + 1)) - 1
            termBuffer[cursorY][cursorX] = text:sub(i, i)
            colorBuffer[cursorY][cursorX] = {textColor, backgroundColor}
            drawChar(cursorX, cursorY, text:sub(i, i), textColor, backgroundColor, false)
            cursorX = cursorX + 1
            if cursorX > width then break end
        end
        redrawCursor()
    end,
    clear = function()
        for i = 1, height do 
            termBuffer[i] = {}
            colorBuffer[i] = {}
            for j = 1, width do
                termBuffer[i][j] = " "
                colorBuffer[i][j] = {textColor, backgroundColor}
                drawChar(j, i, " ", textColor, backgroundColor, false)
            end
        end
        redrawCursor()
    end,
    clearLine = function()
        if cursorY > height then return end
        for j = 1, width do
            termBuffer[cursorY][j] = " "
            colorBuffer[cursorY][j] = {textColor, backgroundColor}
            drawChar(j, cursorY, " ", textColor, backgroundColor, false)
        end
        redrawCursor()
    end,
    getCursorPos = function() return cursorX, cursorY end,
    setCursorPos = function(x, y) cursorX, cursorY = x, y end,
    getCursorBlink = function() return cursorShouldBlink end,
    setCursorBlink = function(b) cursorShouldBlink = b; redrawCursor() end,
    isColor = function() return true end,
    isColour = function() return true end,
    getSize = function() return width, height end,
    scroll = function(n)
        for _ = 1, n do 
            table.remove(termBuffer, 1)
            table.remove(colorBuffer, 1)
            local tr, cr = {}, {}
            for j = 1, width do
                tr[j] = " "
                cr[j] = {textColor, backgroundColor}
            end
            table.insert(termBuffer, tr)
            table.insert(colorBuffer, cr)
        end
        for y = 1, height do for x = 1, width do drawChar(x, y, termBuffer[y][x], colorBuffer[y][x][1], colorBuffer[y][x][2], false) end end
        redrawCursor()
    end,
    setTextColor = function(c) textColor = log2(c) end,
    setTextColour = function(c) textColor = log2(c) end,
    getTextColor = function() return bit.blshift(1, textColor) end,
    getTextColour = function() return bit.blshift(1, textColor) end,
    setBackgroundColor = function(c) backgroundColor = log2(c) end,
    setBackgroundColour = function(c) backgroundColor = log2(c) end,
    getBackgroundColor = function() return bit.blshift(1, backgroundColor) end,
    getBackgroundColour = function() return bit.blshift(1, backgroundColor) end,
    getPaletteColor = nativeTerm.getPaletteColor,
    getPaletteColour = nativeTerm.getPaletteColour,
    setPaletteColor = nativeTerm.setPaletteColor,
    setPaletteColour = nativeTerm.setPaletteColour,
    nativePaletteColor = nativeTerm.nativePaletteColor,
    nativePaletteColour = nativeTerm.nativePaletteColour,
    screenshot = nativeTerm.screenshot,
}

term.setGraphicsMode(1)
term.clear()
oldterm = term.redirect(termObject)
term.setGraphicsMode = function(mode)
    gfxMode = mode
    term.clear()
    if gfxMode == 2 then oldSetGfx(2) else oldSetGfx(1) end
    if gfxMode == 0 then for y = 1, height do for x = 1, width do drawChar(x, y, termBuffer[y][x], colorBuffer[y][x][1], colorBuffer[y][x][2], false) end end end
end
term.getGraphicsMode = function() return gfxMode end

parallel.waitForAny(function()
    while true do
        local ev = {os.pullEvent()}
        if ev[1] == "term_resize" then
            local oldw, oldh = width, height
            nativeWidth, nativeHeight = nativeTerm.getSize()
            nativeWidth = nativeWidth * 6
            nativeHeight = nativeHeight * 9
            width = math.floor(nativeWidth / font.bounds.width)
            height = math.floor(nativeHeight / font.bounds.height)
            if height > oldh then
                for i = oldh+1, height do
                    termBuffer[i] = {}
                    colorBuffer[i] = {}
                    for j = 1, oldw do
                        termBuffer[i][j] = ' '
                        colorBuffer[i][j] = {textColor, backgroundColor}
                    end
                end
            elseif height < oldh then
                for i = height+1, oldh do
                    termBuffer[i] = nil
                    colorBuffer[i] = nil
                end
            end
            if width > oldw then
                for i = 1, height do for j = oldw+1, width do
                    termBuffer[i][j] = ' '
                    colorBuffer[i][j] = {textColor, backgroundColor}
                end end
            elseif width < oldw then
                for i = 1, height do for j = width+1, oldw do
                    termBuffer[i][j] = nil
                    colorBuffer[i][j] = nil
                end end
            end
        elseif ev[1] == "timer" and ev[2] == cursorTimer then
            cursorBlink = not cursorBlink
            cursorTimer = os.startTimer(0.5)
            redrawCursor()
        end
    end
end, function() shell.run("/rom/programs/shell.lua") end)

term.setGraphicsMode = oldSetGfx
term.getGraphicsMode = oldGetGfx
term.redirect(oldterm)
term.setGraphicsMode(0)