Gem-miner example with Comments

-- Example gem-miner by 1lann
-- Free to modify, use and whatever without my permission or credit!

if not term.isColor() then
    print("Not available for use on normal computers")
end
-- Just a quick heads-up
print("Mine all of the yellow gems!")
sleep(3)

-- Declare variables
local score = 0
local yellows = {}
local numYellows = 0
-- Configurable
local possibilities = {colors.orange, colors.lightBlue, colors.lime, colors.yellow}

local function generateBoard()
    term.clear()
    term.setCursorBlink(false)
    local width, height = term.getSize()
    -- Loop through every pixel on the screen except for top row
    -- Note the variable names I used for the current pixel
    for y = 2, height do
        for x = 1, width do
            -- Generate random color
            local curColor = possibilities[math.random(1,#possibilities)]
            -- If the color is yellow then...
            if curColor == colors.yellow then
                -- Set an index of the yellows table to contain the coordinates of the pixel
                -- I used the index to contain the data to remove the need of a loop to check
                -- and for effeciency purposes.
                yellows[tostring(x) .. "," .. tostring(y)] = true
                -- Register a yellow gem
                numYellows = numYellows+1
            end

            -- Set the cursor position
            term.setCursorPos(x, y)
            -- Set the color
            term.setBackgroundColor(curColor)
            -- Using term.write as it is more effecient and is faster
            term.write(" ")
        end
    end
end

-- We'll just get on and generate the board
generateBoard()

local function printScore(score)
    -- Set color and positioning
    term.setCursorPos(37,1)
    term.setBackgroundColor(colors.gray)
    term.setTextColor(colors.white)
    -- Print out score over the number of yellow gems
    term.write("Score: " .. tostring(score).."/"..tostring(numYellows))
    -- If the user has gotten all of the gems then signify to quit!
    if score >= numYellows then return true end
end

local function mainGame()
    -- Clear out top bar for stats
    term.setCursorPos(1,1)
    term.setBackgroundColor(colors.gray)

    term.clearLine()
    -- Print close button and make it noticeable.
    term.setTextColor(colors.red)
    term.write("[X] ")
    -- Now print the program name
    term.setTextColor(colors.white)
    term.write("Gem-miner example program!")
    -- Print out 0 score
    printScore(0)
    -- Main game loop
    while true do
        -- Only get mouse_click events and the x and y events
        -- I'm going to ignore which button was pressed in this example
        local e, _, x, y = os.pullEvent()
        if e == "mouse_click" then
            -- Checking if the pixel clicked was yellow...
            if yellows[tostring(x)..","..tostring(y)] then
                -- If so then increment the score!
                score=score+1
                -- Print it out!
                if printScore(score) then
                    -- If printScore returns true then,
                    -- the user has collected all of the gems!
                    -- Break out of the loop to finish the game
                    break
                end
                -- Clear the pixel/gem
                term.setBackgroundColor(colors.black)
                term.setCursorPos(x,y)
                term.write(" ")
                -- Delete the gem from the database
                yellows[tostring(x)..","..tostring(y)] = nil
            -- Check if the close button was pressed
            -- Round brackets are used to prevent confusion
            -- Further Explaination: I check if the row clicked was the first
            -- (Meaning the top bar) and the limits were within the first 3 characters
            -- (Since [X] is 3 characters long)
            elseif (y == 1) and (x >= 1) and (x <= 3) then
                -- Break the loop to signify ending of game
                break
            end
        end
    end
    -- Loop has quit, meaning user ended the game
    -- Print out ending stuffs.
    term.setBackgroundColor(colors.black)
    term.clear()
    term.setTextColor(colors.yellow)
    term.setCursorPos(1,1)
    -- If the user has won then, congrats!
    if score >= numYellows then
        print("Congratulations, you win!")
    end
    print("Thanks for trying out gem-miner")
    -- Just incase, shouldn't be necessary
    return
end

-- We'll just run the mainGame
mainGame()
-- Just incase, shouldn't be necessary
return