hydraGfxApi

function createBuffer(width, height)
    local buffer = {}
    buffer["width"] = width
    buffer["height"] = height
    buffer["pixels"] = {}

    for i = 1, width * height, 1 do
        buffer["pixels"][i] = colors.black
    end

    return buffer
end

function clearBuffer(buffer, clearColor)
    for y = 1, buffer["height"], 1 do
        for x = 1, buffer["width"], 1 do
            setPixel(buffer, x, y, clearColor)
        end
    end
end

local function isOutOfBounds(buffer, x, y)
    return x < 0 or y < 0 or x > buffer["width"] or y > buffer["height"]
end

local function getBufferIndex(buffer, x, y)
    return y * buffer["width"] + x
end

function setPixel(buffer, x, y, color)
    if(isOutOfBounds(buffer, x, y)) then
        print("OOB! " .. tostring(x) .. "," .. tostring(y))
        return
    end

    local i = y * buffer["width"] + x
    buffer["pixels"][getBufferIndex(buffer, x, y)] = color
end

function getPixel(buffer, x, y)
    if(isOutOfBounds(buffer, x, y)) then
        print("OOB! " .. tostring(x) .. "," .. tostring(y))
        return nil
    end

    return buffer["pixels"][getBufferIndex(buffer, x, y)]
end

function drawLine(buffer, x1, y1, x2, y2, color)
    delta_x = x2 - x1
    ix = delta_x > 0 and 1 or -1
    delta_x = 2 * math.abs(delta_x)

    delta_y = y2 - y1
    iy = delta_y > 0 and 1 or -1
    delta_y = 2 * math.abs(delta_y)

    setPixel(buffer, x1, y1, color)

    if delta_x >= delta_y then
        error = delta_y - delta_x / 2

        while x1 ~= x2 do
            if (error >= 0) and ((error ~= 0) or (ix > 0)) then
                error = error - delta_x
                y1 = y1 + iy
            end

            error = error + delta_y
            x1 = x1 + ix

            setPixel(buffer, x1, y1, color)
        end
    else
        error = delta_x - delta_y / 2

        while y1 ~= y2 do
            if (error >= 0) and ((error ~= 0) or (iy > 0)) then
                error = error - delta_y
                x1 = x1 + ix
            end

            error = error + delta_x
            y1 = y1 + iy

            setPixel(buffer, x1, y1, color)
        end
    end
end

function drawToMonitor(buffer, monitor)
    local col = colors.black
    local prevCol = col
    for y = 1, buffer["height"], 1 do
        for x = 1, buffer["width"], 1 do
            col = getPixel(buffer, x, y)
            print(tostring(x) .. "," .. tostring(y) .. ":" .. tostring(col))
            if(col ~= prevCol) then
                monitor.setBackgroundColor(col)
                prevCol = col
            end
            monitor.setCursorPos(x, y)
            monitor.write(" ")
        end
    end
end