Punished Bernadetta's Minimap w/ Positional Color Caching

main.lua

function init()
  grassColors = {
    {99 / 255, 146 / 255, 103 / 255},
    {84 / 255, 127 / 255, 86 / 255},
    {70 / 255, 107 / 255, 69 / 255}
  }

  map_cache = {}

  resolution = 32
  squareSize = 10
  area = 50
  height = 50

  uiSize = resolution * squareSize
  maxDist = height * 2
end

function draw()
  local map_square_x = 0
  for x = math.floor(area / 2) * -1, math.floor(area / 2), area / resolution do
    map_square_x = map_square_x + 1
    local map_square_y = 0
    for y = math.floor(area / 2) * -1, math.floor(area / 2), area / resolution do
      map_square_y = map_square_y + 1
      local player_position = GetPlayerTransform().pos
      local color = get_color(player_position[1] + x, player_position[3] + y)
      UiPush()
      UiColor(color.r, color.g, color.b)
      UiTranslate(map_square_x * squareSize, map_square_y * squareSize)
      UiAlign("left top")
      UiRect(squareSize, squareSize)
      UiPop()
    end
  end
end

function get_color(x, y)
  -- try to get the cached color at this position
  local cached_color = get_cached_color(x, y)
  if cached_color ~= nil then
    return cached_color
  end

  -- if there wasn't a color cached at this position, get the color and cache it
  --DebugPrint(GetTime() .. ": computing " .. get_cache_key(x, y))
  local color = compute_color_at_position(x, y)
  set_cached_color(x, y, color.r, color.g, color.b)
  return color
end

function compute_color_at_position(x, y)
  local pos = Vec(x, height, y)
  local hit, dist, normal, shape = QueryRaycast(pos, Vec(0, -1, 0), maxDist)
  if hit then
    local hitPoint = VecAdd(pos, VecScale(Vec(0, -1, 0), dist))
    local mat, r, g, b = GetShapeMaterialAtPosition(shape, hitPoint)

    --Thanks Mathias Elgaard for this code
    if r + g + b == 0 then
      local randomMat = grassColors[math.floor((hitPoint[1] * hitPoint[2] * hitPoint[3]) % 3) + 1]
      r, g, b = randomMat[1], randomMat[2], randomMat[3]
    end

    local value = 0.75 + math.min(hitPoint[2] / 10, 10) * 0.25
    return { r = r * value, g = g * value, b = b * value }
  else
    return { r = 0, g = 0, b = 0 }
  end
end

function get_cache_key(x, y)
  return string.format("%.1f", round(x, 0.5)) .. "," .. string.format("%.1f", round(y, 0.5))
end

function get_cached_color(x, y)
  local color = map_cache[get_cache_key(x, y)]
  if color == nil then
    return nil
  end
  return { r = color.r, g = color.g, b = color.b }
end

function set_cached_color(x, y, r, g, b)
  map_cache[get_cache_key(x, y)] = { r = r, g = g, b = b }
end

function round(exact, quantum)
  local quant,frac = math.modf(exact/quantum)
  return quantum * (quant + (frac > 0.5 and 1 or 0))
end