modularizing

flexlove/ImageCache.lua

@@ -0,0 +1,157 @@
+--[[
+ImageCache.lua - Image caching system for FlexLove
+Provides efficient image loading and caching with memory management
+]]
+
+-- ====================
+-- ImageCache
+-- ====================
+
+---@class ImageCache
+---@field _cache table<string, {image: love.Image, imageData: love.ImageData?}>
+local ImageCache = {}
+ImageCache._cache = {}
+
+--- Normalize a file path for consistent cache keys
+---@param path string -- File path to normalize
+---@return string -- Normalized path
+local function normalizePath(path)
+  -- Remove leading/trailing whitespace
+  path = path:match("^%s*(.-)%s*$")
+  -- Convert backslashes to forward slashes
+  path = path:gsub("\\", "/")
+  -- Remove redundant slashes
+  path = path:gsub("/+", "/")
+  return path
+end
+
+--- Load an image from file path with caching
+--- Returns cached image if already loaded, otherwise loads and caches it
+---@param imagePath string -- Path to image file
+---@param loadImageData boolean? -- Optional: also load ImageData for pixel access (default: false)
+---@return love.Image|nil -- Image object or nil on error
+---@return string|nil -- Error message if loading failed
+function ImageCache.load(imagePath, loadImageData)
+  if not imagePath or type(imagePath) ~= "string" or imagePath == "" then
+    return nil, "Invalid image path: path must be a non-empty string"
+  end
+
+  local normalizedPath = normalizePath(imagePath)
+
+  -- Check if already cached
+  if ImageCache._cache[normalizedPath] then
+    return ImageCache._cache[normalizedPath].image, nil
+  end
+
+  -- Try to load the image
+  local success, imageOrError = pcall(love.graphics.newImage, normalizedPath)
+  if not success then
+    return nil, string.format("Failed to load image '%s': %s", imagePath, tostring(imageOrError))
+  end
+
+  local image = imageOrError
+  local imgData = nil
+
+  -- Load ImageData if requested
+  if loadImageData then
+    local dataSuccess, dataOrError = pcall(love.image.newImageData, normalizedPath)
+    if dataSuccess then
+      imgData = dataOrError
+    end
+  end
+
+  -- Cache the image
+  ImageCache._cache[normalizedPath] = {
+    image = image,
+    imageData = imgData,
+  }
+
+  return image, nil
+end
+
+--- Get a cached image without loading
+---@param imagePath string -- Path to image file
+---@return love.Image|nil -- Cached image or nil if not found
+function ImageCache.get(imagePath)
+  if not imagePath or type(imagePath) ~= "string" then
+    return nil
+  end
+
+  local normalizedPath = normalizePath(imagePath)
+  local cached = ImageCache._cache[normalizedPath]
+  return cached and cached.image or nil
+end
+
+--- Get cached ImageData for an image
+---@param imagePath string -- Path to image file
+---@return love.ImageData|nil -- Cached ImageData or nil if not found
+function ImageCache.getImageData(imagePath)
+  if not imagePath or type(imagePath) ~= "string" then
+    return nil
+  end
+
+  local normalizedPath = normalizePath(imagePath)
+  local cached = ImageCache._cache[normalizedPath]
+  return cached and cached.imageData or nil
+end
+
+--- Remove a specific image from cache
+---@param imagePath string -- Path to image file to remove
+---@return boolean -- True if image was removed, false if not found
+function ImageCache.remove(imagePath)
+  if not imagePath or type(imagePath) ~= "string" then
+    return false
+  end
+
+  local normalizedPath = normalizePath(imagePath)
+  if ImageCache._cache[normalizedPath] then
+    -- Release the image
+    local cached = ImageCache._cache[normalizedPath]
+    if cached.image then
+      cached.image:release()
+    end
+    if cached.imageData then
+      cached.imageData:release()
+    end
+    ImageCache._cache[normalizedPath] = nil
+    return true
+  end
+  return false
+end
+
+--- Clear all cached images
+function ImageCache.clear()
+  -- Release all images
+  for path, cached in pairs(ImageCache._cache) do
+    if cached.image then
+      cached.image:release()
+    end
+    if cached.imageData then
+      cached.imageData:release()
+    end
+  end
+  ImageCache._cache = {}
+end
+
+--- Get cache statistics
+---@return {count: number, memoryEstimate: number} -- Cache stats
+function ImageCache.getStats()
+  local count = 0
+  local memoryEstimate = 0
+
+  for path, cached in pairs(ImageCache._cache) do
+    count = count + 1
+    if cached.image then
+      local w, h = cached.image:getDimensions()
+      -- Estimate: 4 bytes per pixel (RGBA)
+      memoryEstimate = memoryEstimate + (w * h * 4)
+    end
+  end
+
+  return {
+    count = count,
+    memoryEstimate = memoryEstimate,
+  }
+end
+
+return ImageCache