modularizing

flexlove/ImageDataReader.lua

@@ -0,0 +1,113 @@
+--[[
+ImageDataReader.lua - Image data reading utilities for FlexLove
+Provides functions to load and read pixel data from images
+]]
+
+-- ====================
+-- Error Handling Utilities
+-- ====================
+
+--- Standardized error message formatter
+---@param module string -- Module name (e.g., "Color", "Theme", "Units")
+---@param message string -- Error message
+---@return string -- Formatted error message
+local function formatError(module, message)
+  return string.format("[FlexLove.%s] %s", module, message)
+end
+
+-- ====================
+-- ImageDataReader
+-- ====================
+
+local ImageDataReader = {}
+
+--- Load ImageData from a file path
+---@param imagePath string
+---@return love.ImageData
+function ImageDataReader.loadImageData(imagePath)
+  if not imagePath then
+    error(formatError("ImageDataReader", "Image path cannot be nil"))
+  end
+
+  local success, result = pcall(function()
+    return love.image.newImageData(imagePath)
+  end)
+
+  if not success then
+    error(formatError("ImageDataReader", "Failed to load image data from '" .. imagePath .. "': " .. tostring(result)))
+  end
+
+  return result
+end
+
+--- Extract all pixels from a specific row
+---@param imageData love.ImageData
+---@param rowIndex number -- 0-based row index
+---@return table -- Array of {r, g, b, a} values (0-255 range)
+function ImageDataReader.getRow(imageData, rowIndex)
+  if not imageData then
+    error(formatError("ImageDataReader", "ImageData cannot be nil"))
+  end
+
+  local width = imageData:getWidth()
+  local height = imageData:getHeight()
+
+  if rowIndex < 0 or rowIndex >= height then
+    error(formatError("ImageDataReader", string.format("Row index %d out of bounds (height: %d)", rowIndex, height)))
+  end
+
+  local pixels = {}
+  for x = 0, width - 1 do
+    local r, g, b, a = imageData:getPixel(x, rowIndex)
+    table.insert(pixels, {
+      r = math.floor(r * 255 + 0.5),
+      g = math.floor(g * 255 + 0.5),
+      b = math.floor(b * 255 + 0.5),
+      a = math.floor(a * 255 + 0.5),
+    })
+  end
+
+  return pixels
+end
+
+--- Extract all pixels from a specific column
+---@param imageData love.ImageData
+---@param colIndex number -- 0-based column index
+---@return table -- Array of {r, g, b, a} values (0-255 range)
+function ImageDataReader.getColumn(imageData, colIndex)
+  if not imageData then
+    error(formatError("ImageDataReader", "ImageData cannot be nil"))
+  end
+
+  local width = imageData:getWidth()
+  local height = imageData:getHeight()
+
+  if colIndex < 0 or colIndex >= width then
+    error(formatError("ImageDataReader", string.format("Column index %d out of bounds (width: %d)", colIndex, width)))
+  end
+
+  local pixels = {}
+  for y = 0, height - 1 do
+    local r, g, b, a = imageData:getPixel(colIndex, y)
+    table.insert(pixels, {
+      r = math.floor(r * 255 + 0.5),
+      g = math.floor(g * 255 + 0.5),
+      b = math.floor(b * 255 + 0.5),
+      a = math.floor(a * 255 + 0.5),
+    })
+  end
+
+  return pixels
+end
+
+--- Check if a pixel is black with full alpha (9-patch marker)
+---@param r number -- Red (0-255)
+---@param g number -- Green (0-255)
+---@param b number -- Blue (0-255)
+---@param a number -- Alpha (0-255)
+---@return boolean
+function ImageDataReader.isBlackPixel(r, g, b, a)
+  return r == 0 and g == 0 and b == 0 and a == 255
+end
+
+return ImageDataReader