Refactor buildCatalogue and monitor drawing functions for improved performance and reduced flickering

inventoryManager.lua

@@ -38,15 +38,33 @@ local function scanInventory(deviceName)
 end
 
 -- Build a full catalogue: itemName -> { {chest=name, total=N}, ... }
+-- Scans all chests in parallel for speed
 local function buildCatalogue()
-    local catalogue = {}  -- itemName -> list of {chest, total}
-    for _, chest in ipairs(getChests()) do
-        local contents = scanInventory(chest)
-        for itemName, info in pairs(contents) do
+    local chests = getChests()
+    local results = {}  -- index -> { chest=name, contents={} }
+
+    -- Build parallel scan tasks
+    local tasks = {}
+    for i, chest in ipairs(chests) do
+        results[i] = { chest = chest, contents = {} }
+        tasks[i] = function()
+            results[i].contents = scanInventory(chest)
+        end
+    end
+
+    -- Run all scans simultaneously
+    if #tasks > 0 then
+        parallel.waitForAll(table.unpack(tasks))
+    end
+
+    -- Merge results into catalogue
+    local catalogue = {}
+    for _, result in ipairs(results) do
+        for itemName, info in pairs(result.contents) do
             if not catalogue[itemName] then
                 catalogue[itemName] = {}
             end
-            table.insert(catalogue[itemName], { chest = chest, total = info.total })
+            table.insert(catalogue[itemName], { chest = result.chest, total = info.total })
         end
     end
     return catalogue
@@ -57,6 +75,7 @@ end
 -------------------------------------------------
 
 local mon = nil
+local buf = nil  -- offscreen buffer to prevent flickering
 
 local function setupMonitor()
     mon = peripheral.wrap(MONITOR_SIDE)
@@ -66,45 +85,52 @@ local function setupMonitor()
     return true
 end
 
--- Helpers
+-- Drawing target (buf or mon, set in drawDashboard)
+local draw = nil
+
+-- Helpers (draw to buffer)
 local function monWrite(x, y, text, fg, bg)
-    mon.setCursorPos(x, y)
-    if fg then mon.setTextColor(fg) end
-    if bg then mon.setBackgroundColor(bg) end
-    mon.write(text)
+    draw.setCursorPos(x, y)
+    if fg then draw.setTextColor(fg) end
+    if bg then draw.setBackgroundColor(bg) end
+    draw.write(text)
 end
 
 local function monFill(y, color)
-    local w, _ = mon.getSize()
-    mon.setCursorPos(1, y)
-    mon.setBackgroundColor(color)
-    mon.write(string.rep(" ", w))
+    local w, _ = draw.getSize()
+    draw.setCursorPos(1, y)
+    draw.setBackgroundColor(color)
+    draw.write(string.rep(" ", w))
 end
 
 local function monCenter(y, text, fg, bg)
-    local w, _ = mon.getSize()
+    local w, _ = draw.getSize()
     local x = math.floor((w - #text) / 2) + 1
     monWrite(x, y, text, fg, bg)
 end
 
 local function monBar(x, y, width, ratio, barColor, bgColor)
     local filled = math.floor(ratio * width)
-    mon.setCursorPos(x, y)
-    mon.setBackgroundColor(barColor)
-    mon.write(string.rep(" ", filled))
-    mon.setBackgroundColor(bgColor)
-    mon.write(string.rep(" ", width - filled))
+    draw.setCursorPos(x, y)
+    draw.setBackgroundColor(barColor)
+    draw.write(string.rep(" ", filled))
+    draw.setBackgroundColor(bgColor)
+    draw.write(string.rep(" ", width - filled))
 end
 
--- Draw the full dashboard
+-- Draw the full dashboard (double-buffered)
 local function drawDashboard()
     if not mon then return end
 
     local w, h = mon.getSize()
 
-    -- Clear
-    mon.setBackgroundColor(colors.black)
-    mon.clear()
+    -- Create offscreen buffer
+    buf = window.create(mon, 1, 1, w, h, false)
+    draw = buf
+
+    -- Clear buffer
+    draw.setBackgroundColor(colors.black)
+    draw.clear()
 
     -- ===== Title bar =====
     monFill(1, colors.blue)
@@ -221,6 +247,10 @@ local function drawDashboard()
     -- Bottom accent
     monFill(h, colors.blue)
     monCenter(h, " \4 Auto-Sort Active \4 ", colors.lightBlue, colors.blue)
+
+    -- Flush buffer to monitor in one go (no flicker)
+    buf.setVisible(true)
+    buf.setVisible(false)
 end
 
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