Add Random Palette example

Author: dacap

Random Palette.lua

@@ -0,0 +1,28 @@
+----------------------------------------------------------------------
+-- Randomize colors in the palette.
+----------------------------------------------------------------------
+
+local spr = app.activeSprite
+if not spr then
+  return app.alert("There is no active sprite")
+end
+
+-- Each Palette:setColor() call will be grouped in one undoable
+-- transaction. In this way the Edit > Undo History will contain only
+-- one item that can be undone.
+app.transaction(
+  function()
+    math.randomseed(os.time())
+    local pal = spr.palettes[1]
+    for i = 0,#pal-1 do
+      -- Here we change each color of the palette with random RGB
+      -- values from 0-255 for each Red, Green, Blue component.
+      pal:setColor(i, Color{ r=math.random(256)-1,
+                             g=math.random(256)-1,
+                             b=math.random(256)-1 })
+    end
+  end)
+
+-- Here we redraw the screen to show the new palette, in a future this
+-- shouldn't be necessary, but just in case...
+app.refresh()