Add new example to stack all sprites in one

Author: dacap

Stack All Sprites in One.lua

@@ -0,0 +1,34 @@
+-- This example shows how to create a new sprite stacking all the
+-- other sprites each in one layer.
+
+if #app.sprites < 1 then
+  return app.alert "You should have at least one sprite opened"
+end
+
+local bounds = Rectangle()
+for i,sprite in ipairs(app.sprites) do
+  bounds = bounds:union(sprite.bounds)
+end
+
+local function getTitle(filename)
+  return filename:match("^.+/(.+)$")
+end
+
+local newSprite = Sprite(bounds.width, bounds.height)
+local firstLayer = newSprite.layers[1]
+newSprite:deleteCel(newSprite.cels[1])
+for i,sprite in ipairs(app.sprites) do
+  if sprite ~= newSprite then
+    while #newSprite.frames < #sprite.frames do
+      newSprite:newEmptyFrame()
+    end
+    local newLayer = newSprite:newLayer()
+    newLayer.name = getTitle(sprite.filename)
+    for j,frame in ipairs(sprite.frames) do
+      local cel = newSprite:newCel(newLayer, frame)
+      cel.image:drawSprite(sprite, frame)
+    end
+  end
+end
+newSprite:deleteLayer(firstLayer)
+app.activeFrame = 1