Add color conversion tests

scripts/color_convert.lua

@@ -0,0 +1,50 @@
+-- Copyright (C) 2019-2021  Igara Studio S.A.
+--
+-- This file is released under the terms of the MIT license.
+-- Read LICENSE.txt for more information.
+
+dofile('./test_utils.lua')
+
+-- this tests and ensures that the alpha-ness of a background
+-- layer is maintained when sprite conversion takes place from
+-- Indexed to RGB
+
+do
+  local sprite = Sprite(2, 2, ColorMode.INDEXED)
+  local pal = sprite.palettes[1]
+
+  assert(sprite.layers[1].isTransparent)
+  assert(sprite.colorMode == ColorMode.INDEXED)
+  assert(#pal == 256)
+
+  local color = pal:getColor(3)
+  color.alpha = 200
+  pal:setColor(3, color)
+
+  local image = sprite.cels[1].image
+  image:drawPixel(0, 0, pal:getColor(2))
+  image:drawPixel(0, 1, pal:getColor(3))
+  image:drawPixel(1, 0, pal:getColor(4))
+  image:drawPixel(1, 1, pal:getColor(5))
+
+  app.command.BackgroundFromLayer()
+
+  local layer = sprite.layers[1]
+  assert(layer.isTransparent == false)
+  assert(layer.name == "Background")
+
+  -- change color mode from Indexed to RGB
+  app.command.ChangePixelFormat {
+    format="rgb"
+  }
+
+  assert(sprite.colorMode == ColorMode.RGB)
+  image = sprite.cels[1].image
+
+  for x=0, 1, 1 do
+    for y=0, 1, 1 do
+      local pixel = image:getPixel(x, y)
+      assert(app.pixelColor.rgbaA(pixel) == 255)
+    end
+  end
+end