Add some tests for Simple and Alpha Compositing inks

scripts/inks.lua

@@ -0,0 +1,87 @@
+-- Copyright (C) 2020  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')
+
+local pencil = "pencil"
+
+function test_inks(colorMode)
+  -- Test ink over a transparent sprite
+  local s = Sprite(3, 3, colorMode)
+  local p, a, b, c, d
+  if colorMode == ColorMode.GRAY then
+    local function gray(g)
+      return app.pixelColor.graya(g, 255)
+    end
+    p = s.palettes[1]
+    a, b, c, d = gray(0), gray(64), gray(128), gray(255)
+  else
+    p = Palette()
+    p:resize(4)
+    p:setColor(0, Color(0, 0, 0))
+    p:setColor(1, Color(64, 64, 64))
+    p:setColor(2, Color(128, 128, 128))
+    p:setColor(3, Color(255, 255, 255))
+    s:setPalette(p)
+
+    a, b, c, d = 0, 1, 2, 3
+    if colorMode == ColorMode.RGB then
+      a = p:getColor(a).rgbaPixel
+      b = p:getColor(b).rgbaPixel
+      c = p:getColor(c).rgbaPixel
+      d = p:getColor(d).rgbaPixel
+    end
+  end
+
+  -- With simple ink opacity doesn't have affect (always the color)
+  local opacities = { 0, 128, 255 }
+  for i = 1,#opacities do
+    print(opacities[i])
+    expect_img(app.activeImage,
+               { 0, 0, 0,
+                 0, 0, 0,
+                 0, 0, 0 })
+    app.useTool{ tool=pencil, color=d, points={ Point(0, 0), Point(2, 2) },
+                 ink=Ink.SIMPLE, opacity=opacities[i] }
+    expect_img(app.activeImage,
+               { d, 0, 0,
+                 0, d, 0,
+                 0, 0, d })
+    if i < #opacities then app.undo() end
+  end
+
+  -- Check that painting with transparent index (color) on a
+  -- transparent layer (using any value of opacity) with alpha
+  -- compositing doesn't modify pixels
+  for i = 1,#opacities do
+    app.useTool{ tool=pencil, color=0, points={ Point(1, 1) },
+                 ink=Ink.ALPHA_COMPOSITING, opacity=opacities[i] }
+    expect_img(app.activeImage,
+               { d, 0, 0,
+                 0, d, 0,
+                 0, 0, d })
+  end
+
+  -- Convert to background layer
+  app.command.BackgroundFromLayer()
+
+  app.useTool{ tool=pencil, color=d, points={ Point(0, 1), Point(2, 1) },
+               ink=Ink.ALPHA_COMPOSITING, opacity=64 }
+  expect_img(app.activeImage,
+             { d, a, a,
+               b, d, b,
+               a, a, d })
+
+  app.useTool{ tool=pencil, color=d, points={ Point(0, 1) },
+               ink=Ink.ALPHA_COMPOSITING, opacity=86 }
+  expect_img(app.activeImage,
+             { d, a, a,
+               c, d, b,
+               a, a, d })
+end
+
+test_inks(ColorMode.RGB)
+test_inks(ColorMode.GRAY)
+test_inks(ColorMode.INDEXED)

scripts/test_utils.lua

@@ -60,11 +60,11 @@ function expect_img(image, expectedPixels)
 			      app.pixelColor.rgbaA(b)))
 	elseif image.colorMode == ColorMode.GRAY then
 	  print(string.format(' - Value A = gray(%d,%d)',
-			      app.pixelColor.grayG(a),
-			      app.pixelColor.grayA(a)))
+			      app.pixelColor.grayaV(a),
+			      app.pixelColor.grayaA(a)))
 	  print(string.format(' - Value B = gray(%d,%d)',
-			      app.pixelColor.grayV(b),
-			      app.pixelColor.grayA(b)))
+			      app.pixelColor.grayaV(b),
+			      app.pixelColor.grayaA(b)))
 	else
 	  print(' - Value A = ' .. tostring(a))
 	  print(' - Value B = ' .. tostring(b))