1 files changed, 49 insertions, 0 deletions
diff --git a/samples/07_advanced_rendering/10_blend_modes/app/main.rb b/samples/07_advanced_rendering/10_blend_modes/app/main.rb
new file mode 100644
index 0000000..7e28ba8
--- /dev/null
+++ b/samples/07_advanced_rendering/10_blend_modes/app/main.rb
@@ -0,0 +1,49 @@
+$gtk.reset
+
+def draw_blendmode args, mode
+  w = 160
+  h = w
+  args.state.x += (1280-w) / (args.state.blendmodes.length + 1)
+  x = args.state.x
+  y = (720 - h) / 2
+  s = 'sprites/blue-feathered.png'
+  args.outputs.sprites << { blendmode_enum: mode.value, x: x, y: y, w: w, h: h, path: s }
+  args.outputs.labels << [x + (w/2), y, mode.name.to_s, 1, 1, 255, 255, 255]
+end
+
+def tick args
+
+  # Different blend modes do different things, depending on what they
+  # blend against (in this case, the pixels of the background color).
+  args.state.bg_element ||= 1
+  args.state.bg_color ||= 255
+  args.state.bg_color_direction ||= 1
+  bg_r = (args.state.bg_element == 1) ? args.state.bg_color : 0
+  bg_g = (args.state.bg_element == 2) ? args.state.bg_color : 0
+  bg_b = (args.state.bg_element == 3) ? args.state.bg_color : 0
+  args.state.bg_color += args.state.bg_color_direction
+  if (args.state.bg_color_direction > 0) && (args.state.bg_color >= 255)
+    args.state.bg_color_direction = -1
+    args.state.bg_color = 255
+  elsif (args.state.bg_color_direction < 0) && (args.state.bg_color <= 0)
+    args.state.bg_color_direction = 1
+    args.state.bg_color = 0
+    args.state.bg_element += 1
+    if args.state.bg_element >= 4
+      args.state.bg_element = 1
+    end
+  end
+
+  args.outputs.background_color = [ bg_r, bg_g, bg_b, 255 ]
+
+  args.state.blendmodes ||= [
+    { name: :none,  value: 0 },
+    { name: :blend, value: 1 },
+    { name: :add,   value: 2 },
+    { name: :mod,   value: 3 },
+    { name: :mul,   value: 4 }
+  ]
+
+  args.state.x = 0  # reset this, draw_blendmode will increment it.
+  args.state.blendmodes.each { |blendmode| draw_blendmode args, blendmode }
+end