Anim Editor: added more animation interpolation types, greyed out timeline that isn't part of the animation

Data/Scripts/901_Anim utilities/001_Anim utilities.rb

@@ -22,16 +22,14 @@ class Bitmap
     end
   end
 
-  # TODO: Add more curve types once it's decided which ones they are. See
-  #       INTERPOLATION_TYPES.
   def draw_interpolation_line(x, y, width, height, gradient, type, color)
+    start_x = x
+    end_x = x + width - 1
+    start_y = (gradient) ? y + height - 1 : y
+    end_y = (gradient) ? y : y + height - 1
     case type
     when :linear
       # NOTE: https://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm
-      start_x = x
-      end_x = x + width - 1
-      start_y = (gradient) ? y + height - 1 : y
-      end_y = (gradient) ? y : y + height - 1
       dx = end_x - start_x
       dy = -((end_y - start_y).abs)
       error = dx + dy
@@ -52,6 +50,40 @@ class Bitmap
           draw_y += (gradient) ? -1 : 1
         end
       end
+    when :ease_in, :ease_out, :ease_both   # Quadratic
+      start_y = y + height - 1
+      end_y = y
+      points = []
+      (width + 1).times do |frame|
+        x = frame / width.to_f
+        case type
+        when :ease_in
+          points[frame] = (end_y - start_y) * x * x
+        when :ease_out
+          points[frame] = (end_y - start_y) * (1 - ((1 - x) * (1 - x)))
+        when :ease_both
+          if x < 0.5
+            points[frame] = (end_y - start_y) * x * x * 2
+          else
+            points[frame] = (end_y - start_y) * (1 - (((-2 * x) + 2) * ((-2 * x) + 2) / 2))
+          end
+        end
+        points[frame] = points[frame].round
+      end
+      width.times do |frame|
+        line_y = points[frame]
+        if frame == 0
+          line_height = 1
+        else
+          line_height = [(points[frame] - points[frame - 1]).abs, 1].max
+        end
+        if !gradient   # Going down
+          line_y = -(height - 1) - line_y - line_height + 1
+        end
+        fill_rect(start_x + frame, start_y + line_y, 1, line_height, color)
+      end
+    else
+      raise _INTL("Unknown interpolation type {1}.", type)
     end
   end
 end