curve.rb in tickly-2.1.5

- old
+ new

@@ -20,32 +20,42 @@
       raise InvalidCurveError, "Curve expression contained no values" unless curve_expression[2]
       
       # Nuke7 sometimes produces curves where the command is a string literal 
       # within quotes, and it contains a trailing space
       cmd = curve_expression[1].to_s.strip
-      raise InvalidCurveError, "Curve expression should start with a 'curve' command" unless cmd == 'curve'
+      raise InvalidCurveError, "Curve expression should start with a 'curve' command" unless cmd =~ /^curve/
       
+      # Compute the curve increment or decrement. It looks like a modifier:
+      # "curve+5" means we have to add 5 to every value on the curve
+      xformer = lambda { |v| v} # Identity
+      if cmd =~ /^(curve)([+-])([\d\.]+)$/
+        operator = $2[0..1] # Ensure only one character gets through
+        modifier = $3.to_f
+        xformer = lambda{|v| v.send(operator, modifier) }
+      end
       
-      expand_curve(curve_expression)
+      expand_curve(curve_expression, &xformer)
     end
     
     # Returns each defined keyframe as a pair of a frame number and a value
     def each(&blk)
       @tuples.each(&blk)
     end
     
     private
     
-    def expand_curve(curve_expression)
+    def expand_curve(curve_expression, &post_lambda)
       # Replace the closing curly brace with a curly brace with space so that it gets caught by split
       atoms = curve_expression[2..-1] # remove the :c curly designator and the "curve" keyword
       
       @tuples = []
-      # Nuke saves curves very efficiently. x(keyframe_number) means that an uninterrupted sequence of values will start,
-      # after which values follow. When the curve is interrupted in some way a new x(keyframe_number) will signifu that we
-      # skip to that specified keyframe and the curve continues from there, in gap size defined by the last fragment.
-      # That is, x1 1 x3 2 3 4 will place 2, 3 and 4 at 2-frame increments.
+      # Nuke saves curves very efficiently. x(keyframe_number) means that an 
+      # uninterrupted sequence of values will start, after which values follow. 
+      # When the curve is interrupted in some way a new x(keyframe_number) will 
+      # signify that we skip to that specified keyframe and the curve continues
+      # from there, in gap size defined by the last fragment. That is, 
+      # x1 1 x3 2 3 4 will place 2, 3 and 4 at 2-frame increments.
       # Thanks to Michael Lester for explaining this.
       last_processed_keyframe = 1
       intraframe_gap_size = 1
       while atom = atoms.shift
         if atom =~ SECTION_START
@@ -53,10 +63,10 @@
           if @tuples.any?
             last_captured_frame = @tuples[-1][0]
             intraframe_gap_size = last_processed_keyframe - last_captured_frame
           end
         elsif  atom =~ KEYFRAME
-          @tuples << [last_processed_keyframe, $1.to_f]
+          @tuples << [last_processed_keyframe, yield($1.to_f)]
           last_processed_keyframe += intraframe_gap_size
         end
       end
     end
   end
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