Parse key pressure events

Author: xaviershay

lib/coremidi.rb

@@ -16,6 +16,7 @@ def self.parse(data)
       klass = {
         Constants::NOTE_ON        => lambda {|data| (data[Events::NoteOn.members.index("velocity")] == 0) ? Events::NoteOff : Events::NoteOn },
         Constants::NOTE_OFF       => Events::NoteOff,
+        Constants::KEY_PRESSURE   => Events::KeyPressure,
         Constants::PROGRAM_CHANGE => Events::ProgramChange
       }.detect {|constant, klass|
         data[0] & Constants::TYPE == constant 
@@ -33,6 +34,7 @@ def self.parse(data)
   module Events
     class NoteOn        < Struct.new(:channel, :pitch, :velocity); end;
     class NoteOff       < Struct.new(:channel, :pitch, :velocity); end;
+    class KeyPressure   < Struct.new(:channel, :pitch, :pressure); end;
     class ProgramChange < Struct.new(:channel, :preset);           end; 
     class Unknown       < Struct.new(:data);                       end;
   end

lib/coremidi/constants.rb

@@ -6,6 +6,7 @@ module Constants
 
     NOTE_OFF       = 0x80
     NOTE_ON        = 0x90
+    KEY_PRESSURE   = 0xA0
     PROGRAM_CHANGE = 0xC0
   end
 end

spec/parsing_spec.rb

@@ -25,6 +25,8 @@ def self.it_parses(data, expected)
   it_parses([0x81, 0x3C, 0x40], CoreMIDI::Events::NoteOff.new(0x01, 0x3C, 0x40))  # Channel 1, Middle C, half velocity
   it_parses([0xC0, 0x01], CoreMIDI::Events::ProgramChange.new(0x00, 0x01)) # Channel 0, Preset #1
   it_parses([0xC1, 0x02], CoreMIDI::Events::ProgramChange.new(0x01, 0x02)) # Channel 1, Preset #2
+  it_parses([0xA0, 0x3C, 0x64], CoreMIDI::Events::KeyPressure.new(0x00, 0x3C, 0x64)) # Channel 0, Middle C, half pressure
+  it_parses([0xA1, 0x3C, 0xFF], CoreMIDI::Events::KeyPressure.new(0x01, 0x3C, 0xFF)) # Channel 1, Middle C, full pressure
 
   # This is technically a NoteOn event, but convention uses it most often in place of a note off event (setting velocity to 0)
   it_parses([0x90, 0x3C, 0x00], CoreMIDI::Events::NoteOff.new(0x00, 0x3C, 0x00))  # Channel 0, Middle C, no velocity