Refactor Config to allow temporary command-line overrides

src/crab.cr

@@ -16,32 +16,41 @@ module Crab
 
   extend self
 
-  def run
+  def run : NoReturn
+    config = Config.new
+
     rom = nil
     bios = nil
-    fifo = false
     headless = false
 
     OptionParser.parse do |parser|
       parser.banner = "#{"crab".colorize.bold} - An accurate and readable Game Boy (Color) (Advance) emulator"
       parser.separator
-      parser.separator("Usage: bin/crab [BIOS] ROM")
+      parser.separator("Usage: bin/crab [BIOS] [ROM]")
       parser.separator
+      parser.separator("All command-line arguments serve as optional overrides to the config.")
       parser.on("-h", "--help", "Show the help message") do
         puts parser
         exit
       end
-      parser.on("--fifo", "Enable FIFO rendering") { fifo = true }
-      parser.on("--headless", "Don't open window or play audio") { headless = true }
+      parser.on("--run-bios", "Run the bios on startup") { config.args.run_bios = true }
+      parser.on("--skip-bios", "Skip the bios on startup") { config.args.run_bios = false }
+      parser.on("--fifo", "Enable per-pixel rendering for GBC") { config.args.fifo = true }
+      parser.on("--scanline", "Enable scanline rendering for GBC") { config.args.fifo = false }
+      parser.on("--headless", "Don't open window or play audio") { config.args.headless = true }
       parser.unknown_args do |args|
         case args.size
+        when 0 # launch the emulator without a rom selected
         when 1 then rom = args[0]
         when 2 then bios, rom = args[0], args[1]
+        else        abort "Unknown args #{args[2..]}. Use '--help' for help"
         end
       end
+      parser.invalid_option { |flag| abort "Unknown flag '#{flag}'. Use '--help' for help" }
+      parser.missing_option { |flag| abort "Option '#{flag}' is missing a value. Use '--help' for help" }
     end
 
-    frontend = Frontend.new(bios, rom, headless)
+    frontend = Frontend.new(config, bios, rom)
     frontend.run
   end
 end

src/crab/common/config.cr

@@ -23,9 +23,19 @@ class Config
     LibSDL::Keycode::R         => Input::R,
   }
   property recents : Array(String) = [] of String
+  property run_bios : Bool = false
   property gba : GBA = GBA.new
   property gbc : GBC = GBC.new
 
+  private class Args
+    property headless : Bool = false
+    property run_bios : Bool?
+    property fifo : Bool?
+  end
+
+  @[YAML::Field(ignore: true)]
+  getter args = Args.new
+
   def self.new : Config
     Config.from_yaml(File.read(CONFIG_FILE))
   end
@@ -34,6 +44,14 @@ class Config
     File.write(CONFIG_FILE, to_yaml)
   end
 
+  def run_bios : Bool
+    unless (run_bios = args.run_bios).nil?
+      run_bios
+    else
+      @run_bios
+    end
+  end
+
   class GBA
     include YAML::Serializable
     property bios : String = "bios.bin"
@@ -45,6 +63,7 @@ class Config
   class GBC
     include YAML::Serializable
     property bios : String?
+    property fifo : Bool = false
 
     def initialize
     end

src/crab/common/frontend.cr

@@ -1,7 +1,6 @@
 abstract class Frontend
-  def self.new(bios : String?, rom : String?, headless = false)
-    config = Config.new
-    if headless
+  def self.new(config : Config, bios : String?, rom : String?)
+    if config.args.headless
       HeadlessFrontend.new(config, bios, rom)
     else
       SDLOpenGLImGuiFrontend.new(config, bios, rom)
@@ -10,7 +9,7 @@ abstract class Frontend
 
   abstract def run : NoReturn
 
-  private def init_controller(bios : String?, rom : String?) : Controller
+  private def init_controller(bios : String?, rom : String?, skip_bios : Bool) : Controller
     return StubbedController.new unless rom
     extension = rom.rpartition('.')[2]
     if GBController.extensions.includes? extension

src/crab/common/frontend/controllers/gb_controller.cr

@@ -1,5 +1,4 @@
 class GBController < Controller
-  @config : Config
   getter emu : GB::GB
   class_getter extensions : Array(String) = ["gb", "gbc"]
   class_getter vertex_shader : String = "identity.vert"
@@ -8,8 +7,13 @@ class GBController < Controller
   getter width : Int32 = 160
   getter height : Int32 = 144
 
-  def initialize(@config : Config, bios : String?, rom : String)
-    @emu = GB::GB.new(bios || @config.gbc.bios, rom, true, false)
+  def initialize(config : Config, bios : String?, rom : String)
+    fifo = if config.args.fifo.nil?
+             config.gbc.fifo
+           else
+             config.args.fifo.not_nil!
+           end
+    @emu = GB::GB.new(bios || config.gbc.bios, rom, fifo, config.args.headless, config.run_bios)
     @emu.post_init
   end
 

src/crab/common/frontend/controllers/gba_controller.cr

@@ -1,5 +1,4 @@
 class GBAController < Controller
-  @config : Config
   getter emu : GBA::GBA
   class_getter extensions : Array(String) = ["gba"]
   class_getter vertex_shader : String = "identity.vert"
@@ -11,8 +10,8 @@ class GBAController < Controller
   @debug_window = false
   @scheduler_window = false
 
-  def initialize(@config : Config, bios : String?, rom : String)
-    @emu = GBA::GBA.new(bios || @config.gba.bios, rom)
+  def initialize(config : Config, bios : String?, rom : String)
+    @emu = GBA::GBA.new(bios || config.gba.bios, rom, config.run_bios)
     @emu.post_init
   end
 

src/crab/common/frontend/headless_frontend.cr

@@ -3,7 +3,7 @@ class HeadlessFrontend < Frontend
   @controller : Controller
 
   def initialize(@config : Config, bios : String?, rom : String?)
-    @controller = init_controller(bios, rom.not_nil!)
+    @controller = init_controller(bios, rom.not_nil!, @config.run_bios)
   end
 
   def run : NoReturn

src/crab/common/frontend/sdl_opengl_imgui_frontend.cr

@@ -44,7 +44,7 @@ class SDLOpenGLImGuiFrontend < Frontend
     LibSDL.joystick_open 0
     at_exit { SDL.quit }
 
-    @controller = init_controller(bios, rom)
+    @controller = init_controller(bios, rom, @config.run_bios)
     @window = SDL::Window.new(
       window_title(59.7),
       @controller.window_width * @scale,
@@ -118,7 +118,7 @@ class SDLOpenGLImGuiFrontend < Frontend
 
   private def load_new_rom(rom : String?) : Nil
     LibSDL.close_audio(1)
-    @controller = init_controller(nil, rom)
+    @controller = init_controller(nil, rom, @config.run_bios)
     @file_explorer.clear_selection
 
     @config.recents.delete(rom)

src/crab/gb/gb.cr

@@ -15,7 +15,8 @@ require "./timer"
 module GB
   class GB < Emu
     getter bootrom : String?
-    getter cgb_ptr : Pointer(Bool) { pointerof(@cgb_enabled) }
+    @cgb_enabled : Bool
+    getter cgb_ptr : Pointer(Bool)
     getter cartridge : Cartridge
 
     getter! apu : APU
@@ -27,9 +28,10 @@ module GB
     getter! scheduler : Scheduler
     getter! timer : Timer
 
-    def initialize(@bootrom : String?, rom_path : String, @fifo : Bool, @headless : Bool)
+    def initialize(@bootrom : String?, rom_path : String, @fifo : Bool, @headless : Bool, @run_bios : Bool)
       @cartridge = Cartridge.new rom_path
-      @cgb_enabled = !(bootrom.nil? && @cartridge.cgb == Cartridge::CGB::NONE)
+      @cgb_enabled = (!bootrom.nil? && @run_bios) || @cartridge.cgb != Cartridge::CGB::NONE
+      @cgb_ptr = pointerof(@cgb_enabled)
     end
 
     def post_init : Nil
@@ -41,7 +43,8 @@ module GB
       @timer = Timer.new self
       @memory = Memory.new self
       @cpu = CPU.new self
-      skip_boot if @bootrom.nil?
+
+      skip_boot if @bootrom.nil? || !@run_bios
     end
 
     private def skip_boot : Nil

src/crab/gb/memory.cr

@@ -107,6 +107,7 @@ module GB
     end
 
     def skip_boot : Nil
+      @bootrom = Bytes.new 0
       write_byte 0xFF10, 0x80_u8 # NR10
       write_byte 0xFF11, 0xBF_u8 # NR11
       write_byte 0xFF12, 0xF3_u8 # NR12

src/crab/gba/cpu.cr

@@ -53,6 +53,10 @@ module GBA
     property halted = false
 
     def initialize(@gba : GBA)
+      clear_pipeline
+    end
+
+    def skip_bios : Nil
       @reg_banks[Mode::USR.bank][5] = @r[13] = 0x03007F00
       @reg_banks[Mode::IRQ.bank][5] = 0x03007FA0
       @reg_banks[Mode::SVC.bank][5] = 0x03007FE0

src/crab/gba/gba.cr

@@ -30,7 +30,7 @@ module GBA
     getter! dma : DMA
     getter! debugger : Debugger
 
-    def initialize(@bios_path : String, @rom_path : String)
+    def initialize(@bios_path : String, @rom_path : String, @run_bios : Bool)
       @scheduler = Scheduler.new
       @cartridge = Cartridge.new @rom_path
       scheduler.schedule 280896, ->handle_saves
@@ -48,6 +48,8 @@ module GBA
       @apu = APU.new self
       @dma = DMA.new self
       @debugger = Debugger.new self
+
+      cpu.skip_bios unless @run_bios
     end
 
     def run_until_frame : Nil