goapple2/sdl/sdl.go

// Simplest possible Apple II that will possibly boot, in SDL. ~ (tilde) to quit.
package main

import (
	"fmt"
	"time"
	"unsafe"

	"github.com/0xe2-0x9a-0x9b/Go-SDL/sdl"
	"github.com/zellyn/goapple2"
	"github.com/zellyn/goapple2/util"
	"github.com/zellyn/goapple2/videoscan"
)

const (
	BORDER_H      = 20
	BORDER_W      = 20
	SCREEN_WIDTH  = 560 + 2*BORDER_W
	SCREEN_HEIGHT = 384 + 2*BORDER_H
	SCREEN_BPP    = 32
)

func plot(x, y uint, color uint32, screen *sdl.Surface) {
	x = x + BORDER_W
	y = y + BORDER_H
	screen.Lock()
	pixels := uintptr(screen.Pixels)
	offset := uintptr(y*uint(screen.Pitch) + x*(SCREEN_BPP/8))
	addr := pixels + offset
	*(*uint32)(unsafe.Pointer(addr)) = color
	screen.Unlock()
}

func Init() (screen *sdl.Surface, err error) {

	// Intialise the SDL subsystems
	if ok := sdl.Init(sdl.INIT_EVERYTHING); ok != 0 {
		return nil, fmt.Errorf("%s", sdl.GetError())
	}

	// Set up the screen
	screen = sdl.SetVideoMode(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, sdl.SWSURFACE)

	// If couldn't get the screen, return false
	if screen == nil {
		return nil, fmt.Errorf("%s", sdl.GetError())

	}

	// Set the window caption (window title)
	sdl.WM_SetCaption("Apple ][", "")

	// Everything went fine
	return screen, nil
}

const (
	M_NONE = iota
	M_SHIFT_OR_NONE
	M_SHIFT
	M_CTRL
	M_ANY
)

type Key struct {
	sym uint32
	mod uint32
}

var KeyToApple = map[Key]byte{
	Key{sdl.K_a, M_SHIFT_OR_NONE}: 'A',
	Key{sdl.K_b, M_SHIFT_OR_NONE}: 'B',
	Key{sdl.K_c, M_SHIFT_OR_NONE}: 'C',
	Key{sdl.K_d, M_SHIFT_OR_NONE}: 'D',
	Key{sdl.K_e, M_SHIFT_OR_NONE}: 'E',
	Key{sdl.K_f, M_SHIFT_OR_NONE}: 'F',
	Key{sdl.K_g, M_SHIFT_OR_NONE}: 'G',
	Key{sdl.K_h, M_SHIFT_OR_NONE}: 'H',
	Key{sdl.K_i, M_SHIFT_OR_NONE}: 'I',
	Key{sdl.K_j, M_SHIFT_OR_NONE}: 'J',
	Key{sdl.K_k, M_SHIFT_OR_NONE}: 'K',
	Key{sdl.K_l, M_SHIFT_OR_NONE}: 'L',
	Key{sdl.K_m, M_SHIFT_OR_NONE}: 'M',
	Key{sdl.K_n, M_SHIFT_OR_NONE}: 'N',
	Key{sdl.K_o, M_SHIFT_OR_NONE}: 'O',
	Key{sdl.K_p, M_SHIFT_OR_NONE}: 'P',
	Key{sdl.K_q, M_SHIFT_OR_NONE}: 'Q',
	Key{sdl.K_r, M_SHIFT_OR_NONE}: 'R',
	Key{sdl.K_s, M_SHIFT_OR_NONE}: 'S',
	Key{sdl.K_t, M_SHIFT_OR_NONE}: 'T',
	Key{sdl.K_u, M_SHIFT_OR_NONE}: 'U',
	Key{sdl.K_v, M_SHIFT_OR_NONE}: 'V',
	Key{sdl.K_w, M_SHIFT_OR_NONE}: 'W',
	Key{sdl.K_x, M_SHIFT_OR_NONE}: 'X',
	Key{sdl.K_y, M_SHIFT_OR_NONE}: 'Y',
	Key{sdl.K_z, M_SHIFT_OR_NONE}: 'Z',

	Key{sdl.K_a, M_CTRL}: 1,
	Key{sdl.K_b, M_CTRL}: 2,
	Key{sdl.K_c, M_CTRL}: 3,
	Key{sdl.K_d, M_CTRL}: 4,
	Key{sdl.K_e, M_CTRL}: 5,
	Key{sdl.K_f, M_CTRL}: 6,
	Key{sdl.K_g, M_CTRL}: 7,
	Key{sdl.K_h, M_CTRL}: 8,
	Key{sdl.K_i, M_CTRL}: 9,
	Key{sdl.K_j, M_CTRL}: 10,
	Key{sdl.K_k, M_CTRL}: 11,
	Key{sdl.K_l, M_CTRL}: 12,
	Key{sdl.K_m, M_CTRL}: 13,
	Key{sdl.K_n, M_CTRL}: 14,
	Key{sdl.K_o, M_CTRL}: 15,
	Key{sdl.K_p, M_CTRL}: 16,
	Key{sdl.K_q, M_CTRL}: 17,
	Key{sdl.K_r, M_CTRL}: 18,
	Key{sdl.K_s, M_CTRL}: 19,
	Key{sdl.K_t, M_CTRL}: 20,
	Key{sdl.K_u, M_CTRL}: 21,
	Key{sdl.K_v, M_CTRL}: 22,
	Key{sdl.K_w, M_CTRL}: 23,
	Key{sdl.K_x, M_CTRL}: 24,
	Key{sdl.K_y, M_CTRL}: 25,
	Key{sdl.K_z, M_CTRL}: 26,

	Key{sdl.K_0, M_NONE}: '0',
	Key{sdl.K_1, M_NONE}: '1',
	Key{sdl.K_2, M_NONE}: '2',
	Key{sdl.K_3, M_NONE}: '3',
	Key{sdl.K_4, M_NONE}: '4',
	Key{sdl.K_5, M_NONE}: '5',
	Key{sdl.K_6, M_NONE}: '6',
	Key{sdl.K_7, M_NONE}: '7',
	Key{sdl.K_8, M_NONE}: '8',
	Key{sdl.K_9, M_NONE}: '9',

	Key{sdl.K_0, M_SHIFT}: '!',
	Key{sdl.K_1, M_SHIFT}: '@',
	Key{sdl.K_2, M_SHIFT}: '#',
	Key{sdl.K_3, M_SHIFT}: '$',
	Key{sdl.K_4, M_SHIFT}: '%',
	Key{sdl.K_5, M_SHIFT}: '^',
	Key{sdl.K_6, M_SHIFT}: '&',
	Key{sdl.K_7, M_SHIFT}: '*',
	Key{sdl.K_8, M_SHIFT}: '(',
	Key{sdl.K_9, M_SHIFT}: ')',

	Key{sdl.K_MINUS, M_NONE}:        '-',
	Key{sdl.K_MINUS, M_SHIFT}:       '_',
	Key{sdl.K_EQUALS, M_NONE}:       '=',
	Key{sdl.K_EQUALS, M_SHIFT}:      '+',
	Key{sdl.K_LEFTBRACKET, M_NONE}:  '[',
	Key{sdl.K_RIGHTBRACKET, M_NONE}: ']',
	Key{sdl.K_SEMICOLON, M_NONE}:    ';',
	Key{sdl.K_SEMICOLON, M_SHIFT}:   ':',
	Key{sdl.K_QUOTE, M_NONE}:        '\'',
	Key{sdl.K_QUOTE, M_SHIFT}:       '"',
	Key{sdl.K_COMMA, M_NONE}:        ',',
	Key{sdl.K_COMMA, M_SHIFT}:       '<',
	Key{sdl.K_PERIOD, M_NONE}:       '.',
	Key{sdl.K_PERIOD, M_SHIFT}:      '>',
	Key{sdl.K_SLASH, M_NONE}:        '/',
	Key{sdl.K_SLASH, M_SHIFT}:       '?',
	Key{sdl.K_BACKSLASH, M_NONE}:    '\\',

	Key{sdl.K_SPACE, M_SHIFT_OR_NONE}: ' ',
	Key{sdl.K_RETURN, M_ANY}:          13,

	Key{sdl.K_BACKSPACE, M_ANY}: 8,
	Key{sdl.K_LEFT, M_ANY}:      8,
	Key{sdl.K_RIGHT, M_ANY}:     21,
}

func sdlToAppleKeyboard(k sdl.Keysym) (key byte, err error) {
	if b, ok := KeyToApple[Key{k.Sym, M_ANY}]; ok {
		return b, nil
	}
	switch k.Mod {
	case sdl.KMOD_NONE:
		if b, ok := KeyToApple[Key{k.Sym, M_NONE}]; ok {
			return b, nil
		}
		if b, ok := KeyToApple[Key{k.Sym, M_SHIFT_OR_NONE}]; ok {
			return b, nil
		}
	case sdl.KMOD_LSHIFT, sdl.KMOD_RSHIFT, sdl.KMOD_LSHIFT | sdl.KMOD_RSHIFT:
		if b, ok := KeyToApple[Key{k.Sym, M_SHIFT}]; ok {
			return b, nil
		}
		if b, ok := KeyToApple[Key{k.Sym, M_SHIFT_OR_NONE}]; ok {
			return b, nil
		}
	case sdl.KMOD_LCTRL, sdl.KMOD_RCTRL, sdl.KMOD_LCTRL | sdl.KMOD_RCTRL:
		if b, ok := KeyToApple[Key{k.Sym, M_CTRL}]; ok {
			return b, nil
		}
	}
	return 0, fmt.Errorf("hi")
}

func ProcessEvents(events <-chan interface{}, a2 *goapple2.Apple2) (done bool) {
	select {
	case _event := <-events:
		switch e := _event.(type) {
		case sdl.QuitEvent:
			return true
		case sdl.KeyboardEvent:
			if e.Type == sdl.KEYDOWN {
				if e.Keysym.Sym == sdl.K_F1 {
					return true
				}
				if e.Keysym.Mod == sdl.KMOD_LCTRL && e.Keysym.Sym == sdl.K_LEFTBRACKET {
					return true
				}
				if key, err := sdlToAppleKeyboard(e.Keysym); err == nil {
					a2.Keypress(key)
				}
			}
		}
	default:
		// Nothing to do here
	}
	return false
}

type SdlPlotter struct {
	screen *sdl.Surface
}

func (s SdlPlotter) Plot(pd videoscan.PlotData) {
	y := uint(pd.Row)
	x := uint(pd.Column) * 14
	data := pd.Data
	for i := uint(0); i < 14; i++ {
		color1 := uint32(0)
		color2 := uint32(0)
		if data&1 > 0 {
			color1 = 0x00ff00
			color2 = 0x008800
		}
		plot(x+i, y*2+0, color1, s.screen)
		plot(x+i, y*2+1, color2, s.screen)
		data >>= 1
	}
	if pd.Column == 39 && y == 191 {
		s.screen.Flip()
	}
}

// Run the emulator
func RunEmulator() {
	rom := util.ReadRomOrDie("../data/roms/apple2+.rom")
	charRom := util.ReadSmallCharacterRomOrDie("../data/roms/apple2-chars.rom")
	screen, err := Init()
	if err != nil {
		panic(err)
	}
	plotter := SdlPlotter{screen}
	a2 := goapple2.NewApple2(plotter, rom, charRom)
	for !ProcessEvents(sdl.Events, a2) {
		err := a2.Step()
		if err != nil {
			fmt.Println(err)
			break
		}
		time.Sleep(1 * time.Nanosecond) // So the keyboard-reading goroutines can run
	}
	sdl.Quit()
}

func main() {
	RunEmulator()
}