1 files changed, 325 insertions, 0 deletions
diff --git a/liust-50/cmd/liustsim/simulator.go b/liust-50/cmd/liustsim/simulator.go
new file mode 100644
index 0000000..2ad69a8
--- /dev/null
+++ b/liust-50/cmd/liustsim/simulator.go
@@ -0,0 +1,325 @@
+package main
+
+import (
+	"bufio"
+	"image"
+	"image/color"
+	"os"
+	"strconv"
+	"strings"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/app"
+	"fyne.io/fyne/v2/canvas"
+
+	"janouch.name/desktop-tools/liust-50/charset"
+)
+
+const (
+	displayWidth  = 20
+	displayHeight = 2
+	charWidth     = 5 + 1
+	charHeight    = 7 + 1
+	magnification = 5
+)
+
+// TODO(p): See how this works exactly, and implement it.
+const (
+	cursorModeOff = iota
+	cursorModeBlink
+	cursorModeLightUp
+)
+
+type Display struct {
+	image      *canvas.Image
+	chars      [displayHeight][displayWidth]uint8
+	charset    uint8
+	cursorX    int
+	cursorY    int
+	cursorMode int
+}
+
+func NewDisplay() *Display {
+	return &Display{charset: 2}
+}
+
+func (d *Display) Clear() {
+	for y := 0; y < displayHeight; y++ {
+		for x := 0; x < displayWidth; x++ {
+			d.chars[y][x] = 0x20 // space
+		}
+	}
+}
+
+func (d *Display) ClearToEnd() {
+	for x := d.cursorX; x < displayWidth; x++ {
+		d.chars[d.cursorY][x] = 0x20 // space
+	}
+}
+
+func (d *Display) drawCharacter(
+	img *image.RGBA, charImg image.Image, cx, cy int) {
+	if charImg == nil {
+		return
+	}
+
+	bounds := charImg.Bounds()
+	width, height := bounds.Dx(), bounds.Dy()
+	for dy := 0; dy < height; dy++ {
+		for dx := 0; dx < width; dx++ {
+			c := charImg.At(bounds.Min.X+dx, bounds.Min.Y+dy)
+			if r, _, _, _ := c.RGBA(); r >= 0x8000 {
+				c = color.RGBA{0x00, 0xFF, 0xC0, 0xFF}
+			} else {
+				c = color.RGBA{0x20, 0x20, 0x20, 0xFF}
+			}
+			img.Set(1+cx*charWidth+dx, 1+cy*charHeight+dy, c)
+		}
+	}
+}
+
+func (d *Display) Render() image.Image {
+	width := 1 + displayWidth*charWidth
+	height := 1 + displayHeight*charHeight
+
+	img := image.NewRGBA(image.Rect(0, 0, width, height))
+	for y := 0; y < height; y++ {
+		for x := 0; x < width; x++ {
+			img.Set(x, y, color.Black)
+		}
+	}
+
+	for cy := 0; cy < displayHeight; cy++ {
+		for cx := 0; cx < displayWidth; cx++ {
+			charImg := charset.ResolveCharToImage(d.chars[cy][cx], d.charset)
+			d.drawCharacter(img, charImg, cx, cy)
+		}
+	}
+
+	return img
+}
+
+func (d *Display) PutChar(ch uint8) {
+	if d.cursorX >= displayWidth || d.cursorY >= displayHeight {
+		return
+	}
+
+	d.chars[d.cursorY][d.cursorX] = ch
+	d.cursorX++
+	if d.cursorX >= displayWidth {
+		d.cursorX = displayWidth - 1
+	}
+}
+
+func (d *Display) LineFeed() {
+	d.cursorY++
+	if d.cursorY >= displayHeight {
+		d.cursorY = displayHeight - 1
+
+		// XXX: This relies on displayHeight being exactly 2.
+		d.chars[0] = d.chars[1]
+		for x := 0; x < displayWidth; x++ {
+			d.chars[1][x] = 0x20
+		}
+	}
+}
+
+func (d *Display) CarriageReturn() {
+	d.cursorX = 0
+}
+
+func (d *Display) Backspace() {
+	if d.cursorX > 0 {
+		d.cursorX--
+	}
+}
+
+func (d *Display) SetCursor(x, y int) {
+	if x >= 0 && x < displayWidth {
+		d.cursorX = x
+	}
+	if y >= 0 && y < displayHeight {
+		d.cursorY = y
+	}
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+func parseANSI(input string) (command string, params []int) {
+	if !strings.HasPrefix(input, "\x1b[") {
+		return "", nil
+	}
+
+	input = input[2:]
+	if len(input) == 0 {
+		return "", nil
+	}
+
+	cmdIdx := len(input) - 1
+	command = string(input[cmdIdx])
+
+	paramStr := input[:cmdIdx]
+	if paramStr == "" {
+		return command, []int{}
+	}
+
+	parts := strings.Split(paramStr, ";")
+	for _, p := range parts {
+		p = strings.TrimSpace(p)
+		if val, err := strconv.Atoi(p); err == nil {
+			params = append(params, val)
+		}
+	}
+	return command, params
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+type escapeParser struct {
+	seq     strings.Builder
+	inEsc   bool
+	inCSI   bool
+	display *Display
+}
+
+func newEscapeParser(d *Display) *escapeParser {
+	return &escapeParser{display: d}
+}
+
+func (ep *escapeParser) reset() {
+	ep.inEsc = false
+	ep.inCSI = false
+	ep.seq.Reset()
+}
+
+func (ep *escapeParser) handleCSICommand() bool {
+	cmd, params := parseANSI(ep.seq.String())
+
+	switch cmd {
+	case "J": // Clear display
+		// XXX: No params case is unverified.
+		if len(params) == 0 || params[0] == 2 {
+			ep.display.Clear()
+		}
+	case "K": // Delete to end of line
+		// XXX: No params case is unverified (but it should work).
+		if len(params) == 0 || params[0] == 0 {
+			ep.display.ClearToEnd()
+		}
+	case "H": // Cursor position
+		y, x := 0, 0
+		if len(params) >= 1 {
+			y = params[0] - 1 // 1-indexed to 0-indexed
+		}
+		if len(params) >= 2 {
+			x = params[1] - 1
+		}
+		ep.display.SetCursor(x, y)
+	}
+	return true
+}
+
+func (ep *escapeParser) handleEscapeSequence(b byte) bool {
+	ep.seq.WriteByte(b)
+
+	if ep.seq.Len() == 2 && b == '[' {
+		ep.inCSI = true
+		return false
+	}
+
+	if ep.seq.Len() == 3 && ep.seq.String()[1] == 'R' {
+		ep.display.charset = b
+		ep.reset()
+		return true
+	}
+
+	if ep.inCSI && (b >= 'A' && b <= 'Z' || b >= 'a' && b <= 'z') {
+		refresh := ep.handleCSICommand()
+		ep.reset()
+		return refresh
+	}
+
+	if ep.seq.Len() == 6 && ep.seq.String()[1:5] == "\\?LC" {
+		ep.display.cursorMode = int(ep.seq.String()[5])
+		return true
+	}
+
+	return false
+}
+
+func (ep *escapeParser) handleControlChar(b byte) bool {
+	switch b {
+	case 0x0A: // LF
+		ep.display.LineFeed()
+		return true
+	case 0x0D: // CR
+		ep.display.CarriageReturn()
+		return true
+	case 0x08: // BS
+		ep.display.Backspace()
+		return true
+	default:
+		if b >= 0x20 {
+			ep.display.PutChar(b)
+			return true
+		}
+	}
+	return false
+}
+
+func (ep *escapeParser) handleByte(b byte) (needsRefresh bool) {
+	if b == 0x1b { // ESC
+		ep.reset()
+		ep.inEsc = true
+		ep.seq.WriteByte(b)
+		return false
+	}
+
+	if ep.inEsc {
+		return ep.handleEscapeSequence(b)
+	}
+
+	return ep.handleControlChar(b)
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+func main() {
+	myApp := app.New()
+	window := myApp.NewWindow("Toshiba Tec LIUST-50 Simulator")
+
+	display := NewDisplay()
+	display.Clear()
+
+	img := canvas.NewImageFromImage(display.Render())
+	img.FillMode = canvas.ImageFillOriginal
+	img.ScaleMode = canvas.ImageScalePixels
+
+	window.SetContent(img)
+
+	window.Resize(fyne.NewSize(600, 100))
+
+	go func() {
+		reader := bufio.NewReader(os.Stdin)
+		parser := newEscapeParser(display)
+
+		for {
+			b, err := reader.ReadByte()
+			if err != nil {
+				fyne.DoAndWait(func() {
+					window.SetTitle(err.Error())
+				})
+				return
+			}
+
+			if parser.handleByte(b) {
+				fyne.DoAndWait(func() {
+					img.Image = display.Render()
+					img.Refresh()
+				})
+			}
+		}
+	}()
+
+	window.ShowAndRun()
+}