3 files changed, 133 insertions(+), 0 deletions(-)

A go.mod
A main.go
A vm.go

@@ 1,8 @@
+module git.sr.ht/~apreiml/octachip
+
+go 1.16
+
+require (
+	github.com/faiface/pixel v0.10.0 // indirect
+	golang.org/x/image v0.0.0-20210504121937-7319ad40d33e // indirect
+)

@@ 1,7 @@
+package main
+
+func main() {
+	vm := &Chip8{}
+
+	vm.Run()
+}

@@ 1,118 @@
+package main
+
+import (
+	"fmt"
+	"math"
+	"time"
+
+	"github.com/faiface/pixel"
+	"github.com/faiface/pixel/pixelgl"
+	"golang.org/x/image/colornames"
+)
+
+const (
+	memSize     = 4 * 1024
+	memReserved = 0x200
+	romStart    = memReserved
+)
+
+type Chip8 struct {
+	mem [memSize]byte
+	v   [16]byte
+	i   uint16
+	dt  byte
+	st  byte
+	pc  uint16
+	sp  byte
+}
+
+func (c *Chip8) LoadRom(rom []byte) error {
+	copy(c.mem[romStart:], rom)
+	return nil
+}
+
+func run() {
+	d := NewDisplay(640, 320)
+	cfg := pixelgl.WindowConfig{
+		Title:  "Octa-Chip",
+		Bounds: d.bounds,
+		VSync:  true,
+	}
+
+	d.buffer[0] = 1
+	d.buffer[2] = 1
+
+	d.buffer[64] = 1
+	d.buffer[64+4] = 1
+
+	d.buffer[31*64] = 1
+
+	win, err := pixelgl.NewWindow(cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	win.Clear(colornames.Black)
+
+	go func() {
+		i := 10
+		ticker := time.NewTicker(time.Second)
+		for {
+			select {
+			case <-ticker.C:
+				d.buffer[i] = 1
+				i += 2
+				fmt.Println(i)
+			}
+		}
+	}()
+
+	for !win.Closed() {
+		sprite := pixel.NewSprite(d, d.Bounds())
+		sprite.Draw(win, pixel.IM.Moved(win.Bounds().Center()))
+		win.Update()
+	}
+}
+
+func (c *Chip8) Run() {
+	pixelgl.Run(run)
+}
+
+type Display struct {
+	bounds       pixel.Rect
+	xm, ym       float64
+	buffer       []byte
+	modeX, modeY int
+}
+
+func NewDisplay(w, h float64) *Display {
+	modeX := 64
+	modeY := 32
+
+	return &Display{
+		bounds: pixel.R(0, 0, w, h),
+		xm:     w / float64(modeX),
+		ym:     h / float64(modeY),
+		modeX:  modeX,
+		modeY:  modeY,
+		buffer: make([]byte, modeX*modeY),
+	}
+}
+
+func (d Display) Bounds() pixel.Rect {
+	return d.bounds
+}
+
+func (d Display) Color(at pixel.Vec) pixel.RGBA {
+	x := int(math.Floor(at.X / d.xm))
+	y := int(math.Floor(at.Y / d.ym))
+
+	y = d.modeY - y - 1
+
+	idx := y*d.modeX + x
+	set := d.buffer[idx]
+	if set == 1 {
+		return pixel.RGB(1, 1, 1)
+	}
+	return pixel.RGB(255, 255, 255)
+}