Stub-out a GUI mode

.github/workflows/ci.yml

@@ -10,7 +10,20 @@ jobs:
 
   build:
     runs-on: ubuntu-latest
+    env:
+      DISPLAY: ':99.0'
+
     steps:
+    - name: Install ebiten build dependencies
+      run: |
+        sudo apt install gcc libc6-dev libgl1-mesa-dev libxcursor-dev \
+                         libxi-dev libxinerama-dev libxrandr-dev \
+                         libxxf86vm-dev libasound2-dev pkg-config
+
+    - name: Run Xvfb for ebitin
+      run: |
+        Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &
+
     - uses: actions/checkout@v3
       with:
         submodules: true

.github/workflows/golangci-lint.yml

@@ -13,6 +13,12 @@ jobs:
     name: lint
     runs-on: ubuntu-latest
     steps:
+      - name: Install ebiten build dependencies
+        run: |
+          sudo apt install gcc libc6-dev libgl1-mesa-dev libxcursor-dev \
+                          libxi-dev libxinerama-dev libxrandr-dev \
+                          libxxf86vm-dev libasound2-dev pkg-config
+
       - uses: actions/checkout@v3
       - uses: actions/setup-go@v4
         with:

.golangci.yml

@@ -0,0 +1,3 @@
+---
+run:
+  modules-download-mode: mod

Makefile

@@ -16,7 +16,7 @@ help:
 
 .PHONY: tidy
 tidy:
-	go fmt ./...
+	go fmt -mod=mod ./...
 	go mod tidy -v
 
 .PHONY: build
@@ -29,15 +29,15 @@ clean:
 
 .PHONY: run
 run:
-	$(GO) run .
+	$(GO) run -mod=mod .
 
 .PHONY: test
 test:
-	$(GO) test -v ./...
+	$(GO) test -mod=mod -v ./...
 
 .PHONY: bin/gogo-gb # This does exist, but we're not tracking its dependencies. Go is
 bin/gogo-gb:
-	$(GO) build -o bin/gogo-gb .
+	$(GO) build -mod=mod -o bin/gogo-gb .
 
 .PHONY: cpu_instrs
 cpu_instrs: bin/gogo-gb vendor/gameboy-doctor/gameboy-doctor vendor/gb-test-roms/cpu_instrs/individual/*.gb

devices/host_interface.go

@@ -0,0 +1,12 @@
+package devices
+
+import "image"
+
+type HostInterface interface {
+	Framebuffer() chan<- image.Image
+	Log(msg string, args ...any)
+	LogErr(msg string, args ...any)
+	LogWarn(msg string, args ...any)
+	Exited() <-chan bool
+	SerialCable() SerialCable
+}

devices/lcd.go

@@ -1,6 +1,11 @@
 package devices
 
-import "github.com/maxfierke/gogo-gb/mem"
+import (
+	"image"
+	"image/color"
+
+	"github.com/maxfierke/gogo-gb/mem"
+)
 
 const (
 	REG_LCD_LY = 0xFF44
@@ -13,6 +18,16 @@ func NewLCD() *LCD {
 	return &LCD{}
 }
 
+func (lcd *LCD) Draw() image.Image {
+	image := image.NewPaletted(
+		image.Rect(0, 0, 160, 144),
+		color.Palette{color.Black, color.Gray{Y: 96}, color.Gray16{Y: 128}, color.White},
+	)
+	image.Set(80, 77, color.Gray{Y: 96})
+
+	return image
+}
+
 func (lcd *LCD) OnRead(mmu *mem.MMU, addr uint16) mem.MemRead {
 	return mem.ReadPassthrough()
 }

devices/serial_port.go

@@ -73,19 +73,23 @@ func (sc *SerialCtrl) SetClockInternal(enabled bool) {
 }
 
 type SerialPort struct {
-	clk  uint
-	ctrl SerialCtrl
-	recv byte
-	buf  byte
-	host HostContext
+	clk   uint
+	ctrl  SerialCtrl
+	recv  byte
+	buf   byte
+	cable SerialCable
 }
 
-func NewSerialPort(host HostContext) *SerialPort {
+func NewSerialPort() *SerialPort {
 	return &SerialPort{
-		host: host,
+		cable: &NullSerialCable{},
 	}
 }
 
+func (sp *SerialPort) AttachCable(cable SerialCable) {
+	sp.cable = cable
+}
+
 func (sp *SerialPort) Step(cycles uint8, ic *InterruptController) {
 	if !sp.ctrl.IsTransferEnabled() {
 		return
@@ -122,18 +126,12 @@ func (sp *SerialPort) OnWrite(mmu *mem.MMU, addr uint16, value byte) mem.MemWrit
 		sp.ctrl.Write(value)
 
 		if sp.ctrl.IsTransferEnabled() && sp.ctrl.IsClockInternal() {
-			cable := sp.host.SerialCable()
-			logger := sp.host.Logger()
-
 			// TODO(GBC): derive this somehow and factor in GBC speeds when relevant
 			sp.clk = 8192
 
-			err := cable.WriteByte(sp.buf)
-			if err != nil {
-				logger.Printf("Unable to write 0x%02X to serial cable: %v\n", value, err)
-			}
+			_ = sp.cable.WriteByte(sp.buf)
 
-			recvVal, err := cable.ReadByte()
+			recvVal, err := sp.cable.ReadByte()
 			if err != nil {
 				sp.recv = 0xFF
 			} else {

go.mod

@@ -1,3 +1,14 @@
 module github.com/maxfierke/gogo-gb
 
 go 1.22.0
+
+require github.com/hajimehoshi/ebiten/v2 v2.7.3
+
+require (
+	github.com/ebitengine/gomobile v0.0.0-20240329170434-1771503ff0a8 // indirect
+	github.com/ebitengine/hideconsole v1.0.0 // indirect
+	github.com/ebitengine/purego v0.7.0 // indirect
+	github.com/jezek/xgb v1.1.1 // indirect
+	golang.org/x/sync v0.6.0 // indirect
+	golang.org/x/sys v0.18.0 // indirect
+)

go.sum

@@ -0,0 +1,16 @@
+github.com/ebitengine/gomobile v0.0.0-20240329170434-1771503ff0a8 h1:5e8X7WEdOWrjrKvgaWF6PRnDvJicfrkEnwAkWtMN74g=
+github.com/ebitengine/gomobile v0.0.0-20240329170434-1771503ff0a8/go.mod h1:tWboRRNagZwwwis4QIgEFG1ZNFwBJ3LAhSLAXAAxobQ=
+github.com/ebitengine/hideconsole v1.0.0 h1:5J4U0kXF+pv/DhiXt5/lTz0eO5ogJ1iXb8Yj1yReDqE=
+github.com/ebitengine/hideconsole v1.0.0/go.mod h1:hTTBTvVYWKBuxPr7peweneWdkUwEuHuB3C1R/ielR1A=
+github.com/ebitengine/purego v0.7.0 h1:HPZpl61edMGCEW6XK2nsR6+7AnJ3unUxpTZBkkIXnMc=
+github.com/ebitengine/purego v0.7.0/go.mod h1:ah1In8AOtksoNK6yk5z1HTJeUkC1Ez4Wk2idgGslMwQ=
+github.com/hajimehoshi/ebiten/v2 v2.7.3 h1:lDpj8KbmmjzwD19rsjXNkyelicu0XGvklZW6/tjrgNs=
+github.com/hajimehoshi/ebiten/v2 v2.7.3/go.mod h1:1vjyPw+h3n30rfTOpIsbWRXSxZ0Oz1cYc6Tq/2DKoQg=
+github.com/jezek/xgb v1.1.1 h1:bE/r8ZZtSv7l9gk6nU0mYx51aXrvnyb44892TwSaqS4=
+github.com/jezek/xgb v1.1.1/go.mod h1:nrhwO0FX/enq75I7Y7G8iN1ubpSGZEiA3v9e9GyRFlk=
+golang.org/x/image v0.15.0 h1:kOELfmgrmJlw4Cdb7g/QGuB3CvDrXbqEIww/pNtNBm8=
+golang.org/x/image v0.15.0/go.mod h1:HUYqC05R2ZcZ3ejNQsIHQDQiwWM4JBqmm6MKANTp4LE=
+golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
+golang.org/x/sync v0.6.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
+golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

hardware/console.go

@@ -0,0 +1,15 @@
+package hardware
+
+import (
+	"github.com/maxfierke/gogo-gb/cart"
+	"github.com/maxfierke/gogo-gb/debug"
+	"github.com/maxfierke/gogo-gb/devices"
+)
+
+type Console interface {
+	AttachDebugger(debugger debug.Debugger)
+	DetachDebugger()
+	LoadCartridge(r *cart.Reader) error
+	Step() error
+	Run(host devices.HostInterface) error
+}