Add argument handling

README.md

@@ -4,6 +4,23 @@ My first attempt at emulation. This Go project aims to emulate a fully working C
 
 Everything works as far as I have tested, except for audio.
 
+## Usage
+```
+Usage: chip8 [--scaling SCALING] [--fps FPS] [--cpuspeed CPUSPEED] ROMPATH
+
+Positional arguments:
+  ROMPATH                Path to CHIP8 ROM file.
+
+Options:
+  --scaling SCALING, -s SCALING
+                         Pixel scaling. Adjusts size of display. [default: 15]
+  --fps FPS, -f FPS      FPS to run display at. [default: 60]
+  --cpuspeed CPUSPEED, -c CPUSPEED
+                         Speed of CPU relative to FPS. [default: 10]
+  --help, -h             display this help and exit
+  --version              display version and exit
+```
+
 ## Controls
  Keys
 
@@ -42,7 +59,6 @@ respectively
 
 
 ## TODO (in no particular order):
-- Create a way to customize controls and settings (maybe using config files, maybe some GUI)
 - Add more invasive features (e.g. Soft reset, Hard reset, memory manipulation, etc.)
 - Implement VIP/Super chip8
 - Implement audio (needs a better understanding of goroutines and channels)

go.mod

@@ -3,6 +3,7 @@ module github.com/soumitradev/chip8
 go 1.16
 
 require (
+	github.com/alexflint/go-arg v1.3.0 // indirect
 	github.com/faiface/pixel v0.10.0
 	github.com/go-gl/gl v0.0.0-20210315015930-ae072cafe09d // indirect
 	github.com/go-gl/glfw/v3.3/glfw v0.0.0-20210311203641-62640a716d48 // indirect

go.sum

@@ -1,5 +1,10 @@
+github.com/alexflint/go-arg v1.3.0 h1:UfldqSdFWeLtoOuVRosqofU4nmhI1pYEbT4ZFS34Bdo=
+github.com/alexflint/go-arg v1.3.0/go.mod h1:9iRbDxne7LcR/GSvEr7ma++GLpdIU1zrghf2y2768kM=
+github.com/alexflint/go-scalar v1.0.0 h1:NGupf1XV/Xb04wXskDFzS0KWOLH632W/EO4fAFi+A70=
+github.com/alexflint/go-scalar v1.0.0/go.mod h1:GpHzbCOZXEKMEcygYQ5n/aa4Aq84zbxjy3MxYW0gjYw=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/faiface/glhf v0.0.0-20181018222622-82a6317ac380 h1:FvZ0mIGh6b3kOITxUnxS3tLZMh7yEoHo75v3/AgUqg0=
 github.com/faiface/glhf v0.0.0-20181018222622-82a6317ac380/go.mod h1:zqnPFFIuYFFxl7uH2gYByJwIVKG7fRqlqQCbzAnHs9g=
 github.com/faiface/mainthread v0.0.0-20171120011319-8b78f0a41ae3 h1:baVdMKlASEHrj19iqjARrPbaRisD7EuZEVJj6ZMLl1Q=
@@ -22,6 +27,7 @@ github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 golang.org/x/image v0.0.0-20190321063152-3fc05d484e9f/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=

main.go

@@ -2,12 +2,26 @@ package main
 
 import (
 	"time"
+
+	"github.com/alexflint/go-arg"
 )
 
-// Adjust these according to your game/preferences
-const SCALING = 15
-const FPS = 60
-const speed = 10
+// Adjust these according to your game preferences
+var SCALING = 15
+var FPS = 60
+var speed = 10
+
+type args struct {
+	ROMPATH  string `arg:"positional" help:"Path to CHIP8 ROM file."`
+	SCALING  int    `default:"15" arg:"-s" help:"Pixel scaling. Adjusts size of display."`
+	FPS      int    `default:"60" arg:"-f" help:"FPS to run display at."`
+	CPUspeed int    `default:"10" arg:"-c" help:"Speed of CPU relative to FPS."`
+}
+
+// Return version info
+func (args) Version() string {
+	return "chip8 v0.1.0"
+}
 
 // Timing vars
 var startTime time.Time
@@ -17,14 +31,23 @@ var elapsed time.Duration
 var fpsInterval time.Duration
 
 func main() {
+	// Use prefs in args
+	var args args
+
+	arg.MustParse(&args)
+	var ROMPATH = args.ROMPATH
+	SCALING = args.SCALING
+	FPS = args.FPS
+	speed = args.CPUspeed
+
 	// Decide how often we render a frame
-	fpsInterval = time.Duration(time.Millisecond * 1000.0 / FPS)
+	fpsInterval = time.Duration(time.Millisecond * 1000.0 / time.Duration(FPS))
 	then = time.Now()
 	startTime = then
 
 	// Load the chip8 font and ROM into memory
 	loadSprites()
-	loadROM("ROMs/SPACEINVADERS.ch8")
+	loadROM(ROMPATH)
 
 	// Start display and take one step forward (render one frame)
 	startDisplay()

screen.go

@@ -83,7 +83,7 @@ func run() {
 	// Configure window
 	cfg := pixelgl.WindowConfig{
 		Title:  "Chip8",
-		Bounds: pixel.R(0, 0, 64*SCALING, 32*SCALING),
+		Bounds: pixel.R(0, 0, float64(64*SCALING), float64(32*SCALING)),
 		VSync:  true,
 	}
 	window, err := pixelgl.NewWindow(cfg)
@@ -134,10 +134,10 @@ func screenRender() {
 	imd.Clear()
 	for i := 0; i < 64*32; i++ {
 		x := float64((i % 64) * SCALING)
-		y := 31*SCALING - float64((i/64)*SCALING)
+		y := float64(31*SCALING - (i/64)*SCALING)
 		if display[i] {
 			imd.Push(pixel.V(x, y))
-			imd.Push(pixel.V(x+SCALING, y+SCALING))
+			imd.Push(pixel.V(x+float64(SCALING), y+float64(SCALING)))
 			imd.Rectangle(0)
 		}
 	}