Initial implementation of go unicorn hat driver

3 files changed, 171 insertions, 133 deletions

diff --git a/FakeUnicorn.go b/FakeUnicorn.go
new file mode 100644
index 0000000..2258e58
--- /dev/null
+++ b/FakeUnicorn.go
@@ -0,0 +1,94 @@
+package main
+
+import (
+	"github.com/veandco/go-sdl2/sdl"
+)
+
+type FakeUnicorn struct {
+	BaseUnicorn
+	displayWidth  int32
+	displayHeight int32
+	window   *sdl.Window
+	renderer *sdl.Renderer
+}
+
+// NewFake ...
+// Constructs a new fake unicorn out of paint and glue
+func NewFake(width, height uint8) (*FakeUnicorn, error) {
+	if err := sdl.Init(sdl.INIT_EVERYTHING); err != nil {
+		return nil, err
+	}
+
+	unicorn := &FakeUnicorn{
+		BaseUnicorn{
+			pixels:        makePixels(width, height),
+		},
+		300,
+		300,
+		nil, 
+		nil,
+	}
+	if err := unicorn.createWindow(); err != nil {
+		unicorn.Close()
+		return nil, err
+	}
+	if err := unicorn.createRenderer(); err != nil {
+		unicorn.Close()
+		return nil, err
+	}
+	return unicorn, nil
+}
+
+func (f *FakeUnicorn) createWindow() error {
+	window, err := sdl.CreateWindow("Fake Unicorn",
+		sdl.WINDOWPOS_UNDEFINED,
+		sdl.WINDOWPOS_UNDEFINED,
+		f.displayWidth,
+		f.displayHeight,
+		sdl.WINDOW_SHOWN)
+	f.window = window
+	return err
+}
+
+func (f *FakeUnicorn) createRenderer() error {
+	renderer, err := sdl.CreateRenderer(f.window, -1, sdl.RENDERER_ACCELERATED)
+	f.renderer = renderer
+	return err
+}
+
+func (f *FakeUnicorn) Close() error {
+	if f.window != nil {
+		f.window.Destroy()
+	}
+	if f.renderer != nil {
+		f.renderer.Destroy()
+	}
+	return nil
+}
+
+func (f *FakeUnicorn) Show() {
+	width, height := f.GetWidth(), f.GetHeight()
+	for x := uint8(0); x < width; x++ {
+		for y := uint8(0); y < height; y++ {
+			r, g, b := rgb(f.pixels[x][y])
+			if err := f.renderer.SetDrawColor(r, g, b, uint8(255)); err != nil {
+				panic(err)
+			}
+			cellWidth := f.displayWidth / int32(width)
+			cellHeight := f.displayHeight / int32(height)
+			if err := f.renderer.FillRect(&sdl.Rect{
+				X: cellWidth * int32(x),
+				Y: f.displayHeight - (cellHeight * int32(y)) - cellHeight, // SDL Y coordinate is from the top
+				W: cellWidth,
+				H: cellHeight,
+			}); err != nil {
+				panic(err)
+			}
+		}
+	}
+	f.renderer.Present()
+}
+
+func (f *FakeUnicorn) Off() {
+	f.Close()
+}
diff --git a/RealUnicorn.go b/RealUnicorn.go
new file mode 100644
index 0000000..d9665d8
--- /dev/null
+++ b/RealUnicorn.go
@@ -0,0 +1,62 @@
+package main
+
+import (
+	"golang.org/x/exp/io/spi"
+	"log"
+)
+
+type RealUnicorn struct {
+	BaseUnicorn
+	device *spi.Device
+}
+
+// NewReal ...
+// Constructs a new real unicorn from fairy dust and sprinkles
+func NewReal() (*RealUnicorn, error) {
+	dev, err := spi.Open(&spi.Devfs{
+		Dev:      "/dev/spidev0.0",
+		Mode:     spi.Mode0,
+		MaxSpeed: 9000000,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return &RealUnicorn{
+		BaseUnicorn{
+			pixels: makePixels(16, 16),
+		},
+		dev,
+	}, nil
+}
+
+func (u *RealUnicorn) Show() {
+	// Width * height * colours + leading bit
+	width := u.GetWidth()
+	height := u.GetHeight()
+	write := make([]byte, (width*height*3)+1)
+
+	// Add the leading bit
+	write[0] = 0x72
+	// Add all the pixel values
+	ix := 1
+	for x := uint8(0); x < width; x++ {
+		for y := uint8(0); y < height; y++ {
+			for j := 0; j < 3; j++ {
+				write[ix] = u.pixels[x][y][j]
+				ix++
+			}
+		}
+	}
+	// Write to the device
+	err := u.device.Tx(write, nil)
+	if err != nil {
+		log.Printf("Error writing to SPI device %v", err)
+	}
+}
+func (u *RealUnicorn) Off() {
+	u.Close()
+}
+func (u *RealUnicorn) Close() error {
+	return u.device.Close()
+}
diff --git a/Unicorn.go b/Unicorn.go
index 2e0e73f..905cc0a 100644
--- a/Unicorn.go
+++ b/Unicorn.go
@@ -1,9 +1,7 @@
 package main
 
 import (
-	"github.com/veandco/go-sdl2/sdl"
-	// "golang.org/x/exp/io/spi"
-	// "github.com/veandco/go-sdl2/sdl"
+	"log"
 )
 
 // Unicorn ...
@@ -33,126 +31,37 @@ type Unicorn interface {
 // Get a unicorn. Tries to get you a real one,
 // if it can't find one then gives you a fake one.
 func GetUnicorn() (unicorn Unicorn, err error) {
-	// unicorn, err = NewReal()
-	// if err != nil {
-	// 	log.Println("Couldn't get a real unicorn, trying a fake one")
-	// 	unicorn, err = NewFake(int8(16), int8(16))
-	// }
+	unicorn, err = NewReal()
+	if err != nil {
+		log.Println("Couldn't get a real unicorn, trying a fake one")
+		unicorn, err = NewFake(uint8(16), uint8(16))
+	}
 	unicorn, err = NewFake(uint8(16), uint8(16))
 	return
 }
 
-// FakeUnicorn ...
-// Shows an SDL window pretending to be a unicorn.
-type FakeUnicorn struct {
+type BaseUnicorn struct {
 	pixels        [][][]uint8
-	displayWidth  int32
-	displayHeight int32
-
-	window   *sdl.Window
-	renderer *sdl.Renderer
-}
-
-// NewFake ...
-// Constructs a new fake unicorn out of paint and glue
-func NewFake(width, height uint8) (*FakeUnicorn, error) {
-	if err := sdl.Init(sdl.INIT_EVERYTHING); err != nil {
-		return nil, err
-	}
-
-	unicorn := &FakeUnicorn{
-		pixels:        makePixels(width, height),
-		window:        nil,
-		renderer:      nil,
-		displayWidth:  300,
-		displayHeight: 300,
-	}
-	if err := unicorn.createWindow(); err != nil {
-		unicorn.Close()
-		return nil, err
-	}
-	if err := unicorn.createRenderer(); err != nil {
-		unicorn.Close()
-		return nil, err
-	}
-	return unicorn, nil
 }
 
-func (f *FakeUnicorn) createWindow() error {
-	window, err := sdl.CreateWindow("Fake Unicorn",
-		sdl.WINDOWPOS_UNDEFINED,
-		sdl.WINDOWPOS_UNDEFINED,
-		f.displayWidth,
-		f.displayHeight,
-		sdl.WINDOW_SHOWN)
-	f.window = window
-	return err
-}
-
-func (f *FakeUnicorn) createRenderer() error {
-	renderer, err := sdl.CreateRenderer(f.window, -1, sdl.RENDERER_ACCELERATED)
-	f.renderer = renderer
-	return err
-}
-
-func (f *FakeUnicorn) Close() error {
-	if f.window != nil {
-		f.window.Destroy()
-	}
-	if f.renderer != nil {
-		f.renderer.Destroy()
-	}
-	return nil
-}
-
-func (f *FakeUnicorn) GetWidth() uint8 {
+func (f *BaseUnicorn) GetWidth() uint8 {
 	return uint8(len(f.pixels))
 }
-func (f *FakeUnicorn) GetHeight() uint8 {
+func (f *BaseUnicorn) GetHeight() uint8 {
 	if len(f.pixels) > 0 {
 		return uint8(len(f.pixels[0]))
 	}
 	return 0
 }
-func (f *FakeUnicorn) GetPixels() [][][]uint8 {
+func (f *BaseUnicorn) GetPixels() [][][]uint8 {
 	return f.pixels
 }
-func (f *FakeUnicorn) SetPixel(x, y, r, g, b uint8) {
+func (f *BaseUnicorn) SetPixel(x, y, r, g, b uint8) {
 	f.pixels[x][y] = []uint8{r, g, b}
 }
-func (f *FakeUnicorn) Show() {
-	width, height := f.GetWidth(), f.GetHeight()
-	for x := uint8(0); x < width; x++ {
-		for y := uint8(0); y < height; y++ {
-			r, g, b := rgb(f.pixels[x][y])
-			if err := f.renderer.SetDrawColor(r, g, b, uint8(255)); err != nil {
-				panic(err)
-			}
-			cellWidth := f.displayWidth / int32(width)
-			cellHeight := f.displayHeight / int32(height)
-			if err := f.renderer.FillRect(&sdl.Rect{
-				X: cellWidth * int32(x),
-				Y: f.displayHeight - (cellHeight * int32(y)) - cellHeight, // SDL Y coordinate is from the top
-				W: cellWidth,
-				H: cellHeight,
-			}); err != nil {
-				panic(err)
-			}
-		}
-	}
-	f.renderer.Present()
-}
-
-func rgb(pixel []uint8) (uint8, uint8, uint8) {
-	return pixel[0], pixel[1], pixel[2]
-}
-
-func (f *FakeUnicorn) Clear() {
+func (f *BaseUnicorn) Clear() {
 	f.pixels = makePixels(f.GetWidth(), f.GetHeight())
 }
-func (f *FakeUnicorn) Off() {
-	f.Close()
-}
 
 func makePixels(width, height uint8) [][][]uint8 {
 	pixels := make([][][]uint8, width)
@@ -165,34 +74,7 @@ func makePixels(width, height uint8) [][][]uint8 {
 	return pixels
 }
 
-// RealUnicorn ...
-// A real one! *gasps*
-// type RealUnicorn struct {}
-
-// // NewReal ...
-// // Constructs a new real unicorn from fairy dust and sprinkles
-// func NewReal() (*RealUnicorn, error) {
-// 	return nil, errors.New("Couldn't make a real unicorn sorry")
-// }
-
-// func (u *RealUnicorn) GetWidth() int8 {
-// 	return 0
-// }
-// func (u *RealUnicorn) GetHeight() int8 {
-// 	return 0
-// }
-// func (u *RealUnicorn) GetPixels() [][][]int8 {
-// 	return nil
-// }
-// func (u *RealUnicorn) SetPixel(x, y, r, g, b int8) {
-
-// }
-// func (u *RealUnicorn) Show() {
 
-// }
-// func (u *RealUnicorn) Clear() {
-
-// }
-// func (u *RealUnicorn) Off() {
-
-// }
+func rgb(pixel []uint8) (uint8, uint8, uint8) {
+	return pixel[0], pixel[1], pixel[2]
+}
\ No newline at end of file