4 files changed, 49 insertions, 13 deletions

diff --git a/unicorn/BaseFakeUnicorn.go b/unicorn/BaseFakeUnicorn.go
index 7910814..19c1d59 100644
--- a/unicorn/BaseFakeUnicorn.go
+++ b/unicorn/BaseFakeUnicorn.go
@@ -1,3 +1,5 @@
+// +build linux,386 linux,amd64
+
 package unicorn
 
 import "github.com/veandco/go-sdl2/sdl"
diff --git a/unicorn/FakeUnicorn2.go b/unicorn/FakeUnicorn2.go
index 27629d2..8728c15 100644
--- a/unicorn/FakeUnicorn2.go
+++ b/unicorn/FakeUnicorn2.go
@@ -1,3 +1,5 @@
+// +build linux,386 linux,amd64
+
 package unicorn
 
 import (
@@ -7,7 +9,7 @@ import (
 )
 
 type FakeUnicorn2 struct {
-	BaseUnicorn2
+	*BaseUnicorn2
 	*BaseFakeUnicorn
 }
 
@@ -37,13 +39,17 @@ func (u *FakeUnicorn2) renderImage(im image.Image) {
 	u.renderer.Present()
 }
 
+func (u *FakeUnicorn2) StartRender() chan bool {
+	return u.StartRenderBase(u.renderImage)
+}
+
 func NewUnicorn2() (*FakeUnicorn2, error) {
 	baseFake, err := NewBaseFakeUnicorn(300, 300)
 	if err != nil {
 		return nil, err
 	}
 	return &FakeUnicorn2{
-		BaseUnicorn2{},
+		NewBaseUnicorn2(),
 		baseFake,
 	}, nil
 }
diff --git a/unicorn/RealUnicorn2.go b/unicorn/RealUnicorn2.go
index 991e79f..72b4ed7 100644
--- a/unicorn/RealUnicorn2.go
+++ b/unicorn/RealUnicorn2.go
@@ -13,7 +13,7 @@ import (
 )
 
 type RealUnicorn2 struct {
-	BaseUnicorn2
+	*BaseUnicorn2
 	device *spi.Device
 }
 
@@ -55,11 +55,17 @@ func NewUnicorn2() (*RealUnicorn2, error) {
 		return nil, err
 	}
 	return &RealUnicorn2{
-		BaseUnicorn2{},
+		NewBaseUnicorn2(),
 		dev,
 	}, nil
 }
 
+// StartRender ...
+// Passes through to base to actually do the render
+func (u *RealUnicorn2) StartRender() chan bool {
+	return u.StartRenderBase(u.renderImage)
+}
+
 // MainLoop ...
 // Just blocks until sigterm
 func (u *RealUnicorn2) MainLoop() {
diff --git a/unicorn/Unicorn2.go b/unicorn/Unicorn2.go
index 04722f7..5dcc6c2 100644
--- a/unicorn/Unicorn2.go
+++ b/unicorn/Unicorn2.go
@@ -5,6 +5,7 @@ package unicorn
 
 import (
 	"image"
+	"image/color/palette"
 	"image/gif"
 	"time"
 )
@@ -18,7 +19,7 @@ type Unicorn2 interface {
 	SetGif(*gif.GIF)
 
 	// Starts the rendering goroutine
-	StartRender()
+	StartRender() chan bool
 
 	// Must be implemented to actually render the image to device
 	renderImage(image.Image)
@@ -42,11 +43,26 @@ func (u *BaseUnicorn2) SetGif(g *gif.GIF) {
 	u.g = g
 }
 
-// StartRender ...
-// Starts rendering the image. If it's an animated image,
-// renders animation frames. Return a channel to stop the
-// image rendering.
-func (u *FakeUnicorn2) StartRender() chan bool {
+func NewBaseUnicorn2() *BaseUnicorn2 {
+	im := image.NewPaletted(
+		image.Rect(0, 0, 16, 16),
+		palette.WebSafe)
+
+	gf := &gif.GIF{
+		Image:           []*image.Paletted{im},
+		Delay:           []int{50},
+		Disposal:        []byte{gif.DisposalBackground},
+		BackgroundIndex: 0, // This is black in the websafe palette
+	}
+
+	return &BaseUnicorn2{
+		g: gf,
+	}
+}
+
+// StartRenderBase ...
+// Deals with the timing aspect of animated GIFs
+func (u *BaseUnicorn2) StartRenderBase(renderImage func(image.Image)) chan bool {
 	stopChan := make(chan bool)
 	go func() {
 		timer := time.NewTimer(0)
@@ -59,14 +75,20 @@ func (u *FakeUnicorn2) StartRender() chan bool {
 				running = false
 			case <-timer.C:
 				gf := u.GetGif()
+
+				// Image could change underneath us, but there should always be 1 image at least.
+				if imageIndex >= len(gf.Image) {
+					imageIndex = 0
+				}
+
 				im := gf.Image[imageIndex]
 				delay := gf.Delay[imageIndex] //100ths of a second, 10^-2
-				u.renderImage(im)
-				
+				renderImage(im)
+
 				timer.Reset(time.Duration(delay * 10000000)) // nanoseconds 10^-9 sec
 				imageIndex = (imageIndex + 1) % len(gf.Image)
 			}
 		}
 	}()
 	return stopChan
-}
\ No newline at end of file
+}