Use dep to vendor things

vendor/github.com/faiface/pixel/batch.go

@@ -0,0 +1,163 @@
+package pixel
+
+import (
+	"fmt"
+	"image/color"
+)
+
+// Batch is a Target that allows for efficient drawing of many objects with the same Picture.
+//
+// To put an object into a Batch, just draw it onto it:
+//   object.Draw(batch)
+type Batch struct {
+	cont Drawer
+
+	mat Matrix
+	col RGBA
+}
+
+var _ BasicTarget = (*Batch)(nil)
+
+// NewBatch creates an empty Batch with the specified Picture and container.
+//
+// The container is where objects get accumulated. Batch will support precisely those Triangles
+// properties, that the supplied container supports. If you retain access to the container and
+// change it, call Dirty to notify Batch about the change.
+//
+// Note, that if the container does not support TrianglesColor, color masking will not work.
+func NewBatch(container Triangles, pic Picture) *Batch {
+	b := &Batch{cont: Drawer{Triangles: container, Picture: pic}}
+	b.SetMatrix(IM)
+	b.SetColorMask(Alpha(1))
+	return b
+}
+
+// Dirty notifies Batch about an external modification of it's container. If you retain access to
+// the Batch's container and change it, call Dirty to notify Batch about the change.
+//
+//   container := &pixel.TrianglesData{}
+//   batch := pixel.NewBatch(container, nil)
+//   container.SetLen(10) // container changed from outside of Batch
+//   batch.Dirty()        // notify Batch about the change
+func (b *Batch) Dirty() {
+	b.cont.Dirty()
+}
+
+// Clear removes all objects from the Batch.
+func (b *Batch) Clear() {
+	b.cont.Triangles.SetLen(0)
+	b.cont.Dirty()
+}
+
+// Draw draws all objects that are currently in the Batch onto another Target.
+func (b *Batch) Draw(t Target) {
+	b.cont.Draw(t)
+}
+
+// SetMatrix sets a Matrix that every point will be projected by.
+func (b *Batch) SetMatrix(m Matrix) {
+	b.mat = m
+}
+
+// SetColorMask sets a mask color used in the following draws onto the Batch.
+func (b *Batch) SetColorMask(c color.Color) {
+	if c == nil {
+		b.col = Alpha(1)
+		return
+	}
+	b.col = ToRGBA(c)
+}
+
+// MakeTriangles returns a specialized copy of the provided Triangles that draws onto this Batch.
+func (b *Batch) MakeTriangles(t Triangles) TargetTriangles {
+	bt := &batchTriangles{
+		tri: t.Copy(),
+		tmp: MakeTrianglesData(t.Len()),
+		dst: b,
+	}
+	return bt
+}
+
+// MakePicture returns a specialized copy of the provided Picture that draws onto this Batch.
+func (b *Batch) MakePicture(p Picture) TargetPicture {
+	if p != b.cont.Picture {
+		panic(fmt.Errorf("(%T).MakePicture: Picture is not the Batch's Picture", b))
+	}
+	bp := &batchPicture{
+		pic: p,
+		dst: b,
+	}
+	return bp
+}
+
+type batchTriangles struct {
+	tri Triangles
+	tmp *TrianglesData
+	dst *Batch
+}
+
+func (bt *batchTriangles) Len() int {
+	return bt.tri.Len()
+}
+
+func (bt *batchTriangles) SetLen(len int) {
+	bt.tri.SetLen(len)
+	bt.tmp.SetLen(len)
+}
+
+func (bt *batchTriangles) Slice(i, j int) Triangles {
+	return &batchTriangles{
+		tri: bt.tri.Slice(i, j),
+		tmp: bt.tmp.Slice(i, j).(*TrianglesData),
+		dst: bt.dst,
+	}
+}
+
+func (bt *batchTriangles) Update(t Triangles) {
+	bt.tri.Update(t)
+}
+
+func (bt *batchTriangles) Copy() Triangles {
+	return &batchTriangles{
+		tri: bt.tri.Copy(),
+		tmp: bt.tmp.Copy().(*TrianglesData),
+		dst: bt.dst,
+	}
+}
+
+func (bt *batchTriangles) draw(bp *batchPicture) {
+	bt.tmp.Update(bt.tri)
+
+	for i := range *bt.tmp {
+		(*bt.tmp)[i].Position = bt.dst.mat.Project((*bt.tmp)[i].Position)
+		(*bt.tmp)[i].Color = bt.dst.col.Mul((*bt.tmp)[i].Color)
+	}
+
+	cont := bt.dst.cont.Triangles
+	cont.SetLen(cont.Len() + bt.tri.Len())
+	added := cont.Slice(cont.Len()-bt.tri.Len(), cont.Len())
+	added.Update(bt.tri)
+	added.Update(bt.tmp)
+	bt.dst.cont.Dirty()
+}
+
+func (bt *batchTriangles) Draw() {
+	bt.draw(nil)
+}
+
+type batchPicture struct {
+	pic Picture
+	dst *Batch
+}
+
+func (bp *batchPicture) Bounds() Rect {
+	return bp.pic.Bounds()
+}
+
+func (bp *batchPicture) Draw(t TargetTriangles) {
+	bt := t.(*batchTriangles)
+	if bp.dst != bt.dst {
+		panic(fmt.Errorf("(%T).Draw: TargetTriangles generated by different Batch", bp))
+	}
+	bt.draw(bp)
+}