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// +build !tinygo
package gfx
import "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 color.Color
}
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)
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 := &gfx.TrianglesData{}
// batch := gfx.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
}
// 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(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(_ *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(Errorf("(%T).Draw: TargetTriangles generated by different Batch", bp))
}
bt.draw(bp)
}
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