draw optimizations

client/world/fake_drawer_test.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"image"
 	"image/color"
+	"sync"
 )
 
 // fakeClipRect describes one clip rectangle in canvas pixel coordinates.
@@ -66,6 +67,7 @@ type fakePrimitiveDrawer struct {
 	commands []fakeDrawerCommand
 	state    fakeDrawerState
 	stack    []fakeDrawerState
+	mu       sync.Mutex
 }
 
 // Ensure fakePrimitiveDrawer implements PrimitiveDrawer.
@@ -248,3 +250,8 @@ func (d *fakePrimitiveDrawer) DrawImage(_ image.Image, x, y int) {
 func (d *fakePrimitiveDrawer) DrawImageScaled(_ image.Image, x, y, w, h int) {
 	d.snapshotCommand("DrawImageScaled", float64(x), float64(y), float64(w), float64(h))
 }
+func (d *fakePrimitiveDrawer) Reset() {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	d.commands = d.commands[:0]
+}