1 files changed, 129 insertions, 0 deletions
diff --git a/vendor/gioui.org/gpu/cpu.go b/vendor/gioui.org/gpu/cpu.go
new file mode 100644
index 0000000..f2f84ad
--- /dev/null
+++ b/vendor/gioui.org/gpu/cpu.go
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package gpu
+
+import (
+	"unsafe"
+
+	"gioui.org/cpu"
+)
+
+// This file contains code specific to running compute shaders on the CPU.
+
+// dispatcher dispatches CPU compute programs across multiple goroutines.
+type dispatcher struct {
+	// done is notified when a worker completes its work slice.
+	done chan struct{}
+	// work receives work slice indices. It is closed when the dispatcher is released.
+	work chan work
+	// dispatch receives compute jobs, which is then split among workers.
+	dispatch chan dispatch
+	// sync receives notification when a Sync completes.
+	sync chan struct{}
+}
+
+type work struct {
+	ctx   *cpu.DispatchContext
+	index int
+}
+
+type dispatch struct {
+	_type   jobType
+	program *cpu.ProgramInfo
+	descSet unsafe.Pointer
+	x, y, z int
+}
+
+type jobType uint8
+
+const (
+	jobDispatch jobType = iota
+	jobBarrier
+	jobSync
+)
+
+func newDispatcher(workers int) *dispatcher {
+	d := &dispatcher{
+		work: make(chan work, workers),
+		done: make(chan struct{}, workers),
+		// Leave some room to avoid blocking calls to Dispatch.
+		dispatch: make(chan dispatch, 20),
+		sync:     make(chan struct{}),
+	}
+	for i := 0; i < workers; i++ {
+		go d.worker()
+	}
+	go d.dispatcher()
+	return d
+}
+
+func (d *dispatcher) dispatcher() {
+	defer close(d.work)
+	var free []*cpu.DispatchContext
+	defer func() {
+		for _, ctx := range free {
+			ctx.Free()
+		}
+	}()
+	var used []*cpu.DispatchContext
+	for job := range d.dispatch {
+		switch job._type {
+		case jobDispatch:
+			if len(free) == 0 {
+				free = append(free, cpu.NewDispatchContext())
+			}
+			ctx := free[len(free)-1]
+			free = free[:len(free)-1]
+			used = append(used, ctx)
+			ctx.Prepare(cap(d.work), job.program, job.descSet, job.x, job.y, job.z)
+			for i := 0; i < cap(d.work); i++ {
+				d.work <- work{
+					ctx:   ctx,
+					index: i,
+				}
+			}
+		case jobBarrier:
+			// Wait for all outstanding dispatches to complete.
+			for i := 0; i < len(used)*cap(d.work); i++ {
+				<-d.done
+			}
+			free = append(free, used...)
+			used = used[:0]
+		case jobSync:
+			d.sync <- struct{}{}
+		}
+	}
+}
+
+func (d *dispatcher) worker() {
+	thread := cpu.NewThreadContext()
+	defer thread.Free()
+	for w := range d.work {
+		w.ctx.Dispatch(w.index, thread)
+		d.done <- struct{}{}
+	}
+}
+
+func (d *dispatcher) Barrier() {
+	d.dispatch <- dispatch{_type: jobBarrier}
+}
+
+func (d *dispatcher) Sync() {
+	d.dispatch <- dispatch{_type: jobSync}
+	<-d.sync
+}
+
+func (d *dispatcher) Dispatch(program *cpu.ProgramInfo, descSet unsafe.Pointer, x, y, z int) {
+	d.dispatch <- dispatch{
+		_type:   jobDispatch,
+		program: program,
+		descSet: descSet,
+		x:       x,
+		y:       y,
+		z:       z,
+	}
+}
+
+func (d *dispatcher) Stop() {
+	close(d.dispatch)
+}