Text + MXL logo pattern

internal/generator/wgpu.go

@@ -35,6 +35,8 @@ type WGPUGenerator struct {
 	out       *wgpu.Buffer
 	host      *wgpu.Buffer
 	uniform   *wgpu.Buffer
+	logo      *wgpu.Buffer
+	logoPlane []uint32
 	params    []byte
 	width     int
 	height    int
@@ -44,13 +46,27 @@ type WGPUGenerator struct {
 
 var _ FrameGenerator = (*WGPUGenerator)(nil)
 
-func NewWGPUGenerator(width, height uint, kernelPath string) (*WGPUGenerator, error) {
+// WGPUOption customizes NewWGPUGenerator.
+type WGPUOption func(*WGPUGenerator)
+
+// WithLogo attaches a packed logo plane (see BuildLogoPlane) as read-only
+// storage binding 2 for kernels that sample it (v210_dvd_logo.wgsl).
+func WithLogo(plane []uint32) WGPUOption {
+	return func(g *WGPUGenerator) {
+		g.logoPlane = plane
+	}
+}
+
+func NewWGPUGenerator(width, height uint, kernelPath string, opts ...WGPUOption) (*WGPUGenerator, error) {
 	g := &WGPUGenerator{
 		width:  int(width),
 		height: int(height),
 		blocks: int(width*height) / 6,
 		params: make([]byte, 16),
 	}
+	for _, opt := range opts {
+		opt(g)
+	}
 	g.frameSize = uint64(g.blocks) * 16
 	binary.LittleEndian.PutUint32(g.params[0:], uint32(width))
 	binary.LittleEndian.PutUint32(g.params[4:], uint32(height))
@@ -105,22 +121,48 @@ func NewWGPUGenerator(width, height uint, kernelPath string) (*WGPUGenerator, er
 		g.Close()
 		return nil, fmt.Errorf("wgpu: write params: %w", err)
 	}
+	bglEntries := []gputypes.BindGroupLayoutEntry{
+		{Binding: 0, Visibility: wgpu.ShaderStageCompute, Buffer: &gputypes.BufferBindingLayout{Type: gputypes.BufferBindingTypeStorage}},
+		{Binding: 1, Visibility: wgpu.ShaderStageCompute, Buffer: &gputypes.BufferBindingLayout{Type: gputypes.BufferBindingTypeUniform}},
+	}
+	bgEntries := []wgpu.BindGroupEntry{
+		{Binding: 0, Buffer: g.out, Size: g.frameSize},
+		{Binding: 1, Buffer: g.uniform, Size: uint64(len(g.params))},
+	}
+	if g.logoPlane != nil {
+		logoBytes := make([]byte, 4*len(g.logoPlane))
+		for i, v := range g.logoPlane {
+			binary.LittleEndian.PutUint32(logoBytes[4*i:], v)
+		}
+		if g.logo, err = g.device.CreateBuffer(&wgpu.BufferDescriptor{
+			Label: "v210-logo", Size: uint64(len(logoBytes)),
+			Usage: wgpu.BufferUsageStorage | wgpu.BufferUsageCopyDst,
+		}); err != nil {
+			g.Close()
+			return nil, fmt.Errorf("wgpu: logo buffer: %w", err)
+		}
+		if err := g.queue.WriteBuffer(g.logo, 0, logoBytes); err != nil {
+			g.Close()
+			return nil, fmt.Errorf("wgpu: write logo: %w", err)
+		}
+		bglEntries = append(bglEntries, gputypes.BindGroupLayoutEntry{
+			Binding: 2, Visibility: wgpu.ShaderStageCompute,
+			Buffer: &gputypes.BufferBindingLayout{Type: gputypes.BufferBindingTypeReadOnlyStorage},
+		})
+		bgEntries = append(bgEntries, wgpu.BindGroupEntry{
+			Binding: 2, Buffer: g.logo, Size: uint64(len(logoBytes)),
+		})
+	}
 	if g.bgl, err = g.device.CreateBindGroupLayout(&wgpu.BindGroupLayoutDescriptor{
-		Label: "v210-bgl",
-		Entries: []gputypes.BindGroupLayoutEntry{
-			{Binding: 0, Visibility: wgpu.ShaderStageCompute, Buffer: &gputypes.BufferBindingLayout{Type: gputypes.BufferBindingTypeStorage}},
-			{Binding: 1, Visibility: wgpu.ShaderStageCompute, Buffer: &gputypes.BufferBindingLayout{Type: gputypes.BufferBindingTypeUniform}},
-		},
+		Label:   "v210-bgl",
+		Entries: bglEntries,
 	}); err != nil {
 		g.Close()
 		return nil, fmt.Errorf("wgpu: bind group layout: %w", err)
 	}
 	if g.bg, err = g.device.CreateBindGroup(&wgpu.BindGroupDescriptor{
 		Label: "v210-bg", Layout: g.bgl,
-		Entries: []wgpu.BindGroupEntry{
-			{Binding: 0, Buffer: g.out, Size: g.frameSize},
-			{Binding: 1, Buffer: g.uniform, Size: uint64(len(g.params))},
-		},
+		Entries: bgEntries,
 	}); err != nil {
 		g.Close()
 		return nil, fmt.Errorf("wgpu: bind group: %w", err)
@@ -212,6 +254,10 @@ func (g *WGPUGenerator) Close() error {
 		g.uniform.Release()
 		g.uniform = nil
 	}
+	if g.logo != nil {
+		g.logo.Release()
+		g.logo = nil
+	}
 	if g.host != nil {
 		g.host.Release()
 		g.host = nil