Files
netbird/client/vnc/server/capture_dxgi_windows.go

100 lines
2.4 KiB
Go

//go:build windows
package server
import (
"errors"
"fmt"
"image"
"github.com/kirides/go-d3d/d3d11"
"github.com/kirides/go-d3d/outputduplication"
)
// dxgiCapturer captures the desktop using DXGI Desktop Duplication.
// Provides GPU-accelerated capture with native dirty rect tracking.
// Only works from the interactive user session, not Session 0.
//
// Uses a double-buffer: DXGI writes into img, then we copy to the current
// output buffer and hand it out. Alternating between two output buffers
// avoids allocating a new image.RGBA per frame (~8MB at 1080p, 30fps).
type dxgiCapturer struct {
dup *outputduplication.OutputDuplicator
device *d3d11.ID3D11Device
ctx *d3d11.ID3D11DeviceContext
img *image.RGBA
out [2]*image.RGBA
outIdx int
width int
height int
}
func newDXGICapturer() (*dxgiCapturer, error) {
device, deviceCtx, err := d3d11.NewD3D11Device()
if err != nil {
return nil, fmt.Errorf("create D3D11 device: %w", err)
}
dup, err := outputduplication.NewIDXGIOutputDuplication(device, deviceCtx, 0)
if err != nil {
device.Release()
deviceCtx.Release()
return nil, fmt.Errorf("create output duplication: %w", err)
}
w, h := screenSize()
if w == 0 || h == 0 {
dup.Release()
device.Release()
deviceCtx.Release()
return nil, fmt.Errorf("screen dimensions are zero")
}
rect := image.Rect(0, 0, w, h)
c := &dxgiCapturer{
dup: dup,
device: device,
ctx: deviceCtx,
img: image.NewRGBA(rect),
out: [2]*image.RGBA{image.NewRGBA(rect), image.NewRGBA(rect)},
width: w,
height: h,
}
// Grab the initial frame with a longer timeout to ensure we have
// a valid image before returning.
_ = dup.GetImage(c.img, 2000)
return c, nil
}
func (c *dxgiCapturer) capture() (*image.RGBA, error) {
err := c.dup.GetImage(c.img, 100)
if err != nil && !errors.Is(err, outputduplication.ErrNoImageYet) {
return nil, err
}
// Copy into the next output buffer. The DesktopCapturer hands out the
// returned pointer to VNC sessions that read pixels concurrently, so we
// alternate between two pre-allocated buffers instead of allocating per frame.
out := c.out[c.outIdx]
c.outIdx ^= 1
copy(out.Pix, c.img.Pix)
return out, nil
}
func (c *dxgiCapturer) close() {
if c.dup != nil {
c.dup.Release()
c.dup = nil
}
if c.ctx != nil {
c.ctx.Release()
c.ctx = nil
}
if c.device != nil {
c.device.Release()
c.device = nil
}
}