core: add screenshot utility

core/internal/wayland/client/helpers.go

@@ -0,0 +1,26 @@
+package client
+
+import wlclient "github.com/AvengeMedia/DankMaterialShell/core/pkg/go-wayland/wayland/client"
+
+func Roundtrip(display *wlclient.Display, ctx *wlclient.Context) error {
+	callback, err := display.Sync()
+	if err != nil {
+		return err
+	}
+
+	done := make(chan struct{})
+	callback.SetDoneHandler(func(e wlclient.CallbackDoneEvent) {
+		close(done)
+	})
+
+	for {
+		select {
+		case <-done:
+			return nil
+		default:
+			if err := ctx.Dispatch(); err != nil {
+				return err
+			}
+		}
+	}
+}

core/internal/wayland/shm/buffer.go

@@ -0,0 +1,139 @@
+package shm
+
+import (
+	"fmt"
+
+	"golang.org/x/sys/unix"
+)
+
+type PixelFormat uint32
+
+const (
+	FormatARGB8888 PixelFormat = 0
+	FormatXRGB8888 PixelFormat = 1
+	FormatABGR8888 PixelFormat = 0x34324241
+	FormatXBGR8888 PixelFormat = 0x34324258
+)
+
+type Buffer struct {
+	fd     int
+	data   []byte
+	size   int
+	Width  int
+	Height int
+	Stride int
+	Format PixelFormat
+}
+
+func CreateBuffer(width, height, stride int) (*Buffer, error) {
+	size := stride * height
+
+	fd, err := unix.MemfdCreate("dms-shm", 0)
+	if err != nil {
+		return nil, fmt.Errorf("memfd_create: %w", err)
+	}
+
+	if err := unix.Ftruncate(fd, int64(size)); err != nil {
+		unix.Close(fd)
+		return nil, fmt.Errorf("ftruncate: %w", err)
+	}
+
+	data, err := unix.Mmap(fd, 0, size, unix.PROT_READ|unix.PROT_WRITE, unix.MAP_SHARED)
+	if err != nil {
+		unix.Close(fd)
+		return nil, fmt.Errorf("mmap: %w", err)
+	}
+
+	return &Buffer{
+		fd:     fd,
+		data:   data,
+		size:   size,
+		Width:  width,
+		Height: height,
+		Stride: stride,
+	}, nil
+}
+
+func (b *Buffer) Fd() int      { return b.fd }
+func (b *Buffer) Size() int    { return b.size }
+func (b *Buffer) Data() []byte { return b.data }
+
+func (b *Buffer) Close() error {
+	var firstErr error
+
+	if b.data != nil {
+		if err := unix.Munmap(b.data); err != nil && firstErr == nil {
+			firstErr = fmt.Errorf("munmap: %w", err)
+		}
+		b.data = nil
+	}
+
+	if b.fd >= 0 {
+		if err := unix.Close(b.fd); err != nil && firstErr == nil {
+			firstErr = fmt.Errorf("close: %w", err)
+		}
+		b.fd = -1
+	}
+
+	return firstErr
+}
+
+func (b *Buffer) GetPixelRGBA(x, y int) (r, g, b2, a uint8) {
+	if x < 0 || x >= b.Width || y < 0 || y >= b.Height {
+		return
+	}
+
+	off := y*b.Stride + x*4
+	if off+3 >= len(b.data) {
+		return
+	}
+
+	return b.data[off+2], b.data[off+1], b.data[off], b.data[off+3]
+}
+
+func (b *Buffer) GetPixelBGRA(x, y int) (b2, g, r, a uint8) {
+	if x < 0 || x >= b.Width || y < 0 || y >= b.Height {
+		return
+	}
+
+	off := y*b.Stride + x*4
+	if off+3 >= len(b.data) {
+		return
+	}
+
+	return b.data[off], b.data[off+1], b.data[off+2], b.data[off+3]
+}
+
+func (b *Buffer) ConvertBGRAtoRGBA() {
+	for y := 0; y < b.Height; y++ {
+		rowOff := y * b.Stride
+		for x := 0; x < b.Width; x++ {
+			off := rowOff + x*4
+			if off+3 >= len(b.data) {
+				continue
+			}
+			b.data[off], b.data[off+2] = b.data[off+2], b.data[off]
+		}
+	}
+}
+
+func (b *Buffer) FlipVertical() {
+	tmp := make([]byte, b.Stride)
+	for y := 0; y < b.Height/2; y++ {
+		topOff := y * b.Stride
+		botOff := (b.Height - 1 - y) * b.Stride
+		copy(tmp, b.data[topOff:topOff+b.Stride])
+		copy(b.data[topOff:topOff+b.Stride], b.data[botOff:botOff+b.Stride])
+		copy(b.data[botOff:botOff+b.Stride], tmp)
+	}
+}
+
+func (b *Buffer) Clear() {
+	for i := range b.data {
+		b.data[i] = 0
+	}
+}
+
+func (b *Buffer) CopyFrom(src *Buffer) {
+	copy(b.data, src.data)
+}