sneak
402c0797d5
Features: - Beautiful system statistics display using IBM Plex Mono font - Direct framebuffer rendering without X11/Wayland - Multiple screens with automatic carousel rotation - Real-time system monitoring (CPU, memory, disk, network, processes) - Systemd service integration with install command - Clean architecture using uber/fx dependency injection Architecture: - Cobra CLI with daemon, install, status, and info commands - Modular design with separate packages for display, rendering, and stats - Font embedding for zero runtime dependencies - Layout API for clean text rendering - Support for multiple screen types (overview, top CPU, top memory) Technical details: - Uses gopsutil for cross-platform system stats collection - Direct Linux framebuffer access via memory mapping - Anti-aliased text rendering with freetype - Configurable screen rotation and update intervals - Structured logging with slog - Comprehensive test coverage and linting setup This initial version provides a solid foundation for displaying rich system information on resource-constrained devices like Raspberry Pis.
140 lines
3.0 KiB
Go
140 lines
3.0 KiB
Go
package display
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import (
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"fmt"
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"image"
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"log/slog"
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"os"
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"syscall"
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"unsafe"
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)
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// Display interface for showing images
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type Display interface {
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Show(img *image.RGBA) error
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Clear() error
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Close() error
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}
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// FramebufferDisplay implements Display for Linux framebuffer
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type FramebufferDisplay struct {
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file *os.File
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info *fbVarScreenInfo
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memory []byte
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logger *slog.Logger
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}
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type fbVarScreenInfo struct {
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XRes uint32
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YRes uint32
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XResVirtual uint32
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YResVirtual uint32
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XOffset uint32
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YOffset uint32
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BitsPerPixel uint32
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Grayscale uint32
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Red fbBitfield
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Green fbBitfield
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Blue fbBitfield
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Transp fbBitfield
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_ [4]byte
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}
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type fbBitfield struct {
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Offset uint32
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Length uint32
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Right uint32
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}
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const (
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fbiogetVscreeninfo = 0x4600
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)
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// NewFramebufferDisplay creates a new framebuffer display
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func NewFramebufferDisplay(device string, logger *slog.Logger) (*FramebufferDisplay, error) {
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file, err := os.OpenFile(device, os.O_RDWR, 0)
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if err != nil {
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return nil, fmt.Errorf("opening framebuffer: %w", err)
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}
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var info fbVarScreenInfo
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_, _, errno := syscall.Syscall(syscall.SYS_IOCTL, file.Fd(), fbiogetVscreeninfo, uintptr(unsafe.Pointer(&info)))
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if errno != 0 {
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file.Close()
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return nil, fmt.Errorf("getting screen info: %v", errno)
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}
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size := int(info.XRes * info.YRes * info.BitsPerPixel / 8)
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memory, err := syscall.Mmap(int(file.Fd()), 0, size, syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED)
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if err != nil {
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file.Close()
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return nil, fmt.Errorf("mapping framebuffer: %w", err)
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}
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logger.Info("framebuffer initialized",
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"device", device,
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"width", info.XRes,
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"height", info.YRes,
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"bpp", info.BitsPerPixel)
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return &FramebufferDisplay{
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file: file,
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info: &info,
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memory: memory,
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logger: logger,
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}, nil
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}
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// Show displays an image on the framebuffer
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func (d *FramebufferDisplay) Show(img *image.RGBA) error {
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bounds := img.Bounds()
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width := bounds.Dx()
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height := bounds.Dy()
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if width > int(d.info.XRes) {
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width = int(d.info.XRes)
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}
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if height > int(d.info.YRes) {
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height = int(d.info.YRes)
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}
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for y := 0; y < height; y++ {
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for x := 0; x < width; x++ {
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r, g, b, a := img.At(x, y).RGBA()
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r, g, b = r>>8, g>>8, b>>8
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offset := (y*int(d.info.XRes) + x) * int(d.info.BitsPerPixel/8)
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if offset+3 < len(d.memory) {
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if d.info.BitsPerPixel == 32 {
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d.memory[offset] = byte(b)
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d.memory[offset+1] = byte(g)
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d.memory[offset+2] = byte(r)
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d.memory[offset+3] = byte(a >> 8)
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} else if d.info.BitsPerPixel == 24 {
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d.memory[offset] = byte(b)
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d.memory[offset+1] = byte(g)
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d.memory[offset+2] = byte(r)
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}
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}
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}
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}
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return nil
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}
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// Clear clears the framebuffer
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func (d *FramebufferDisplay) Clear() error {
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for i := range d.memory {
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d.memory[i] = 0
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}
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return nil
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}
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// Close closes the framebuffer
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func (d *FramebufferDisplay) Close() error {
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if err := syscall.Munmap(d.memory); err != nil {
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d.logger.Error("unmapping framebuffer", "error", err)
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}
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return d.file.Close()
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}
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