type Backend interface {
	// Lifecycle methods

	// Begin initializes the backend for rendering at the given dimensions.
	// This must be called before any drawing operations.
	// Returns an error if initialization fails.
	Begin(width, height int) error

	// End finalizes the rendering and prepares the output.
	// After End is called, output methods (WriteTo, SaveToFile) can be used.
	// Returns an error if finalization fails.
	End() error

	// State management methods

	// Save saves the current graphics state (transform, clip) onto a stack.
	// The state can be restored with Restore.
	Save()

	// Restore restores the graphics state from the stack.
	// If the stack is empty, this is a no-op.
	Restore()

	// Transform methods

	// SetTransform sets the current transformation matrix.
	// This replaces any existing transform.
	SetTransform(m Matrix)

	// Clipping methods

	// SetClip sets the clipping region to the given path.
	// Only pixels inside the path (according to the fill rule) will be drawn.
	// The clip is intersected with any existing clip.
	SetClip(path *gg.Path, rule FillRule)

	// ClearClip removes any clipping region.
	ClearClip()

	// Drawing methods

	// FillPath fills the given path with the brush color/pattern.
	// The rule determines how to handle self-intersecting paths.
	FillPath(path *gg.Path, brush Brush, rule FillRule)

	// StrokePath strokes the given path with the brush and stroke style.
	StrokePath(path *gg.Path, brush Brush, stroke Stroke)

	// FillRect is an optimized method for filling axis-aligned rectangles.
	// Backends may implement this more efficiently than FillPath with a rect path.
	FillRect(rect Rect, brush Brush)

	// DrawImage draws an image from the source rectangle to the destination rectangle.
	// The opts parameter specifies interpolation quality and alpha.
	DrawImage(img image.Image, src, dst Rect, opts ImageOptions)

	// DrawText draws text at the given position with the specified font face and brush.
	// The position (x, y) is the baseline origin of the text.
	DrawText(s string, x, y float64, face text.Face, brush Brush)
}

type WriterBackend interface {
	Backend

	// WriteTo writes the rendered content to the given writer.
	// This should only be called after End().
	// Returns the number of bytes written and any error.
	WriteTo(w io.Writer) (int64, error)
}

type FileBackend interface {
	Backend

	// SaveToFile saves the rendered content to a file at the given path.
	// This should only be called after End().
	// Returns an error if the file cannot be written.
	SaveToFile(path string) error
}

type PixmapBackend interface {
	Backend

	// Pixmap returns the rendered pixmap.
	// This should only be called after End().
	// Returns nil if no pixmap is available.
	Pixmap() *gg.Pixmap
}