func (p ProgressBarPainter) PaintProgressBar(canvas widget.Canvas, ps progressbar.PaintState) {
	if ps.Bounds.IsEmpty() {
		return
	}

	// Determine the color scheme to use.
	colors := ps.ProgressBarColorScheme
	if colors == (progressbar.ProgressBarColorScheme{}) {
		colors = p.resolveColors()
	}

	radius := ps.Radius
	if radius <= 0 {
		radius = m3ProgressBarRadius
	}

	bounds := ps.Bounds

	// Calculate bar rect centered vertically in bounds.
	barY := bounds.Min.Y + (bounds.Height()-ps.BarHeight)/2
	barRect := geometry.NewRect(bounds.Min.X, barY, bounds.Width(), ps.BarHeight)

	// Draw track.
	trackColor := colors.Track
	if ps.Disabled {
		trackColor = colors.DisabledTrack
	}
	canvas.DrawRoundRect(barRect, trackColor, radius)

	// Draw filled portion.
	fillWidth := barRect.Width() * float32(ps.Value)
	if fillWidth > 0 {
		barColor := colors.Bar
		if ps.Disabled {
			barColor = colors.DisabledBar
		}
		fillRect := geometry.NewRect(barRect.Min.X, barRect.Min.Y, fillWidth, ps.BarHeight)

		// Clip to the track's rounded rect so the fill never exceeds the track shape.
		canvas.PushClipRoundRect(barRect, radius)
		canvas.DrawRoundRect(fillRect, barColor, radius)
		canvas.PopClip()
	}

	// Draw label if enabled.
	if ps.ShowLabel && ps.Label != "" {
		canvas.DrawText(ps.Label, barRect, m3ProgressBarFontSize, colors.Label, false, m3ProgressBarTextAlign)
	}
}

type ProgressBarPainter struct {
	Theme *Theme	// nil uses default M3 purple fallback
}