onRender method

@override void onRender(Canvas canvas, Matrix4 viewProjection)

Override for custom rendering.

Implementation

@override
void onRender(Canvas canvas, Matrix4 viewProjection) {
  final mvp = viewProjection * worldMatrix;
  final center4 = mvp.transformed(Vector4(0, 0, 0, 1));
  if (center4.w <= 0.001) return;

  final ndcX = center4.x / center4.w;
  final ndcY = center4.y / center4.w;
  final depth = center4.w;
  final scaledFontSize = fontSize / depth;

  // SOTA Vector-Based Sharp Rendering (SDF Simulation):
  // Instead of rendering small fonts (which pixelates under lens magnifying glass),
  // we render at a high-resolution base (120px) and scale down the Canvas transform.
  // This forces the rasterizer to construct ultra-high density vector font contours.
  const double baseHighResSize = 120.0;
  final double scaleRatio = scaledFontSize / baseHighResSize;

  canvas.save();
  canvas.translate(ndcX, ndcY);
  canvas.scale(scaleRatio, scaleRatio);

  final textPainter = TextPainter(
    text: TextSpan(
      text: text,
      style: TextStyle(
        color: color,
        fontSize: baseHighResSize,
        fontWeight: fontWeight,
      ),
    ),
    textDirection: TextDirection.ltr,
    textAlign: textAlign,
  )..layout(maxWidth: (800 / depth) / scaleRatio);

  textPainter.paint(
    canvas,
    Offset(-textPainter.width / 2, -textPainter.height / 2),
  );

  canvas.restore();
}