pointToCanvas method

Offset pointToCanvas(ChartDataPoint point, Size size, double minX, double maxX, double minY, double maxY,)

Convert data point to canvas coordinates (optimized).

Transforms a data point from data space (x, y values) to canvas space (pixel coordinates). This method includes comprehensive validation to prevent NaN and Infinity values that could cause rendering issues.

Parameters:

• point - The data point to transform
• size - The size of the canvas
• minX, maxX, minY, maxY - The data bounds

Returns an Offset representing the canvas position, or a safe fallback position if the input is invalid.

Example

final canvasPos = pointToCanvas(
  ChartDataPoint(x: 10, y: 20),
  Size(400, 300),
  0, 100, 0, 50,
);
canvas.drawCircle(canvasPos, 5, paint);

Implementation

Offset pointToCanvas(
  ChartDataPoint point,
  Size size,
  double minX,
  double maxX,
  double minY,
  double maxY,
) {
  // Validate inputs
  if (!point.x.isFinite || !point.y.isFinite) {
    return Offset(size.width / 2, size.height / 2);
  }

  if (!size.width.isFinite ||
      !size.height.isFinite ||
      size.width <= 0 ||
      size.height <= 0) {
    return const Offset(0, 0);
  }

  if (!minX.isFinite || !maxX.isFinite || !minY.isFinite || !maxY.isFinite) {
    return Offset(size.width / 2, size.height / 2);
  }

  // Pre-calculate ranges for better performance
  final xRange = maxX - minX;
  final yRange = maxY - minY;

  // Avoid division by zero or invalid ranges
  if (xRange <= 0 || !xRange.isFinite || yRange <= 0 || !yRange.isFinite) {
    return Offset(size.width / 2, size.height / 2);
  }

  // Calculate coordinates with validation
  final x = ((point.x - minX) / xRange) * size.width;
  final y = size.height - ((point.y - minY) / yRange) * size.height;

  // Validate calculated values are finite before returning
  if (!x.isFinite || !y.isFinite) {
    return Offset(size.width / 2, size.height / 2);
  }

  return Offset(x, y);
}