Image Crossbar Adder

function processImage(originalImg, style = 'cross', thickness = 10, color = '#FF0000', opacity = 0.8, posX = 50, posY = 50) {
    const canvas = document.createElement('canvas');
    const ctx = canvas.getContext('2d');
    const width = originalImg.width;
    const height = originalImg.height;

    canvas.width = width;
    canvas.height = height;

    // Draw the original image onto the canvas
    ctx.drawImage(originalImg, 0, 0);

    // Parse and sanitize parameters
    const lineThickness = Math.max(1, Number(thickness) || 10);
    const alpha = Math.max(0, Math.min(1, Number(opacity)));
    const positionX = Number(posX) >= 0 && Number(posX) <= 100 ? Number(posX) : 50;
    const positionY = Number(posY) >= 0 && Number(posY) <= 100 ? Number(posY) : 50;
    
    // Calculate actual pixel coordinates from percentages
    const xPos = (positionX / 100) * width;
    const yPos = (positionY / 100) * height;

    // Configure crossbar drawing properties
    ctx.lineWidth = lineThickness;
    ctx.strokeStyle = color || '#FF0000';
    ctx.globalAlpha = isNaN(alpha) ? 0.8 : alpha;
    ctx.lineCap = 'butt'; // Gives sharp edges to the end of the lines

    ctx.beginPath();
    const drawStyle = String(style).toLowerCase().trim();
    
    if (drawStyle === 'x') {
        // Draw an 'X' from corner to corner
        ctx.moveTo(0, 0);
        ctx.lineTo(width, height);
        ctx.moveTo(width, 0);
        ctx.lineTo(0, height);
    } else if (drawStyle === 'horizontal') {
        // Draw a single horizontal bar
        ctx.moveTo(0, yPos);
        ctx.lineTo(width, yPos);
    } else if (drawStyle === 'vertical') {
        // Draw a single vertical bar
        ctx.moveTo(xPos, 0);
        ctx.lineTo(xPos, height);
    } else {
        // Default to 'cross' - intersecting horizontal and vertical bars
        ctx.moveTo(0, yPos);
        ctx.lineTo(width, yPos);
        ctx.moveTo(xPos, 0);
        ctx.lineTo(xPos, height);
    }
    
    // Apply the drawing
    ctx.stroke();

    // Reset global alpha back to default
    ctx.globalAlpha = 1.0;

    return canvas;
}