FS_RECTF constructor is confusing.

FS_RECTF() { left = x1, top = y1, right = x2, bottom = y2 };


float pageWidth = page.Width; // 595
float pageHeight = page.Height; // 841


float rectangleWidth = 105.0f;
float rectangleHeight = 320.0f;

float left = 10.0f; // The x-coordinate of the left - top corner.
float top = 330.0f; // The y-coordinate of the left-top corner.

float right = left + rectangleWidth; //The x-coordinate of the right-bottom corner.
float bottom = top + rectangleHeight; // The y-coordinate of the right-bottom corner.

var rect = new FS_RECTF() { left = left, top = top, right = right, bottom = bottom };

// rect has negative height! Why

Thanks in advance