Rectangle Construction and Positioning in IronPDF

Coordinate Origin

The origin point (0, 0) sits at the bottom-left corner of the page. When you specify a rectangle, that origin is treated as the rectangle's top-left corner, which determines the direction the shape is drawn.

Axis Behavior

How the x and y values shift the rectangle:

• Y-coordinate: increasing y moves the rectangle up; decreasing it moves the rectangle down. A negative y places the rectangle below the (0, 0) point.
• X-coordinate: increasing x moves the rectangle to the right. Decreasing x, or supplying a negative value, shifts it to the left.

Width and Height

Dimensions can be drawn in either direction from the starting point:

• Width: a positive width draws to the right; a negative or decreasing width draws to the left.
• Height: a positive height extends upward; a negative height draws downward.

Unit of Measurement

IronPDF measures its drawing API in points, giving the precision needed for document rendering and layout. The other Iron Software libraries differ:

• IronOCR: uses pixels exclusively, matching its focus on image-based text recognition.
• IronBarcode: uses pixels to locate barcode objects, but switches to points when stamping barcodes into a PDF so placement stays accurate in document formats.