PDFiumPas 文件

PixelsToPoints 函数

组件: TPdf · 单元: PDFium

将指定 DPI 下的像素测量值转换为 PDF 点（1/72 英寸）

Syntax

function PixelsToPoints(Pixels, PixelsPerInch: Double): Double;

Description

Static helper that converts a measurement value between pixel / point / inch units. PDF coordinates are expressed in points (1 pt = 1/72 inch).

Convert a pixel measurement at the given DPI to PDF points (1/72 inch). The conversion formula is value * 72 / DPI.

These helpers are class functions; you can call them without instantiating TPdf (e.g. TPdf.PixelsToPoints(96)).

Remarks

DPI defaults to 96 (the Windows default screen DPI) when the parameter is omitted.
Use these helpers to translate between TBitmap pixel coordinates and PDF rectangles before passing them to AddImage / Annotation APIs.
Inverse conversions are available as the matching *To* functions on TPdf and TPdfView.

Example

var
  Margin: Double;
begin
  Margin := TPdf.PixelsToPoints(300);
  Memo1.Lines.Add(Format('PixelsToPoints(300) = %.4f', [Margin]));
end;

See Also

PixelsToInches, PointsToInches, PointsToPixels