THPDFViewer Coordinate Transforms

在 PDF 页面空间与渲染后的 Viewer 位图之间双向转换点坐标

点类型

THPDFViewerPoint= record X: Single; Y: Single; end;

声明

function PagePointToView(PageIndex: Integer; const PagePoint: THPDFViewerPoint; out ViewPoint: THPDFViewerPoint; DPI: Integer= 150): boolean; function ViewPointToPage(PageIndex: Integer; const ViewPoint: THPDFViewerPoint; out PagePoint: THPDFViewerPoint; DPI: Integer= 150): boolean;

坐标空间

• PDF 页面坐标使用页面 MediaBox，原点在左下
• 查看器坐标使用渲染像素，原点在左上
• PDF 页面的 /Rotate 值先于 ViewRotation
• DPI 低于 1 时按 1 处理；更高的值保持精确，使变换覆盖查看器的完整缩放范围
• 页面状态无效时返回 False 并清空输出点

往返换算

if Model.PagePointToView(0, PagePoint, ViewPoint, 144) then Model.ViewPointToPage(0, ViewPoint, RestoredPoint, 144);