THotPDF.BeginLoadedPageProgressiveRegionRender Method

Begins a resumable loaded-page render whose bitmap covers only the requested PDF user-space window

声明

function BeginLoadedPageProgressiveRegionRender(PageIndex: Integer;
  RegionLeft, RegionBottom, RegionRight, RegionTop: Single;
  DPI: Integer; CancellationToken: THPDFCancellationToken = nil):
  THPDFLoadedPageRenderSession;

参数

行为

• The region must have positive width and height and uses the unrotated page user space with a lower-left origin
• The returned bitmap dimensions are the region dimensions scaled by DPI / 72, with page rotation honoured
• The session reuses the cached display list and suppresses only paint objects with conservative bounds proven outside the region
• Graphics state, clipping, paths, text advancement, cancellation, and progressive JPEG continuation remain resumable at operator boundaries
• RegionVisiblePaintObjects 和 RegionCulledPaintObjects report the selection made at session creation

相关 API

• THPDFLoadedPageRenderSession
• THotPDF.BeginLoadedPageProgressiveRender
• 渐进式渲染与取消