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THPDFRenderDocAccess 记录

把渲染器绑定到文档服务，用于解析引用、读取流、解码图像、定位字体和评估图层可见性

声明

THPDFRenderDocAccess= record
  Context: Pointer;
  SharedCache: THPDFRendererSharedCache;
  ShareRenderCaches: boolean;
  // v2.375.0 generic indirect-ref resolver (any object type). The typed
  // Resolve* fields below predate it and return nil for non-matching
  // types, which silently dropped indirect refs to arrays (e.g. a
  // /ColorSpace entry pointing at a [/Separation ...] array object)
  ResolveObject: function(Context: Pointer; Obj: THPDFObject): THPDFObject;
  ResolveDictionary: function(Context: Pointer; Obj: THPDFObject): THPDFDictionaryObject;
  ResolveStream: function(Context: Pointer; Obj: THPDFObject): THPDFStreamObject;
  ReadDecodedStreamBytes: function(Context: Pointer; Stream: THPDFStreamObject; out Bytes: TBytes): boolean;
  AcquireDecodedImageStream: function(Context: Pointer;
    Stream: THPDFStreamObject): IHPDFDecodedBitmapHandle;
  DecodeImageStream: function(Context: Pointer; Stream: THPDFStreamObject): TBitmap;
  BeginProgressiveImageDecode: function(Context: Pointer;
    Stream: THPDFStreamObject;
    CancellationToken: THPDFCancellationToken): IHPDFProgressiveImageDecoder;
  DecodeImageRegion: function(Context: Pointer; Stream: THPDFStreamObject;
    RegionLeft, RegionTop, RegionRight, RegionBottom,
    DesiredWidth, DesiredHeight: Integer): TBitmap;
  AcquireDecodedImageRegion: function(Context: Pointer;
    Stream: THPDFStreamObject; RegionLeft, RegionTop, RegionRight,
    RegionBottom, DesiredWidth,
    DesiredHeight: Integer): IHPDFDecodedBitmapHandle;
  // v2.425.0 inline-image decoder: builds a throwaway stream from the raw
  // ID..EI bytes and the normalised BI key set, then decodes it without the
  // ObjectNumber-keyed cache (inline images have no object number). Returns
  // a TBitmap the caller owns, or nil on failure. Nil hook = inline images
  // are not rendered (legacy behaviour)
  DecodeInlineImage: function(Context: Pointer; const Bytes: TBytes;
    const Keys: THPDFInlineImgKeys): TBitmap;
  // Colour-key /Mask array of an image XObject as a soft mask, white where
  // the image shows and black where it is masked out. Returns a TBitmap the
  // caller owns, or nil when the image has no usable colour-key mask; a nil
  // hook draws such images unmasked
  DecodeColorKeyMask: function(Context: Pointer;
    Stream: THPDFStreamObject): TBitmap;
  // Look up a font dictionary by resource key in a Resources dict, following
  // indirect refs at both /Resources and /Font levels. Returns nil if absent
  ResolveFontDict: function(Context: Pointer; PageObj: THPDFDictionaryObject;
    const FontKey: AnsiString): THPDFDictionaryObject;
  // v2.377.0 optional-content visibility oracle: evaluates an /OC property
  // object (OCG or OCMD) against the document's layer states. Nil hook or
  // a True result means the content is drawn
  EvalOCVisibility: function(Context: Pointer; PropObj: THPDFObject): boolean;
  CancellationToken: THPDFCancellationToken;
  ColourIntent: Integer;
  FallbackPolicy: THPDFRenderFallbackPolicy;
  FallbackDiagnosticLimit: Integer;
  OverprintPreview: boolean;
  ProofICCProfile: TBytes;
  OutputICCProfile: TBytes;
  BlackPointCompensation: boolean;
  SeparationPlate: AnsiString;
end;

单元

HPDFPageRenderer

字段

字段用途
Context调用方提供的上下文指针，作为每个回调的第一个参数传入；文档在此绑定自身
SharedCache当启用 ShareRenderCaches 时，可供多个页面共享的渲染器缓存
ShareRenderCaches文档允许并发渲染器共享解码缓存时为 True
ResolveObject适用于任意对象类型的通用间接引用解析器；因类型化解析器对不匹配的类型返回 nil 而补充
ResolveDictionary把间接引用解析为字典对象，其他类型返回 nil
ResolveStream把间接引用解析为流对象
ReadDecodedStreamBytes把流完全解码后读入字节数组
AcquireDecodedImageStream把图像 XObject 解码为共享的引用计数位图句柄
DecodeImageStream把图像 XObject 解码为调用方持有的位图
BeginProgressiveImageDecode为大型图像流启动可取消的渐进解码器
DecodeImageRegion按请求的像素尺寸解码图像的子区域
AcquireDecodedImageRegion区域变体，返回共享的引用计数位图句柄
DecodeInlineImage从原始 ID..EI 字节和规范化 BI 键集解码内联图像，绕过按对象号索引的缓存；钩子为 nil 表示不渲染内联图像
DecodeColorKeyMask把图像 XObject 的 color-key /Mask 数组变成图像尺寸的黑白软掩码；图像没有可用的 color-key 掩码时为 nil，钩子为 nil 时这类图像不带掩码绘制
ResolveFontDict按资源键查找字体字典，跟随 /Resources 和 /Font 两级的间接引用；不存在时为 nil
EvalOCVisibility对照文档图层状态评估 /OC 属性对象；钩子为 nil 或结果为 True 都表示绘制该内容
CancellationToken长时间解码操作期间检查的取消令牌
ColourIntent应用到渲染图形状态的颜色处理意图
FallbackPolicy选择忽略、报告不支持的功能，还是把它们当作严格失败
FallbackDiagnosticLimit限制回退期间收集的诊断消息数量
OverprintPreview启用叠印预览模拟
ProofICCProfile用于色彩管线校样侧的 ICC profile 字节
OutputICCProfile描述输出设备的 ICC profile 字节
BlackPointCompensation在 ICC 变换中启用黑点补偿
SeparationPlate要隔离的分色印版名称；为空时正常渲染

使用说明

相关 API