Graphics32

Appearance

Member Filters
Show Inherited
Show Protected
Show abstract
GR32_Rasterizers🞂TRasterizerClass

TRasterizer

Abstract base class for bitmap-specific rasterizers that transfer spatial samples into target bitmap buffers.

Inheritance:TObject 🞂 TPersistent 🞂 TPlainInterfacedPersistent 🞂 TNotifiablePersistent 🞂 TThreadPersistent 🞂 TRasterizer

Declaration ​

pascal
type
  TRasterizer = class abstract(TThreadPersistent)
    ...
  TRasterizerClass = class of TRasterizer;

Description ​

TRasterizer serves as the abstract base class for all rasterization engines in Graphics32. Rasterizers iterate across 2D pixel coordinates within a destination bitmap (TCustomBitmap32), querying color values from an attached TCustomSampler and writing the resulting pixels using configurable combination and blend modes (TCombineInfo).

Key capabilities provided by TRasterizer include:

  • Managing an attached TCustomSampler reference via the Sampler property.
  • Handling drawing modes (dmOpaque, dmBlend, dmTransparent, dmCustom) and master alpha transparency.
  • Managing sampling life cycle calls (FSampler.PrepareSampling and FSampler.FinalizeSampling).
  • Providing flexible overloaded Rasterize entry points accepting custom target rectangles, combine info records, or source bitmap settings.

Derived classes override the protected DoRasterize method to implement specialized coordinate traversal and sampling order strategies (such as regular scanlines, swizzling fractal curves, progressive subsampling, or multi-threading).