GetCoverageFiller returns the registered CoverageFiller, or nil if none.

func GetCoverageFiller() CoverageFiller {
	coverageMu.RLock()
	f := coverageFiller
	coverageMu.RUnlock()
	return f
}

RegisterCoverageFiller registers a tile-based coverage filler for complex paths.

 

Only one filler can be registered. Subsequent calls replace the previous one.

Typical usage via blank import in the gpu package:

 

func init() {

gg.RegisterCoverageFiller(&gpuimpl.SparseStripsFiller{})

}

func RegisterCoverageFiller(f CoverageFiller) {
	coverageMu.Lock()
	coverageFiller = f
	coverageMu.Unlock()
}

CoverageFiller is a tile-based coverage rasterizer for complex paths.

 

When registered via RegisterCoverageFiller, the SoftwareRenderer auto-selects

it for paths above a complexity threshold (coverageFillerThreshold elements).

For simpler paths, the AnalyticFiller (scanline) is used directly.

 

The callback receives per-pixel coverage values (0-255) that the caller

composites onto the target pixmap using source-over blending.

 

Implementations:

- SparseStripsFiller (4x4 tiles, CPU/SIMD-optimized) — default

- TileComputeFiller (16x16 tiles, GPU workgroup-ready) — alternative

type CoverageFiller interface {
	// FillCoverage rasterizes the path and calls callback for each pixel
	// with non-zero coverage. The coverage value is 0-255 (anti-aliased alpha).
	FillCoverage(path *Path, width, height int, fillRule FillRule,
		callback func(x, y int, coverage uint8))
}

ForceableFiller is an optional interface for CoverageFillers that support

forced algorithm selection. When the user sets RasterizerSparseStrips or

RasterizerTileCompute mode, the renderer uses SparseFiller() or ComputeFiller()

instead of the adaptive auto-selection.

type ForceableFiller interface {
	CoverageFiller
	// SparseFiller returns the SparseStrips (4x4 tiles) filler component.
	SparseFiller() CoverageFiller
	// ComputeFiller returns the TileCompute (16x16 tiles) filler component.
	ComputeFiller() CoverageFiller
}