skgpu::graphite::DrawAtlasConfig Class Reference

#include <DrawAtlas.h>

Public Member Functions
	DrawAtlasConfig (int maxTextureSize, size_t maxBytes)
SkISize	atlasDimensions (MaskFormat type) const
SkISize	plotDimensions (MaskFormat type) const

Detailed Description

Definition at line 270 of file DrawAtlas.h.

Constructor & Destructor Documentation

DrawAtlasConfig()

skgpu::graphite::DrawAtlasConfig::DrawAtlasConfig	(	int	maxTextureSize,
		size_t	maxBytes
	)

Definition at line 533 of file DrawAtlas.cpp.

                                                                    {
    static const SkISize kARGBDimensions[] = {
        {256, 256},   // maxBytes < 2^19
        {512, 256},   // 2^19 <= maxBytes < 2^20
        {512, 512},   // 2^20 <= maxBytes < 2^21
        {1024, 512},  // 2^21 <= maxBytes < 2^22
        {1024, 1024}, // 2^22 <= maxBytes < 2^23
        {2048, 1024}, // 2^23 <= maxBytes
    };
 
    // Index 0 corresponds to maxBytes of 2^18, so start by dividing it by that
    maxBytes >>= 18;
    // Take the floor of the log to get the index
    int index = maxBytes > 0
        ? SkTPin<int>(SkPrevLog2(maxBytes), 0, std::size(kARGBDimensions) - 1)
        : 0;
 
    SkASSERT(kARGBDimensions[index].width() <= kMaxAtlasDim);
    SkASSERT(kARGBDimensions[index].height() <= kMaxAtlasDim);
    fARGBDimensions.set(std::min<int>(kARGBDimensions[index].width(), maxTextureSize),
                        std::min<int>(kARGBDimensions[index].height(), maxTextureSize));
    fMaxTextureSize = std::min<int>(maxTextureSize, kMaxAtlasDim);
}

Member Function Documentation

atlasDimensions()

SkISize skgpu::graphite::DrawAtlasConfig::atlasDimensions

(

MaskFormat

type

)

const

Definition at line 557 of file DrawAtlas.cpp.

                                                              {
    if (MaskFormat::kA8 == type) {
        // A8 is always 2x the ARGB dimensions, clamped to the max allowed texture size
        return { std::min<int>(2 * fARGBDimensions.width(), fMaxTextureSize),
                 std::min<int>(2 * fARGBDimensions.height(), fMaxTextureSize) };
    } else {
        return fARGBDimensions;
    }
}

plotDimensions()

SkISize skgpu::graphite::DrawAtlasConfig::plotDimensions

(

MaskFormat

type

)

const

Definition at line 567 of file DrawAtlas.cpp.

                                                             {
    if (MaskFormat::kA8 == type) {
        SkISize atlasDimensions = this->atlasDimensions(type);
        // For A8 we want to grow the plots at larger texture sizes to accept more of the
        // larger SDF glyphs. Since the largest SDF glyph can be 170x170 with padding, this
        // allows us to pack 3 in a 512x256 plot, or 9 in a 512x512 plot.
 
        // This will give us 512x256 plots for 2048x1024, 512x512 plots for 2048x2048,
        // and 256x256 plots otherwise.
        int plotWidth = atlasDimensions.width() >= 2048 ? 512 : 256;
        int plotHeight = atlasDimensions.height() >= 2048 ? 512 : 256;
 
        return { plotWidth, plotHeight };
    } else {
        // ARGB and LCD always use 256x256 plots -- this has been shown to be faster
        return { 256, 256 };
    }
}

---

The documentation for this class was generated from the following files:

• third_party/skia/src/gpu/graphite/DrawAtlas.h
• third_party/skia/src/gpu/graphite/DrawAtlas.cpp