GrDataUtils.h File Reference

#include "include/core/SkColor.h"
#include "include/private/base/SkTArray.h"
#include <array>
#include <cstddef>

Go to the source code of this file.

Functions
size_t	GrComputeTightCombinedBufferSize (size_t bytesPerPixel, SkISize baseDimensions, skia_private::TArray< size_t > *individualMipOffsets, int mipLevelCount)
bool	GrConvertPixels (const GrPixmap &dst, const GrCPixmap &src, bool flipY=false)
bool	GrClearImage (const GrImageInfo &dstInfo, void *dst, size_t dstRB, std::array< float, 4 > color)

Function Documentation

GrClearImage()

bool GrClearImage	(	const GrImageInfo &	dstInfo,
		void *	dst,
		size_t	dstRB,
		std::array< float, 4 >	color
	)

Clears the dst image to a constant color.

Definition at line 507 of file GrDataUtils.cpp.

                                                                                                 {
    TRACE_EVENT0("skia.gpu", TRACE_FUNC);
 
    if (!dstInfo.isValid()) {
        return false;
    }
    if (!dst) {
        return false;
    }
    if (dstRB < dstInfo.minRowBytes()) {
        return false;
    }
    if (dstInfo.colorType() == GrColorType::kRGB_888) {
        // SkRasterPipeline doesn't handle writing to RGB_888. So we handle that specially here.
        uint32_t rgba = SkColor4f{color[0], color[1], color[2], color[3]}.toBytes_RGBA();
        for (int y = 0; y < dstInfo.height(); ++y) {
            char* d = static_cast<char*>(dst) + y * dstRB;
            for (int x = 0; x < dstInfo.width(); ++x, d += 3) {
                memcpy(d, &rgba, 3);
            }
        }
        return true;
    }
 
    LumMode lumMode;
    bool isNormalized;
    bool dstIsSRGB;
    SkRasterPipelineOp store;
    skgpu::Swizzle storeSwizzle = get_dst_swizzle_and_store(dstInfo.colorType(), &store, &lumMode,
                                                            &isNormalized, &dstIsSRGB);
    char block[64];
    SkArenaAlloc alloc(block, sizeof(block), 1024);
    SkRasterPipeline_<256> pipeline;
    pipeline.appendConstantColor(&alloc, color.data());
    switch (lumMode) {
        case LumMode::kNone:
            break;
        case LumMode::kToRGB:
            pipeline.append(SkRasterPipelineOp::bt709_luminance_or_luma_to_rgb);
            break;
        case LumMode::kToAlpha:
            pipeline.append(SkRasterPipelineOp::bt709_luminance_or_luma_to_alpha);
            // If we ever need to store srgb-encoded gray (e.g. GL_SLUMINANCE8) then we should use
            // ToRGB and then a swizzle stage rather than ToAlpha. The subsequent transfer function
            // stage ignores the alpha channel (where we just stashed the gray).
            SkASSERT(!dstIsSRGB);
            break;
    }
    if (dstIsSRGB) {
        pipeline.appendTransferFunction(*skcms_sRGB_Inverse_TransferFunction());
    }
    storeSwizzle.apply(&pipeline);
    SkRasterPipeline_MemoryCtx dstCtx{dst, SkToInt(dstRB/dstInfo.bpp())};
    pipeline.append(store, &dstCtx);
    pipeline.run(0, 0, dstInfo.width(), dstInfo.height());
 
    return true;
}

GrComputeTightCombinedBufferSize()

size_t GrComputeTightCombinedBufferSize	(	size_t	bytesPerPixel,
		SkISize	baseDimensions,
		skia_private::TArray< size_t > *	individualMipOffsets,
		int	mipLevelCount
	)

Definition at line 124 of file GrDataUtils.cpp.

                                                                                                 {
    SkASSERT(individualMipOffsets && individualMipOffsets->empty());
    SkASSERT(mipLevelCount >= 1);
 
    individualMipOffsets->push_back(0);
 
    size_t combinedBufferSize = baseDimensions.width() * bytesPerPixel * baseDimensions.height();
    SkISize levelDimensions = baseDimensions;
 
    // The Vulkan spec for copying a buffer to an image requires that the alignment must be at
    // least 4 bytes and a multiple of the bytes per pixel of the image config.
    SkASSERT(bytesPerPixel == 1 || bytesPerPixel == 2 || bytesPerPixel == 3 ||
             bytesPerPixel == 4 || bytesPerPixel == 8 || bytesPerPixel == 16);
    int desiredAlignment = (bytesPerPixel == 3) ? 12 : (bytesPerPixel > 4 ? bytesPerPixel : 4);
 
    for (int currentMipLevel = 1; currentMipLevel < mipLevelCount; ++currentMipLevel) {
        levelDimensions = {std::max(1, levelDimensions.width() /2),
                           std::max(1, levelDimensions.height()/2)};
 
        size_t trimmedSize = levelDimensions.area() * bytesPerPixel;
        const size_t alignmentDiff = combinedBufferSize % desiredAlignment;
        if (alignmentDiff != 0) {
            combinedBufferSize += desiredAlignment - alignmentDiff;
        }
        SkASSERT((0 == combinedBufferSize % 4) && (0 == combinedBufferSize % bytesPerPixel));
 
        individualMipOffsets->push_back(combinedBufferSize);
        combinedBufferSize += trimmedSize;
    }
 
    SkASSERT(individualMipOffsets->size() == mipLevelCount);
    return combinedBufferSize;
}

GrConvertPixels()

bool GrConvertPixels	(	const GrPixmap &	dst,
		const GrCPixmap &	src,
		bool	flipY = false
	)

Definition at line 335 of file GrDataUtils.cpp.

                                                                            {
    TRACE_EVENT0("skia.gpu", TRACE_FUNC);
    if (src.dimensions().isEmpty() || dst.dimensions().isEmpty()) {
        return false;
    }
    if (src.colorType() == GrColorType::kUnknown || dst.colorType() == GrColorType::kUnknown) {
        return false;
    }
    if (!src.hasPixels() || !dst.hasPixels()) {
        return false;
    }
    if (dst.dimensions() != src.dimensions()) {
        return false;
    }
    if (dst.colorType() == GrColorType::kRGB_888) {
        // SkRasterPipeline doesn't handle writing to RGB_888. So we have it write to RGB_888x and
        // then do another conversion that does the 24bit packing. We could be cleverer and skip the
        // temp pixmap if this is the only conversion but this is rare so keeping it simple.
        GrPixmap temp = GrPixmap::Allocate(dst.info().makeColorType(GrColorType::kRGB_888x));
        if (!GrConvertPixels(temp, src, flipY)) {
            return false;
        }
        auto* tRow = reinterpret_cast<const char*>(temp.addr());
        auto* dRow = reinterpret_cast<char*>(dst.addr());
        for (int y = 0; y < dst.height(); ++y, tRow += temp.rowBytes(), dRow += dst.rowBytes()) {
            for (int x = 0; x < dst.width(); ++x) {
                auto t = tRow + x*sizeof(uint32_t);
                auto d = dRow + x*3;
                memcpy(d, t, 3);
            }
        }
        return true;
    } else if (src.colorType() == GrColorType::kRGB_888) {
        // SkRasterPipeline doesn't handle reading from RGB_888. So convert it to RGB_888x and then
        // do a recursive call if there is any remaining conversion.
        GrPixmap temp = GrPixmap::Allocate(src.info().makeColorType(GrColorType::kRGB_888x));
        auto* sRow = reinterpret_cast<const char*>(src.addr());
        auto* tRow = reinterpret_cast<char*>(temp.addr());
        for (int y = 0; y < src.height(); ++y, sRow += src.rowBytes(), tRow += temp.rowBytes()) {
            for (int x = 0; x < src.width(); ++x) {
                auto s = sRow + x*3;
                auto t = tRow + x*sizeof(uint32_t);
                memcpy(t, s, 3);
                t[3] = static_cast<char>(0xFF);
            }
        }
        return GrConvertPixels(dst, temp, flipY);
    }
 
    size_t srcBpp = src.info().bpp();
    size_t dstBpp = dst.info().bpp();
 
    // SkRasterPipeline operates on row-pixels not row-bytes.
    SkASSERT(dst.rowBytes() % dstBpp == 0);
    SkASSERT(src.rowBytes() % srcBpp == 0);
 
    bool premul   = src.alphaType() == kUnpremul_SkAlphaType &&
                    dst.alphaType() == kPremul_SkAlphaType;
    bool unpremul = src.alphaType() == kPremul_SkAlphaType &&
                    dst.alphaType() == kUnpremul_SkAlphaType;
    bool alphaOrCSConversion =
            premul || unpremul || !SkColorSpace::Equals(src.colorSpace(), dst.colorSpace());
 
    if (src.colorType() == dst.colorType() && !alphaOrCSConversion) {
        size_t tightRB = dstBpp * dst.width();
        if (flipY) {
            auto s = static_cast<const char*>(src.addr());
            auto d = SkTAddOffset<char>(dst.addr(), dst.rowBytes()*(dst.height() - 1));
            for (int y = 0; y < dst.height(); ++y, d -= dst.rowBytes(), s += src.rowBytes()) {
                memcpy(d, s, tightRB);
            }
        } else {
            SkRectMemcpy(dst.addr(), dst.rowBytes(),
                         src.addr(), src.rowBytes(),
                         tightRB, src.height());
        }
        return true;
    }
 
    SkRasterPipelineOp load;
    bool srcIsNormalized;
    bool srcIsSRGB;
    auto loadSwizzle = get_load_and_src_swizzle(src.colorType(),
                                                &load,
                                                &srcIsNormalized,
                                                &srcIsSRGB);
 
    SkRasterPipelineOp store;
    LumMode lumMode;
    bool dstIsNormalized;
    bool dstIsSRGB;
    auto storeSwizzle = get_dst_swizzle_and_store(dst.colorType(),
                                                  &store,
                                                  &lumMode,
                                                  &dstIsNormalized,
                                                  &dstIsSRGB);
 
    SkTLazy<SkColorSpaceXformSteps> steps;
    skgpu::Swizzle loadStoreSwizzle;
    if (alphaOrCSConversion) {
        steps.init(src.colorSpace(), src.alphaType(), dst.colorSpace(), dst.alphaType());
    } else {
        loadStoreSwizzle = skgpu::Swizzle::Concat(loadSwizzle, storeSwizzle);
    }
    int cnt = 1;
    int height = src.height();
    SkRasterPipeline_MemoryCtx
            srcCtx{const_cast<void*>(src.addr()), SkToInt(src.rowBytes()/srcBpp)},
            dstCtx{                   dst.addr(), SkToInt(dst.rowBytes()/dstBpp)};
 
    if (flipY) {
        // It *almost* works to point the src at the last row and negate the stride and run the
        // whole rectangle. However, SkRasterPipeline::run()'s control loop uses size_t loop
        // variables so it winds up relying on unsigned overflow math. It works out in practice
        // but UBSAN says "no!" as it's technically undefined and in theory a compiler could emit
        // code that didn't do what is intended. So we go one row at a time. :(
        srcCtx.pixels = static_cast<char*>(srcCtx.pixels) + src.rowBytes()*(height - 1);
        std::swap(cnt, height);
    }
 
    bool hasConversion = alphaOrCSConversion || lumMode != LumMode::kNone;
 
    if (srcIsSRGB && dstIsSRGB && !hasConversion) {
        // No need to convert from srgb if we are just going to immediately convert it back.
        srcIsSRGB = dstIsSRGB = false;
    }
 
    hasConversion = hasConversion || srcIsSRGB || dstIsSRGB;
 
    SkRasterPipeline_<256> pipeline;
    pipeline.append(load, &srcCtx);
    if (hasConversion) {
        loadSwizzle.apply(&pipeline);
        if (srcIsSRGB) {
            pipeline.appendTransferFunction(*skcms_sRGB_TransferFunction());
        }
        if (alphaOrCSConversion) {
            steps->apply(&pipeline);
        }
        switch (lumMode) {
            case LumMode::kNone:
                break;
            case LumMode::kToRGB:
                pipeline.append(SkRasterPipelineOp::bt709_luminance_or_luma_to_rgb);
                break;
            case LumMode::kToAlpha:
                pipeline.append(SkRasterPipelineOp::bt709_luminance_or_luma_to_alpha);
                // If we ever need to store srgb-encoded gray (e.g. GL_SLUMINANCE8) then we
                // should use ToRGB and then a swizzle stage rather than ToAlpha. The subsequent
                // transfer function stage ignores the alpha channel (where we just stashed the
                // gray).
                SkASSERT(!dstIsSRGB);
                break;
        }
        if (dstIsSRGB) {
            pipeline.appendTransferFunction(*skcms_sRGB_Inverse_TransferFunction());
        }
        storeSwizzle.apply(&pipeline);
    } else {
        loadStoreSwizzle.apply(&pipeline);
    }
    pipeline.append(store, &dstCtx);
    auto pipelineFn = pipeline.compile();
    for (int i = 0; i < cnt; ++i) {
        pipelineFn(0, 0, src.width(), height);
        srcCtx.pixels = static_cast<char*>(srcCtx.pixels) - src.rowBytes();
        dstCtx.pixels = static_cast<char*>(dstCtx.pixels) + dst.rowBytes();
    }
 
    return true;
}