diff options
author | msarett <msarett@google.com> | 2016-07-20 12:58:52 -0700 |
---|---|---|
committer | Commit bot <commit-bot@chromium.org> | 2016-07-20 12:58:52 -0700 |
commit | 2aec3ffe32558505d7314f064b88ecb7f13b1c16 (patch) | |
tree | 37238abca4b2630e8068d0d36e9b3cef6dbdd4a4 /src/core/SkColorSpace_ICC.cpp | |
parent | cf5c846b4176da82bccb5d5b45788bf0d45a8dd8 (diff) |
Revert of Refactor parsing and storage of SkGammas (patchset #7 id:220001 of https://codereview.chromium.org/2117773002/ )
Reason for revert:
Broken bots.
Original issue's description:
> Refactor parsing and storage of SkGammas
>
> Benefits:
> (1) Parses and stores gamma tags in a single allocation.
> (2) Recognizes equal gamma tags to skip parsing work and
> save memory.
>
> Non-Benefits:
> (1) Not less complicated.
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2117773002
>
> Committed: https://skia.googlesource.com/skia/+/2ea944c2b710caf29d4795ac953bad14224796f7
TBR=reed@google.com,brianosman@google.com,mtklein@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:
Review-Url: https://codereview.chromium.org/2159253005
Diffstat (limited to 'src/core/SkColorSpace_ICC.cpp')
-rw-r--r-- | src/core/SkColorSpace_ICC.cpp | 850 |
1 files changed, 311 insertions, 539 deletions
diff --git a/src/core/SkColorSpace_ICC.cpp b/src/core/SkColorSpace_ICC.cpp index c428009a02..5585fbbb38 100644 --- a/src/core/SkColorSpace_ICC.cpp +++ b/src/core/SkColorSpace_ICC.cpp @@ -238,384 +238,287 @@ static bool load_xyz(float dst[3], const uint8_t* src, size_t len) { static constexpr uint32_t kTAG_CurveType = SkSetFourByteTag('c', 'u', 'r', 'v'); static constexpr uint32_t kTAG_ParaCurveType = SkSetFourByteTag('p', 'a', 'r', 'a'); -static SkGammas::Type set_gamma_value(SkGammas::Data* data, float value) { - if (color_space_almost_equal(2.2f, value)) { - data->fNamed = SkColorSpace::k2Dot2Curve_GammaNamed; - return SkGammas::Type::kNamed_Type; - } - - if (color_space_almost_equal(1.0f, value)) { - data->fNamed = SkColorSpace::kLinear_GammaNamed; - return SkGammas::Type::kNamed_Type; - } - - if (color_space_almost_equal(0.0f, value)) { - return SkGammas::Type::kNone_Type; - } - - data->fValue = value; - return SkGammas::Type::kValue_Type; -} - -static float read_big_endian_16_dot_16(const uint8_t buf[4]) { - // It just so happens that SkFixed is also 16.16! - return SkFixedToFloat(read_big_endian_int(buf)); -} - -/** - * @param outData Set to the appropriate value on success. If we have table or - * parametric gamma, it is the responsibility of the caller to set - * fOffset. - * @param outParams If this is a parametric gamma, this is set to the appropriate - * parameters on success. - * @param outTagBytes Will be set to the length of the tag on success. - * @src Pointer to tag data. - * @len Length of tag data in bytes. - * - * @return kNone_Type on failure, otherwise the type of the gamma tag. - */ -static SkGammas::Type parse_gamma(SkGammas::Data* outData, SkGammas::Params* outParams, - size_t* outTagBytes, const uint8_t* src, size_t len) { - if (len < 12) { - SkColorSpacePrintf("gamma tag is too small (%d bytes)", len); - return SkGammas::Type::kNone_Type; - } - - // In the case of consecutive gamma tags, we need to count the number of bytes in the - // tag, so that we can move on to the next tag. - size_t tagBytes; - - uint32_t type = read_big_endian_uint(src); - // Bytes 4-7 are reserved and should be set to zero. - switch (type) { - case kTAG_CurveType: { - uint32_t count = read_big_endian_uint(src + 8); - - // tagBytes = 12 + 2 * count - // We need to do safe addition here to avoid integer overflow. - if (!safe_add(count, count, &tagBytes) || - !safe_add((size_t) 12, tagBytes, &tagBytes)) - { - SkColorSpacePrintf("Invalid gamma count"); - return SkGammas::Type::kNone_Type; - } - - if (len < tagBytes) { - SkColorSpacePrintf("gamma tag is too small (%d bytes)", len); - return SkGammas::Type::kNone_Type; - } - *outTagBytes = tagBytes; - - if (0 == count) { - // Some tags require a gamma curve, but the author doesn't actually want - // to transform the data. In this case, it is common to see a curve with - // a count of 0. - outData->fNamed = SkColorSpace::kLinear_GammaNamed; - return SkGammas::Type::kNamed_Type; - } - - const uint16_t* table = (const uint16_t*) (src + 12); - if (1 == count) { - // The table entry is the gamma (with a bias of 256). - float value = (read_big_endian_short((const uint8_t*) table)) / 256.0f; - SkColorSpacePrintf("gamma %g\n", value); - - return set_gamma_value(outData, value); - } +static bool load_gammas(SkGammaCurve* gammas, uint32_t numGammas, const uint8_t* src, size_t len) { + for (uint32_t i = 0; i < numGammas; i++) { + if (len < 12) { + // FIXME (msarett): + // We could potentially return false here after correctly parsing *some* of the + // gammas correctly. Should we somehow try to indicate a partial success? + SkColorSpacePrintf("gamma tag is too small (%d bytes)", len); + return false; + } - // Check for frequently occurring sRGB curves. - // We do this by sampling a few values and see if they match our expectation. - // A more robust solution would be to compare each value in this curve against - // an sRGB curve to see if we remain below an error threshold. At this time, - // we haven't seen any images in the wild that make this kind of - // calculation necessary. We encounter identical gamma curves over and - // over again, but relatively few variations. - if (1024 == count) { - // The magic values were chosen because they match both the very common - // HP sRGB gamma table and the less common Canon sRGB gamma table (which use - // different rounding rules). - if (0 == read_big_endian_short((const uint8_t*) &table[0]) && - 3366 == read_big_endian_short((const uint8_t*) &table[257]) && - 14116 == read_big_endian_short((const uint8_t*) &table[513]) && - 34318 == read_big_endian_short((const uint8_t*) &table[768]) && - 65535 == read_big_endian_short((const uint8_t*) &table[1023])) { - outData->fNamed = SkColorSpace::kSRGB_GammaNamed; - return SkGammas::Type::kNamed_Type; - } - } + // We need to count the number of bytes in the tag, so we are able to move to the + // next tag on the next loop iteration. + size_t tagBytes; - if (26 == count) { - // The magic values were chosen because they match a very common LCMS sRGB - // gamma table. - if (0 == read_big_endian_short((const uint8_t*) &table[0]) && - 3062 == read_big_endian_short((const uint8_t*) &table[6]) && - 12824 == read_big_endian_short((const uint8_t*) &table[12]) && - 31237 == read_big_endian_short((const uint8_t*) &table[18]) && - 65535 == read_big_endian_short((const uint8_t*) &table[25])) { - outData->fNamed = SkColorSpace::kSRGB_GammaNamed; - return SkGammas::Type::kNamed_Type; - } - } + uint32_t type = read_big_endian_uint(src); + switch (type) { + case kTAG_CurveType: { + uint32_t count = read_big_endian_uint(src + 8); - if (4096 == count) { - // The magic values were chosen because they match Nikon, Epson, and - // LCMS sRGB gamma tables (all of which use different rounding rules). - if (0 == read_big_endian_short((const uint8_t*) &table[0]) && - 950 == read_big_endian_short((const uint8_t*) &table[515]) && - 3342 == read_big_endian_short((const uint8_t*) &table[1025]) && - 14079 == read_big_endian_short((const uint8_t*) &table[2051]) && - 65535 == read_big_endian_short((const uint8_t*) &table[4095])) { - outData->fNamed = SkColorSpace::kSRGB_GammaNamed; - return SkGammas::Type::kNamed_Type; + // tagBytes = 12 + 2 * count + // We need to do safe addition here to avoid integer overflow. + if (!safe_add(count, count, &tagBytes) || + !safe_add((size_t) 12, tagBytes, &tagBytes)) + { + SkColorSpacePrintf("Invalid gamma count"); + return false; } - } - // Otherwise, we will represent gamma with a table. - outData->fTable.fSize = count; - return SkGammas::Type::kTable_Type; - } - case kTAG_ParaCurveType: { - enum ParaCurveType { - kExponential_ParaCurveType = 0, - kGAB_ParaCurveType = 1, - kGABC_ParaCurveType = 2, - kGABDE_ParaCurveType = 3, - kGABCDEF_ParaCurveType = 4, - }; - - // Determine the format of the parametric curve tag. - uint16_t format = read_big_endian_short(src + 8); - if (format > kGABCDEF_ParaCurveType) { - SkColorSpacePrintf("Unsupported gamma tag type %d\n", type); - return SkGammas::Type::kNone_Type; - } - - if (kExponential_ParaCurveType == format) { - tagBytes = 12 + 4; - if (len < tagBytes) { + if (0 == count) { + // Some tags require a gamma curve, but the author doesn't actually want + // to transform the data. In this case, it is common to see a curve with + // a count of 0. + gammas[i].fNamed = SkColorSpace::kLinear_GammaNamed; + break; + } else if (len < tagBytes) { SkColorSpacePrintf("gamma tag is too small (%d bytes)", len); - return SkGammas::Type::kNone_Type; + return false; } - // Y = X^g - float g = read_big_endian_16_dot_16(src + 12); - - *outTagBytes = tagBytes; - return set_gamma_value(outData, g); - } - - // Here's where the real parametric gammas start. There are many - // permutations of the same equations. - // - // Y = (aX + b)^g + c for X >= d - // Y = eX + f otherwise - // - // We will fill in with zeros as necessary to always match the above form. - if (len < 24) { - SkColorSpacePrintf("gamma tag is too small (%d bytes)", len); - return SkGammas::Type::kNone_Type; - } - float g = read_big_endian_16_dot_16(src + 12); - float a = read_big_endian_16_dot_16(src + 16); - float b = read_big_endian_16_dot_16(src + 20); - float c = 0.0f, d = 0.0f, e = 0.0f, f = 0.0f; - switch(format) { - case kGAB_ParaCurveType: - tagBytes = 12 + 12; - - // Y = (aX + b)^g for X >= -b/a - // Y = 0 otherwise - d = -b / a; + const uint16_t* table = (const uint16_t*) (src + 12); + if (1 == count) { + // The table entry is the gamma (with a bias of 256). + float value = (read_big_endian_short((const uint8_t*) table)) / 256.0f; + set_gamma_value(&gammas[i], value); + SkColorSpacePrintf("gamma %g\n", value); break; - case kGABC_ParaCurveType: - tagBytes = 12 + 16; - if (len < tagBytes) { - SkColorSpacePrintf("gamma tag is too small (%d bytes)", len); - return SkGammas::Type::kNone_Type; - } + } - // Y = (aX + b)^g + c for X >= -b/a - // Y = c otherwise - c = read_big_endian_16_dot_16(src + 24); - d = -b / a; - f = c; - break; - case kGABDE_ParaCurveType: - tagBytes = 12 + 20; - if (len < tagBytes) { - SkColorSpacePrintf("gamma tag is too small (%d bytes)", len); - return SkGammas::Type::kNone_Type; + // Check for frequently occurring sRGB curves. + // We do this by sampling a few values and see if they match our expectation. + // A more robust solution would be to compare each value in this curve against + // an sRGB curve to see if we remain below an error threshold. At this time, + // we haven't seen any images in the wild that make this kind of + // calculation necessary. We encounter identical gamma curves over and + // over again, but relatively few variations. + if (1024 == count) { + // The magic values were chosen because they match a very common sRGB + // gamma table and the less common Canon sRGB gamma table (which use + // different rounding rules). + if (0 == read_big_endian_short((const uint8_t*) &table[0]) && + 3366 == read_big_endian_short((const uint8_t*) &table[257]) && + 14116 == read_big_endian_short((const uint8_t*) &table[513]) && + 34318 == read_big_endian_short((const uint8_t*) &table[768]) && + 65535 == read_big_endian_short((const uint8_t*) &table[1023])) { + gammas[i].fNamed = SkColorSpace::kSRGB_GammaNamed; + break; } + } else if (26 == count) { + // The magic values were chosen because they match a very common sRGB + // gamma table. + if (0 == read_big_endian_short((const uint8_t*) &table[0]) && + 3062 == read_big_endian_short((const uint8_t*) &table[6]) && + 12824 == read_big_endian_short((const uint8_t*) &table[12]) && + 31237 == read_big_endian_short((const uint8_t*) &table[18]) && + 65535 == read_big_endian_short((const uint8_t*) &table[25])) { + gammas[i].fNamed = SkColorSpace::kSRGB_GammaNamed; + break; + } + } else if (4096 == count) { + // The magic values were chosen because they match Nikon, Epson, and + // LCMS sRGB gamma tables (all of which use different rounding rules). + if (0 == read_big_endian_short((const uint8_t*) &table[0]) && + 950 == read_big_endian_short((const uint8_t*) &table[515]) && + 3342 == read_big_endian_short((const uint8_t*) &table[1025]) && + 14079 == read_big_endian_short((const uint8_t*) &table[2051]) && + 65535 == read_big_endian_short((const uint8_t*) &table[4095])) { + gammas[i].fNamed = SkColorSpace::kSRGB_GammaNamed; + break; + } + } - // Y = (aX + b)^g for X >= d - // Y = eX otherwise - d = read_big_endian_16_dot_16(src + 28); - - // Not a bug! We define |e| to always be the coefficient on X in the - // second equation. The spec calls this |c| in this particular equation. - // We don't follow their convention because then |c| would have a - // different meaning in each of our cases. - e = read_big_endian_16_dot_16(src + 24); - break; - case kGABCDEF_ParaCurveType: - tagBytes = 12 + 28; + // Otherwise, fill in the interpolation table. + gammas[i].fTableSize = count; + gammas[i].fTable = std::unique_ptr<float[]>(new float[count]); + for (uint32_t j = 0; j < count; j++) { + gammas[i].fTable[j] = + (read_big_endian_short((const uint8_t*) &table[j])) / 65535.0f; + } + break; + } + case kTAG_ParaCurveType: { + enum ParaCurveType { + kExponential_ParaCurveType = 0, + kGAB_ParaCurveType = 1, + kGABC_ParaCurveType = 2, + kGABDE_ParaCurveType = 3, + kGABCDEF_ParaCurveType = 4, + }; + + // Determine the format of the parametric curve tag. + uint16_t format = read_big_endian_short(src + 8); + if (kExponential_ParaCurveType == format) { + tagBytes = 12 + 4; if (len < tagBytes) { SkColorSpacePrintf("gamma tag is too small (%d bytes)", len); - return SkGammas::Type::kNone_Type; + return false; } + // Y = X^g + int32_t g = read_big_endian_int(src + 12); + set_gamma_value(&gammas[i], SkFixedToFloat(g)); + } else { + // Here's where the real parametric gammas start. There are many + // permutations of the same equations. + // // Y = (aX + b)^g + c for X >= d // Y = eX + f otherwise - // NOTE: The ICC spec writes "cX" in place of "eX" but I think - // it's a typo. - c = read_big_endian_16_dot_16(src + 24); - d = read_big_endian_16_dot_16(src + 28); - e = read_big_endian_16_dot_16(src + 32); - f = read_big_endian_16_dot_16(src + 36); - break; - default: - SkASSERT(false); - return SkGammas::Type::kNone_Type; - } - - // Recognize and simplify a very common parametric representation of sRGB gamma. - if (color_space_almost_equal(0.9479f, a) && - color_space_almost_equal(0.0521f, b) && - color_space_almost_equal(0.0000f, c) && - color_space_almost_equal(0.0405f, d) && - color_space_almost_equal(0.0774f, e) && - color_space_almost_equal(0.0000f, f) && - color_space_almost_equal(2.4000f, g)) { - outData->fNamed = SkColorSpace::kSRGB_GammaNamed; - return SkGammas::Type::kNamed_Type; - } - - // Fail on invalid gammas. - if (SkScalarIsNaN(d)) { - return SkGammas::Type::kNone_Type; - } + // + // We will fill in with zeros as necessary to always match the above form. + float g = 0.0f, a = 0.0f, b = 0.0f, c = 0.0f, d = 0.0f, e = 0.0f, f = 0.0f; + switch(format) { + case kGAB_ParaCurveType: { + tagBytes = 12 + 12; + if (len < tagBytes) { + SkColorSpacePrintf("gamma tag is too small (%d bytes)", len); + return false; + } + + // Y = (aX + b)^g for X >= -b/a + // Y = 0 otherwise + g = SkFixedToFloat(read_big_endian_int(src + 12)); + a = SkFixedToFloat(read_big_endian_int(src + 16)); + if (0.0f == a) { + return false; + } + + b = SkFixedToFloat(read_big_endian_int(src + 20)); + d = -b / a; + break; + } + case kGABC_ParaCurveType: + tagBytes = 12 + 16; + if (len < tagBytes) { + SkColorSpacePrintf("gamma tag is too small (%d bytes)", len); + return false; + } + + // Y = (aX + b)^g + c for X >= -b/a + // Y = c otherwise + g = SkFixedToFloat(read_big_endian_int(src + 12)); + a = SkFixedToFloat(read_big_endian_int(src + 16)); + if (0.0f == a) { + return false; + } + + b = SkFixedToFloat(read_big_endian_int(src + 20)); + c = SkFixedToFloat(read_big_endian_int(src + 24)); + d = -b / a; + f = c; + break; + case kGABDE_ParaCurveType: + tagBytes = 12 + 20; + if (len < tagBytes) { + SkColorSpacePrintf("gamma tag is too small (%d bytes)", len); + return false; + } + + // Y = (aX + b)^g for X >= d + // Y = cX otherwise + g = SkFixedToFloat(read_big_endian_int(src + 12)); + a = SkFixedToFloat(read_big_endian_int(src + 16)); + b = SkFixedToFloat(read_big_endian_int(src + 20)); + d = SkFixedToFloat(read_big_endian_int(src + 28)); + e = SkFixedToFloat(read_big_endian_int(src + 24)); + break; + case kGABCDEF_ParaCurveType: + tagBytes = 12 + 28; + if (len < tagBytes) { + SkColorSpacePrintf("gamma tag is too small (%d bytes)", len); + return false; + } + + // Y = (aX + b)^g + c for X >= d + // Y = eX + f otherwise + // NOTE: The ICC spec writes "cX" in place of "eX" but I think + // it's a typo. + g = SkFixedToFloat(read_big_endian_int(src + 12)); + a = SkFixedToFloat(read_big_endian_int(src + 16)); + b = SkFixedToFloat(read_big_endian_int(src + 20)); + c = SkFixedToFloat(read_big_endian_int(src + 24)); + d = SkFixedToFloat(read_big_endian_int(src + 28)); + e = SkFixedToFloat(read_big_endian_int(src + 32)); + f = SkFixedToFloat(read_big_endian_int(src + 36)); + break; + default: + SkColorSpacePrintf("Invalid parametric curve type\n"); + return false; + } - if (d <= 0.0f) { - // Y = (aX + b)^g + c for always - if (0.0f == a || 0.0f == g) { - SkColorSpacePrintf("A or G is zero, constant gamma function " - "is nonsense"); - return SkGammas::Type::kNone_Type; - } - } + // Recognize and simplify a very common parametric representation of sRGB gamma. + if (color_space_almost_equal(0.9479f, a) && + color_space_almost_equal(0.0521f, b) && + color_space_almost_equal(0.0000f, c) && + color_space_almost_equal(0.0405f, d) && + color_space_almost_equal(0.0774f, e) && + color_space_almost_equal(0.0000f, f) && + color_space_almost_equal(2.4000f, g)) { + gammas[i].fNamed = SkColorSpace::kSRGB_GammaNamed; + } else { + // Fail on invalid gammas. + if (d <= 0.0f) { + // Y = (aX + b)^g + c for always + if (0.0f == a || 0.0f == g) { + SkColorSpacePrintf("A or G is zero, constant gamma function " + "is nonsense"); + return false; + } + } else if (d >= 1.0f) { + // Y = eX + f for always + if (0.0f == e) { + SkColorSpacePrintf("E is zero, constant gamma function is " + "nonsense"); + return false; + } + } else if ((0.0f == a || 0.0f == g) && 0.0f == e) { + SkColorSpacePrintf("A or G, and E are zero, constant gamma function " + "is nonsense"); + return false; + } - if (d >= 1.0f) { - // Y = eX + f for always - if (0.0f == e) { - SkColorSpacePrintf("E is zero, constant gamma function is " - "nonsense"); - return SkGammas::Type::kNone_Type; + gammas[i].fG = g; + gammas[i].fA = a; + gammas[i].fB = b; + gammas[i].fC = c; + gammas[i].fD = d; + gammas[i].fE = e; + gammas[i].fF = f; + } } - } - if ((0.0f == a || 0.0f == g) && 0.0f == e) { - SkColorSpacePrintf("A or G, and E are zero, constant gamma function " - "is nonsense"); - return SkGammas::Type::kNone_Type; + break; } - - *outTagBytes = tagBytes; - - outParams->fG = g; - outParams->fA = a; - outParams->fB = b; - outParams->fC = c; - outParams->fD = d; - outParams->fE = e; - outParams->fF = f; - return SkGammas::Type::kParam_Type; + default: + SkColorSpacePrintf("Unsupported gamma tag type %d\n", type); + return false; } - default: - SkColorSpacePrintf("Unsupported gamma tag type %d\n", type); - return SkGammas::Type::kNone_Type; - } -} - -/** - * Returns the additional size in bytes needed to store the gamma tag. - */ -static size_t gamma_alloc_size(SkGammas::Type type, const SkGammas::Data& data) { - switch (type) { - case SkGammas::Type::kNamed_Type: - case SkGammas::Type::kValue_Type: - return 0; - case SkGammas::Type::kTable_Type: - return sizeof(float) * data.fTable.fSize; - case SkGammas::Type::kParam_Type: - return sizeof(SkGammas::Params); - default: - SkASSERT(false); - return 0; - } -} -/** - * Sets invalid gamma to the default value. - */ -static void handle_invalid_gamma(SkGammas::Type* type, SkGammas::Data* data) { - if (SkGammas::Type::kNone_Type == *type) { - *type = SkGammas::Type::kNamed_Type; - data->fNamed = SkColorSpace::kSRGB_GammaNamed; - } -} + // Ensure that we have successfully read a gamma representation. + SkASSERT(gammas[i].isNamed() || gammas[i].isValue() || gammas[i].isTable() || + gammas[i].isParametric()); -/** - * Finish loading the gammas, now that we have allocated memory for the SkGammas struct. - * - * There's nothing to do for the simple cases, but for table gammas we need to actually - * read the table into heap memory. And for parametric gammas, we need to copy over the - * parameter values. - * - * @param memory Pointer to start of the SkGammas memory block - * @param offset Bytes of memory (after the SkGammas struct) that are already in use. - * @param data In-out variable. Will fill in the offset to the table or parameters - * if necessary. - * @param params Parameters for gamma curve. Only initialized/used when we have a - * parametric gamma. - * @param src Pointer to start of the gamma tag. - * - * @return Additional bytes of memory that are being used by this gamma curve. - */ -static size_t load_gammas(void* memory, size_t offset, SkGammas::Type type, - SkGammas::Data* data, const SkGammas::Params& params, - const uint8_t* src) { - void* storage = SkTAddOffset<void>(memory, offset + sizeof(SkGammas)); - - switch (type) { - case SkGammas::Type::kNamed_Type: - case SkGammas::Type::kValue_Type: - // Nothing to do here. - return 0; - case SkGammas::Type::kTable_Type: { - data->fTable.fOffset = offset; - - float* outTable = (float*) storage; - const uint16_t* inTable = (const uint16_t*) (src + 12); - for (int i = 0; i < data->fTable.fSize; i++) { - outTable[i] = read_big_endian_16_dot_16((const uint8_t*) &inTable[i]); + // Adjust src and len if there is another gamma curve to load. + if (i != numGammas - 1) { + // Each curve is padded to 4-byte alignment. + tagBytes = SkAlign4(tagBytes); + if (len < tagBytes) { + return false; } - return sizeof(float) * data->fTable.fSize; + src += tagBytes; + len -= tagBytes; } - case SkGammas::Type::kParam_Type: - data->fTable.fOffset = offset; - memcpy(storage, ¶ms, sizeof(SkGammas::Params)); - return sizeof(SkGammas::Params); - default: - SkASSERT(false); - return 0; } + + return true; } static constexpr uint32_t kTAG_AtoBType = SkSetFourByteTag('m', 'A', 'B', ' '); -static bool load_color_lut(SkColorLookUpTable* colorLUT, uint32_t inputChannels, - uint32_t outputChannels, const uint8_t* src, size_t len) { +bool load_color_lut(SkColorLookUpTable* colorLUT, uint32_t inputChannels, uint32_t outputChannels, + const uint8_t* src, size_t len) { // 16 bytes reserved for grid points, 2 for precision, 2 for padding. // The color LUT data follows after this header. static constexpr uint32_t kColorLUTHeaderSize = 20; @@ -684,7 +587,7 @@ static bool load_color_lut(SkColorLookUpTable* colorLUT, uint32_t inputChannels, return true; } -static bool load_matrix(SkMatrix44* toXYZ, const uint8_t* src, size_t len) { +bool load_matrix(SkMatrix44* toXYZ, const uint8_t* src, size_t len) { if (len < 48) { SkColorSpacePrintf("Matrix tag is too small (%d bytes).", len); return false; @@ -713,8 +616,8 @@ static bool load_matrix(SkMatrix44* toXYZ, const uint8_t* src, size_t len) { return true; } -static bool load_a2b0(SkColorLookUpTable* colorLUT, SkColorSpace::GammaNamed* gammaNamed, - sk_sp<SkGammas>* gammas, SkMatrix44* toXYZ, const uint8_t* src, size_t len) { +bool load_a2b0(SkColorLookUpTable* colorLUT, SkGammaCurve* gammas, SkMatrix44* toXYZ, + const uint8_t* src, size_t len) { if (len < 32) { SkColorSpacePrintf("A to B tag is too small (%d bytes).", len); return false; @@ -762,77 +665,11 @@ static bool load_a2b0(SkColorLookUpTable* colorLUT, SkColorSpace::GammaNamed* ga uint32_t offsetToMCurves = read_big_endian_int(src + 20); if (0 != offsetToMCurves && offsetToMCurves < len) { - const uint8_t* rTagPtr = src + offsetToMCurves; - size_t tagLen = len - offsetToMCurves; - - SkGammas::Data rData; - SkGammas::Params rParams; - - // On an invalid first gamma, tagBytes remains set as zero. This causes the two - // subsequent to be treated as identical (which is what we want). - size_t tagBytes = 0; - SkGammas::Type rType = parse_gamma(&rData, &rParams, &tagBytes, rTagPtr, tagLen); - handle_invalid_gamma(&rType, &rData); - size_t alignedTagBytes = SkAlign4(tagBytes); - - if ((3 * alignedTagBytes <= tagLen) && - !memcmp(rTagPtr, rTagPtr + 1 * alignedTagBytes, tagBytes) && - !memcmp(rTagPtr, rTagPtr + 2 * alignedTagBytes, tagBytes)) - { - if (SkGammas::Type::kNamed_Type == rType) { - *gammaNamed = rData.fNamed; - } else { - size_t allocSize = sizeof(SkGammas) + gamma_alloc_size(rType, rData); - void* memory = sk_malloc_throw(allocSize); - *gammas = sk_sp<SkGammas>(new (memory) SkGammas()); - load_gammas(memory, 0, rType, &rData, rParams, rTagPtr); - - (*gammas)->fRedType = rType; - (*gammas)->fGreenType = rType; - (*gammas)->fBlueType = rType; - - (*gammas)->fRedData = rData; - (*gammas)->fGreenData = rData; - (*gammas)->fBlueData = rData; - } - } else { - const uint8_t* gTagPtr = rTagPtr + alignedTagBytes; - tagLen = tagLen > alignedTagBytes ? tagLen - alignedTagBytes : 0; - SkGammas::Data gData; - SkGammas::Params gParams; - tagBytes = 0; - SkGammas::Type gType = parse_gamma(&gData, &gParams, &tagBytes, gTagPtr, - tagLen); - handle_invalid_gamma(&gType, &gData); - - alignedTagBytes = SkAlign4(tagBytes); - const uint8_t* bTagPtr = gTagPtr + alignedTagBytes; - tagLen = tagLen > alignedTagBytes ? tagLen - alignedTagBytes : 0; - SkGammas::Data bData; - SkGammas::Params bParams; - SkGammas::Type bType = parse_gamma(&bData, &bParams, &tagBytes, bTagPtr, - tagLen); - handle_invalid_gamma(&bType, &bData); - - size_t allocSize = sizeof(SkGammas) + gamma_alloc_size(rType, rData) - + gamma_alloc_size(gType, gData) - + gamma_alloc_size(bType, bData); - void* memory = sk_malloc_throw(allocSize); - *gammas = sk_sp<SkGammas>(new (memory) SkGammas()); - - uint32_t offset = 0; - (*gammas)->fRedType = rType; - offset += load_gammas(memory, offset, rType, &rData, rParams, rTagPtr); - - (*gammas)->fGreenType = gType; - offset += load_gammas(memory, offset, gType, &gData, gParams, gTagPtr); - - (*gammas)->fBlueType = bType; - load_gammas(memory, offset, bType, &bData, bParams, bTagPtr); - - (*gammas)->fRedData = rData; - (*gammas)->fGreenData = gData; - (*gammas)->fBlueData = bData; + if (!load_gammas(gammas, outputChannels, src + offsetToMCurves, len - offsetToMCurves)) { + SkColorSpacePrintf("Failed to read M curves from A to B tag. Using linear gamma.\n"); + gammas[0].fNamed = SkColorSpace::kLinear_GammaNamed; + gammas[1].fNamed = SkColorSpace::kLinear_GammaNamed; + gammas[2].fNamed = SkColorSpace::kLinear_GammaNamed; } } @@ -847,22 +684,6 @@ static bool load_a2b0(SkColorLookUpTable* colorLUT, SkColorSpace::GammaNamed* ga return true; } -static bool tag_equals(const ICCTag* a, const ICCTag* b, const uint8_t* base) { - if (!a || !b) { - return a == b; - } - - if (a->fLength != b->fLength) { - return false; - } - - if (a->fOffset == b->fOffset) { - return true; - } - - return !memcmp(a->addr(base), b->addr(base), a->fLength); -} - sk_sp<SkColorSpace> SkColorSpace::NewICC(const void* input, size_t len) { if (!input || len < kICCHeaderSize) { return_null("Data is null or not large enough to contain an ICC profile"); @@ -872,8 +693,8 @@ sk_sp<SkColorSpace> SkColorSpace::NewICC(const void* input, size_t len) { void* memory = sk_malloc_throw(len); memcpy(memory, input, len); sk_sp<SkData> data = SkData::MakeFromMalloc(memory, len); - const uint8_t* base = data->bytes(); - const uint8_t* ptr = base; + const void* base = data->data(); + const uint8_t* ptr = (const uint8_t*) base; // Read the ICC profile header and check to make sure that it is valid. ICCProfileHeader header; @@ -919,112 +740,44 @@ sk_sp<SkColorSpace> SkColorSpace::NewICC(const void* input, size_t len) { const ICCTag* b = ICCTag::Find(tags.get(), tagCount, kTAG_bXYZ); if (r && g && b) { float toXYZ[9]; - if (!load_xyz(&toXYZ[0], r->addr(base), r->fLength) || - !load_xyz(&toXYZ[3], g->addr(base), g->fLength) || - !load_xyz(&toXYZ[6], b->addr(base), b->fLength)) + if (!load_xyz(&toXYZ[0], r->addr((const uint8_t*) base), r->fLength) || + !load_xyz(&toXYZ[3], g->addr((const uint8_t*) base), g->fLength) || + !load_xyz(&toXYZ[6], b->addr((const uint8_t*) base), b->fLength)) { return_null("Need valid rgb tags for XYZ space"); } SkMatrix44 mat(SkMatrix44::kUninitialized_Constructor); mat.set3x3RowMajorf(toXYZ); + // It is not uncommon to see missing or empty gamma tags. This indicates + // that we should use unit gamma. + SkGammaCurve curves[3]; r = ICCTag::Find(tags.get(), tagCount, kTAG_rTRC); g = ICCTag::Find(tags.get(), tagCount, kTAG_gTRC); b = ICCTag::Find(tags.get(), tagCount, kTAG_bTRC); - - // If some, but not all, of the gamma tags are missing, assume that all - // gammas are meant to be the same. This behavior is an arbitrary guess, - // but it simplifies the code below. - if ((!r || !g || !b) && (r || g || b)) { - if (!r) { - r = g ? g : b; - } - - if (!g) { - g = r ? r : b; - } - - if (!b) { - b = r ? r : g; - } + if (!r || !load_gammas(&curves[0], 1, r->addr((const uint8_t*) base), r->fLength)) + { + SkColorSpacePrintf("Failed to read R gamma tag.\n"); + curves[0].fNamed = SkColorSpace::kLinear_GammaNamed; } - - GammaNamed gammaNamed = kNonStandard_GammaNamed; - sk_sp<SkGammas> gammas = nullptr; - size_t tagBytes; - if (r && g && b) { - if (tag_equals(r, g, base) && tag_equals(g, b, base)) { - SkGammas::Data data; - SkGammas::Params params; - SkGammas::Type Type = - parse_gamma(&data, ¶ms, &tagBytes, r->addr(base), r->fLength); - handle_invalid_gamma(&Type, &data); - - if (SkGammas::Type::kNamed_Type == Type) { - gammaNamed = data.fNamed; - } else { - size_t allocSize = sizeof(SkGammas) + gamma_alloc_size(Type, data); - void* memory = sk_malloc_throw(allocSize); - gammas = sk_sp<SkGammas>(new (memory) SkGammas()); - load_gammas(memory, 0, Type, &data, params, r->addr(base)); - - gammas->fRedType = Type; - gammas->fGreenType = Type; - gammas->fBlueType = Type; - - gammas->fRedData = data; - gammas->fGreenData = data; - gammas->fBlueData = data; - } - } else { - SkGammas::Data rData; - SkGammas::Params rParams; - SkGammas::Type rType = - parse_gamma(&rData, &rParams, &tagBytes, r->addr(base), r->fLength); - handle_invalid_gamma(&rType, &rData); - - SkGammas::Data gData; - SkGammas::Params gParams; - SkGammas::Type gType = - parse_gamma(&gData, &gParams, &tagBytes, g->addr(base), g->fLength); - handle_invalid_gamma(&gType, &gData); - - SkGammas::Data bData; - SkGammas::Params bParams; - SkGammas::Type bType = - parse_gamma(&bData, &bParams, &tagBytes, b->addr(base), b->fLength); - handle_invalid_gamma(&bType, &bData); - - size_t allocSize = sizeof(SkGammas) + gamma_alloc_size(rType, rData) - + gamma_alloc_size(gType, gData) - + gamma_alloc_size(bType, bData); - void* memory = sk_malloc_throw(allocSize); - gammas = sk_sp<SkGammas>(new (memory) SkGammas()); - - uint32_t offset = 0; - gammas->fRedType = rType; - offset += load_gammas(memory, offset, rType, &rData, rParams, - r->addr(base)); - - gammas->fGreenType = gType; - offset += load_gammas(memory, offset, gType, &gData, gParams, - g->addr(base)); - - gammas->fBlueType = bType; - load_gammas(memory, offset, bType, &bData, bParams, b->addr(base)); - - gammas->fRedData = rData; - gammas->fGreenData = gData; - gammas->fBlueData = bData; - } - } else { - gammaNamed = kLinear_GammaNamed; + if (!g || !load_gammas(&curves[1], 1, g->addr((const uint8_t*) base), g->fLength)) + { + SkColorSpacePrintf("Failed to read G gamma tag.\n"); + curves[1].fNamed = SkColorSpace::kLinear_GammaNamed; + } + if (!b || !load_gammas(&curves[2], 1, b->addr((const uint8_t*) base), b->fLength)) + { + SkColorSpacePrintf("Failed to read B gamma tag.\n"); + curves[2].fNamed = SkColorSpace::kLinear_GammaNamed; } + GammaNamed gammaNamed = SkGammas::Named(curves); if (kNonStandard_GammaNamed == gammaNamed) { - return sk_sp<SkColorSpace>(new SkColorSpace_Base(nullptr, gammaNamed, - std::move(gammas), mat, - std::move(data))); + sk_sp<SkGammas> gammas = sk_make_sp<SkGammas>(std::move(curves[0]), + std::move(curves[1]), + std::move(curves[2])); + return sk_sp<SkColorSpace>(new SkColorSpace_Base(nullptr, std::move(gammas), + mat, std::move(data))); } else { return SkColorSpace_Base::NewRGB(gammaNamed, mat); } @@ -1033,20 +786,24 @@ sk_sp<SkColorSpace> SkColorSpace::NewICC(const void* input, size_t len) { // Recognize color profile specified by A2B0 tag. const ICCTag* a2b0 = ICCTag::Find(tags.get(), tagCount, kTAG_A2B0); if (a2b0) { - GammaNamed gammaNamed = kNonStandard_GammaNamed; - sk_sp<SkGammas> gammas = nullptr; sk_sp<SkColorLookUpTable> colorLUT = sk_make_sp<SkColorLookUpTable>(); + SkGammaCurve curves[3]; SkMatrix44 toXYZ(SkMatrix44::kUninitialized_Constructor); - if (!load_a2b0(colorLUT.get(), &gammaNamed, &gammas, &toXYZ, a2b0->addr(base), + if (!load_a2b0(colorLUT.get(), curves, &toXYZ, a2b0->addr((const uint8_t*) base), a2b0->fLength)) { return_null("Failed to parse A2B0 tag"); } + GammaNamed gammaNamed = SkGammas::Named(curves); colorLUT = colorLUT->fTable ? colorLUT : nullptr; if (colorLUT || kNonStandard_GammaNamed == gammaNamed) { + sk_sp<SkGammas> gammas = sk_make_sp<SkGammas>(std::move(curves[0]), + std::move(curves[1]), + std::move(curves[2])); + return sk_sp<SkColorSpace>(new SkColorSpace_Base(std::move(colorLUT), - gammaNamed, std::move(gammas), - toXYZ, std::move(data))); + std::move(gammas), toXYZ, + std::move(data))); } else { return SkColorSpace_Base::NewRGB(gammaNamed, toXYZ); } @@ -1188,6 +945,23 @@ static void write_trc_tag(uint32_t* ptr, float value) { ptr16[1] = 0; } +static float get_gamma_value(const SkGammaCurve* curve) { + switch (curve->fNamed) { + case SkColorSpace::kSRGB_GammaNamed: + // FIXME (msarett): + // kSRGB cannot be represented by a value. Here we fall through to 2.2f, + // which is a close guess. To be more accurate, we need to represent sRGB + // gamma with a parametric curve. + case SkColorSpace::k2Dot2Curve_GammaNamed: + return 2.2f; + case SkColorSpace::kLinear_GammaNamed: + return 1.0f; + default: + SkASSERT(curve->isValue()); + return curve->fValue; + } +} + sk_sp<SkData> SkColorSpace_Base::writeToICC() const { // Return if this object was created from a profile, or if we have already serialized // the profile. @@ -1231,13 +1005,11 @@ sk_sp<SkData> SkColorSpace_Base::writeToICC() const { // Write TRC tags GammaNamed gammaNamed = this->gammaNamed(); if (kNonStandard_GammaNamed == gammaNamed) { - // FIXME (msarett): - // Write the correct gamma representation rather than 2.2f. - write_trc_tag((uint32_t*) ptr, 2.2f); + write_trc_tag((uint32_t*) ptr, get_gamma_value(&as_CSB(this)->fGammas->fRed)); ptr += SkAlign4(kTAG_TRC_Bytes); - write_trc_tag((uint32_t*) ptr, 2.2f); + write_trc_tag((uint32_t*) ptr, get_gamma_value(&as_CSB(this)->fGammas->fGreen)); ptr += SkAlign4(kTAG_TRC_Bytes); - write_trc_tag((uint32_t*) ptr, 2.2f); + write_trc_tag((uint32_t*) ptr, get_gamma_value(&as_CSB(this)->fGammas->fBlue)); ptr += SkAlign4(kTAG_TRC_Bytes); } else { switch (gammaNamed) { |