Move existing writeICC() code into SkICC

BUG=skia:

Change-Id: Ifb7db7adcc69104fa9abe1765fd60b7f627bdbaf
Reviewed-on: https://skia-review.googlesource.com/6261
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

1 files changed, 236 insertions, 0 deletions

diff --git a/src/core/SkICC.cpp b/src/core/SkICC.cpp
index 9a1a3c6e33..7b8ae9f5a0 100644
--- a/src/core/SkICC.cpp
+++ b/src/core/SkICC.cpp
@@ -6,7 +6,11 @@
  */
 
 #include "SkColorSpace_Base.h"
+#include "SkColorSpace_XYZ.h"
+#include "SkEndian.h"
+#include "SkFixed.h"
 #include "SkICC.h"
+#include "SkICCPriv.h"
 
 SkICC::SkICC(sk_sp<SkColorSpace> colorSpace)
     : fColorSpace(std::move(colorSpace))
@@ -34,3 +38,235 @@ bool SkICC::toXYZD50(SkMatrix44* toXYZD50) const {
 bool SkICC::isNumericalTransferFn(SkColorSpaceTransferFn* coeffs) const {
     return as_CSB(fColorSpace)->onIsNumericalTransferFn(coeffs);
 }
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+// We will write a profile with the minimum nine required tags.
+static constexpr uint32_t kICCNumEntries = 9;
+
+static constexpr uint32_t kTAG_desc = SkSetFourByteTag('d', 'e', 's', 'c');
+static constexpr uint32_t kTAG_desc_Bytes = 12;
+static constexpr uint32_t kTAG_desc_Offset = kICCHeaderSize + kICCNumEntries*kICCTagTableEntrySize;
+
+static constexpr uint32_t kTAG_XYZ_Bytes = 20;
+static constexpr uint32_t kTAG_rXYZ_Offset = kTAG_desc_Offset + kTAG_desc_Bytes;
+static constexpr uint32_t kTAG_gXYZ_Offset = kTAG_rXYZ_Offset + kTAG_XYZ_Bytes;
+static constexpr uint32_t kTAG_bXYZ_Offset = kTAG_gXYZ_Offset + kTAG_XYZ_Bytes;
+
+static constexpr uint32_t kTAG_TRC_Bytes = 14;
+static constexpr uint32_t kTAG_rTRC_Offset = kTAG_bXYZ_Offset + kTAG_XYZ_Bytes;
+static constexpr uint32_t kTAG_gTRC_Offset = kTAG_rTRC_Offset + SkAlign4(kTAG_TRC_Bytes);
+static constexpr uint32_t kTAG_bTRC_Offset = kTAG_gTRC_Offset + SkAlign4(kTAG_TRC_Bytes);
+
+static constexpr uint32_t kTAG_wtpt = SkSetFourByteTag('w', 't', 'p', 't');
+static constexpr uint32_t kTAG_wtpt_Offset = kTAG_bTRC_Offset + SkAlign4(kTAG_TRC_Bytes);
+
+static constexpr uint32_t kTAG_cprt = SkSetFourByteTag('c', 'p', 'r', 't');
+static constexpr uint32_t kTAG_cprt_Bytes = 12;
+static constexpr uint32_t kTAG_cprt_Offset = kTAG_wtpt_Offset + kTAG_XYZ_Bytes;
+
+static constexpr uint32_t kICCProfileSize = kTAG_cprt_Offset + kTAG_cprt_Bytes;
+
+static constexpr uint32_t gICCHeader[kICCHeaderSize / 4] {
+    SkEndian_SwapBE32(kICCProfileSize),  // Size of the profile
+    0,                                   // Preferred CMM type (ignored)
+    SkEndian_SwapBE32(0x02100000),       // Version 2.1
+    SkEndian_SwapBE32(kDisplay_Profile), // Display device profile
+    SkEndian_SwapBE32(kRGB_ColorSpace),  // RGB input color space
+    SkEndian_SwapBE32(kXYZ_PCSSpace),    // XYZ profile connection space
+    0, 0, 0,                             // Date and time (ignored)
+    SkEndian_SwapBE32(kACSP_Signature),  // Profile signature
+    0,                                   // Platform target (ignored)
+    0x00000000,                          // Flags: not embedded, can be used independently
+    0,                                   // Device manufacturer (ignored)
+    0,                                   // Device model (ignored)
+    0, 0,                                // Device attributes (ignored)
+    SkEndian_SwapBE32(1),                // Relative colorimetric rendering intent
+    SkEndian_SwapBE32(0x0000f6d6),       // D50 standard illuminant (X)
+    SkEndian_SwapBE32(0x00010000),       // D50 standard illuminant (Y)
+    SkEndian_SwapBE32(0x0000d32d),       // D50 standard illuminant (Z)
+    0,                                   // Profile creator (ignored)
+    0, 0, 0, 0,                          // Profile id checksum (ignored)
+    0, 0, 0, 0, 0, 0, 0,                 // Reserved (ignored)
+    SkEndian_SwapBE32(kICCNumEntries),   // Number of tags
+};
+
+static constexpr uint32_t gICCTagTable[3 * kICCNumEntries] {
+    // Profile description
+    SkEndian_SwapBE32(kTAG_desc),
+    SkEndian_SwapBE32(kTAG_desc_Offset),
+    SkEndian_SwapBE32(kTAG_desc_Bytes),
+
+    // rXYZ
+    SkEndian_SwapBE32(kTAG_rXYZ),
+    SkEndian_SwapBE32(kTAG_rXYZ_Offset),
+    SkEndian_SwapBE32(kTAG_XYZ_Bytes),
+
+    // gXYZ
+    SkEndian_SwapBE32(kTAG_gXYZ),
+    SkEndian_SwapBE32(kTAG_gXYZ_Offset),
+    SkEndian_SwapBE32(kTAG_XYZ_Bytes),
+
+    // bXYZ
+    SkEndian_SwapBE32(kTAG_bXYZ),
+    SkEndian_SwapBE32(kTAG_bXYZ_Offset),
+    SkEndian_SwapBE32(kTAG_XYZ_Bytes),
+
+    // rTRC
+    SkEndian_SwapBE32(kTAG_rTRC),
+    SkEndian_SwapBE32(kTAG_rTRC_Offset),
+    SkEndian_SwapBE32(kTAG_TRC_Bytes),
+
+    // gTRC
+    SkEndian_SwapBE32(kTAG_gTRC),
+    SkEndian_SwapBE32(kTAG_gTRC_Offset),
+    SkEndian_SwapBE32(kTAG_TRC_Bytes),
+
+    // bTRC
+    SkEndian_SwapBE32(kTAG_bTRC),
+    SkEndian_SwapBE32(kTAG_bTRC_Offset),
+    SkEndian_SwapBE32(kTAG_TRC_Bytes),
+
+    // White point
+    SkEndian_SwapBE32(kTAG_wtpt),
+    SkEndian_SwapBE32(kTAG_wtpt_Offset),
+    SkEndian_SwapBE32(kTAG_XYZ_Bytes),
+
+    // Copyright
+    SkEndian_SwapBE32(kTAG_cprt),
+    SkEndian_SwapBE32(kTAG_cprt_Offset),
+    SkEndian_SwapBE32(kTAG_cprt_Bytes),
+};
+
+static constexpr uint32_t kTAG_TextType = SkSetFourByteTag('m', 'l', 'u', 'c');
+static constexpr uint32_t gEmptyTextTag[3] {
+    SkEndian_SwapBE32(kTAG_TextType), // Type signature
+    0,                                // Reserved
+    0,                                // Zero records
+};
+
+static void write_xyz_tag(uint32_t* ptr, const SkMatrix44& toXYZ, int col) {
+    ptr[0] = SkEndian_SwapBE32(kXYZ_PCSSpace);
+    ptr[1] = 0;
+    ptr[2] = SkEndian_SwapBE32(SkFloatToFixed(toXYZ.getFloat(0, col)));
+    ptr[3] = SkEndian_SwapBE32(SkFloatToFixed(toXYZ.getFloat(1, col)));
+    ptr[4] = SkEndian_SwapBE32(SkFloatToFixed(toXYZ.getFloat(2, col)));
+}
+
+static void write_trc_tag(uint32_t* ptr, float value) {
+    ptr[0] = SkEndian_SwapBE32(kTAG_CurveType);
+    ptr[1] = 0;
+
+    // Gamma will be specified with a single value.
+    ptr[2] = SkEndian_SwapBE32(1);
+
+    // Convert gamma to 16-bit fixed point.
+    uint16_t* ptr16 = (uint16_t*) (ptr + 3);
+    ptr16[0] = SkEndian_SwapBE16((uint16_t) (value * 256.0f));
+
+    // Pad tag with zero.
+    ptr16[1] = 0;
+}
+
+sk_sp<SkData> SkColorSpace_Base::writeToICC() const {
+    // Return if this object was created from a profile, or if we have already serialized
+    // the profile.
+    if (fProfileData) {
+        return fProfileData;
+    }
+    // Profile Data is be mandatory for A2B0 Color Spaces
+    SkASSERT(type() == Type::kXYZ);
+
+    // The client may create an SkColorSpace using an SkMatrix44, but currently we only
+    // support writing profiles with 3x3 matrices.
+    // TODO (msarett): Fix this!
+    const SkColorSpace_XYZ* thisXYZ = static_cast<const SkColorSpace_XYZ*>(this);
+    const SkMatrix44& toXYZD50 = *thisXYZ->toXYZD50();
+    if (0.0f != toXYZD50.getFloat(3, 0) || 0.0f != toXYZD50.getFloat(3, 1) ||
+        0.0f != toXYZD50.getFloat(3, 2) || 0.0f != toXYZD50.getFloat(0, 3) ||
+        0.0f != toXYZD50.getFloat(1, 3) || 0.0f != toXYZD50.getFloat(2, 3))
+    {
+        return nullptr;
+    }
+
+    SkAutoMalloc profile(kICCProfileSize);
+    uint8_t* ptr = (uint8_t*) profile.get();
+
+    // Write profile header
+    memcpy(ptr, gICCHeader, sizeof(gICCHeader));
+    ptr += sizeof(gICCHeader);
+
+    // Write tag table
+    memcpy(ptr, gICCTagTable, sizeof(gICCTagTable));
+    ptr += sizeof(gICCTagTable);
+
+    // Write profile description tag
+    memcpy(ptr, gEmptyTextTag, sizeof(gEmptyTextTag));
+    ptr += sizeof(gEmptyTextTag);
+
+    // Write XYZ tags
+    write_xyz_tag((uint32_t*) ptr, toXYZD50, 0);
+    ptr += kTAG_XYZ_Bytes;
+    write_xyz_tag((uint32_t*) ptr, toXYZD50, 1);
+    ptr += kTAG_XYZ_Bytes;
+    write_xyz_tag((uint32_t*) ptr, toXYZD50, 2);
+    ptr += kTAG_XYZ_Bytes;
+
+    // Write TRC tags
+    SkGammaNamed gammaNamed = thisXYZ->gammaNamed();
+    if (kNonStandard_SkGammaNamed == gammaNamed) {
+        // FIXME (msarett):
+        // Write the correct gamma representation rather than 2.2f.
+        write_trc_tag((uint32_t*) ptr, 2.2f);
+        ptr += SkAlign4(kTAG_TRC_Bytes);
+        write_trc_tag((uint32_t*) ptr, 2.2f);
+        ptr += SkAlign4(kTAG_TRC_Bytes);
+        write_trc_tag((uint32_t*) ptr, 2.2f);
+        ptr += SkAlign4(kTAG_TRC_Bytes);
+    } else {
+        switch (gammaNamed) {
+            case kSRGB_SkGammaNamed:
+                // 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 k2Dot2Curve_SkGammaNamed:
+                write_trc_tag((uint32_t*) ptr, 2.2f);
+                ptr += SkAlign4(kTAG_TRC_Bytes);
+                write_trc_tag((uint32_t*) ptr, 2.2f);
+                ptr += SkAlign4(kTAG_TRC_Bytes);
+                write_trc_tag((uint32_t*) ptr, 2.2f);
+                ptr += SkAlign4(kTAG_TRC_Bytes);
+                break;
+            case kLinear_SkGammaNamed:
+                write_trc_tag((uint32_t*) ptr, 1.0f);
+                ptr += SkAlign4(kTAG_TRC_Bytes);
+                write_trc_tag((uint32_t*) ptr, 1.0f);
+                ptr += SkAlign4(kTAG_TRC_Bytes);
+                write_trc_tag((uint32_t*) ptr, 1.0f);
+                ptr += SkAlign4(kTAG_TRC_Bytes);
+                break;
+            default:
+                SkASSERT(false);
+                break;
+        }
+    }
+
+    // Write white point tag
+    uint32_t* ptr32 = (uint32_t*) ptr;
+    ptr32[0] = SkEndian_SwapBE32(kXYZ_PCSSpace);
+    ptr32[1] = 0;
+    // TODO (msarett): These values correspond to the D65 white point.  This may not always be
+    //                 correct.
+    ptr32[2] = SkEndian_SwapBE32(0x0000f351);
+    ptr32[3] = SkEndian_SwapBE32(0x00010000);
+    ptr32[4] = SkEndian_SwapBE32(0x000116cc);
+    ptr += kTAG_XYZ_Bytes;
+
+    // Write copyright tag
+    memcpy(ptr, gEmptyTextTag, sizeof(gEmptyTextTag));
+
+    // TODO (msarett): Should we try to hold onto the data so we can return immediately if
+    //                 the client calls again?
+    return SkData::MakeFromMalloc(profile.release(), kICCProfileSize);
+}