color: Don't use QCMS for transforms unless necessary

ui/gfx/color_space.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/color_space.h"
 
 #include <map>
 
 #include "base/lazy_instance.h"
 #include "base/synchronization/lock.h"
 #include "third_party/skia/include/core/SkColorSpace.h"
+#include "third_party/skia/include/core/SkData.h"
+#include "third_party/skia/include/core/SkICC.h"
 #include "ui/gfx/icc_profile.h"
 #include "ui/gfx/skia_color_space_util.h"
 #include "ui/gfx/transform.h"
 
 namespace gfx {
 
 ColorSpace::PrimaryID ColorSpace::PrimaryIDFromInt(int primary_id) {
   if (primary_id < 0 || primary_id > static_cast<int>(PrimaryID::LAST))
     return PrimaryID::UNKNOWN;
   if (primary_id > static_cast<int>(PrimaryID::LAST_STANDARD_VALUE) &&
@@ skipping 67 matching lines @@
   return *this != gfx::ColorSpace();
 }
 
 // static
 ColorSpace ColorSpace::CreateSRGB() {
   return ColorSpace(PrimaryID::BT709, TransferID::IEC61966_2_1, MatrixID::RGB,
                     RangeID::FULL);
 }
 
 // static
+ColorSpace ColorSpace::CreateCustom(const SkMatrix44& to_XYZD50,
+                                    const SkColorSpaceTransferFn& fn) {
+  ColorSpace result(ColorSpace::PrimaryID::CUSTOM,

[hubbe, 2017/02/16 01:28:29]

It would be really cool if we could map custom transfer & primaries back to
their enum values.

It would help optimize things and also help code like color_space_win.cc figure
out what to do better.

Maybe add a TODO for it?

[ccameron, 2017/02/16 01:58:47]

Added a TODO. Might get to it soon (w/ some pending patches for
SkTransferFunctions).

+                    ColorSpace::TransferID::CUSTOM, ColorSpace::MatrixID::RGB,
+                    ColorSpace::RangeID::FULL);
+  for (int row = 0; row < 3; ++row) {
+    for (int col = 0; col < 3; ++col) {
+      result.custom_primary_matrix_[3 * row + col] = to_XYZD50.get(row, col);
+    }
+  }
+  result.custom_transfer_params_[0] = fn.fA;
+  result.custom_transfer_params_[1] = fn.fB;
+  result.custom_transfer_params_[2] = fn.fC;
+  result.custom_transfer_params_[3] = fn.fD;
+  result.custom_transfer_params_[4] = fn.fE;
+  result.custom_transfer_params_[5] = fn.fF;
+  result.custom_transfer_params_[6] = fn.fG;
+  return result;
+}
+
+// static
 ColorSpace ColorSpace::CreateSCRGBLinear() {
   return ColorSpace(PrimaryID::BT709, TransferID::LINEAR_HDR, MatrixID::RGB,
                     RangeID::FULL);
 }
 
 // Static
 ColorSpace ColorSpace::CreateXYZD50() {
   return ColorSpace(PrimaryID::XYZ_D50, TransferID::LINEAR, MatrixID::RGB,
                     RangeID::FULL);
 }
@@ skipping 126 matching lines @@
 
   // Use the parametric transfer function if no other option is available.
   SkColorSpaceTransferFn fn;
   if (!GetTransferFunction(&fn)) {
     DLOG(ERROR) << "Failed to parameterize transfer function for SkColorSpace";
     return nullptr;
   }
   return SkColorSpace::MakeRGB(fn, to_xyz_d50);
 }
 
+bool ColorSpace::GetICCProfile(ICCProfile* icc_profile) const {
+  if (!IsValid())
+    return false;
+
+  // If this was created from an ICC profile, retrieve that exact profile.
+  ICCProfile result;
+  if (ICCProfile::FromId(icc_profile_id_, false, icc_profile))
+    return true;
+
+  // Otherwise, construct an ICC profile based on the best approximated
+  // primaries and matrix.
+  SkMatrix44 to_XYZD50_matrix;
+  GetPrimaryMatrix(&to_XYZD50_matrix);
+  SkColorSpaceTransferFn fn;
+  if (!GetTransferFunction(&fn)) {
+    DLOG(ERROR) << "Failed to get ColorSpace transfer function for ICCProfile.";
+    return false;
+  }
+  sk_sp<SkData> data = SkICC::WriteToICC(fn, to_XYZD50_matrix);
+  if (!data) {
+    DLOG(ERROR) << "Failed to create SkICC.";
+    return false;
+  }
+  *icc_profile = ICCProfile::FromData(data->data(), data->size());
+  DCHECK(icc_profile->IsValid());
+  return true;
+}
+
 void ColorSpace::GetPrimaryMatrix(SkMatrix44* to_XYZD50) const {
   SkColorSpacePrimaries primaries = {0};
   switch (primaries_) {
     case ColorSpace::PrimaryID::CUSTOM:
       to_XYZD50->set3x3RowMajorf(custom_primary_matrix_);
       return;
 
     case ColorSpace::PrimaryID::RESERVED0:
     case ColorSpace::PrimaryID::RESERVED:
     case ColorSpace::PrimaryID::UNSPECIFIED:
@@ skipping 333 matching lines @@
     case MatrixID::BT2020_CL:
     case MatrixID::YDZDX:
     case MatrixID::UNKNOWN:
       matrix->setScale(255.0f/219.0f, 255.0f/224.0f, 255.0f/224.0f);
       matrix->postTranslate(-16.0f/219.0f, -15.5f/224.0f, -15.5f/224.0f);
       break;
   }
 }
 
 }  // namespace gfx