Move HalfFloatMaker to media

cc/resources/video_resource_updater_unittest.cc

 // Copyright 2013 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 "cc/resources/video_resource_updater.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/bind.h"
@@ skipping 501 matching lines @@
   EXPECT_EQ(1, context3d_->TextureCreationCount());
 
   // The texture copy path requires the use of CopyTextureCHROMIUM, which
   // enforces that the target texture not be immutable, as it may need
   // to alter the storage of the texture. Therefore, this test asserts
   // that an immutable texture wasn't created by glTexStorage2DEXT, when
   // that extension is supported.
   EXPECT_FALSE(context3d_->WasImmutableTextureCreated());
 }
 
-namespace {
-
-// Convert an IEEE 754 half-float to a double value
-// that we can do math on.
-double FromHalfFloat(uint16_t half_float) {
-  if (!half_float)
-    return 0.0;
-  int sign = (half_float & 0x8000) ? -1 : 1;
-  int exponent = (half_float >> 10) & 0x1F;
-  int fraction = half_float & 0x3FF;
-  if (exponent == 0) {
-    return pow(2.0, -24.0) * fraction;
-  } else if (exponent == 0x1F) {
-    return sign * 1000000000000.0;
-  } else {
-    return pow(2.0, exponent - 25) * (0x400 + fraction);
-  }
-}
-
-}  // namespace
-
-TEST_F(VideoResourceUpdaterTest, MakeHalfFloatTest) {
-  unsigned short integers[1 << 16];
-  unsigned short half_floats[1 << 16];
-  for (int bits = 9; bits <= 16; bits++) {
-    std::unique_ptr<VideoResourceUpdater::HalfFloatMaker> half_float_maker;
-    half_float_maker = VideoResourceUpdater::NewHalfFloatMaker(bits);
-    int num_values = 1 << bits;
-    for (int i = 0; i < num_values; i++)
-      integers[i] = i;
-
-    half_float_maker->MakeHalfFloats(integers, num_values, half_floats);
-    // Multiplier to converting integers to 0.0..1.0 range.
-    double multiplier = 1.0 / (num_values - 1);
-
-    for (int i = 0; i < num_values; i++) {
-      // This value is in range 0..1
-      float value = integers[i] * multiplier;
-      // Reverse the effect of offset and multiplier to get the expected
-      // output value from the half-float converter.
-      float expected_value =
-          value / half_float_maker->Multiplier() + half_float_maker->Offset();
-      EXPECT_EQ(integers[i], i);
-
-      // We expect the result to be within +/- one least-significant bit.
-      // Within the range we care about, half-floats values and
-      // their representation both sort in the same order, so we
-      // can just add one to get the next bigger half-float.
-      float expected_precision =
-          FromHalfFloat(half_floats[i] + 1) - FromHalfFloat(half_floats[i]);
-      EXPECT_NEAR(FromHalfFloat(half_floats[i]), expected_value,
-                  expected_precision)
-          << "i = " << i << " bits = " << bits;
-    }
-  }
-}
-
 }  // namespace
 }  // namespace cc