Always use valid enum values in gfx::ColorSpace

ui/gfx/color_transform.cc

 // Copyright (c) 2016 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_transform.h"
 
 #include <vector>
 
 #include "base/logging.h"
 #include "ui/gfx/color_space.h"
@@ skipping 22 matching lines @@
   return color;
 }
 
 ColorTransform::TriStim Xy2xyz(float x, float y) {
   return ColorTransform::TriStim(x, y, 1.0f - x - y);
 }
 
 void GetPrimaries(ColorSpace::PrimaryID id,
                   ColorTransform::TriStim primaries[4]) {
   switch (id) {
-    default:
-    // If we don't know, assume BT709
+    case ColorSpace::PrimaryID::CUSTOM:
+      NOTREACHED();
 
+    case ColorSpace::PrimaryID::RESERVED0:
+    case ColorSpace::PrimaryID::RESERVED:
+    case ColorSpace::PrimaryID::UNSPECIFIED:
+    case ColorSpace::PrimaryID::UNKNOWN:
     case ColorSpace::PrimaryID::BT709:
-      // Red
-      primaries[0] = Xy2xyz(0.640f, 0.330f);
-      // Green
-      primaries[1] = Xy2xyz(0.300f, 0.600f);
-      // Blue
-      primaries[2] = Xy2xyz(0.150f, 0.060f);
-      // Whitepoint (D65f)
-      primaries[3] = Xy2xyz(0.3127f, 0.3290f);
-      break;
+      // BT709 is our default case. Put it after the switch just
+      // in case we somehow get an id which is not listed in the switch.
+      // (We don't want to use "default", because we want the compiler
+      //  to tell us if we forgot some enum values.)
+      return;
 
     case ColorSpace::PrimaryID::BT470M:
       // Red
       primaries[0] = Xy2xyz(0.67f, 0.33f);
       // Green
       primaries[1] = Xy2xyz(0.21f, 0.71f);
       // Blue
       primaries[2] = Xy2xyz(0.14f, 0.08f);
       // Whitepoint
       primaries[3] = Xy2xyz(0.31f, 0.316f);
-      break;
+      return;
 
     case ColorSpace::PrimaryID::BT470BG:
       // Red
       primaries[0] = Xy2xyz(0.64f, 0.33f);
       // Green
       primaries[1] = Xy2xyz(0.29f, 0.60f);
       // Blue
       primaries[2] = Xy2xyz(0.15f, 0.06f);
       // Whitepoint (D65f)
       primaries[3] = Xy2xyz(0.3127f, 0.3290f);
-      break;
+      return;
 
     case ColorSpace::PrimaryID::SMPTE170M:
     case ColorSpace::PrimaryID::SMPTE240M:
       // Red
       primaries[0] = Xy2xyz(0.630f, 0.340f);
       // Green
       primaries[1] = Xy2xyz(0.310f, 0.595f);
       // Blue
       primaries[2] = Xy2xyz(0.155f, 0.070f);
       // Whitepoint (D65f)
       primaries[3] = Xy2xyz(0.3127f, 0.3290f);
-      break;
+      return;
 
     case ColorSpace::PrimaryID::FILM:
       // Red
       primaries[0] = Xy2xyz(0.681f, 0.319f);
       // Green
       primaries[1] = Xy2xyz(0.243f, 0.692f);
       // Blue
       primaries[2] = Xy2xyz(0.145f, 0.049f);
       // Whitepoint (Cf)
       primaries[3] = Xy2xyz(0.310f, 0.136f);
-      break;
+      return;
 
     case ColorSpace::PrimaryID::BT2020:
       // Red
       primaries[0] = Xy2xyz(0.708f, 0.292f);
       // Green
       primaries[1] = Xy2xyz(0.170f, 0.797f);
       // Blue
       primaries[2] = Xy2xyz(0.131f, 0.046f);
       // Whitepoint (D65f)
       primaries[3] = Xy2xyz(0.3127f, 0.3290f);
-      break;
+      return;
 
     case ColorSpace::PrimaryID::SMPTEST428_1:
       // X
       primaries[0] = Xy2xyz(1.0f, 0.0f);
       // Y
       primaries[1] = Xy2xyz(0.0f, 1.0f);
       // Z
       primaries[2] = Xy2xyz(0.0f, 0.0f);
       // Whitepoint (Ef)
       primaries[3] = Xy2xyz(1.0f / 3.0f, 1.0f / 3.0f);
-      break;
+      return;
 
     case ColorSpace::PrimaryID::SMPTEST431_2:
       // Red
       primaries[0] = Xy2xyz(0.680f, 0.320f);
       // Green
       primaries[1] = Xy2xyz(0.265f, 0.690f);
       // Blue
       primaries[2] = Xy2xyz(0.150f, 0.060f);
       // Whitepoint
       primaries[3] = Xy2xyz(0.314f, 0.351f);
-      break;
+      return;
 
     case ColorSpace::PrimaryID::SMPTEST432_1:
       // Red
       primaries[0] = Xy2xyz(0.680f, 0.320f);
       // Green
       primaries[1] = Xy2xyz(0.265f, 0.690f);
       // Blue
       primaries[2] = Xy2xyz(0.150f, 0.060f);
       // Whitepoint (D65f)
       primaries[3] = Xy2xyz(0.3127f, 0.3290f);
-      break;
+      return;
 
     case ColorSpace::PrimaryID::XYZ_D50:
       // X
       primaries[0] = Xy2xyz(1.0f, 0.0f);
       // Y
       primaries[1] = Xy2xyz(0.0f, 1.0f);
       // Z
       primaries[2] = Xy2xyz(0.0f, 0.0f);
       // D50
       primaries[3] = Xy2xyz(0.34567f, 0.35850f);
-      break;
+      return;
   }
+
+  // Red
+  primaries[0] = Xy2xyz(0.640f, 0.330f);
+  // Green
+  primaries[1] = Xy2xyz(0.300f, 0.600f);
+  // Blue
+  primaries[2] = Xy2xyz(0.150f, 0.060f);
+  // Whitepoint (D65f)
+  primaries[3] = Xy2xyz(0.3127f, 0.3290f);
 }
 
 GFX_EXPORT Transform GetPrimaryMatrix(ColorSpace::PrimaryID id) {
   ColorTransform::TriStim primaries[4];
   GetPrimaries(id, primaries);
   ColorTransform::TriStim WXYZ(primaries[3].x() / primaries[3].y(), 1.0f,
                                primaries[3].z() / primaries[3].y());
 
   Transform ret(
       primaries[0].x(), primaries[1].x(), primaries[2].x(), 0.0f,  // 1
@@ skipping 17 matching lines @@
   Transform adapter;
   adapter.Scale3d(dest_response.x() / source_response.x(),
                   dest_response.y() / source_response.y(),
                   dest_response.z() / source_response.z());
 
   return Invert(bradford) * adapter * bradford * ret;
 }
 
 GFX_EXPORT float FromLinear(ColorSpace::TransferID id, float v) {
   switch (id) {
-    default:
+    case ColorSpace::TransferID::SMPTEST2084_NON_HDR:
+      // Should already be handled.
+      NOTREACHED();
+    case ColorSpace::TransferID::CUSTOM:
+    // TODO(hubbe): Actually implement custom transfer functions.
+    case ColorSpace::TransferID::RESERVED0:
+    case ColorSpace::TransferID::RESERVED:
+    case ColorSpace::TransferID::UNSPECIFIED:
+    case ColorSpace::TransferID::UNKNOWN:
+    // All unknown values default to BT709
+
     case ColorSpace::TransferID::BT709:
     case ColorSpace::TransferID::SMPTE170M:
     case ColorSpace::TransferID::BT2020_10:
-    case ColorSpace::TransferID::BT2020_12: {
-      v = fmax(0.0f, v);
-      float a = 1.099296826809442f;
-      float b = 0.018053968510807f;
-      if (v <= b) {
-        return 4.5f * v;
-      } else {
-        return a * powf(v, 0.45f) - (a - 1.0f);
-      }
-    }
+    case ColorSpace::TransferID::BT2020_12:
+      // BT709 is our "default" cause, so put the code after the switch
+      // to avoid "control reaches end of non-void function" errors.
+      break;
 
     case ColorSpace::TransferID::GAMMA22:
       v = fmax(0.0f, v);
       return powf(v, 1.0f / 2.2f);
 
     case ColorSpace::TransferID::GAMMA28:
       v = fmax(0.0f, v);
       return powf(v, 1.0f / 2.8f);
 
     case ColorSpace::TransferID::SMPTE240M: {
@@ skipping 67 matching lines @@
 
     case ColorSpace::TransferID::SMPTEST428_1:
       v = fmax(0.0f, v);
       return powf(48.0f * v + 52.37f, 1.0f / 2.6f);
 
     // Chrome-specific values below
     case ColorSpace::TransferID::GAMMA24:
       v = fmax(0.0f, v);
       return powf(v, 1.0f / 2.4f);
   }
+
+  v = fmax(0.0f, v);
+  float a = 1.099296826809442f;
+  float b = 0.018053968510807f;
+  if (v <= b) {
+    return 4.5f * v;
+  } else {
+    return a * powf(v, 0.45f) - (a - 1.0f);
+  }
 }
 
 GFX_EXPORT float ToLinear(ColorSpace::TransferID id, float v) {
   switch (id) {
-    default:
+    case ColorSpace::TransferID::CUSTOM:
+    // TODO(hubbe): Actually implement custom transfer functions.
+    case ColorSpace::TransferID::RESERVED0:
+    case ColorSpace::TransferID::RESERVED:
+    case ColorSpace::TransferID::UNSPECIFIED:
+    case ColorSpace::TransferID::UNKNOWN:
+    // All unknown values default to BT709
+
     case ColorSpace::TransferID::BT709:
     case ColorSpace::TransferID::SMPTE170M:
     case ColorSpace::TransferID::BT2020_10:
-    case ColorSpace::TransferID::BT2020_12: {
-      v = fmax(0.0f, v);
-      float a = 1.099296826809442f;
-      float b = 0.018053968510807f;
-      if (v < FromLinear(ColorSpace::TransferID::BT709, b)) {
-        return v / 4.5f;
-      } else {
-        return powf((v + a - 1.0f) / a, 1.0f / 0.45f);
-      }
-    }
+    case ColorSpace::TransferID::BT2020_12:
+      // BT709 is our "default" cause, so put the code after the switch
+      // to avoid "control reaches end of non-void function" errors.
+      break;
 
     case ColorSpace::TransferID::GAMMA22:
       v = fmax(0.0f, v);
       return powf(v, 2.2f);
 
     case ColorSpace::TransferID::GAMMA28:
       v = fmax(0.0f, v);
       return powf(v, 2.8f);
 
     case ColorSpace::TransferID::SMPTE240M: {
@@ skipping 73 matching lines @@
 
     // Chrome-specific values below
     case ColorSpace::TransferID::GAMMA24:
       v = fmax(0.0f, v);
       return powf(v, 2.4f);
 
     case ColorSpace::TransferID::SMPTEST2084_NON_HDR:
       v = fmax(0.0f, v);
       return fmin(2.3f * pow(v, 2.8f), v / 5.0f + 0.8f);
   }
+
+  v = fmax(0.0f, v);
+  float a = 1.099296826809442f;
+  float b = 0.018053968510807f;
+  if (v < FromLinear(ColorSpace::TransferID::BT709, b)) {
+    return v / 4.5f;
+  } else {
+    return powf((v + a - 1.0f) / a, 1.0f / 0.45f);
+  }
 }
 
 namespace {
 // Assumes bt2020
 float Luma(const ColorTransform::TriStim& c) {
   return c.x() * 0.2627f + c.y() * 0.6780f + c.z() * 0.0593f;
 }
 };
 
 GFX_EXPORT ColorTransform::TriStim ToLinear(ColorSpace::TransferID id,
                                             ColorTransform::TriStim color) {
   ColorTransform::TriStim ret(ToLinear(id, color.x()), ToLinear(id, color.y()),
                               ToLinear(id, color.z()));
 
   if (id == ColorSpace::TransferID::SMPTEST2084_NON_HDR) {
     if (Luma(ret) > 0.0) {
       ColorTransform::TriStim smpte2084(
           ToLinear(ColorSpace::TransferID::SMPTEST2084, color.x()),
           ToLinear(ColorSpace::TransferID::SMPTEST2084, color.y()),
           ToLinear(ColorSpace::TransferID::SMPTEST2084, color.z()));
       smpte2084.Scale(Luma(ret) / Luma(smpte2084));
       ret = smpte2084;
     }
   }
 
   return ret;
 }
 
 GFX_EXPORT Transform GetTransferMatrix(ColorSpace::MatrixID id) {
-  float Kr = 0.0f, Kb = 0.0f;
+  // Default values for BT709;
+  float Kr = 0.2126f;
+  float Kb = 0.0722f;
   switch (id) {
     case ColorSpace::MatrixID::RGB:
       return Transform();
 
     case ColorSpace::MatrixID::BT709:
     case ColorSpace::MatrixID::UNSPECIFIED:
     case ColorSpace::MatrixID::RESERVED:
-      Kr = 0.2126f;
-      Kb = 0.0722f;
+    case ColorSpace::MatrixID::UNKNOWN:
+      // Default values are already set.
       break;
 
     case ColorSpace::MatrixID::FCC:
       Kr = 0.30f;
       Kb = 0.11f;
       break;
 
     case ColorSpace::MatrixID::BT470BG:
     case ColorSpace::MatrixID::SMPTE170M:
       Kr = 0.299f;
@@ skipping 53 matching lines @@
     case ColorSpace::MatrixID::BT709:
     case ColorSpace::MatrixID::UNSPECIFIED:
     case ColorSpace::MatrixID::RESERVED:
     case ColorSpace::MatrixID::FCC:
     case ColorSpace::MatrixID::BT470BG:
     case ColorSpace::MatrixID::SMPTE170M:
     case ColorSpace::MatrixID::SMPTE240M:
     case ColorSpace::MatrixID::BT2020_NCL:
     case ColorSpace::MatrixID::BT2020_CL:
     case ColorSpace::MatrixID::YDZDX:
+    case ColorSpace::MatrixID::UNKNOWN:
       return Transform(255.0f / 219.0f, 0.0f, 0.0f, -16.0f / 219.0f,  // 1
                        0.0f, 255.0f / 224.0f, 0.0f, -15.5f / 224.0f,  // 2
                        0.0f, 0.0f, 255.0f / 224.0f, -15.5f / 224.0f,  // 3
                        0.0f, 0.0f, 0.0f, 1.0f);                       // 4
   }
   NOTREACHED();
   return Transform();
 }
 
 class ColorSpaceToColorSpaceTransform : public ColorTransform {
@@ skipping 171 matching lines @@
           std::unique_ptr<ColorTransform>(
               new QCMSColorTransform(GetXYZD50Profile(), to_profile))));
     } else {
       return std::unique_ptr<ColorTransform>(
           new ColorSpaceToColorSpaceTransform(from, to, intent));
     }
   }
 }
 
 }  // namespace gfx