Extracting more than one wallpaper prominent color

ui/gfx/color_analysis.h

 // 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.
 
 #ifndef UI_GFX_COLOR_ANALYSIS_H_
 #define UI_GFX_COLOR_ANALYSIS_H_
 
 #include <stdint.h>
 
 #include "base/compiler_specific.h"
@@ skipping 105 matching lines @@
   LIGHT,
   NORMAL,
   DARK,
 };
 
 enum class SaturationRange {
   VIBRANT,
   MUTED,
 };
 
-// Returns a single RGB color that represents the bitmap. If a value is
-// succesfully calculated, the return value is fully opaque. For failure, the
-// return value is transparent. This currently calculates one color at a time.
-// We could save computation by calculating multiple colors at once, but there's
-// currently no need to calculate multiple colors.
-GFX_EXPORT SkColor CalculateProminentColorOfBitmap(const SkBitmap& bitmap,
-                                                   LumaRange luma,
-                                                   SaturationRange saturation);
+struct ColorProfile {
+  ColorProfile() = default;
+  ColorProfile(LumaRange l, SaturationRange s) : luma(l), saturation(s) {}
+
+  LumaRange luma = LumaRange::DARK;
+  SaturationRange saturation = SaturationRange::MUTED;
+};
+
+// Returns a vector of RGB colors that represents the bitmap based on the
+// |color_profiles| provided. For each value, if a value is succesfully
+// calculated, the calculated value is fully opaque. For failure, the calculated
+// value is transparent.
+GFX_EXPORT std::vector<SkColor> CalculateProminentColorsOfBitmap(
+    const SkBitmap& bitmap,
+    const std::vector<ColorProfile>& color_profiles);
 
 // Compute color covariance matrix for the input bitmap.
 GFX_EXPORT gfx::Matrix3F ComputeColorCovariance(const SkBitmap& bitmap);
 
 // Apply a color reduction transform defined by |color_transform| vector to
 // |source_bitmap|. The result is put into |target_bitmap|, which is expected
 // to be initialized to the required size and type (SkBitmap::kA8_Config).
 // If |fit_to_range|, result is transfored linearly to fit 0-0xFF range.
 // Otherwise, data is clipped.
 // Returns true if the target has been computed.
 GFX_EXPORT bool ApplyColorReduction(const SkBitmap& source_bitmap,
                                    const gfx::Vector3dF& color_transform,
                                    bool fit_to_range,
                                    SkBitmap* target_bitmap);
 
 // Compute a monochrome image representing the principal color component of
 // the |source_bitmap|. The result is stored in |target_bitmap|, which must be
 // initialized to the required size and type (SkBitmap::kA8_Config).
 // Returns true if the conversion succeeded. Note that there might be legitimate
 // reasons for the process to fail even if all input was correct. This is a
 // condition the caller must be able to handle.
 GFX_EXPORT bool ComputePrincipalComponentImage(const SkBitmap& source_bitmap,
                                               SkBitmap* target_bitmap);
 
 }  // namespace color_utils
 
 #endif  // UI_GFX_COLOR_ANALYSIS_H_