Fix SVACE error in pixel-buffer-impl.cpp

[platform/core/uifw/dali-adaptor.git] / dali / internal / imaging / common / pixel-buffer-impl.cpp

diff --git a/dali/internal/imaging/common/pixel-buffer-impl.cpp b/dali/internal/imaging/common/pixel-buffer-impl.cpp
index 1b74988..6ed2e31 100644 (file)
--- a/dali/internal/imaging/common/pixel-buffer-impl.cpp
+++ b/dali/internal/imaging/common/pixel-buffer-impl.cpp
@@ -37,6 +37,10 @@ namespace Adaptor
 namespace
 {
 const float TWO_PI = 2.f * Math::PI; ///< 360 degrees in radians
+// based on W3C Recommendations (https://www.w3.org/TR/AERT/#color-contrast)
+constexpr uint32_t BRIGHTNESS_CONSTANT_R = 299;
+constexpr uint32_t BRIGHTNESS_CONSTANT_G = 587;
+constexpr uint32_t BRIGHTNESS_CONSTANT_B = 114;
 } // namespace
 
 PixelBuffer::PixelBuffer(unsigned char*      buffer,
@@ -466,6 +470,37 @@ bool PixelBuffer::IsAlphaPreMultiplied() const
   return mPreMultiplied;
 }
 
+uint32_t PixelBuffer::GetBrightness() const
+{
+  uint32_t brightness = 0;
+
+  uint32_t bytesPerPixel = Pixel::GetBytesPerPixel(mPixelFormat);
+  if(bytesPerPixel)
+  {
+    unsigned char* pixel      = mBuffer;
+    const uint32_t bufferSize = mWidth * mHeight;
+
+    if(bufferSize) // avoid division by zero to calculate brightness
+    {
+      uint64_t red   = 0;
+      uint64_t green = 0;
+      uint64_t blue  = 0;
+
+      for(uint32_t i = 0; i < bufferSize; ++i)
+      {
+        red += ReadChannel(pixel, mPixelFormat, Adaptor::RED);
+        green += ReadChannel(pixel, mPixelFormat, Adaptor::GREEN);
+        blue += ReadChannel(pixel, mPixelFormat, Adaptor::BLUE);
+        pixel += bytesPerPixel;
+      }
+      // http://www.w3.org/TR/AERT#color-contrast
+      brightness = (red * BRIGHTNESS_CONSTANT_R + green * BRIGHTNESS_CONSTANT_G + blue * BRIGHTNESS_CONSTANT_B) / (1000uLL * bufferSize);
+    }
+  }
+
+  return brightness;
+}
+
 } // namespace Adaptor
 } // namespace Internal
 } // namespace Dali