rework Color to have R,G,B,A public variables

Color is a wrapper around a sal_uInt32 variable. With a union,
separate channels R, G, B, A sal_uInt8 variables can be added
that occupy the same memory. This makes it much easier to access
each color component separately, which is used quite a lot by
various algorithms. This also adds the variables to public so
everyone can enjoy the benefits.

Tests have been extended to make sure this doesn't break the
existing algroithms.

Change-Id: I2e78e12df68e8c7f0f49420eef5e659b335ee397
Reviewed-on: https://gerrit.libreoffice.org/71002
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

1 files changed, 25 insertions, 25 deletions

diff --git a/tools/source/generic/color.cxx b/tools/source/generic/color.cxx
index 4c26d76e98c8..4bb5221c13d6 100644
--- a/tools/source/generic/color.cxx
+++ b/tools/source/generic/color.cxx
@@ -31,25 +31,25 @@
 
 sal_uInt8 Color::GetColorError( const Color& rCompareColor ) const
 {
-    const long nErrAbs = labs( static_cast<long>(rCompareColor.GetRed()) - GetRed() ) +
-                         labs( static_cast<long>(rCompareColor.GetGreen()) - GetGreen() ) +
-                         labs( static_cast<long>(rCompareColor.GetBlue()) - GetBlue() );
+    const long nErrAbs = labs(long(rCompareColor.R) - R) +
+                         labs(long(rCompareColor.G) - G) +
+                         labs(long(rCompareColor.B) - B);
 
     return static_cast<sal_uInt8>(FRound( nErrAbs * 0.3333333333 ));
 }
 
-void Color::IncreaseLuminance( sal_uInt8 cLumInc )
+void Color::IncreaseLuminance(sal_uInt8 cLumInc)
 {
-    SetRed( static_cast<sal_uInt8>(std::clamp( static_cast<long>(COLORDATA_RED( mnColor )) + cLumInc, 0L, 255L )) );
-    SetGreen( static_cast<sal_uInt8>(std::clamp( static_cast<long>(COLORDATA_GREEN( mnColor )) + cLumInc, 0L, 255L )) );
-    SetBlue( static_cast<sal_uInt8>(std::clamp( static_cast<long>(COLORDATA_BLUE( mnColor )) + cLumInc, 0L, 255L )) );
+    R = sal_uInt8(std::clamp(long(R) + cLumInc, 0L, 255L));
+    G = sal_uInt8(std::clamp(long(G) + cLumInc, 0L, 255L));
+    B = sal_uInt8(std::clamp(long(B) + cLumInc, 0L, 255L));
 }
 
-void Color::DecreaseLuminance( sal_uInt8 cLumDec )
+void Color::DecreaseLuminance(sal_uInt8 cLumDec)
 {
-    SetRed( static_cast<sal_uInt8>(std::clamp( static_cast<long>(COLORDATA_RED( mnColor )) - cLumDec, 0L, 255L )) );
-    SetGreen( static_cast<sal_uInt8>(std::clamp( static_cast<long>(COLORDATA_GREEN( mnColor )) - cLumDec, 0L, 255L )) );
-    SetBlue( static_cast<sal_uInt8>(std::clamp( static_cast<long>(COLORDATA_BLUE( mnColor )) - cLumDec, 0L, 255L )) );
+    R = sal_uInt8(std::clamp(long(R) - cLumDec, 0L, 255L));
+    G = sal_uInt8(std::clamp(long(G) - cLumDec, 0L, 255L));
+    B = sal_uInt8(std::clamp(long(B) - cLumDec, 0L, 255L));
 }
 
 void Color::DecreaseContrast( sal_uInt8 cContDec )
@@ -59,17 +59,17 @@ void Color::DecreaseContrast( sal_uInt8 cContDec )
         const double fM = ( 128.0 - 0.4985 * cContDec ) / 128.0;
         const double fOff = 128.0 - fM * 128.0;
 
-        SetRed( static_cast<sal_uInt8>(std::clamp( FRound( COLORDATA_RED( mnColor ) * fM + fOff ), 0L, 255L )) );
-        SetGreen( static_cast<sal_uInt8>(std::clamp( FRound( COLORDATA_GREEN( mnColor ) * fM + fOff ), 0L, 255L )) );
-        SetBlue( static_cast<sal_uInt8>(std::clamp( FRound( COLORDATA_BLUE( mnColor ) * fM + fOff ), 0L, 255L )) );
+        R = sal_uInt8(std::clamp(FRound(R * fM + fOff), 0L, 255L));
+        G = sal_uInt8(std::clamp(FRound(G * fM + fOff), 0L, 255L));
+        B = sal_uInt8(std::clamp(FRound(B * fM + fOff), 0L, 255L));
     }
 }
 
 void Color::Invert()
 {
-    SetRed( ~COLORDATA_RED( mnColor ) );
-    SetGreen( ~COLORDATA_GREEN( mnColor ) );
-    SetBlue( ~COLORDATA_BLUE( mnColor ) );
+    R = ~R;
+    G = ~G;
+    B = ~B;
 }
 
 bool Color::IsDark() const
@@ -89,9 +89,9 @@ void Color::RGBtoHSB( sal_uInt16& nHue, sal_uInt16& nSat, sal_uInt16& nBri ) con
     sal_uInt8 c[3];
     sal_uInt8 cMax, cMin;
 
-    c[0] = GetRed();
-    c[1] = GetGreen();
-    c[2] = GetBlue();
+    c[0] = R;
+    c[1] = G;
+    c[2] = B;
 
     cMax = c[0];
     if( c[1] > cMax )
@@ -186,13 +186,13 @@ Color Color::HSBtoRGB( sal_uInt16 nHue, sal_uInt16 nSat, sal_uInt16 nBri )
 
 SvStream& Color::Read( SvStream& rIStm )
 {
-    rIStm.ReadUInt32( mnColor );
+    rIStm.ReadUInt32(mValue);
     return rIStm;
 }
 
 SvStream& Color::Write( SvStream& rOStm ) const
 {
-    rOStm.WriteUInt32( mnColor );
+    rOStm.WriteUInt32(mValue);
     return rOStm;
 }
 
@@ -290,9 +290,9 @@ void Color::ApplyTintOrShade(sal_Int16 n100thPercent)
     aBColor.setBlue(fResult);
     aBColor = basegfx::utils::hsl2rgb(aBColor);
 
-    SetRed(sal_uInt8((  aBColor.getRed()   * 255.0) + 0.5));
-    SetGreen(sal_uInt8((aBColor.getGreen() * 255.0) + 0.5));
-    SetBlue(sal_uInt8(( aBColor.getBlue()  * 255.0) + 0.5));
+    R = sal_uInt8(std::lround(aBColor.getRed()   * 255.0));
+    G = sal_uInt8(std::lround(aBColor.getGreen() * 255.0));
+    B = sal_uInt8(std::lround(aBColor.getBlue()  * 255.0));
 }
 
 SvStream& WriteColor( SvStream& rOStream, const Color& rColor )