[Scummvm-cvs-logs] SF.net SVN: scummvm:[39691] scummvm/trunk/engines/cine

[buddha_ at users.sourceforge.net]

Revision: 39691
          http://scummvm.svn.sourceforge.net/scummvm/?rev=39691&view=rev
Author:   buddha_
Date:     2009-03-25 19:52:08 +0000 (Wed, 25 Mar 2009)

Log Message:
-----------
Cine::Palette::saturatedAddNormalizedGray: Use fractional representation (dividend/denominator) of the normalized gray value in range [-1, +1] rather than a floating point.

Modified Paths:
--------------
    scummvm/trunk/engines/cine/pal.cpp
    scummvm/trunk/engines/cine/pal.h

Modified: scummvm/trunk/engines/cine/pal.cpp
===================================================================
--- scummvm/trunk/engines/cine/pal.cpp	2009-03-25 17:51:22 UTC (rev 39690)
+++ scummvm/trunk/engines/cine/pal.cpp	2009-03-25 19:52:08 UTC (rev 39691)
@@ -257,12 +257,11 @@
 	return output;
 }
 
-Palette &Palette::saturatedAddNormalizedGray(Palette& output, byte firstIndex, byte lastIndex, double normalizedGray) {
-	// Calculate the gray value rounded up away from zero
-	const double signedHalf = ((normalizedGray >= 0) ? +0.5 : -0.5);
-	const signed r = (signed)(_rMax * normalizedGray + signedHalf);
-	const signed g = (signed)(_gMax * normalizedGray + signedHalf);
-	const signed b = (signed)(_bMax * normalizedGray + signedHalf);
+Palette &Palette::saturatedAddNormalizedGray(Palette& output, byte firstIndex, byte lastIndex, int grayDividend, int grayDenominator) {
+	assert(grayDenominator != 0);
+	const signed r = _rMax * grayDividend / grayDenominator;
+	const signed g = _gMax * grayDividend / grayDenominator;
+	const signed b = _bMax * grayDividend / grayDenominator;
 
 	return saturatedAddColor(output, firstIndex, lastIndex, r, g, b);
 }

Modified: scummvm/trunk/engines/cine/pal.h
===================================================================
--- scummvm/trunk/engines/cine/pal.h	2009-03-25 17:51:22 UTC (rev 39690)
+++ scummvm/trunk/engines/cine/pal.h	2009-03-25 19:52:08 UTC (rev 39691)
@@ -116,7 +116,18 @@
 
 	Palette &rotateRight(byte firstIndex, byte lastIndex);
 	Palette &saturatedAddColor(Palette& output, byte firstIndex, byte lastIndex, signed r, signed g, signed b);
-	Palette &saturatedAddNormalizedGray(Palette& output, byte firstIndex, byte lastIndex, double normalizedGray);
+
+	/*! \brief Saturated add a normalized gray value to current palette's subset and save the modified colors in the given output palette.
+	 * \param output The output palette (Only this palette is modified)
+	 * \param firstIndex First color index of the palette's subset (Inclusive range)
+	 * \param lastIndex Last color index of the palette's subset (Inclusive range)
+	 * \param grayDividend Dividend of the normalized gray value
+	 * \param grayDenominator Denominator of the normalized gray value
+	 * \note The normalized gray value (i.e. in range [-1, +1]) is given as a fractional number
+	 * (i.e. the normalized gray value is calculated by dividing grayDividend by grayDenominator).
+	 */
+	Palette &saturatedAddNormalizedGray(Palette& output, byte firstIndex, byte lastIndex, signed grayDividend, signed grayDenominator);
+
 	uint colorCount() const;
 
 	Palette &fillWithBlack();


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