diff options
| -rw-r--r-- | engines/cine/pal.cpp | 45 |
1 files changed, 26 insertions, 19 deletions
diff --git a/engines/cine/pal.cpp b/engines/cine/pal.cpp index ea8f6fbaab..582a707be7 100644 --- a/engines/cine/pal.cpp +++ b/engines/cine/pal.cpp @@ -103,14 +103,7 @@ void loadRelatedPalette(const char *fileName) { } } -/*! \brief Shift byte to the left by given amount (Handles negative shifting amounts too, otherwise this would be trivial). */ -byte shiftByteLeft(const byte value, const signed shiftLeft) { - if (shiftLeft >= 0) - return value << shiftLeft; - else // right shift with negative shiftLeft values - return value >> abs(shiftLeft); -} - +namespace { /*! \brief Is given endian type big endian? (Handles native endian type too, otherwise this would be trivial). */ bool isBigEndian(const EndianType endian) { assert(endian == CINE_NATIVE_ENDIAN || endian == CINE_LITTLE_ENDIAN || endian == CINE_BIG_ENDIAN); @@ -138,6 +131,15 @@ int bytePos(const int bitPos, const int numBytes, const bool bigEndian) { return bitPos / 8; } +/*! \brief Calculate the value of "base" to the power of "power". */ +int power(int base, int power) { + int result = 1; + while (power--) + result *= base; + return result; +} +} // end of anonymous namespace + // a.k.a. palRotate Palette &Palette::rotateRight(byte firstIndex, byte lastIndex, signed rotationAmount) { assert(rotationAmount == 0 || rotationAmount == 1); @@ -317,25 +319,30 @@ byte *Palette::save(byte *buf, const uint size, const Graphics::PixelFormat form // Clear the part of the output palette we're going to be writing to with all black memset(buf, 0, format.bytesPerPixel * numColors); - // Calculate how much bit shifting the color components need (for positioning them correctly) - const signed rShiftLeft = (colorFormat().rLoss - (signed) format.rLoss) + (format.rShift % 8); - const signed gShiftLeft = (colorFormat().gLoss - (signed) format.gLoss) + (format.gShift % 8); - const signed bShiftLeft = (colorFormat().bLoss - (signed) format.bLoss) + (format.bShift % 8); + // Calculate original R/G/B max values + const int rOrigMax = power(2, 8 - colorFormat().rLoss) - 1; + const int gOrigMax = power(2, 8 - colorFormat().gLoss) - 1; + const int bOrigMax = power(2, 8 - colorFormat().bLoss) - 1; - // Calculate the byte masks for each color component (for masking away excess bits) - const byte rMask = format.rMax() << (format.rShift % 8); - const byte gMask = format.gMax() << (format.gShift % 8); - const byte bMask = format.bMax() << (format.bShift % 8); + // Calculate new R/G/B max values + const int rNewMax = power(2, 8 - format.rLoss) - 1; + const int gNewMax = power(2, 8 - format.gLoss) - 1; + const int bNewMax = power(2, 8 - format.bLoss) - 1; + // Calculate the byte position const int rBytePos = bytePos(format.rShift, format.bytesPerPixel, isBigEndian(endian)); const int gBytePos = bytePos(format.gShift, format.bytesPerPixel, isBigEndian(endian)); const int bBytePos = bytePos(format.bShift, format.bytesPerPixel, isBigEndian(endian)); // Save the palette to the output in the specified format for (uint i = firstIndex; i < firstIndex + numColors; i++) { - buf[i * format.bytesPerPixel + rBytePos] |= (shiftByteLeft(_colors[i].r, rShiftLeft) & rMask); - buf[i * format.bytesPerPixel + gBytePos] |= (shiftByteLeft(_colors[i].g, gShiftLeft) & gMask); - buf[i * format.bytesPerPixel + bBytePos] |= (shiftByteLeft(_colors[i].b, bShiftLeft) & bMask); + const uint r = (_colors[i].r * rNewMax) / rOrigMax; + const uint g = (_colors[i].g * gNewMax) / gOrigMax; + const uint b = (_colors[i].b * bNewMax) / bOrigMax; + + buf[i * format.bytesPerPixel + rBytePos] |= r << (format.rShift % 8); + buf[i * format.bytesPerPixel + gBytePos] |= g << (format.gShift % 8); + buf[i * format.bytesPerPixel + bBytePos] |= b << (format.bShift % 8); } // Return the pointer to the output palette |