diff options
| -rw-r--r-- | graphics/scaler/aspect.cpp | 5 | ||||
| -rw-r--r-- | graphics/scaler/intern.h | 10 |
2 files changed, 11 insertions, 4 deletions
diff --git a/graphics/scaler/aspect.cpp b/graphics/scaler/aspect.cpp index 85768fbced..85b79ab6cd 100644 --- a/graphics/scaler/aspect.cpp +++ b/graphics/scaler/aspect.cpp @@ -79,10 +79,7 @@ static inline void interpolate5Line(uint16 *dst, const uint16 *srcA, const uint1 } } else { while (width--) { - // TODO: We really would like to use interpolate16_5_3, but that - // does not exist (yet), so we use this trick instead. - uint16 tmp = *srcA++; - *dst++ = interpolate16_5_2_1<ColorMask>(*srcB++, tmp, tmp); + *dst++ = interpolate16_5_3<ColorMask>(*srcB++, *srcA++); } } } diff --git a/graphics/scaler/intern.h b/graphics/scaler/intern.h index 4addd6d3bd..7317745e62 100644 --- a/graphics/scaler/intern.h +++ b/graphics/scaler/intern.h @@ -77,6 +77,16 @@ static inline unsigned interpolate16_3_1(unsigned p1, unsigned p2) { } /** + * Interpolate two 16 bit pixels with weights 5 and 3 and 1, i.e., (5*p1+3*p2)/8. + */ +template<typename ColorMask> +static inline unsigned interpolate16_5_3(unsigned p1, unsigned p2) { + const unsigned lowbits = (((p1 & ColorMask::kLowBits) << 2) + (p1 & ColorMask::kLow3Bits) + + ((p2 & ColorMask::kLow2Bits) << 1) + (p2 & ColorMask::kLow3Bits)) & ColorMask::kLow3Bits; + return ((p1*5 + p2*3) - lowbits) >> 3; +} + +/** * Interpolate two 16 bit pixels with weights 7 and 1, i.e., (7*p1+p2)/8. */ template<typename ColorMask> |