diff options
| -rw-r--r-- | graphics/scaler/intern.h | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/graphics/scaler/intern.h b/graphics/scaler/intern.h index 8f1b546685..c9fd550d35 100644 --- a/graphics/scaler/intern.h +++ b/graphics/scaler/intern.h @@ -41,23 +41,22 @@ /** * Interpolate two 16 bit pixel *pairs* at once with equal weights 1. * In particular, p1 and p2 can contain two pixels each in the upper - * and lower halves. Requires only 5 operations! - * See <http://www.slack.net/~ant/info/rgb_mixing.html> for details on how this works. + * and lower halves. */ template<int bitFormat> static inline uint32 interpolate32_1_1(uint32 p1, uint32 p2) { - return (p1 + p2 - ((p1 ^ p2) & kLowBitsMask)) >> 1; + return (((p1 & kHighBitsMask) >> 1) + ((p2 & kHighBitsMask) >> 1) + (p1 & p2 & kLowBitsMask)); } /** * Interpolate two 16 bit pixel *pairs* at once with weights 3 resp. 1. - * In particular, A and B can contain two pixels/each in the upper + * In particular, p1 and p2 can contain two pixels/each in the upper * and lower halves. */ template<int bitFormat> -static inline uint32 interpolate32_3_1(uint32 A, uint32 B) { - register uint32 x = ((A & qhighBits) >> 2) * 3 + ((B & qhighBits) >> 2); - register uint32 y = ((A & qlowBits) * 3 + (B & qlowBits)) >> 2; +static inline uint32 interpolate32_3_1(uint32 p1, uint32 p2) { + register uint32 x = ((p1 & qhighBits) >> 2) * 3 + ((p2 & qhighBits) >> 2); + register uint32 y = ((p1 & qlowBits) * 3 + (p2 & qlowBits)) >> 2; y &= qlowBits; return x + y; @@ -65,13 +64,13 @@ static inline uint32 interpolate32_3_1(uint32 A, uint32 B) { /** * Interpolate four 16 bit pixel pairs at once with equal weights 1. - * In particular, A and B can contain two pixels/each in the upper + * In particular, p1, p2, p3 and p3 can each contain two pixels in the upper * and lower halves. */ template<int bitFormat> -static inline uint32 interpolate32_1_1_1_1(uint32 A, uint32 B, uint32 C, uint32 D) { - register uint32 x = ((A & qhighBits) >> 2) + ((B & qhighBits) >> 2) + ((C & qhighBits) >> 2) + ((D & qhighBits) >> 2); - register uint32 y = ((A & qlowBits) + (B & qlowBits) + (C & qlowBits) + (D & qlowBits)) >> 2; +static inline uint32 interpolate32_1_1_1_1(uint32 p1, uint32 p2, uint32 p3, uint32 p4) { + register uint32 x = ((p1 & qhighBits) >> 2) + ((p2 & qhighBits) >> 2) + ((p3 & qhighBits) >> 2) + ((p4 & qhighBits) >> 2); + register uint32 y = ((p1 & qlowBits) + (p2 & qlowBits) + (p3 & qlowBits) + (p4 & qlowBits)) >> 2; y &= qlowBits; return x + y; |