From 0be5e5e86522616543975331c1f979147d4c8cdb Mon Sep 17 00:00:00 2001 From: Olivier Goffart Date: Fri, 3 Sep 2010 17:10:07 +0200 Subject: qdrawhelper: small optimisations in fetchTransformBilinear Another way to compute the interpolation that does less multiplications. Small inpact on benchmark Made-with: Samuel --- src/gui/painting/qdrawhelper.cpp | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/src/gui/painting/qdrawhelper.cpp b/src/gui/painting/qdrawhelper.cpp index 03ed597..6d921da 100644 --- a/src/gui/painting/qdrawhelper.cpp +++ b/src/gui/painting/qdrawhelper.cpp @@ -659,16 +659,19 @@ const uint * QT_FASTCALL fetchTransformed(uint *buffer, const Operator *, const interpolate 4 argb pixels with the distx and disty factor. distx and disty bust be between 0 and 16 */ -static inline uint interpolate_4_pixels_16(uint tl, uint tr, uint bl, uint br, int distx, int disty, int idistx, int idisty) -{ - uint tlrb = ((tl & 0x00ff00ff) * idistx * idisty); - uint tlag = (((tl & 0xff00ff00) >> 8) * idistx * idisty); - uint trrb = ((tr & 0x00ff00ff) * distx * idisty); - uint trag = (((tr & 0xff00ff00) >> 8) * distx * idisty); - uint blrb = ((bl & 0x00ff00ff) * idistx * disty); - uint blag = (((bl & 0xff00ff00) >> 8) * idistx * disty); - uint brrb = ((br & 0x00ff00ff) * distx * disty); - uint brag = (((br & 0xff00ff00) >> 8) * distx * disty); +static inline uint interpolate_4_pixels_16(uint tl, uint tr, uint bl, uint br, int distx, int disty) +{ + uint distxy = distx * disty; + //idistx * disty = (16-distx) * disty = 16*disty - distxy + //idistx * idisty = (16-distx) * (16-disty) = 16*16 - 16*distx -16*dity + distxy + uint tlrb = (tl & 0x00ff00ff) * (16*16 - 16*distx - 16*disty + distxy); + uint tlag = ((tl & 0xff00ff00) >> 8) * (16*16 - 16*distx - 16*disty + distxy); + uint trrb = ((tr & 0x00ff00ff) * (distx*16 - distxy)); + uint trag = (((tr & 0xff00ff00) >> 8) * (distx*16 - distxy)); + uint blrb = ((bl & 0x00ff00ff) * (disty*16 - distxy)); + uint blag = (((bl & 0xff00ff00) >> 8) * (disty*16 - distxy)); + uint brrb = ((br & 0x00ff00ff) * (distxy)); + uint brag = (((br & 0xff00ff00) >> 8) * (distxy)); return (((tlrb + trrb + blrb + brrb) >> 8) & 0x00ff00ff) | ((tlag + trag + blag + brag) & 0xff00ff00); } @@ -879,7 +882,6 @@ const uint * QT_FASTCALL fetchTransformedBilinear(uint *buffer, const Operator * const uchar *s1 = data->texture.scanLine(y1); const uchar *s2 = data->texture.scanLine(y2); int disty = (fy & 0x0000ffff) >> 12; - int idisty = 16 - disty; while (b < end) { int x1 = (fx >> 16); int x2; @@ -889,8 +891,7 @@ const uint * QT_FASTCALL fetchTransformedBilinear(uint *buffer, const Operator * uint bl = fetch(s2, x1, data->texture.colorTable); uint br = fetch(s2, x2, data->texture.colorTable); int distx = (fx & 0x0000ffff) >> 12; - int idistx = 16 - distx; - *b = interpolate_4_pixels_16(tl, tr, bl, br, distx, disty, idistx, idisty); + *b = interpolate_4_pixels_16(tl, tr, bl, br, distx, disty); fx += fdx; ++b; } @@ -949,10 +950,8 @@ const uint * QT_FASTCALL fetchTransformedBilinear(uint *buffer, const Operator * int distx = (fx & 0x0000ffff) >> 12; int disty = (fy & 0x0000ffff) >> 12; - int idistx = 16 - distx; - int idisty = 16 - disty; - *b = interpolate_4_pixels_16(tl, tr, bl, br, distx, disty, idistx, idisty); + *b = interpolate_4_pixels_16(tl, tr, bl, br, distx, disty); fx += fdx; fy += fdy; -- cgit v0.12