lkml.org 
[lkml]   [2006]   [May]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[patch 02/11] input: fix accuracy of fixp-arith.h
    Add the value of cos(90) = 0 to the table. This also moves the results so that
    sin(x) == sin(180-x) is true as expected.

    Signed-off-by: Anssi Hannula <anssi.hannula@gmail.com>

    ---
    drivers/input/fixp-arith.h | 6 +++---
    1 files changed, 3 insertions(+), 3 deletions(-)

    Index: linux-2.6.16-git20/drivers/input/fixp-arith.h
    ===================================================================
    --- linux-2.6.16-git20.orig/drivers/input/fixp-arith.h 2006-04-10 21:02:50.000000000 +0300
    +++ linux-2.6.16-git20/drivers/input/fixp-arith.h 2006-04-10 21:03:45.000000000 +0300
    @@ -38,13 +38,13 @@ typedef s16 fixp_t;
    #define FRAC_MASK ((1<<FRAC_N)-1)

    // Not to be used directly. Use fixp_{cos,sin}
    -static const fixp_t cos_table[45] = {
    +static const fixp_t cos_table[46] = {
    0x0100, 0x00FF, 0x00FF, 0x00FE, 0x00FD, 0x00FC, 0x00FA, 0x00F8,
    0x00F6, 0x00F3, 0x00F0, 0x00ED, 0x00E9, 0x00E6, 0x00E2, 0x00DD,
    0x00D9, 0x00D4, 0x00CF, 0x00C9, 0x00C4, 0x00BE, 0x00B8, 0x00B1,
    0x00AB, 0x00A4, 0x009D, 0x0096, 0x008F, 0x0087, 0x0080, 0x0078,
    0x0070, 0x0068, 0x005F, 0x0057, 0x004F, 0x0046, 0x003D, 0x0035,
    - 0x002C, 0x0023, 0x001A, 0x0011, 0x0008
    + 0x002C, 0x0023, 0x001A, 0x0011, 0x0008, 0x0000
    };


    @@ -69,7 +69,7 @@ static inline fixp_t fixp_cos(unsigned i
    unsigned int i = degrees % 90;

    if (quadrant == 1 || quadrant == 3) {
    - i = 89 - i;
    + i = 90 - i;
    }

    i >>= 1;
    --
    Anssi Hannula
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2006-05-15 23:18    [W:0.021 / U:0.020 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site