diff options
| author | Corbin Simpson <MostAwesomeDude@gmail.com> | 2008-08-07 18:08:54 -0700 |
|---|---|---|
| committer | Pierre Ossman <pierre@ossman.eu> | 2008-12-01 19:21:52 +0100 |
| commit | 01ed5462fad56f5b7bf867041d00443bdf81c653 (patch) | |
| tree | 4bc558e5640d67a37633ed9f805bf966a4c3e7e7 /src/radeon_textured_video.c | |
| parent | 85bbe889045aa434f71a3eb0ba8153b7d2cc5023 (diff) | |
Switch to Mesa-style 24-bit float packing.
Seems like Mesa's got it right, so we should follow suit.
Diffstat (limited to 'src/radeon_textured_video.c')
| -rw-r--r-- | src/radeon_textured_video.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/src/radeon_textured_video.c b/src/radeon_textured_video.c index 8fc380e1..c7d06202 100644 --- a/src/radeon_textured_video.c +++ b/src/radeon_textured_video.c @@ -80,6 +80,32 @@ static __inline__ uint32_t F_TO_DW(float val) return tmp.l; } +/* Borrowed from Mesa */ +static __inline__ uint32_t F_TO_24(float val) +{ + float mantissa; + int exponent; + uint32_t float24 = 0; + + if (val == 0.0) + return 0; + + mantissa = frexpf(val, &exponent); + + /* Handle -ve */ + if (mantissa < 0) { + float24 |= (1 << 23); + mantissa = mantissa * -1.0; + } + /* Handle exponent, bias of 63 */ + exponent += 62; + float24 |= (exponent << 16); + /* Kill 7 LSB of mantissa */ + float24 |= (F_TO_DW(mantissa) & 0x7FFFFF) >> 7; + + return float24; +} + #define ACCEL_MMIO #define ACCEL_PREAMBLE() unsigned char *RADEONMMIO = info->MMIO #define BEGIN_ACCEL(n) RADEONWaitForFifo(pScrn, (n)) |