diff options
Diffstat (limited to 'src/mesa/drivers/dri/r300/r300_context.h')
| -rw-r--r-- | src/mesa/drivers/dri/r300/r300_context.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/r300/r300_context.h b/src/mesa/drivers/dri/r300/r300_context.h index c287871b37..2408497c48 100644 --- a/src/mesa/drivers/dri/r300/r300_context.h +++ b/src/mesa/drivers/dri/r300/r300_context.h @@ -102,6 +102,37 @@ static __inline__ uint32_t r300PackFloat32(float fl) return u.u; } +/* This is probably wrong for some values, I need to test this + * some more. Range checking would be a good idea also.. + * + * But it works for most things. I'll fix it later if someone + * else with a better clue doesn't + */ +static __inline__ uint32_t r300PackFloat24(float f) +{ + float mantissa; + int exponent; + uint32_t float24 = 0; + + if (f == 0.0) + return 0; + + mantissa = frexpf(f, &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 |= (r300PackFloat32(mantissa) & 0x7FFFFF) >> 7; + + return float24; +} + /************ DMA BUFFERS **************/ /* Need refcounting on dma buffers: |