diff options
Diffstat (limited to 'nx-X11/extras/Mesa/src/mesa/drivers/dri/savage/savagespan.h')
| -rw-r--r-- | nx-X11/extras/Mesa/src/mesa/drivers/dri/savage/savagespan.h | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/nx-X11/extras/Mesa/src/mesa/drivers/dri/savage/savagespan.h b/nx-X11/extras/Mesa/src/mesa/drivers/dri/savage/savagespan.h new file mode 100644 index 000000000..f6a312e82 --- /dev/null +++ b/nx-X11/extras/Mesa/src/mesa/drivers/dri/savage/savagespan.h @@ -0,0 +1,137 @@ +/* + * Copyright 1998-2003 VIA Technologies, Inc. All Rights Reserved. + * Copyright 2001-2003 S3 Graphics, Inc. All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sub license, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the + * next paragraph) shall be included in all copies or substantial portions + * of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL + * VIA, S3 GRAPHICS, AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +#ifndef _SAVAGE_SPAN_H +#define _SAVAGE_SPAN_H + +#include "drirenderbuffer.h" + + +extern void savageDDInitSpanFuncs( GLcontext *ctx ); + +extern void +savageSetSpanFunctions(driRenderbuffer *rb, const GLvisual *vis, + GLboolean float_depth); + + +/* + * Savage 16-bit float depth format with zExpOffset=16: + * 4 bit unsigned exponent, 12 bit mantissa + * + * The meaning of the mantissa is different from IEEE floatint point + * formats. The same number can't be encoded with different exponents. + * So no bits are wasted. + * + * exponent | range encoded by mantissa | accuracy or mantissa + * ---------+---------------------------+--------------------- + * 15 | 2^-1 .. 1 | 2^-13 + * 14 | 2^-2 .. 2^-1 | 2^-14 + * 13 | 2^-3 .. 2^-2 | 2^-15 + * ... | ... | + * 2 | 2^-14 .. 2^-13 | 2^-27 + * 1 | 2^-15 .. 2^-14 | 2^-27 + * 0 | 2^-16 .. 2^-15 | 2^-28 + * + * Note that there is no encoding for numbers < 2^-16. + */ +static __inline GLuint savageEncodeFloat16( GLdouble x ) +{ + GLint r = (GLint)(x * 0x10000000); + GLint exp = 0; + if (r < 0x1000) + return 0; + while (r - 0x1000 > 0x0fff) { + r >>= 1; + exp++; + } + return exp > 0xf ? 0xffff : (r - 0x1000) | (exp << 12); +} +static __inline GLdouble savageDecodeFloat16( GLuint x ) +{ + static const GLdouble pow2[16] = { + 1.0/(1<<28), 1.0/(1<<27), 1.0/(1<<26), 1.0/(1<<25), + 1.0/(1<<24), 1.0/(1<<23), 1.0/(1<<22), 1.0/(1<<21), + 1.0/(1<<20), 1.0/(1<<19), 1.0/(1<<18), 1.0/(1<<17), + 1.0/(1<<16), 1.0/(1<<15), 1.0/(1<<14), 1.0/(1<<13) + }; + static const GLdouble bias[16] = { + 1.0/(1<<16), 1.0/(1<<15), 1.0/(1<<14), 1.0/(1<<13), + 1.0/(1<<12), 1.0/(1<<11), 1.0/(1<<10), 1.0/(1<< 9), + 1.0/(1<< 8), 1.0/(1<< 7), 1.0/(1<< 6), 1.0/(1<< 5), + 1.0/(1<< 4), 1.0/(1<< 3), 1.0/(1<< 2), 1.0/(1<< 1) + }; + GLuint mant = x & 0x0fff; + GLuint exp = (x >> 12) & 0xf; + return bias[exp] + pow2[exp]*mant; +} + +/* + * Savage 24-bit float depth format with zExpOffset=32: + * 5 bit unsigned exponent, 19 bit mantissa + * + * Details analogous to the 16-bit format. + */ +static __inline GLuint savageEncodeFloat24( GLdouble x ) +{ + int64_t r = (int64_t)(x * ((int64_t)1 << (19+32))); + GLint exp = 0; + if (r < 0x80000) + return 0; + while (r - 0x80000 > 0x7ffff) { + r >>= 1; + exp++; + } + return exp > 0x1f ? 0xffffff : (r - 0x80000) | (exp << 19); +} +#define _1 (int64_t)1 +static __inline GLdouble savageDecodeFloat24( GLuint x ) +{ + static const GLdouble pow2[32] = { + 1.0/(_1<<51), 1.0/(_1<<50), 1.0/(_1<<49), 1.0/(_1<<48), + 1.0/(_1<<47), 1.0/(_1<<46), 1.0/(_1<<45), 1.0/(_1<<44), + 1.0/(_1<<43), 1.0/(_1<<42), 1.0/(_1<<41), 1.0/(_1<<40), + 1.0/(_1<<39), 1.0/(_1<<38), 1.0/(_1<<37), 1.0/(_1<<36), + 1.0/(_1<<35), 1.0/(_1<<34), 1.0/(_1<<33), 1.0/(_1<<32), + 1.0/(_1<<31), 1.0/(_1<<30), 1.0/(_1<<29), 1.0/(_1<<28), + 1.0/(_1<<27), 1.0/(_1<<26), 1.0/(_1<<25), 1.0/(_1<<24), + 1.0/(_1<<23), 1.0/(_1<<22), 1.0/(_1<<21), 1.0/(_1<<20) + }; + static const GLdouble bias[32] = { + 1.0/(_1<<32), 1.0/(_1<<31), 1.0/(_1<<30), 1.0/(_1<<29), + 1.0/(_1<<28), 1.0/(_1<<27), 1.0/(_1<<26), 1.0/(_1<<25), + 1.0/(_1<<24), 1.0/(_1<<23), 1.0/(_1<<22), 1.0/(_1<<21), + 1.0/(_1<<20), 1.0/(_1<<19), 1.0/(_1<<18), 1.0/(_1<<17), + 1.0/(_1<<16), 1.0/(_1<<15), 1.0/(_1<<14), 1.0/(_1<<13), + 1.0/(_1<<12), 1.0/(_1<<11), 1.0/(_1<<10), 1.0/(_1<< 9), + 1.0/(_1<< 8), 1.0/(_1<< 7), 1.0/(_1<< 6), 1.0/(_1<< 5), + 1.0/(_1<< 4), 1.0/(_1<< 3), 1.0/(_1<< 2), 1.0/(_1<< 1) + }; + GLuint mant = x & 0x7ffff; + GLuint exp = (x >> 19) & 0x1f; + return bias[exp] + pow2[exp]*mant; +} +#undef _1 + + +#endif |