diff options
Diffstat (limited to 'src/mesa/drivers/dri/sis/sis_fog.c')
| -rw-r--r-- | src/mesa/drivers/dri/sis/sis_fog.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/sis/sis_fog.c b/src/mesa/drivers/dri/sis/sis_fog.c new file mode 100644 index 0000000000..8daa9a0f5e --- /dev/null +++ b/src/mesa/drivers/dri/sis/sis_fog.c @@ -0,0 +1,181 @@ +/************************************************************************** + +Copyright 2000 Silicon Integrated Systems Corp, Inc., HsinChu, Taiwan. +Copyright 2003 Eric Anholt +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 +on 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 +ATI, PRECISION INSIGHT AND/OR THEIR 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. + +**************************************************************************/ +/* $XFree86: xc/lib/GL/mesa/src/drv/sis/sis_fog.c,v 1.3 2000/09/26 15:56:48 tsi Exp $ */ + +/* + * Authors: + * Sung-Ching Lin <sclin@sis.com.tw> + * Eric Anholt <anholt@FreeBSD.org> + */ + +#include "sis_context.h" +#include "sis_state.h" +#include "swrast/swrast.h" +#include "macros.h" + +static GLint convertFtToFogFt( GLfloat dwInValue ); + +void +sisDDFogfv( GLcontext *ctx, GLenum pname, const GLfloat *params ) +{ + sisContextPtr smesa = SIS_CONTEXT(ctx); + __GLSiSHardware *current = &smesa->current; + + float fArg; + GLint fogColor; + + switch (pname) + { + case GL_FOG_MODE: + current->hwFog &= ~MASK_FogMode; + switch (ctx->Fog.Mode) + { + case GL_LINEAR: + current->hwFog |= FOGMODE_LINEAR; + _swrast_allow_pixel_fog( ctx, GL_TRUE ); + _swrast_allow_vertex_fog( ctx, GL_FALSE ); + break; + case GL_EXP: + if (ctx->Hint.Fog == GL_NICEST || smesa->AGPCmdModeEnabled) { + current->hwFog |= FOGMODE_EXP; + _swrast_allow_pixel_fog( ctx, GL_TRUE ); + _swrast_allow_vertex_fog( ctx, GL_FALSE ); + } else { /* GL_DONTCARE or GL_FASTEST */ + current->hwFog |= FOGMODE_CHEAP; + _swrast_allow_pixel_fog( ctx, GL_FALSE ); + _swrast_allow_vertex_fog( ctx, GL_TRUE ); + } + break; + case GL_EXP2: + current->hwFog |= FOGMODE_EXP2; + _swrast_allow_pixel_fog( ctx, GL_TRUE ); + _swrast_allow_vertex_fog( ctx, GL_FALSE ); + break; + } + break; + case GL_FOG_DENSITY: + current->hwFogDensity = convertFtToFogFt( ctx->Fog.Density ); + break; + case GL_FOG_START: + case GL_FOG_END: + fArg = 1.0 / (ctx->Fog.End - ctx->Fog.Start); + current->hwFogInverse = doFPtoFixedNoRound( fArg, 10 ); + if (pname == GL_FOG_END) + { + if (smesa->Chipset == PCI_CHIP_SIS300) + current->hwFogFar = doFPtoFixedNoRound( ctx->Fog.End, 10 ); + else + current->hwFogFar = doFPtoFixedNoRound( ctx->Fog.End, 6 ); + } + break; + case GL_FOG_INDEX: + /* TODO */ + break; + case GL_FOG_COLOR: + fogColor = FLOAT_TO_UBYTE( ctx->Fog.Color[0] ) << 16; + fogColor |= FLOAT_TO_UBYTE( ctx->Fog.Color[1] ) << 8; + fogColor |= FLOAT_TO_UBYTE( ctx->Fog.Color[2] ); + current->hwFog &= 0xff000000; + current->hwFog |= fogColor; + break; + } +} + +GLint +doFPtoFixedNoRound( GLfloat dwInValue, int nFraction ) +{ + GLint dwMantissa; + int nTemp; + union { int i; float f; } u; + GLint val; + + u.f = dwInValue; + val = u.i; + + if (val == 0) + return 0; + nTemp = (int) (val & 0x7F800000) >> 23; + nTemp = nTemp - 127 + nFraction - 23; + dwMantissa = (val & 0x007FFFFF) | 0x00800000; + + if (nTemp < -25) + return 0; + if (nTemp > 0) + dwMantissa <<= nTemp; + else { + nTemp = -nTemp; + dwMantissa >>= nTemp; + } + if (val & 0x80000000) + dwMantissa = ~dwMantissa + 1; + return dwMantissa; +} + +/* s[8].23->s[7].10 */ +static GLint +convertFtToFogFt( GLfloat dwInValue ) +{ + GLint dwMantissa, dwExp; + GLint dwRet; + union { int i; float f; } u; + GLint val; + + u.f = dwInValue; + val = u.i; + + if (val == 0) + return 0; + + /* ----- Standard float Format: s[8].23 ----- + * ----- = (-1)^S * 2^(E - 127) * (1 + M / 2^23) ----- + * ----- = (-1)^S * 2^((E-63) - 64) * (1 + (M/2^13) / 2^10) ----- + * ----- Density float Format: s[7].10 ----- + * ----- New Exponential = E - 63 ----- + * ----- New Mantissa = M / 2^13 ----- + * ----- ----- + */ + + dwExp = (val & 0x7F800000) >> 23; + dwExp -= 63; + + if (dwExp < 0) + return 0; + + if (dwExp <= 0x7F) + dwMantissa = (val & 0x007FFFFF) >> (23 - 10); + else { + /* ----- To Return +Max(or -Max) ----- */ + dwExp = 0x7F; + dwMantissa = 0x3FF; + } + + dwRet = (val & 0x80000000) >> (31 - 17); /* Shift Sign Bit */ + + dwRet |= (dwExp << 10) | dwMantissa; + + return dwRet; +} |