1 /**************************************************************************
3 Copyright 2000 Silicon Integrated Systems Corp, Inc., HsinChu, Taiwan.
4 Copyright 2003 Eric Anholt
7 Permission is hereby granted, free of charge, to any person obtaining a
8 copy of this software and associated documentation files (the "Software"),
9 to deal in the Software without restriction, including without limitation
10 on the rights to use, copy, modify, merge, publish, distribute, sub
11 license, and/or sell copies of the Software, and to permit persons to whom
12 the Software is furnished to do so, subject to the following conditions:
14 The above copyright notice and this permission notice (including the next
15 paragraph) shall be included in all copies or substantial portions of the
18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 ERIC ANHOLT OR SILICON INTEGRATED SYSTEMS CORP BE LIABLE FOR ANY CLAIM,
22 DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 USE OR OTHER DEALINGS IN THE SOFTWARE.
26 **************************************************************************/
30 * Sung-Ching Lin <sclin@sis.com.tw>
31 * Eric Anholt <anholt@FreeBSD.org>
34 #include "sis_context.h"
35 #include "sis_state.h"
36 #include "swrast/swrast.h"
38 #include "main/macros.h"
40 static GLint
convertFtToFogFt( GLfloat dwInValue
);
41 static GLint
doFPtoFixedNoRound( GLfloat dwInValue
, int nFraction
);
44 sisDDFogfv( GLcontext
*ctx
, GLenum pname
, const GLfloat
*params
)
46 sisContextPtr smesa
= SIS_CONTEXT(ctx
);
47 __GLSiSHardware
*prev
= &smesa
->prev
;
48 __GLSiSHardware
*current
= &smesa
->current
;
55 case GL_FOG_COORDINATE_SOURCE_EXT
:
56 current
->hwFog
&= ~MASK_FogMode
;
57 switch (ctx
->Fog
.FogCoordinateSource
)
59 case GL_FOG_COORDINATE_EXT
:
60 current
->hwFog
&= ~MASK_FogZLookup
;
62 case GL_FRAGMENT_DEPTH_EXT
:
63 current
->hwFog
|= MASK_FogZLookup
;
66 if (current
->hwFog
!= prev
->hwFog
) {
67 prev
->hwFog
= current
->hwFog
;
68 smesa
->GlobalFlag
|= GFLAG_FOGSETTING
;
72 current
->hwFog
&= ~MASK_FogMode
;
73 switch (ctx
->Fog
.Mode
)
76 current
->hwFog
|= FOGMODE_LINEAR
;
79 current
->hwFog
|= FOGMODE_EXP
;
82 current
->hwFog
|= FOGMODE_EXP2
;
85 if (current
->hwFog
!= prev
->hwFog
) {
86 prev
->hwFog
= current
->hwFog
;
87 smesa
->GlobalFlag
|= GFLAG_FOGSETTING
;
91 current
->hwFogDensity
= convertFtToFogFt( ctx
->Fog
.Density
);
92 if (current
->hwFogDensity
!= prev
->hwFogDensity
) {
93 prev
->hwFogDensity
= current
->hwFogDensity
;
94 smesa
->GlobalFlag
|= GFLAG_FOGSETTING
;
99 fArg
= 1.0 / (ctx
->Fog
.End
- ctx
->Fog
.Start
);
100 current
->hwFogInverse
= doFPtoFixedNoRound( fArg
, 10 );
101 if (pname
== GL_FOG_END
)
103 if (smesa
->Chipset
== PCI_CHIP_SIS300
)
104 current
->hwFogFar
= doFPtoFixedNoRound( ctx
->Fog
.End
, 10 );
106 current
->hwFogFar
= doFPtoFixedNoRound( ctx
->Fog
.End
, 6 );
108 if (current
->hwFogFar
!= prev
->hwFogFar
||
109 current
->hwFogInverse
!= prev
->hwFogInverse
)
111 prev
->hwFogFar
= current
->hwFogFar
;
112 prev
->hwFogInverse
= current
->hwFogInverse
;
113 smesa
->GlobalFlag
|= GFLAG_FOGSETTING
;
120 fogColor
= FLOAT_TO_UBYTE( ctx
->Fog
.Color
[0] ) << 16;
121 fogColor
|= FLOAT_TO_UBYTE( ctx
->Fog
.Color
[1] ) << 8;
122 fogColor
|= FLOAT_TO_UBYTE( ctx
->Fog
.Color
[2] );
123 current
->hwFog
&= 0xff000000;
124 current
->hwFog
|= fogColor
;
125 if (current
->hwFog
!= prev
->hwFog
) {
126 prev
->hwFog
= current
->hwFog
;
127 smesa
->GlobalFlag
|= GFLAG_FOGSETTING
;
134 doFPtoFixedNoRound( GLfloat dwInValue
, int nFraction
)
138 union { int i
; float f
; } u
;
146 nTemp
= (int) (val
& 0x7F800000) >> 23;
147 nTemp
= nTemp
- 127 + nFraction
- 23;
148 dwMantissa
= (val
& 0x007FFFFF) | 0x00800000;
153 dwMantissa
<<= nTemp
;
156 dwMantissa
>>= nTemp
;
158 if (val
& 0x80000000)
159 dwMantissa
= ~dwMantissa
+ 1;
163 /* s[8].23->s[7].10 */
165 convertFtToFogFt( GLfloat dwInValue
)
167 GLint dwMantissa
, dwExp
;
169 union { int i
; float f
; } u
;
178 /* ----- Standard float Format: s[8].23 -----
179 * ----- = (-1)^S * 2^(E - 127) * (1 + M / 2^23) -----
180 * ----- = (-1)^S * 2^((E-63) - 64) * (1 + (M/2^13) / 2^10) -----
181 * ----- Density float Format: s[7].10 -----
182 * ----- New Exponential = E - 63 -----
183 * ----- New Mantissa = M / 2^13 -----
187 dwExp
= (val
& 0x7F800000) >> 23;
194 dwMantissa
= (val
& 0x007FFFFF) >> (23 - 10);
196 /* ----- To Return +Max(or -Max) ----- */
201 dwRet
= (val
& 0x80000000) >> (31 - 17); /* Shift Sign Bit */
203 dwRet
|= (dwExp
<< 10) | dwMantissa
;