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1 /*
2  * Mesa 3-D graphics library
3  *
4  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included
14  * in all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22  * OTHER DEALINGS IN THE SOFTWARE.
23  */
24 
25 
26 #ifndef _M_XFORM_H
27 #define _M_XFORM_H
28 
29 
30 #include "main/compiler.h"
31 #include "main/glheader.h"
32 #include "math/m_matrix.h"
33 #include "math/m_vector.h"
34 
35 
36 extern void
37 _math_init_transformation(void);
38 extern void
39 init_c_cliptest(void);
40 
41 /* KW: Clip functions now do projective divide as well.  The projected
42  * coordinates are very useful to us because they let us cull
43  * backfaces and eliminate vertices from lighting, fogging, etc
44  * calculations.  Despite the fact that this divide could be done one
45  * day in hardware, we would still have a reason to want to do it here
46  * as long as those other calculations remain in software.
47  *
48  * Clipping is a convenient place to do the divide on x86 as it should be
49  * possible to overlap with integer outcode calculations.
50  *
51  * There are two cases where we wouldn't want to do the divide in cliptest:
52  *    - When we aren't clipping.  We still might want to cull backfaces
53  *      so the divide should be done elsewhere.  This currently never
54  *      happens.
55  *
56  *    - When culling isn't likely to help us, such as when the GL culling
57  *      is disabled and we not lighting or are only lighting
58  *      one-sided.  In this situation, backface determination provides
59  *      us with no useful information.  A tricky case to detect is when
60  *      all input data is already culled, although hopefully the
61  *      application wouldn't turn on culling in such cases.
62  *
63  * We supply a buffer to hold the [x/w,y/w,z/w,1/w] values which
64  * are the result of the projection.  This is only used in the
65  * 4-vector case - in other cases, we just use the clip coordinates
66  * as the projected coordinates - they are identical.
67  *
68  * This is doubly convenient because it means the Win[] array is now
69  * of the same stride as all the others, so I can now turn map_vertices
70  * into a straight-forward matrix transformation, with asm acceleration
71  * automatically available.
72  */
73 
74 /* Vertex buffer clipping flags
75  */
76 #define CLIP_RIGHT_SHIFT 	0
77 #define CLIP_LEFT_SHIFT 	1
78 #define CLIP_TOP_SHIFT  	2
79 #define CLIP_BOTTOM_SHIFT       3
80 #define CLIP_NEAR_SHIFT  	4
81 #define CLIP_FAR_SHIFT  	5
82 
83 #define CLIP_RIGHT_BIT   0x01
84 #define CLIP_LEFT_BIT    0x02
85 #define CLIP_TOP_BIT     0x04
86 #define CLIP_BOTTOM_BIT  0x08
87 #define CLIP_NEAR_BIT    0x10
88 #define CLIP_FAR_BIT     0x20
89 #define CLIP_USER_BIT    0x40
90 #define CLIP_CULL_BIT    0x80
91 #define CLIP_FRUSTUM_BITS    0x3f
92 
93 
94 typedef GLvector4f * (*clip_func)(GLvector4f *vClip,
95                                   GLvector4f *vProj,
96                                   GLubyte clipMask[],
97                                   GLubyte *orMask,
98                                   GLubyte *andMask,
99                                   GLboolean viewport_z_clip);
100 
101 typedef void (*dotprod_func)( GLfloat *out,
102 			      GLuint out_stride,
103 			      const GLvector4f *coord_vec,
104 			      const GLfloat plane[4] );
105 
106 typedef void (*vec_copy_func)( GLvector4f *to,
107 			       const GLvector4f *from );
108 
109 
110 
111 /*
112  * Functions for transformation of normals in the VB.
113  */
114 typedef void (*normal_func)(const GLmatrix *mat,
115                             GLfloat scale,
116                             const GLvector4f *in,
117                             const GLfloat lengths[],
118                             GLvector4f *dest);
119 
120 
121 /* Flags for selecting a normal transformation function.
122  */
123 #define NORM_RESCALE   0x1		/* apply the scale factor */
124 #define NORM_NORMALIZE 0x2		/* normalize */
125 #define NORM_TRANSFORM 0x4		/* apply the transformation matrix */
126 #define NORM_TRANSFORM_NO_ROT 0x8	/* apply the transformation matrix */
127 
128 
129 
130 
131 /* KW: New versions of the transform function allow a mask array
132  *     specifying that individual vector transform should be skipped
133  *     when the mask byte is zero.  This is always present as a
134  *     parameter, to allow a unified interface.
135  */
136 typedef void (*transform_func)(GLvector4f *to_vec,
137                                const GLfloat m[16],
138                                const GLvector4f *from_vec);
139 
140 
141 extern dotprod_func  _mesa_dotprod_tab[5];
142 extern vec_copy_func _mesa_copy_tab[0x10];
143 extern vec_copy_func _mesa_copy_clean_tab[5];
144 extern clip_func     _mesa_clip_tab[5];
145 extern clip_func     _mesa_clip_np_tab[5];
146 extern normal_func   _mesa_normal_tab[0xf];
147 
148 /* Use of 2 layers of linked 1-dimensional arrays to reduce
149  * cost of lookup.
150  */
151 extern transform_func *_mesa_transform_tab[5];
152 
153 
154 
155 #define TransformRaw( to, mat, from ) \
156    ( _mesa_transform_tab[(from)->size][(mat)->type]( to, (mat)->m, from ), \
157      (to) )
158 
159 
160 #endif
161