src/mesa/math/m_xform.h

   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 "util/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