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      1 /*
      2  * Mesa 3-D graphics library
      3  * Version:  7.3
      4  *
      5  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
      6  *
      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  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     11  * and/or sell copies of the Software, and to permit persons to whom the
     12  * Software is furnished to do so, subject to the following conditions:
     13  *
     14  * The above copyright notice and this permission notice shall be included
     15  * in all copies or substantial portions of the Software.
     16  *
     17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
     18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
     21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
     22  * CONNECTION WITH THE SOFTWARE OR THE USE OR 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 #ifdef USE_X86_ASM
     36 #define _XFORMAPI _ASMAPI
     37 #define _XFORMAPIP _ASMAPIP
     38 #else
     39 #define _XFORMAPI
     40 #define _XFORMAPIP *
     41 #endif
     42 
     43 
     44 extern void
     45 _math_init_transformation(void);
     46 extern void
     47 init_c_cliptest(void);
     48 
     49 /* KW: Clip functions now do projective divide as well.  The projected
     50  * coordinates are very useful to us because they let us cull
     51  * backfaces and eliminate vertices from lighting, fogging, etc
     52  * calculations.  Despite the fact that this divide could be done one
     53  * day in hardware, we would still have a reason to want to do it here
     54  * as long as those other calculations remain in software.
     55  *
     56  * Clipping is a convenient place to do the divide on x86 as it should be
     57  * possible to overlap with integer outcode calculations.
     58  *
     59  * There are two cases where we wouldn't want to do the divide in cliptest:
     60  *    - When we aren't clipping.  We still might want to cull backfaces
     61  *      so the divide should be done elsewhere.  This currently never
     62  *      happens.
     63  *
     64  *    - When culling isn't likely to help us, such as when the GL culling
     65  *      is disabled and we not lighting or are only lighting
     66  *      one-sided.  In this situation, backface determination provides
     67  *      us with no useful information.  A tricky case to detect is when
     68  *      all input data is already culled, although hopefully the
     69  *      application wouldn't turn on culling in such cases.
     70  *
     71  * We supply a buffer to hold the [x/w,y/w,z/w,1/w] values which
     72  * are the result of the projection.  This is only used in the
     73  * 4-vector case - in other cases, we just use the clip coordinates
     74  * as the projected coordinates - they are identical.
     75  *
     76  * This is doubly convenient because it means the Win[] array is now
     77  * of the same stride as all the others, so I can now turn map_vertices
     78  * into a straight-forward matrix transformation, with asm acceleration
     79  * automatically available.
     80  */
     81 
     82 /* Vertex buffer clipping flags
     83  */
     84 #define CLIP_RIGHT_SHIFT 	0
     85 #define CLIP_LEFT_SHIFT 	1
     86 #define CLIP_TOP_SHIFT  	2
     87 #define CLIP_BOTTOM_SHIFT       3
     88 #define CLIP_NEAR_SHIFT  	4
     89 #define CLIP_FAR_SHIFT  	5
     90 
     91 #define CLIP_RIGHT_BIT   0x01
     92 #define CLIP_LEFT_BIT    0x02
     93 #define CLIP_TOP_BIT     0x04
     94 #define CLIP_BOTTOM_BIT  0x08
     95 #define CLIP_NEAR_BIT    0x10
     96 #define CLIP_FAR_BIT     0x20
     97 #define CLIP_USER_BIT    0x40
     98 #define CLIP_CULL_BIT    0x80
     99 #define CLIP_FRUSTUM_BITS    0x3f
    100 
    101 
    102 typedef GLvector4f * (_XFORMAPIP clip_func)( GLvector4f *vClip,
    103 					     GLvector4f *vProj,
    104 					     GLubyte clipMask[],
    105 					     GLubyte *orMask,
    106 					     GLubyte *andMask,
    107 					     GLboolean viewport_z_clip );
    108 
    109 typedef void (*dotprod_func)( GLfloat *out,
    110 			      GLuint out_stride,
    111 			      CONST GLvector4f *coord_vec,
    112 			      CONST GLfloat plane[4] );
    113 
    114 typedef void (*vec_copy_func)( GLvector4f *to,
    115 			       CONST GLvector4f *from );
    116 
    117 
    118 
    119 /*
    120  * Functions for transformation of normals in the VB.
    121  */
    122 typedef void (_NORMAPIP normal_func)( CONST GLmatrix *mat,
    123 				      GLfloat scale,
    124 				      CONST GLvector4f *in,
    125 				      CONST GLfloat lengths[],
    126 				      GLvector4f *dest );
    127 
    128 
    129 /* Flags for selecting a normal transformation function.
    130  */
    131 #define NORM_RESCALE   0x1		/* apply the scale factor */
    132 #define NORM_NORMALIZE 0x2		/* normalize */
    133 #define NORM_TRANSFORM 0x4		/* apply the transformation matrix */
    134 #define NORM_TRANSFORM_NO_ROT 0x8	/* apply the transformation matrix */
    135 
    136 
    137 
    138 
    139 /* KW: New versions of the transform function allow a mask array
    140  *     specifying that individual vector transform should be skipped
    141  *     when the mask byte is zero.  This is always present as a
    142  *     parameter, to allow a unified interface.
    143  */
    144 typedef void (_XFORMAPIP transform_func)( GLvector4f *to_vec,
    145 					  CONST GLfloat m[16],
    146 					  CONST GLvector4f *from_vec );
    147 
    148 
    149 extern dotprod_func  _mesa_dotprod_tab[5];
    150 extern vec_copy_func _mesa_copy_tab[0x10];
    151 extern vec_copy_func _mesa_copy_clean_tab[5];
    152 extern clip_func     _mesa_clip_tab[5];
    153 extern clip_func     _mesa_clip_np_tab[5];
    154 extern normal_func   _mesa_normal_tab[0xf];
    155 
    156 /* Use of 2 layers of linked 1-dimensional arrays to reduce
    157  * cost of lookup.
    158  */
    159 extern transform_func *_mesa_transform_tab[5];
    160 
    161 
    162 
    163 #define TransformRaw( to, mat, from ) \
    164    ( _mesa_transform_tab[(from)->size][(mat)->type]( to, (mat)->m, from ), \
    165      (to) )
    166 
    167 
    168 #endif
    169