src/mesa/tnl/t_vb_vertex.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5
   4  *
   5  * Copyright (C) 1999-2006  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  * Authors:
  25  *    Keith Whitwell <keith@tungstengraphics.com>
  26  */
  27
  28
  29 #include "main/glheader.h"
  30 #include "main/colormac.h"
  31 #include "main/macros.h"
  32 #include "main/imports.h"
  33 #include "main/mtypes.h"
  34
  35 #include "math/m_xform.h"
  36
  37 #include "t_context.h"
  38 #include "t_pipeline.h"
  39
  40
  41
  42 struct vertex_stage_data {
  43    GLvector4f eye;
  44    GLvector4f clip;
  45    GLvector4f proj;
  46    GLubyte *clipmask;
  47    GLubyte ormask;
  48    GLubyte andmask;
  49 };
  50
  51 #define VERTEX_STAGE_DATA(stage) ((struct vertex_stage_data *)stage->privatePtr)
  52
  53
  54
  55
  56 /* This function implements cliptesting for user-defined clip planes.
  57  * The clipping of primitives to these planes is implemented in
  58  * t_render_clip.h.
  59  */
  60 #define USER_CLIPTEST(NAME, SZ)                                 \
  61 static void NAME( struct gl_context *ctx,                               \
  62                   GLvector4f *clip,                             \
  63                   GLubyte *clipmask,                            \
  64                   GLubyte *clipormask,                          \
  65                   GLubyte *clipandmask )                        \
  66 {                                                               \
  67    GLuint p;                                                    \
  68                                                                 \
  69    for (p = 0; p < ctx->Const.MaxClipPlanes; p++)               \
  70       if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {        \
  71          GLuint nr, i;                                          \
  72          const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; \
  73          const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; \
  74          const GLfloat c = ctx->Transform._ClipUserPlane[p][2]; \
  75          const GLfloat d = ctx->Transform._ClipUserPlane[p][3]; \
  76          GLfloat *coord = (GLfloat *)clip->data;                \
  77          GLuint stride = clip->stride;                          \
  78          GLuint count = clip->count;                            \
  79                                                                 \
  80          for (nr = 0, i = 0 ; i < count ; i++) {                \
  81             GLfloat dp = coord[0] * a + coord[1] * b;           \
  82             if (SZ > 2) dp += coord[2] * c;                     \
  83             if (SZ > 3) dp += coord[3] * d; else dp += d;       \
  84                                                                 \
  85             if (dp < 0) {                                       \
  86                nr++;                                            \
  87                clipmask[i] |= CLIP_USER_BIT;                    \
  88             }                                                   \
  89                                                                 \
  90             STRIDE_F(coord, stride);                            \
  91          }                                                      \
  92                                                                 \
  93          if (nr > 0) {                                          \
  94             *clipormask |= CLIP_USER_BIT;                       \
  95             if (nr == count) {                                  \
  96                *clipandmask |= CLIP_USER_BIT;                   \
  97                return;                                          \
  98             }                                                   \
  99          }                                                      \
 100       }                                                         \
 101 }
 102
 103
 104 USER_CLIPTEST(userclip2, 2)
 105 USER_CLIPTEST(userclip3, 3)
 106 USER_CLIPTEST(userclip4, 4)
 107
 108 static void (*(usercliptab[5]))( struct gl_context *,
 109                                  GLvector4f *, GLubyte *,
 110                                  GLubyte *, GLubyte * ) =
 111 {
 112    NULL,
 113    NULL,
 114    userclip2,
 115    userclip3,
 116    userclip4
 117 };
 118
 119
 120 void
 121 tnl_clip_prepare(struct gl_context *ctx)
 122 {
 123    /* Neither the x86 nor sparc asm cliptest functions have been updated
 124     * for ARB_depth_clamp, so force the C paths.
 125     */
 126    if (ctx->Transform.DepthClamp) {
 127       static GLboolean c_funcs_installed = GL_FALSE;
 128       if (!c_funcs_installed) {
 129          init_c_cliptest();
 130          c_funcs_installed = GL_TRUE;
 131       }
 132    }
 133 }
 134
 135
 136
 137 static GLboolean run_vertex_stage( struct gl_context *ctx,
 138                                    struct tnl_pipeline_stage *stage )
 139 {
 140    struct vertex_stage_data *store = (struct vertex_stage_data *)stage->privatePtr;
 141    TNLcontext *tnl = TNL_CONTEXT(ctx);
 142    struct vertex_buffer *VB = &tnl->vb;
 143
 144    if (ctx->VertexProgram._Current)
 145       return GL_TRUE;
 146
 147    tnl_clip_prepare(ctx);
 148
 149    if (ctx->_NeedEyeCoords) {
 150       /* Separate modelview transformation:
 151        * Use combined ModelProject to avoid some depth artifacts
 152        */
 153       if (ctx->ModelviewMatrixStack.Top->type == MATRIX_IDENTITY)
 154          VB->EyePtr = VB->AttribPtr[_TNL_ATTRIB_POS];
 155       else
 156          VB->EyePtr = TransformRaw( &store->eye,
 157                                     ctx->ModelviewMatrixStack.Top,
 158                                     VB->AttribPtr[_TNL_ATTRIB_POS]);
 159    }
 160
 161    VB->ClipPtr = TransformRaw( &store->clip,
 162                                &ctx->_ModelProjectMatrix,
 163                                VB->AttribPtr[_TNL_ATTRIB_POS] );
 164
 165    /* Drivers expect this to be clean to element 4...
 166     */
 167    switch (VB->ClipPtr->size) {
 168    case 1:
 169       /* impossible */
 170    case 2:
 171       _mesa_vector4f_clean_elem( VB->ClipPtr, VB->Count, 2 );
 172       /* fall-through */
 173    case 3:
 174       _mesa_vector4f_clean_elem( VB->ClipPtr, VB->Count, 3 );
 175       /* fall-through */
 176    case 4:
 177       break;
 178    }
 179
 180
 181    /* Cliptest and perspective divide.  Clip functions must clear
 182     * the clipmask.
 183     */
 184    store->ormask = 0;
 185    store->andmask = CLIP_FRUSTUM_BITS;
 186
 187    if (tnl->NeedNdcCoords) {
 188       VB->NdcPtr =
 189          _mesa_clip_tab[VB->ClipPtr->size]( VB->ClipPtr,
 190                                             &store->proj,
 191                                             store->clipmask,
 192                                             &store->ormask,
 193                                             &store->andmask,
 194                                             !ctx->Transform.DepthClamp );
 195    }
 196    else {
 197       VB->NdcPtr = NULL;
 198       _mesa_clip_np_tab[VB->ClipPtr->size]( VB->ClipPtr,
 199                                             NULL,
 200                                             store->clipmask,
 201                                             &store->ormask,
 202                                             &store->andmask,
 203                                             !ctx->Transform.DepthClamp );
 204    }
 205
 206    if (store->andmask)
 207       return GL_FALSE;
 208
 209
 210    /* Test userclip planes.  This contributes to VB->ClipMask, so
 211     * is essentially required to be in this stage.
 212     */
 213    if (ctx->Transform.ClipPlanesEnabled) {
 214       usercliptab[VB->ClipPtr->size]( ctx,
 215                                       VB->ClipPtr,
 216                                       store->clipmask,
 217                                       &store->ormask,
 218                                       &store->andmask );
 219
 220       if (store->andmask)
 221          return GL_FALSE;
 222    }
 223
 224    VB->ClipAndMask = store->andmask;
 225    VB->ClipOrMask = store->ormask;
 226    VB->ClipMask = store->clipmask;
 227
 228    return GL_TRUE;
 229 }
 230
 231
 232 static GLboolean init_vertex_stage( struct gl_context *ctx,
 233                                     struct tnl_pipeline_stage *stage )
 234 {
 235    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 236    struct vertex_stage_data *store;
 237    GLuint size = VB->Size;
 238
 239    stage->privatePtr = CALLOC(sizeof(*store));
 240    store = VERTEX_STAGE_DATA(stage);
 241    if (!store)
 242       return GL_FALSE;
 243
 244    _mesa_vector4f_alloc( &store->eye, 0, size, 32 );
 245    _mesa_vector4f_alloc( &store->clip, 0, size, 32 );
 246    _mesa_vector4f_alloc( &store->proj, 0, size, 32 );
 247
 248    store->clipmask = (GLubyte *) _mesa_align_malloc(sizeof(GLubyte)*size, 32 );
 249
 250    if (!store->clipmask ||
 251        !store->eye.data ||
 252        !store->clip.data ||
 253        !store->proj.data)
 254       return GL_FALSE;
 255
 256    return GL_TRUE;
 257 }
 258
 259 static void dtr( struct tnl_pipeline_stage *stage )
 260 {
 261    struct vertex_stage_data *store = VERTEX_STAGE_DATA(stage);
 262
 263    if (store) {
 264       _mesa_vector4f_free( &store->eye );
 265       _mesa_vector4f_free( &store->clip );
 266       _mesa_vector4f_free( &store->proj );
 267       _mesa_align_free( store->clipmask );
 268       FREE(store);
 269       stage->privatePtr = NULL;
 270       stage->run = init_vertex_stage;
 271    }
 272 }
 273
 274
 275 const struct tnl_pipeline_stage _tnl_vertex_transform_stage =
 276 {
 277    "modelview/project/cliptest/divide",
 278    NULL,                        /* private data */
 279    init_vertex_stage,
 280    dtr,                         /* destructor */
 281    NULL,
 282    run_vertex_stage             /* run -- initially set to init */
 283 };