src/mesa/tnl/t_vb_vertex.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.1
   4  *
   5  * Copyright (C) 1999-2004  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 "glheader.h"
  30 #include "colormac.h"
  31 #include "context.h"
  32 #include "macros.h"
  33 #include "imports.h"
  34 #include "mtypes.h"
  35
  36 #include "math/m_xform.h"
  37
  38 #include "t_context.h"
  39 #include "t_pipeline.h"
  40
  41
  42
  43 struct vertex_stage_data {
  44    GLvector4f eye;
  45    GLvector4f clip;
  46    GLvector4f proj;
  47    GLubyte *clipmask;
  48    GLubyte ormask;
  49    GLubyte andmask;
  50
  51
  52    /* Need these because it's difficult to replay the sideeffects
  53     * analytically.
  54     */
  55    GLvector4f *save_eyeptr;
  56    GLvector4f *save_clipptr;
  57    GLvector4f *save_ndcptr;
  58 };
  59
  60 #define VERTEX_STAGE_DATA(stage) ((struct vertex_stage_data *)stage->privatePtr)
  61
  62
  63
  64
  65 /* This function implements cliptesting for user-defined clip planes.
  66  * The clipping of primitives to these planes is implemented in
  67  * t_render_clip.h.
  68  */
  69 #define USER_CLIPTEST(NAME, SZ)                                 \
  70 static void NAME( GLcontext *ctx,                               \
  71                   GLvector4f *clip,                             \
  72                   GLubyte *clipmask,                            \
  73                   GLubyte *clipormask,                          \
  74                   GLubyte *clipandmask )                        \
  75 {                                                               \
  76    GLuint p;                                                    \
  77                                                                 \
  78    for (p = 0; p < ctx->Const.MaxClipPlanes; p++)               \
  79       if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {        \
  80          GLuint nr, i;                                          \
  81          const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; \
  82          const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; \
  83          const GLfloat c = ctx->Transform._ClipUserPlane[p][2]; \
  84          const GLfloat d = ctx->Transform._ClipUserPlane[p][3]; \
  85          GLfloat *coord = (GLfloat *)clip->data;                \
  86          GLuint stride = clip->stride;                          \
  87          GLuint count = clip->count;                            \
  88                                                                 \
  89          for (nr = 0, i = 0 ; i < count ; i++) {                \
  90             GLfloat dp = coord[0] * a + coord[1] * b;           \
  91             if (SZ > 2) dp += coord[2] * c;                     \
  92             if (SZ > 3) dp += coord[3] * d; else dp += d;       \
  93                                                                 \
  94             if (dp < 0) {                                       \
  95                nr++;                                            \
  96                clipmask[i] |= CLIP_USER_BIT;                    \
  97             }                                                   \
  98                                                                 \
  99             STRIDE_F(coord, stride);                            \
 100          }                                                      \
 101                                                                 \
 102          if (nr > 0) {                                          \
 103             *clipormask |= CLIP_USER_BIT;                       \
 104             if (nr == count) {                                  \
 105                *clipandmask |= CLIP_USER_BIT;                   \
 106                return;                                          \
 107             }                                                   \
 108          }                                                      \
 109       }                                                         \
 110 }
 111
 112
 113 USER_CLIPTEST(userclip2, 2)
 114 USER_CLIPTEST(userclip3, 3)
 115 USER_CLIPTEST(userclip4, 4)
 116
 117 static void (*(usercliptab[5]))( GLcontext *,
 118                                  GLvector4f *, GLubyte *,
 119                                  GLubyte *, GLubyte * ) =
 120 {
 121    0,
 122    0,
 123    userclip2,
 124    userclip3,
 125    userclip4
 126 };
 127
 128
 129
 130 static GLboolean run_vertex_stage( GLcontext *ctx,
 131                                    struct tnl_pipeline_stage *stage )
 132 {
 133    struct vertex_stage_data *store = (struct vertex_stage_data *)stage->privatePtr;
 134    TNLcontext *tnl = TNL_CONTEXT(ctx);
 135    struct vertex_buffer *VB = &tnl->vb;
 136
 137    ASSERT(!ctx->VertexProgram._Enabled);
 138
 139    if (stage->changed_inputs) {
 140
 141       if (ctx->_NeedEyeCoords) {
 142          /* Separate modelview transformation:
 143           * Use combined ModelProject to avoid some depth artifacts
 144           */
 145          if (ctx->ModelviewMatrixStack.Top->type == MATRIX_IDENTITY)
 146             VB->EyePtr = VB->ObjPtr;
 147          else
 148             VB->EyePtr = TransformRaw( &store->eye,
 149                                        ctx->ModelviewMatrixStack.Top,
 150                                        VB->ObjPtr);
 151       }
 152
 153       VB->ClipPtr = TransformRaw( &store->clip,
 154                                   &ctx->_ModelProjectMatrix,
 155                                   VB->ObjPtr );
 156
 157       /* Drivers expect this to be clean to element 4...
 158        */
 159       switch (VB->ClipPtr->size) {
 160       case 1:
 161          /* impossible */
 162       case 2:
 163          _mesa_vector4f_clean_elem( VB->ClipPtr, VB->Count, 2 );
 164          /* fall-through */
 165       case 3:
 166          _mesa_vector4f_clean_elem( VB->ClipPtr, VB->Count, 3 );
 167          /* fall-through */
 168       case 4:
 169          break;
 170       }
 171
 172       /* Cliptest and perspective divide.  Clip functions must clear
 173        * the clipmask.
 174        */
 175       store->ormask = 0;
 176       store->andmask = CLIP_ALL_BITS;
 177
 178       if (tnl->NeedNdcCoords) {
 179          VB->NdcPtr =
 180             _mesa_clip_tab[VB->ClipPtr->size]( VB->ClipPtr,
 181                                                &store->proj,
 182                                                store->clipmask,
 183                                                &store->ormask,
 184                                                &store->andmask );
 185       }
 186       else {
 187          VB->NdcPtr = 0;
 188          _mesa_clip_np_tab[VB->ClipPtr->size]( VB->ClipPtr,
 189                                                0,
 190                                                store->clipmask,
 191                                                &store->ormask,
 192                                                &store->andmask );
 193       }
 194
 195       if (store->andmask)
 196          return GL_FALSE;
 197
 198
 199       /* Test userclip planes.  This contributes to VB->ClipMask, so
 200        * is essentially required to be in this stage.
 201        */
 202       if (ctx->Transform.ClipPlanesEnabled) {
 203          usercliptab[VB->ClipPtr->size]( ctx,
 204                                          VB->ClipPtr,
 205                                          store->clipmask,
 206                                          &store->ormask,
 207                                          &store->andmask );
 208
 209          if (store->andmask)
 210             return GL_FALSE;
 211       }
 212
 213       VB->ClipAndMask = store->andmask;
 214       VB->ClipOrMask = store->ormask;
 215       VB->ClipMask = store->clipmask;
 216
 217       store->save_eyeptr = VB->EyePtr;
 218       store->save_clipptr = VB->ClipPtr;
 219       store->save_ndcptr = VB->NdcPtr;
 220    }
 221    else {
 222       /* Replay the sideeffects.
 223        */
 224       VB->EyePtr = store->save_eyeptr;
 225       VB->ClipPtr = store->save_clipptr;
 226       VB->NdcPtr = store->save_ndcptr;
 227       VB->ClipMask = store->clipmask;
 228       VB->ClipAndMask = store->andmask;
 229       VB->ClipOrMask = store->ormask;
 230       if (store->andmask)
 231          return GL_FALSE;
 232    }
 233
 234    return GL_TRUE;
 235 }
 236
 237
 238 static void check_vertex( GLcontext *ctx, struct tnl_pipeline_stage *stage )
 239 {
 240    stage->active = !ctx->VertexProgram._Enabled;
 241 }
 242
 243 static GLboolean init_vertex_stage( GLcontext *ctx,
 244                                     struct tnl_pipeline_stage *stage )
 245 {
 246    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 247    struct vertex_stage_data *store;
 248    GLuint size = VB->Size;
 249
 250    stage->privatePtr = CALLOC(sizeof(*store));
 251    store = VERTEX_STAGE_DATA(stage);
 252    if (!store)
 253       return GL_FALSE;
 254
 255    _mesa_vector4f_alloc( &store->eye, 0, size, 32 );
 256    _mesa_vector4f_alloc( &store->clip, 0, size, 32 );
 257    _mesa_vector4f_alloc( &store->proj, 0, size, 32 );
 258
 259    store->clipmask = (GLubyte *) ALIGN_MALLOC(sizeof(GLubyte)*size, 32 );
 260
 261    if (!store->clipmask ||
 262        !store->eye.data ||
 263        !store->clip.data ||
 264        !store->proj.data)
 265       return GL_FALSE;
 266
 267    /* Now run the stage.
 268     */
 269    stage->run = run_vertex_stage;
 270    return stage->run( ctx, stage );
 271 }
 272
 273 static void dtr( struct tnl_pipeline_stage *stage )
 274 {
 275    struct vertex_stage_data *store = VERTEX_STAGE_DATA(stage);
 276
 277    if (store) {
 278       _mesa_vector4f_free( &store->eye );
 279       _mesa_vector4f_free( &store->clip );
 280       _mesa_vector4f_free( &store->proj );
 281       ALIGN_FREE( store->clipmask );
 282       FREE(store);
 283       stage->privatePtr = NULL;
 284       stage->run = init_vertex_stage;
 285    }
 286 }
 287
 288
 289 const struct tnl_pipeline_stage _tnl_vertex_transform_stage =
 290 {
 291    "modelview/project/cliptest/divide",
 292    _NEW_PROGRAM,                /* check_state: only care about vertex prog */
 293    _MESA_NEW_NEED_EYE_COORDS |  /* run_state: when to invalidate / re-run */
 294    _NEW_MODELVIEW|
 295    _NEW_PROJECTION|
 296    _NEW_PROGRAM|
 297    _NEW_TRANSFORM,
 298    GL_TRUE,                     /* active */
 299    _TNL_BIT_POS,                /* inputs */
 300    _TNL_BIT_POS,                /* outputs */
 301    0,                           /* changed_inputs */
 302    NULL,                        /* private data */
 303    dtr,                         /* destructor */
 304    check_vertex,                /* check */
 305    init_vertex_stage            /* run -- initially set to init */
 306 };