src/mesa/tnl/t_vb_vertex.c

   1 /* $Id: t_vb_vertex.c,v 1.15 2002/10/24 23:57:25 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.5
   6  *
   7  * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  * Authors:
  27  *    Keith Whitwell <keithw@valinux.com>
  28  */
  29
  30
  31 #include "glheader.h"
  32 #include "colormac.h"
  33 #include "context.h"
  34 #include "macros.h"
  35 #include "imports.h"
  36 #include "mmath.h"
  37 #include "mtypes.h"
  38
  39 #include "math/m_xform.h"
  40
  41 #include "t_context.h"
  42 #include "t_pipeline.h"
  43
  44
  45
  46 struct vertex_stage_data {
  47    GLvector4f eye;
  48    GLvector4f clip;
  49    GLvector4f proj;
  50    GLubyte *clipmask;
  51    GLubyte ormask;
  52    GLubyte andmask;
  53
  54
  55    /* Need these because it's difficult to replay the sideeffects
  56     * analytically.
  57     */
  58    GLvector4f *save_eyeptr;
  59    GLvector4f *save_clipptr;
  60    GLvector4f *save_ndcptr;
  61 };
  62
  63 #define VERTEX_STAGE_DATA(stage) ((struct vertex_stage_data *)stage->privatePtr)
  64
  65
  66
  67
  68 /* This function implements cliptesting for user-defined clip planes.
  69  * The clipping of primitives to these planes is implemented in
  70  * t_render_clip.h.
  71  */
  72 #define USER_CLIPTEST(NAME, SZ)                                 \
  73 static void NAME( GLcontext *ctx,                               \
  74                   GLvector4f *clip,                             \
  75                   GLubyte *clipmask,                            \
  76                   GLubyte *clipormask,                          \
  77                   GLubyte *clipandmask )                        \
  78 {                                                               \
  79    GLuint p;                                                    \
  80                                                                 \
  81    for (p = 0; p < ctx->Const.MaxClipPlanes; p++)               \
  82       if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {        \
  83          GLuint nr, i;                                          \
  84          const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; \
  85          const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; \
  86          const GLfloat c = ctx->Transform._ClipUserPlane[p][2]; \
  87          const GLfloat d = ctx->Transform._ClipUserPlane[p][3]; \
  88          GLfloat *coord = (GLfloat *)clip->data;                \
  89          GLuint stride = clip->stride;                          \
  90          GLuint count = clip->count;                            \
  91                                                                 \
  92          for (nr = 0, i = 0 ; i < count ; i++) {                \
  93             GLfloat dp = coord[0] * a + coord[1] * b;           \
  94             if (SZ > 2) dp += coord[2] * c;                     \
  95             if (SZ > 3) dp += coord[3] * d; else dp += d;       \
  96                                                                 \
  97             if (dp < 0) {                                       \
  98                nr++;                                            \
  99                clipmask[i] |= CLIP_USER_BIT;                    \
 100             }                                                   \
 101                                                                 \
 102             STRIDE_F(coord, stride);                            \
 103          }                                                      \
 104                                                                 \
 105          if (nr > 0) {                                          \
 106             *clipormask |= CLIP_USER_BIT;                       \
 107             if (nr == count) {                                  \
 108                *clipandmask |= CLIP_USER_BIT;                   \
 109                return;                                          \
 110             }                                                   \
 111          }                                                      \
 112       }                                                         \
 113 }
 114
 115
 116 USER_CLIPTEST(userclip2, 2)
 117 USER_CLIPTEST(userclip3, 3)
 118 USER_CLIPTEST(userclip4, 4)
 119
 120 static void (*(usercliptab[5]))( GLcontext *,
 121                                  GLvector4f *, GLubyte *,
 122                                  GLubyte *, GLubyte * ) =
 123 {
 124    0,
 125    0,
 126    userclip2,
 127    userclip3,
 128    userclip4
 129 };
 130
 131
 132
 133 static GLboolean run_vertex_stage( GLcontext *ctx,
 134                                    struct gl_pipeline_stage *stage )
 135 {
 136    struct vertex_stage_data *store = (struct vertex_stage_data *)stage->privatePtr;
 137    TNLcontext *tnl = TNL_CONTEXT(ctx);
 138    struct vertex_buffer *VB = &tnl->vb;
 139
 140    if (stage->changed_inputs) {
 141
 142       if (ctx->_NeedEyeCoords) {
 143          /* Separate modelview transformation:
 144           * Use combined ModelProject to avoid some depth artifacts
 145           */
 146          if (ctx->ModelviewMatrixStack.Top->type == MATRIX_IDENTITY)
 147             VB->EyePtr = VB->ObjPtr;
 148          else
 149             VB->EyePtr = TransformRaw( &store->eye,
 150                                        ctx->ModelviewMatrixStack.Top,
 151                                        VB->ObjPtr);
 152
 153          if (ctx->ProjectionMatrixStack.Top->type == MATRIX_IDENTITY)
 154             VB->ClipPtr = VB->EyePtr;
 155          else
 156             VB->ClipPtr = TransformRaw( &store->clip,
 157                                         &ctx->_ModelProjectMatrix,
 158                                         VB->ObjPtr );
 159       }
 160       else {
 161          /* Combined modelviewproject transform:
 162           */
 163          if (ctx->_ModelProjectMatrix.type == MATRIX_IDENTITY)
 164             VB->ClipPtr = VB->ObjPtr;
 165          else
 166             VB->ClipPtr = TransformRaw( &store->clip,
 167                                         &ctx->_ModelProjectMatrix,
 168                                         VB->ObjPtr );
 169       }
 170
 171       /* Drivers expect this to be clean to element 4...
 172        */
 173       if (VB->ClipPtr->size < 4) {
 174          if (VB->ClipPtr->flags & VEC_NOT_WRITEABLE) {
 175             ASSERT(VB->ClipPtr == VB->ObjPtr);
 176             VB->import_data( ctx, VERT_BIT_POS, VEC_NOT_WRITEABLE );
 177             VB->ClipPtr = VB->ObjPtr;
 178          }
 179          if (VB->ClipPtr->size == 2)
 180             _mesa_vector4f_clean_elem( VB->ClipPtr, VB->Count, 2 );
 181          _mesa_vector4f_clean_elem( VB->ClipPtr, VB->Count, 3 );
 182       }
 183
 184       /* Cliptest and perspective divide.  Clip functions must clear
 185        * the clipmask.
 186        */
 187       store->ormask = 0;
 188       store->andmask = CLIP_ALL_BITS;
 189
 190       if (tnl->NeedNdcCoords) {
 191          VB->NdcPtr =
 192             _mesa_clip_tab[VB->ClipPtr->size]( VB->ClipPtr,
 193                                                &store->proj,
 194                                                store->clipmask,
 195                                                &store->ormask,
 196                                                &store->andmask );
 197
 198       }
 199       else {
 200          VB->NdcPtr = 0;
 201          _mesa_clip_np_tab[VB->ClipPtr->size]( VB->ClipPtr,
 202                                                0,
 203                                                store->clipmask,
 204                                                &store->ormask,
 205                                                &store->andmask );
 206       }
 207
 208       if (store->andmask)
 209          return GL_FALSE;
 210
 211
 212       /* Test userclip planes.  This contributes to VB->ClipMask, so
 213        * is essentially required to be in this stage.
 214        */
 215       if (ctx->Transform.ClipPlanesEnabled) {
 216          usercliptab[VB->ClipPtr->size]( ctx,
 217                                          VB->ClipPtr,
 218                                          store->clipmask,
 219                                          &store->ormask,
 220                                          &store->andmask );
 221
 222          if (store->andmask)
 223             return GL_FALSE;
 224       }
 225
 226       VB->ClipOrMask = store->ormask;
 227       VB->ClipMask = store->clipmask;
 228
 229       if (VB->ClipPtr == VB->ObjPtr && (VB->importable_data & VERT_BIT_POS))
 230          VB->importable_data |= VERT_BIT_CLIP;
 231
 232       store->save_eyeptr = VB->EyePtr;
 233       store->save_clipptr = VB->ClipPtr;
 234       store->save_ndcptr = VB->NdcPtr;
 235    }
 236    else {
 237       /* Replay the sideeffects.
 238        */
 239       VB->EyePtr = store->save_eyeptr;
 240       VB->ClipPtr = store->save_clipptr;
 241       VB->NdcPtr = store->save_ndcptr;
 242       VB->ClipMask = store->clipmask;
 243       VB->ClipOrMask = store->ormask;
 244       if (VB->ClipPtr == VB->ObjPtr && (VB->importable_data & VERT_BIT_POS))
 245          VB->importable_data |= VERT_BIT_CLIP;
 246       if (store->andmask)
 247          return GL_FALSE;
 248    }
 249
 250    return GL_TRUE;
 251 }
 252
 253
 254 static void check_vertex( GLcontext *ctx, struct gl_pipeline_stage *stage )
 255 {
 256    stage->active = !ctx->VertexProgram.Enabled;
 257 }
 258
 259 static GLboolean init_vertex_stage( GLcontext *ctx,
 260                                     struct gl_pipeline_stage *stage )
 261 {
 262    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 263    struct vertex_stage_data *store;
 264    GLuint size = VB->Size;
 265
 266    stage->privatePtr = CALLOC(sizeof(*store));
 267    store = VERTEX_STAGE_DATA(stage);
 268    if (!store)
 269       return GL_FALSE;
 270
 271    _mesa_vector4f_alloc( &store->eye, 0, size, 32 );
 272    _mesa_vector4f_alloc( &store->clip, 0, size, 32 );
 273    _mesa_vector4f_alloc( &store->proj, 0, size, 32 );
 274
 275    store->clipmask = (GLubyte *) ALIGN_MALLOC(sizeof(GLubyte)*size, 32 );
 276
 277    if (!store->clipmask ||
 278        !store->eye.data ||
 279        !store->clip.data ||
 280        !store->proj.data)
 281       return GL_FALSE;
 282
 283    /* Now run the stage.
 284     */
 285    stage->run = run_vertex_stage;
 286    return stage->run( ctx, stage );
 287 }
 288
 289 static void dtr( struct gl_pipeline_stage *stage )
 290 {
 291    struct vertex_stage_data *store = VERTEX_STAGE_DATA(stage);
 292
 293    if (store) {
 294       _mesa_vector4f_free( &store->eye );
 295       _mesa_vector4f_free( &store->clip );
 296       _mesa_vector4f_free( &store->proj );
 297       ALIGN_FREE( store->clipmask );
 298       FREE(store);
 299       stage->privatePtr = NULL;
 300       stage->run = init_vertex_stage;
 301    }
 302 }
 303
 304
 305 const struct gl_pipeline_stage _tnl_vertex_transform_stage =
 306 {
 307    "modelview/project/cliptest/divide",
 308    0,                           /* re-check -- always on */
 309    _MESA_NEW_NEED_EYE_COORDS |
 310    _NEW_MODELVIEW|
 311    _NEW_PROJECTION|
 312    _NEW_TRANSFORM,              /* re-run */
 313    GL_TRUE,                     /* active */
 314    VERT_BIT_POS,                /* inputs */
 315    VERT_BIT_EYE|VERT_BIT_CLIP,          /* outputs */
 316    0,                           /* changed_inputs */
 317    NULL,                        /* private data */
 318    dtr,                         /* destructor */
 319    check_vertex,                /* check */
 320    init_vertex_stage            /* run -- initially set to init */
 321 };