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/context.h"
  32 #include "main/macros.h"
  33 #include "main/imports.h"
  34 #include "main/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 #define VERTEX_STAGE_DATA(stage) ((struct vertex_stage_data *)stage->privatePtr)
  53
  54
  55
  56
  57 /* This function implements cliptesting for user-defined clip planes.
  58  * The clipping of primitives to these planes is implemented in
  59  * t_render_clip.h.
  60  */
  61 #define USER_CLIPTEST(NAME, SZ)                                 \
  62 static void NAME( GLcontext *ctx,                               \
  63                   GLvector4f *clip,                             \
  64                   GLubyte *clipmask,                            \
  65                   GLubyte *clipormask,                          \
  66                   GLubyte *clipandmask )                        \
  67 {                                                               \
  68    GLuint p;                                                    \
  69                                                                 \
  70    for (p = 0; p < ctx->Const.MaxClipPlanes; p++)               \
  71       if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {        \
  72          GLuint nr, i;                                          \
  73          const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; \
  74          const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; \
  75          const GLfloat c = ctx->Transform._ClipUserPlane[p][2]; \
  76          const GLfloat d = ctx->Transform._ClipUserPlane[p][3]; \
  77          GLfloat *coord = (GLfloat *)clip->data;                \
  78          GLuint stride = clip->stride;                          \
  79          GLuint count = clip->count;                            \
  80                                                                 \
  81          for (nr = 0, i = 0 ; i < count ; i++) {                \
  82             GLfloat dp = coord[0] * a + coord[1] * b;           \
  83             if (SZ > 2) dp += coord[2] * c;                     \
  84             if (SZ > 3) dp += coord[3] * d; else dp += d;       \
  85                                                                 \
  86             if (dp < 0) {                                       \
  87                nr++;                                            \
  88                clipmask[i] |= CLIP_USER_BIT;                    \
  89             }                                                   \
  90                                                                 \
  91             STRIDE_F(coord, stride);                            \
  92          }                                                      \
  93                                                                 \
  94          if (nr > 0) {                                          \
  95             *clipormask |= CLIP_USER_BIT;                       \
  96             if (nr == count) {                                  \
  97                *clipandmask |= CLIP_USER_BIT;                   \
  98                return;                                          \
  99             }                                                   \
 100          }                                                      \
 101       }                                                         \
 102 }
 103
 104
 105 USER_CLIPTEST(userclip2, 2)
 106 USER_CLIPTEST(userclip3, 3)
 107 USER_CLIPTEST(userclip4, 4)
 108
 109 static void (*(usercliptab[5]))( GLcontext *,
 110                                  GLvector4f *, GLubyte *,
 111                                  GLubyte *, GLubyte * ) =
 112 {
 113    NULL,
 114    NULL,
 115    userclip2,
 116    userclip3,
 117    userclip4
 118 };
 119
 120
 121 void
 122 tnl_clip_prepare(GLcontext *ctx)
 123 {
 124    /* Neither the x86 nor sparc asm cliptest functions have been updated
 125     * for ARB_depth_clamp, so force the C paths.
 126     */
 127    if (ctx->Transform.DepthClamp) {
 128       static GLboolean c_funcs_installed = GL_FALSE;
 129       if (!c_funcs_installed) {
 130          init_c_cliptest();
 131          c_funcs_installed = GL_TRUE;
 132       }
 133    }
 134 }
 135
 136
 137
 138 static GLboolean run_vertex_stage( GLcontext *ctx,
 139                                    struct tnl_pipeline_stage *stage )
 140 {
 141    struct vertex_stage_data *store = (struct vertex_stage_data *)stage->privatePtr;
 142    TNLcontext *tnl = TNL_CONTEXT(ctx);
 143    struct vertex_buffer *VB = &tnl->vb;
 144
 145    if (ctx->VertexProgram._Current)
 146       return GL_TRUE;
 147
 148    tnl_clip_prepare(ctx);
 149
 150    if (ctx->_NeedEyeCoords) {
 151       /* Separate modelview transformation:
 152        * Use combined ModelProject to avoid some depth artifacts
 153        */
 154       if (ctx->ModelviewMatrixStack.Top->type == MATRIX_IDENTITY)
 155          VB->EyePtr = VB->AttribPtr[_TNL_ATTRIB_POS];
 156       else
 157          VB->EyePtr = TransformRaw( &store->eye,
 158                                     ctx->ModelviewMatrixStack.Top,
 159                                     VB->AttribPtr[_TNL_ATTRIB_POS]);
 160    }
 161
 162    VB->ClipPtr = TransformRaw( &store->clip,
 163                                &ctx->_ModelProjectMatrix,
 164                                VB->AttribPtr[_TNL_ATTRIB_POS] );
 165
 166    /* Drivers expect this to be clean to element 4...
 167     */
 168    switch (VB->ClipPtr->size) {
 169    case 1:
 170       /* impossible */
 171    case 2:
 172       _mesa_vector4f_clean_elem( VB->ClipPtr, VB->Count, 2 );
 173       /* fall-through */
 174    case 3:
 175       _mesa_vector4f_clean_elem( VB->ClipPtr, VB->Count, 3 );
 176       /* fall-through */
 177    case 4:
 178       break;
 179    }
 180
 181
 182    /* Cliptest and perspective divide.  Clip functions must clear
 183     * the clipmask.
 184     */
 185    store->ormask = 0;
 186    store->andmask = CLIP_FRUSTUM_BITS;
 187
 188    if (tnl->NeedNdcCoords) {
 189       VB->NdcPtr =
 190          _mesa_clip_tab[VB->ClipPtr->size]( VB->ClipPtr,
 191                                             &store->proj,
 192                                             store->clipmask,
 193                                             &store->ormask,
 194                                             &store->andmask,
 195                                             !ctx->Transform.DepthClamp );
 196    }
 197    else {
 198       VB->NdcPtr = NULL;
 199       _mesa_clip_np_tab[VB->ClipPtr->size]( VB->ClipPtr,
 200                                             NULL,
 201                                             store->clipmask,
 202                                             &store->ormask,
 203                                             &store->andmask,
 204                                             !ctx->Transform.DepthClamp );
 205    }
 206
 207    if (store->andmask)
 208       return GL_FALSE;
 209
 210
 211    /* Test userclip planes.  This contributes to VB->ClipMask, so
 212     * is essentially required to be in this stage.
 213     */
 214    if (ctx->Transform.ClipPlanesEnabled) {
 215       usercliptab[VB->ClipPtr->size]( ctx,
 216                                       VB->ClipPtr,
 217                                       store->clipmask,
 218                                       &store->ormask,
 219                                       &store->andmask );
 220
 221       if (store->andmask)
 222          return GL_FALSE;
 223    }
 224
 225    VB->ClipAndMask = store->andmask;
 226    VB->ClipOrMask = store->ormask;
 227    VB->ClipMask = store->clipmask;
 228
 229    return GL_TRUE;
 230 }
 231
 232
 233 static GLboolean init_vertex_stage( GLcontext *ctx,
 234                                     struct tnl_pipeline_stage *stage )
 235 {
 236    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 237    struct vertex_stage_data *store;
 238    GLuint size = VB->Size;
 239
 240    stage->privatePtr = CALLOC(sizeof(*store));
 241    store = VERTEX_STAGE_DATA(stage);
 242    if (!store)
 243       return GL_FALSE;
 244
 245    _mesa_vector4f_alloc( &store->eye, 0, size, 32 );
 246    _mesa_vector4f_alloc( &store->clip, 0, size, 32 );
 247    _mesa_vector4f_alloc( &store->proj, 0, size, 32 );
 248
 249    store->clipmask = (GLubyte *) ALIGN_MALLOC(sizeof(GLubyte)*size, 32 );
 250
 251    if (!store->clipmask ||
 252        !store->eye.data ||
 253        !store->clip.data ||
 254        !store->proj.data)
 255       return GL_FALSE;
 256
 257    return GL_TRUE;
 258 }
 259
 260 static void dtr( struct tnl_pipeline_stage *stage )
 261 {
 262    struct vertex_stage_data *store = VERTEX_STAGE_DATA(stage);
 263
 264    if (store) {
 265       _mesa_vector4f_free( &store->eye );
 266       _mesa_vector4f_free( &store->clip );
 267       _mesa_vector4f_free( &store->proj );
 268       ALIGN_FREE( store->clipmask );
 269       FREE(store);
 270       stage->privatePtr = NULL;
 271       stage->run = init_vertex_stage;
 272    }
 273 }
 274
 275
 276 const struct tnl_pipeline_stage _tnl_vertex_transform_stage =
 277 {
 278    "modelview/project/cliptest/divide",
 279    NULL,                        /* private data */
 280    init_vertex_stage,
 281    dtr,                         /* destructor */
 282    NULL,
 283    run_vertex_stage             /* run -- initially set to init */
 284 };