src/mesa/tnl/t_vb_vertex.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  *
  24  * Authors:
  25  *    Keith Whitwell <keithw@vmware.com>
  26  */
  27
  28
  29 #include "main/glheader.h"
  30 #include "main/macros.h"
  31 #include "main/imports.h"
  32 #include "main/mtypes.h"
  33
  34 #include "math/m_xform.h"
  35
  36 #include "t_context.h"
  37 #include "t_pipeline.h"
  38
  39
  40
  41 struct vertex_stage_data {
  42    GLvector4f eye;
  43    GLvector4f clip;
  44    GLvector4f proj;
  45    GLubyte *clipmask;
  46    GLubyte ormask;
  47    GLubyte andmask;
  48 };
  49
  50 #define VERTEX_STAGE_DATA(stage) ((struct vertex_stage_data *)stage->privatePtr)
  51
  52
  53
  54
  55 /* This function implements cliptesting for user-defined clip planes.
  56  * The clipping of primitives to these planes is implemented in
  57  * t_render_clip.h.
  58  */
  59 #define USER_CLIPTEST(NAME, SZ)                                 \
  60 static void NAME( struct gl_context *ctx,                               \
  61                   GLvector4f *clip,                             \
  62                   GLubyte *clipmask,                            \
  63                   GLubyte *clipormask,                          \
  64                   GLubyte *clipandmask )                        \
  65 {                                                               \
  66    GLuint p;                                                    \
  67                                                                 \
  68    for (p = 0; p < ctx->Const.MaxClipPlanes; p++)               \
  69       if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {        \
  70          GLuint nr, i;                                          \
  71          const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; \
  72          const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; \
  73          const GLfloat c = ctx->Transform._ClipUserPlane[p][2]; \
  74          const GLfloat d = ctx->Transform._ClipUserPlane[p][3]; \
  75          GLfloat *coord = (GLfloat *)clip->data;                \
  76          GLuint stride = clip->stride;                          \
  77          GLuint count = clip->count;                            \
  78                                                                 \
  79          for (nr = 0, i = 0 ; i < count ; i++) {                \
  80             GLfloat dp = coord[0] * a + coord[1] * b;           \
  81             if (SZ > 2) dp += coord[2] * c;                     \
  82             if (SZ > 3) dp += coord[3] * d; else dp += d;       \
  83                                                                 \
  84             if (dp < 0) {                                       \
  85                nr++;                                            \
  86                clipmask[i] |= CLIP_USER_BIT;                    \
  87             }                                                   \
  88                                                                 \
  89             STRIDE_F(coord, stride);                            \
  90          }                                                      \
  91                                                                 \
  92          if (nr > 0) {                                          \
  93             *clipormask |= CLIP_USER_BIT;                       \
  94             if (nr == count) {                                  \
  95                *clipandmask |= CLIP_USER_BIT;                   \
  96                return;                                          \
  97             }                                                   \
  98          }                                                      \
  99       }                                                         \
 100 }
 101
 102
 103 USER_CLIPTEST(userclip2, 2)
 104 USER_CLIPTEST(userclip3, 3)
 105 USER_CLIPTEST(userclip4, 4)
 106
 107 static void (*(usercliptab[5]))( struct gl_context *,
 108                                  GLvector4f *, GLubyte *,
 109                                  GLubyte *, GLubyte * ) =
 110 {
 111    NULL,
 112    NULL,
 113    userclip2,
 114    userclip3,
 115    userclip4
 116 };
 117
 118
 119 void
 120 tnl_clip_prepare(struct gl_context *ctx)
 121 {
 122    /* Neither the x86 nor sparc asm cliptest functions have been updated
 123     * for ARB_depth_clamp, so force the C paths.
 124     */
 125    if (ctx->Transform.DepthClamp) {
 126       static GLboolean c_funcs_installed = GL_FALSE;
 127       if (!c_funcs_installed) {
 128          init_c_cliptest();
 129          c_funcs_installed = GL_TRUE;
 130       }
 131    }
 132 }
 133
 134
 135
 136 static GLboolean run_vertex_stage( struct gl_context *ctx,
 137                                    struct tnl_pipeline_stage *stage )
 138 {
 139    struct vertex_stage_data *store = (struct vertex_stage_data *)stage->privatePtr;
 140    TNLcontext *tnl = TNL_CONTEXT(ctx);
 141    struct vertex_buffer *VB = &tnl->vb;
 142
 143    if (ctx->VertexProgram._Current)
 144       return GL_TRUE;
 145
 146    tnl_clip_prepare(ctx);
 147
 148    if (ctx->_NeedEyeCoords) {
 149       /* Separate modelview transformation:
 150        * Use combined ModelProject to avoid some depth artifacts
 151        */
 152       if (ctx->ModelviewMatrixStack.Top->type == MATRIX_IDENTITY)
 153          VB->EyePtr = VB->AttribPtr[_TNL_ATTRIB_POS];
 154       else
 155          VB->EyePtr = TransformRaw( &store->eye,
 156                                     ctx->ModelviewMatrixStack.Top,
 157                                     VB->AttribPtr[_TNL_ATTRIB_POS]);
 158    }
 159
 160    VB->ClipPtr = TransformRaw( &store->clip,
 161                                &ctx->_ModelProjectMatrix,
 162                                VB->AttribPtr[_TNL_ATTRIB_POS] );
 163
 164    /* Drivers expect this to be clean to element 4...
 165     */
 166    switch (VB->ClipPtr->size) {
 167    case 1:
 168       /* impossible */
 169    case 2:
 170       _mesa_vector4f_clean_elem( VB->ClipPtr, VB->Count, 2 );
 171       /* fall-through */
 172    case 3:
 173       _mesa_vector4f_clean_elem( VB->ClipPtr, VB->Count, 3 );
 174       /* fall-through */
 175    case 4:
 176       break;
 177    }
 178
 179
 180    /* Cliptest and perspective divide.  Clip functions must clear
 181     * the clipmask.
 182     */
 183    store->ormask = 0;
 184    store->andmask = CLIP_FRUSTUM_BITS;
 185
 186    if (tnl->NeedNdcCoords) {
 187       VB->NdcPtr =
 188          _mesa_clip_tab[VB->ClipPtr->size]( VB->ClipPtr,
 189                                             &store->proj,
 190                                             store->clipmask,
 191                                             &store->ormask,
 192                                             &store->andmask,
 193                                             !ctx->Transform.DepthClamp );
 194    }
 195    else {
 196       VB->NdcPtr = NULL;
 197       _mesa_clip_np_tab[VB->ClipPtr->size]( VB->ClipPtr,
 198                                             NULL,
 199                                             store->clipmask,
 200                                             &store->ormask,
 201                                             &store->andmask,
 202                                             !ctx->Transform.DepthClamp );
 203    }
 204
 205    if (store->andmask)
 206       return GL_FALSE;
 207
 208
 209    /* Test userclip planes.  This contributes to VB->ClipMask, so
 210     * is essentially required to be in this stage.
 211     */
 212    if (ctx->Transform.ClipPlanesEnabled) {
 213       usercliptab[VB->ClipPtr->size]( ctx,
 214                                       VB->ClipPtr,
 215                                       store->clipmask,
 216                                       &store->ormask,
 217                                       &store->andmask );
 218
 219       if (store->andmask)
 220          return GL_FALSE;
 221    }
 222
 223    VB->ClipAndMask = store->andmask;
 224    VB->ClipOrMask = store->ormask;
 225    VB->ClipMask = store->clipmask;
 226
 227    return GL_TRUE;
 228 }
 229
 230
 231 static GLboolean init_vertex_stage( struct gl_context *ctx,
 232                                     struct tnl_pipeline_stage *stage )
 233 {
 234    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 235    struct vertex_stage_data *store;
 236    GLuint size = VB->Size;
 237
 238    stage->privatePtr = calloc(1, sizeof(*store));
 239    store = VERTEX_STAGE_DATA(stage);
 240    if (!store)
 241       return GL_FALSE;
 242
 243    _mesa_vector4f_alloc( &store->eye, 0, size, 32 );
 244    _mesa_vector4f_alloc( &store->clip, 0, size, 32 );
 245    _mesa_vector4f_alloc( &store->proj, 0, size, 32 );
 246
 247    store->clipmask = _mesa_align_malloc(sizeof(GLubyte)*size, 32 );
 248
 249    if (!store->clipmask ||
 250        !store->eye.data ||
 251        !store->clip.data ||
 252        !store->proj.data)
 253       return GL_FALSE;
 254
 255    return GL_TRUE;
 256 }
 257
 258 static void dtr( struct tnl_pipeline_stage *stage )
 259 {
 260    struct vertex_stage_data *store = VERTEX_STAGE_DATA(stage);
 261
 262    if (store) {
 263       _mesa_vector4f_free( &store->eye );
 264       _mesa_vector4f_free( &store->clip );
 265       _mesa_vector4f_free( &store->proj );
 266       _mesa_align_free( store->clipmask );
 267       free(store);
 268       stage->privatePtr = NULL;
 269       stage->run = init_vertex_stage;
 270    }
 271 }
 272
 273
 274 const struct tnl_pipeline_stage _tnl_vertex_transform_stage =
 275 {
 276    "modelview/project/cliptest/divide",
 277    NULL,                        /* private data */
 278    init_vertex_stage,
 279    dtr,                         /* destructor */
 280    NULL,
 281    run_vertex_stage             /* run -- initially set to init */
 282 };