src/mesa/main/polygon.c

   1 /**
   2  * \file polygon.c
   3  * Polygon operations.
   4  */
   5
   6 /*
   7  * Mesa 3-D graphics library
   8  * Version:  4.1
   9  *
  10  * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a
  13  * copy of this software and associated documentation files (the "Software"),
  14  * to deal in the Software without restriction, including without limitation
  15  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  16  * and/or sell copies of the Software, and to permit persons to whom the
  17  * Software is furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included
  20  * in all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  23  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  25  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  26  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  27  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28  */
  29
  30
  31 #include "glheader.h"
  32 #include "imports.h"
  33 #include "context.h"
  34 #include "image.h"
  35 #include "enums.h"
  36 #include "macros.h"
  37 #include "polygon.h"
  38 #include "mtypes.h"
  39
  40
  41 /**
  42  * Specify whether to cull front- or back-facing facets.
  43  *
  44  * \param mode culling mode.
  45  *
  46  * \sa glCullFace().
  47  *
  48  * Verifies the parameter and updates gl_polygon_attrib::CullFaceMode. On
  49  * change, flushes the vertices and notifies the driver via
  50  * the dd_function_table::CullFace callback.
  51  */
  52 void GLAPIENTRY
  53 _mesa_CullFace( GLenum mode )
  54 {
  55    GET_CURRENT_CONTEXT(ctx);
  56    ASSERT_OUTSIDE_BEGIN_END(ctx);
  57
  58    if (MESA_VERBOSE&VERBOSE_API)
  59       _mesa_debug(ctx, "glCullFace %s\n", _mesa_lookup_enum_by_nr(mode));
  60
  61    if (mode!=GL_FRONT && mode!=GL_BACK && mode!=GL_FRONT_AND_BACK) {
  62       _mesa_error( ctx, GL_INVALID_ENUM, "glCullFace" );
  63       return;
  64    }
  65
  66    if (ctx->Polygon.CullFaceMode == mode)
  67       return;
  68
  69    FLUSH_VERTICES(ctx, _NEW_POLYGON);
  70    ctx->Polygon.CullFaceMode = mode;
  71
  72    if (ctx->Driver.CullFace)
  73       ctx->Driver.CullFace( ctx, mode );
  74 }
  75
  76
  77 /**
  78  * Define front- and back-facing
  79  *
  80  * \param mode orientation of front-facing polygons.
  81  *
  82  * \sa glFrontFace().
  83  *
  84  * Verifies the parameter and updates gl_polygon_attrib::FrontFace. On change
  85  * flushes the vertices and notifies the driver via
  86  * the dd_function_table::FrontFace callback.
  87  */
  88 void GLAPIENTRY
  89 _mesa_FrontFace( GLenum mode )
  90 {
  91    GET_CURRENT_CONTEXT(ctx);
  92    ASSERT_OUTSIDE_BEGIN_END(ctx);
  93
  94    if (MESA_VERBOSE&VERBOSE_API)
  95       _mesa_debug(ctx, "glFrontFace %s\n", _mesa_lookup_enum_by_nr(mode));
  96
  97    if (mode!=GL_CW && mode!=GL_CCW) {
  98       _mesa_error( ctx, GL_INVALID_ENUM, "glFrontFace" );
  99       return;
 100    }
 101
 102    if (ctx->Polygon.FrontFace == mode)
 103       return;
 104
 105    FLUSH_VERTICES(ctx, _NEW_POLYGON);
 106    ctx->Polygon.FrontFace = mode;
 107
 108    ctx->Polygon._FrontBit = (GLboolean) (mode == GL_CW);
 109
 110    if (ctx->Driver.FrontFace)
 111       ctx->Driver.FrontFace( ctx, mode );
 112 }
 113
 114
 115 /**
 116  * Set the polygon rasterization mode.
 117  *
 118  * \param face the polygons which \p mode applies to.
 119  * \param mode how polygons should be rasterized.
 120  *
 121  * \sa glPolygonMode().
 122  *
 123  * Verifies the parameters and updates gl_polygon_attrib::FrontMode and
 124  * gl_polygon_attrib::BackMode. On change flushes the vertices and notifies the
 125  * driver via the dd_function_table::PolygonMode callback.
 126  */
 127 void GLAPIENTRY
 128 _mesa_PolygonMode( GLenum face, GLenum mode )
 129 {
 130    GET_CURRENT_CONTEXT(ctx);
 131    ASSERT_OUTSIDE_BEGIN_END(ctx);
 132
 133    if (MESA_VERBOSE&VERBOSE_API)
 134       _mesa_debug(ctx, "glPolygonMode %s %s\n",
 135                   _mesa_lookup_enum_by_nr(face),
 136                   _mesa_lookup_enum_by_nr(mode));
 137
 138    if (mode!=GL_POINT && mode!=GL_LINE && mode!=GL_FILL) {
 139       _mesa_error( ctx, GL_INVALID_ENUM, "glPolygonMode(mode)" );
 140       return;
 141    }
 142
 143    switch (face) {
 144    case GL_FRONT:
 145       if (ctx->Polygon.FrontMode == mode)
 146          return;
 147       FLUSH_VERTICES(ctx, _NEW_POLYGON);
 148       ctx->Polygon.FrontMode = mode;
 149       break;
 150    case GL_FRONT_AND_BACK:
 151       if (ctx->Polygon.FrontMode == mode &&
 152           ctx->Polygon.BackMode == mode)
 153          return;
 154       FLUSH_VERTICES(ctx, _NEW_POLYGON);
 155       ctx->Polygon.FrontMode = mode;
 156       ctx->Polygon.BackMode = mode;
 157       break;
 158    case GL_BACK:
 159       if (ctx->Polygon.BackMode == mode)
 160          return;
 161       FLUSH_VERTICES(ctx, _NEW_POLYGON);
 162       ctx->Polygon.BackMode = mode;
 163       break;
 164    default:
 165       _mesa_error( ctx, GL_INVALID_ENUM, "glPolygonMode(face)" );
 166       return;
 167    }
 168
 169    ctx->_TriangleCaps &= ~DD_TRI_UNFILLED;
 170    if (ctx->Polygon.FrontMode!=GL_FILL || ctx->Polygon.BackMode!=GL_FILL)
 171       ctx->_TriangleCaps |= DD_TRI_UNFILLED;
 172
 173    if (ctx->Driver.PolygonMode) {
 174       (*ctx->Driver.PolygonMode)( ctx, face, mode );
 175    }
 176 }
 177
 178 #if _HAVE_FULL_GL
 179
 180 void GLAPIENTRY
 181 _mesa_PolygonStipple( const GLubyte *pattern )
 182 {
 183    GET_CURRENT_CONTEXT(ctx);
 184    ASSERT_OUTSIDE_BEGIN_END(ctx);
 185
 186    if (MESA_VERBOSE&VERBOSE_API)
 187       _mesa_debug(ctx, "glPolygonStipple\n");
 188
 189    FLUSH_VERTICES(ctx, _NEW_POLYGONSTIPPLE);
 190    _mesa_unpack_polygon_stipple(pattern, ctx->PolygonStipple, &ctx->Unpack);
 191
 192    if (ctx->Driver.PolygonStipple)
 193       ctx->Driver.PolygonStipple( ctx, (const GLubyte *) ctx->PolygonStipple );
 194 }
 195
 196
 197
 198 void GLAPIENTRY
 199 _mesa_GetPolygonStipple( GLubyte *dest )
 200 {
 201    GET_CURRENT_CONTEXT(ctx);
 202    ASSERT_OUTSIDE_BEGIN_END(ctx);
 203
 204    if (MESA_VERBOSE&VERBOSE_API)
 205       _mesa_debug(ctx, "glGetPolygonStipple\n");
 206
 207    _mesa_pack_polygon_stipple(ctx->PolygonStipple, dest, &ctx->Pack);
 208 }
 209
 210
 211 void GLAPIENTRY
 212 _mesa_PolygonOffset( GLfloat factor, GLfloat units )
 213 {
 214    GET_CURRENT_CONTEXT(ctx);
 215    ASSERT_OUTSIDE_BEGIN_END(ctx);
 216
 217    if (MESA_VERBOSE&VERBOSE_API)
 218       _mesa_debug(ctx, "glPolygonOffset %f %f\n", factor, units);
 219
 220    if (ctx->Polygon.OffsetFactor == factor &&
 221        ctx->Polygon.OffsetUnits == units)
 222       return;
 223
 224    FLUSH_VERTICES(ctx, _NEW_POLYGON);
 225    ctx->Polygon.OffsetFactor = factor;
 226    ctx->Polygon.OffsetUnits = units;
 227
 228    if (ctx->Driver.PolygonOffset)
 229       ctx->Driver.PolygonOffset( ctx, factor, units );
 230 }
 231
 232
 233
 234 void GLAPIENTRY
 235 _mesa_PolygonOffsetEXT( GLfloat factor, GLfloat bias )
 236 {
 237    GET_CURRENT_CONTEXT(ctx);
 238    _mesa_PolygonOffset(factor, bias * ctx->DepthMaxF );
 239 }
 240
 241 #endif
 242
 243
 244 /**********************************************************************/
 245 /** \name State Management */
 246 /*@{*/
 247
 248 /*
 249  * Check polygon state and set DD_TRI_CULL_FRONT_BACK and/or DD_TRI_OFFSET
 250  * in ctx->_TriangleCaps if needed.
 251  */
 252 void _mesa_update_polygon( GLcontext *ctx )
 253 {
 254    ctx->_TriangleCaps &= ~(DD_TRI_CULL_FRONT_BACK | DD_TRI_OFFSET);
 255
 256    if (ctx->Polygon.CullFlag && ctx->Polygon.CullFaceMode == GL_FRONT_AND_BACK)
 257       ctx->_TriangleCaps |= DD_TRI_CULL_FRONT_BACK;
 258
 259    /* Any Polygon offsets enabled? */
 260    if (ctx->Polygon.OffsetPoint ||
 261        ctx->Polygon.OffsetLine ||
 262        ctx->Polygon.OffsetFill) {
 263       ctx->_TriangleCaps |= DD_TRI_OFFSET;
 264    }
 265 }
 266
 267 /*@}*/
 268
 269
 270 /**********************************************************************/
 271 /** \name Initialization */
 272 /*@{*/
 273
 274 /**
 275  * Initialize the context polygon state.
 276  *
 277  * \param ctx GL context.
 278  *
 279  * Initializes __GLcontextRec::Polygon and __GLcontextRec::PolygonStipple
 280  * attribute groups.
 281  */
 282 void _mesa_init_polygon( GLcontext * ctx )
 283 {
 284    /* Polygon group */
 285    ctx->Polygon.CullFlag = GL_FALSE;
 286    ctx->Polygon.CullFaceMode = GL_BACK;
 287    ctx->Polygon.FrontFace = GL_CCW;
 288    ctx->Polygon._FrontBit = 0;
 289    ctx->Polygon.FrontMode = GL_FILL;
 290    ctx->Polygon.BackMode = GL_FILL;
 291    ctx->Polygon.SmoothFlag = GL_FALSE;
 292    ctx->Polygon.StippleFlag = GL_FALSE;
 293    ctx->Polygon.OffsetFactor = 0.0F;
 294    ctx->Polygon.OffsetUnits = 0.0F;
 295    ctx->Polygon.OffsetPoint = GL_FALSE;
 296    ctx->Polygon.OffsetLine = GL_FALSE;
 297    ctx->Polygon.OffsetFill = GL_FALSE;
 298
 299
 300    /* Polygon Stipple group */
 301    MEMSET( ctx->PolygonStipple, 0xff, 32*sizeof(GLuint) );
 302 }
 303
 304 /*@}*/