tess.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
 * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice including the dates of first publication and
 * either this permission notice or a reference to
 * http://oss.sgi.com/projects/FreeB/
 * shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Except as contained in this notice, the name of Silicon Graphics, Inc.
 * shall not be used in advertising or otherwise to promote the sale, use or
 * other dealings in this Software without prior written authorization from
 * Silicon Graphics, Inc.
 */
/*
** Author: Eric Veach, July 1994.
**
*/

#include "gluos.h"
#include <stddef.h>
#include <assert.h>
#include <setjmp.h>
#include "memalloc.h"
#include "tess.h"
#include "mesh.h"
#include "normal.h"
#include "sweep.h"
#include "tessmono.h"
#include "render.h"

#define GLU_TESS_DEFAULT_TOLERANCE 0.0
#define GLU_TESS_MESH		100112	/* void (*)(GLUmesh *mesh)	    */

#define TRUE 1
#define FALSE 0

/*ARGSUSED*/ static void GLAPIENTRY noBegin( GLenum type ) {}
/*ARGSUSED*/ static void GLAPIENTRY noEdgeFlag( GLboolean boundaryEdge ) {}
/*ARGSUSED*/ static void GLAPIENTRY noVertex( void *data ) {}
/*ARGSUSED*/ static void GLAPIENTRY noEnd( void ) {}
/*ARGSUSED*/ static void GLAPIENTRY noError( GLenum errnum ) {}
/*ARGSUSED*/ static void GLAPIENTRY noCombine( GLdouble coords[3], void *data[4],
				    GLfloat weight[4], void **dataOut ) {}
/*ARGSUSED*/ static void GLAPIENTRY noMesh( GLUmesh *mesh ) {}


/*ARGSUSED*/ void GLAPIENTRY __gl_noBeginData( GLenum type,
					     void *polygonData ) {}
/*ARGSUSED*/ void GLAPIENTRY __gl_noEdgeFlagData( GLboolean boundaryEdge,
				       void *polygonData ) {}
/*ARGSUSED*/ void GLAPIENTRY __gl_noVertexData( void *data,
					      void *polygonData ) {}
/*ARGSUSED*/ void GLAPIENTRY __gl_noEndData( void *polygonData ) {}
/*ARGSUSED*/ void GLAPIENTRY __gl_noErrorData( GLenum errnum,
					     void *polygonData ) {}
/*ARGSUSED*/ void GLAPIENTRY __gl_noCombineData( GLdouble coords[3],
					       void *data[4],
					       GLfloat weight[4],
					       void **outData,
					       void *polygonData ) {}

/* Half-edges are allocated in pairs (see mesh.c) */
typedef struct { GLUhalfEdge e, eSym; } EdgePair;

#undef	MAX
#define MAX(a,b)	((a) > (b) ? (a) : (b))
#define MAX_FAST_ALLOC	(MAX(sizeof(EdgePair), \
                         MAX(sizeof(GLUvertex),sizeof(GLUface))))


GLUtesselator * GLAPIENTRY
gluNewTess( void )
{
  GLUtesselator *tess;

  /* Only initialize fields which can be changed by the api.  Other fields
   * are initialized where they are used.
   */

  if (memInit( MAX_FAST_ALLOC ) == 0) {
     return 0;			/* out of memory */
  }
  tess = (GLUtesselator *)memAlloc( sizeof( GLUtesselator ));
  if (tess == NULL) {
     return 0;			/* out of memory */
  }

  tess->state = T_DORMANT;

  tess->normal[0] = 0;
  tess->normal[1] = 0;
  tess->normal[2] = 0;

  tess->relTolerance = GLU_TESS_DEFAULT_TOLERANCE;
  tess->windingRule = GLU_TESS_WINDING_ODD;
  tess->flagBoundary = FALSE;
  tess->boundaryOnly = FALSE;

  tess->callBegin = &noBegin;
  tess->callEdgeFlag = &noEdgeFlag;
  tess->callVertex = &noVertex;
  tess->callEnd = &noEnd;

  tess->callError = &noError;
  tess->callCombine = &noCombine;
  tess->callMesh = &noMesh;

  tess->callBeginData= &__gl_noBeginData;
  tess->callEdgeFlagData= &__gl_noEdgeFlagData;
  tess->callVertexData= &__gl_noVertexData;
  tess->callEndData= &__gl_noEndData;
  tess->callErrorData= &__gl_noErrorData;
  tess->callCombineData= &__gl_noCombineData;

  tess->polygonData= NULL;

  return tess;
}

static void MakeDormant( GLUtesselator *tess )
{
  /* Return the tessellator to its original dormant state. */

  if( tess->mesh != NULL ) {
    __gl_meshDeleteMesh( tess->mesh );
  }
  tess->state = T_DORMANT;
  tess->lastEdge = NULL;
  tess->mesh = NULL;
}

#define RequireState( tess, s )   if( tess->state != s ) GotoState(tess,s)

static void GotoState( GLUtesselator *tess, enum TessState newState )
{
  while( tess->state != newState ) {
    /* We change the current state one level at a time, to get to
     * the desired state.
     */
    if( tess->state < newState ) {
      switch( tess->state ) {
      case T_DORMANT:
	CALL_ERROR_OR_ERROR_DATA( GLU_TESS_MISSING_BEGIN_POLYGON );
	gluTessBeginPolygon( tess, NULL );
	break;
      case T_IN_POLYGON:
	CALL_ERROR_OR_ERROR_DATA( GLU_TESS_MISSING_BEGIN_CONTOUR );
	gluTessBeginContour( tess );
	break;
      default:
	 ;
      }
    } else {
      switch( tess->state ) {
      case T_IN_CONTOUR:
	CALL_ERROR_OR_ERROR_DATA( GLU_TESS_MISSING_END_CONTOUR );
	gluTessEndContour( tess );
	break;
      case T_IN_POLYGON:
	CALL_ERROR_OR_ERROR_DATA( GLU_TESS_MISSING_END_POLYGON );
	/* gluTessEndPolygon( tess ) is too much work! */
	MakeDormant( tess );
	break;
      default:
	 ;
      }
    }
  }
}


void GLAPIENTRY
gluDeleteTess( GLUtesselator *tess )
{
  RequireState( tess, T_DORMANT );
  memFree( tess );
}


void GLAPIENTRY
gluTessProperty( GLUtesselator *tess, GLenum which, GLdouble value )
{
  GLenum windingRule;

  switch( which ) {
  case GLU_TESS_TOLERANCE:
    if( value < 0.0 || value > 1.0 ) break;
    tess->relTolerance = value;
    return;

  case GLU_TESS_WINDING_RULE:
    windingRule = (GLenum) value;
    if( windingRule != value ) break;	/* not an integer */

    switch( windingRule ) {
    case GLU_TESS_WINDING_ODD:
    case GLU_TESS_WINDING_NONZERO:
    case GLU_TESS_WINDING_POSITIVE:
    case GLU_TESS_WINDING_NEGATIVE:
    case GLU_TESS_WINDING_ABS_GEQ_TWO:
      tess->windingRule = windingRule;
      return;
    default:
      break;
    }

  case GLU_TESS_BOUNDARY_ONLY:
    tess->boundaryOnly = (value != 0);
    return;

  default:
    CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_ENUM );
    return;
  }
  CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_VALUE );
}

/* Returns tessellator property */
void GLAPIENTRY
gluGetTessProperty( GLUtesselator *tess, GLenum which, GLdouble *value )
{
   switch (which) {
   case GLU_TESS_TOLERANCE:
      /* tolerance should be in range [0..1] */
      assert(0.0 <= tess->relTolerance && tess->relTolerance <= 1.0);
      *value= tess->relTolerance;
      break;
   case GLU_TESS_WINDING_RULE:
      assert(tess->windingRule == GLU_TESS_WINDING_ODD ||
	     tess->windingRule == GLU_TESS_WINDING_NONZERO ||
	     tess->windingRule == GLU_TESS_WINDING_POSITIVE ||
	     tess->windingRule == GLU_TESS_WINDING_NEGATIVE ||
	     tess->windingRule == GLU_TESS_WINDING_ABS_GEQ_TWO);
      *value= tess->windingRule;
      break;
   case GLU_TESS_BOUNDARY_ONLY:
      assert(tess->boundaryOnly == TRUE || tess->boundaryOnly == FALSE);
      *value= tess->boundaryOnly;
      break;
   default:
      *value= 0.0;
      CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_ENUM );
      break;
   }
} /* gluGetTessProperty() */

void GLAPIENTRY
gluTessNormal( GLUtesselator *tess, GLdouble x, GLdouble y, GLdouble z )
{
  tess->normal[0] = x;
  tess->normal[1] = y;
  tess->normal[2] = z;
}

void GLAPIENTRY
gluTessCallback( GLUtesselator *tess, GLenum which, _GLUfuncptr fn)
{
  switch( which ) {
  case GLU_TESS_BEGIN:
    tess->callBegin = (fn == NULL) ? &noBegin : (void (GLAPIENTRY *)(GLenum)) fn;
    return;
  case GLU_TESS_BEGIN_DATA:
    tess->callBeginData = (fn == NULL) ?
	&__gl_noBeginData : (void (GLAPIENTRY *)(GLenum, void *)) fn;
    return;
  case GLU_TESS_EDGE_FLAG:
    tess->callEdgeFlag = (fn == NULL) ? &noEdgeFlag :
					(void (GLAPIENTRY *)(GLboolean)) fn;
    /* If the client wants boundary edges to be flagged,
     * we render everything as separate triangles (no strips or fans).
     */
    tess->flagBoundary = (fn != NULL);
    return;
  case GLU_TESS_EDGE_FLAG_DATA:
    tess->callEdgeFlagData= (fn == NULL) ?
	&__gl_noEdgeFlagData : (void (GLAPIENTRY *)(GLboolean, void *)) fn;
    /* If the client wants boundary edges to be flagged,
     * we render everything as separate triangles (no strips or fans).
     */
    tess->flagBoundary = (fn != NULL);
    return;
  case GLU_TESS_VERTEX:
    tess->callVertex = (fn == NULL) ? &noVertex :
				      (void (GLAPIENTRY *)(void *)) fn;
    return;
  case GLU_TESS_VERTEX_DATA:
    tess->callVertexData = (fn == NULL) ?
	&__gl_noVertexData : (void (GLAPIENTRY *)(void *, void *)) fn;
    return;
  case GLU_TESS_END:
    tess->callEnd = (fn == NULL) ? &noEnd : (void (GLAPIENTRY *)(void)) fn;
    return;
  case GLU_TESS_END_DATA:
    tess->callEndData = (fn == NULL) ? &__gl_noEndData :
				       (void (GLAPIENTRY *)(void *)) fn;
    return;
  case GLU_TESS_ERROR:
    tess->callError = (fn == NULL) ? &noError : (void (GLAPIENTRY *)(GLenum)) fn;
    return;