Files
third_party_mesa3d/src/glu/mesa/tess.c
1999-09-16 06:41:42 +00:00

983 lines
27 KiB
C

/* $Id: tess.c,v 1.7 1999/09/16 06:41:42 gareth Exp $ */
/*
* Mesa 3-D graphics library
* Version: 3.1
*
* Copyright (C) 1999 Brian Paul 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 and this permission notice 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
* BRIAN PAUL 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.
*/
/*
* $Log: tess.c,v $
* Revision 1.7 1999/09/16 06:41:42 gareth
* Misc winding rule bug fixes.
*
* Revision 1.6 1999/09/15 02:11:10 gareth
* Fixed vector macro calls, specifically COPY_3V params.
*
* Revision 1.5 1999/09/14 05:37:58 gareth
* Fixed legacy gluNextContour impact on gluTessEndContour.
*
* Revision 1.4 1999/09/13 22:20:13 gareth
* Fixed file headers. Tracking down macro bugs.
*
*/
/*****************************************************************************
*
* GLU 1.3 Polygon Tessellation by Gareth Hughes <garethh@lucent.com>
*
*****************************************************************************/
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <GL/glu.h>
#include "tess.h"
#include "tess_macros.h"
#include "tess_fist.h"
#if 0
#include "tess_grid.h"
#endif
/*****************************************************************************
* Internal function prototypes:
*****************************************************************************/
static void init_callbacks( tess_callbacks_t *callbacks );
static void tess_cleanup( GLUtesselator *tobj );
static void inspect_current_contour( GLUtesselator *tobj );
static void delete_current_contour( GLUtesselator *tobj );
static void delete_all_contours( GLUtesselator *tobj );
#define TESS_CHECK_ERRORS(t) if ( (t)->error != GLU_NO_ERROR ) goto cleanup
/*****************************************************************************
*
* GLU TESSELLATION FUNCTIONS
*
*****************************************************************************/
/*****************************************************************************
* gluNewTess
*****************************************************************************/
GLUtesselator* GLAPIENTRY gluNewTess( void )
{
GLUtesselator *tobj;
DEBUGP( 3, ( "-> gluNewTess()\n" ) );
if ( ( tobj = (GLUtesselator *)
malloc( sizeof(GLUtesselator) ) ) == NULL )
{
return NULL;
}
init_callbacks( &tobj->callbacks );
tobj->boundary_only = GL_FALSE;
tobj->winding_rule = GLU_TESS_WINDING_ODD;
tobj->tolerance = 0.0;
tobj->plane.normal[X] = 0.0;
tobj->plane.normal[Y] = 0.0;
tobj->plane.normal[Z] = 0.0;
tobj->plane.dist = 0.0;
tobj->contour_count = 0;
tobj->contours = tobj->last_contour = NULL;
tobj->current_contour = NULL;
CLEAR_BBOX_2DV( tobj->mins, tobj->maxs );
tobj->vertex_count = 0;
tobj->sorted_vertices = NULL;
#if 0
tobj->grid = NULL;
#endif
tobj->error = GLU_NO_ERROR;
DEBUGP( 3, ( "<- gluNewTess() tobj:%p\n", tobj ) );
return tobj;
}
/*****************************************************************************
* gluDeleteTess
*****************************************************************************/
void GLAPIENTRY gluDeleteTess( GLUtesselator *tobj )
{
DEBUGP( 3, ( "-> gluDeleteTess( tobj:%p )\n", tobj ) );
if ( tobj->error == GLU_NO_ERROR && ( tobj->contour_count > 0 ) )
{
/* gluEndPolygon was not called. */
DEBUGP( 0, ( "*** error 3 ***\n" ) );
tess_error_callback( tobj, GLU_TESS_ERROR3, NULL );
}
/* Delete all internal structures. */
tess_cleanup( tobj );
free( tobj );
DEBUGP( 3, ( "<- gluDeleteTess()\n" ) );
}
/*****************************************************************************
* gluTessBeginPolygon
*****************************************************************************/
void GLAPIENTRY gluTessBeginPolygon( GLUtesselator *tobj, void *polygon_data )
{
DEBUGP( 3, ( "-> gluTessBeginPolygon( tobj:%p data:%p )\n", tobj, polygon_data ) );
tobj->error = GLU_NO_ERROR;
if ( tobj->current_contour != NULL )
{
/* gluEndPolygon was not called. */
DEBUGP( 0, ( "*** error 3 ***\n" ) );
tess_error_callback( tobj, GLU_TESS_ERROR3, NULL );
tess_cleanup( tobj );
}
DEBUGP( 3, ( "<- gluTessBeginPolygon( tobj:%p data:%p )\n", tobj, polygon_data ) );
}
/*****************************************************************************
* gluTessBeginContour
*****************************************************************************/
void GLAPIENTRY gluTessBeginContour( GLUtesselator *tobj )
{
DEBUGP( 3, ( " -> gluTessBeginContour( tobj:%p )\n", tobj ) );
TESS_CHECK_ERRORS( tobj );
if ( tobj->current_contour != NULL )
{
/* gluTessEndContour was not called. */
DEBUGP( 0, ( "*** error 4 ***\n" ) );
tess_error_callback( tobj, GLU_TESS_ERROR4, NULL );
return;
}
if ( ( tobj->current_contour =
(tess_contour_t *) malloc( sizeof(tess_contour_t) ) ) == NULL )
{
DEBUGP( 0, ( "*** memory error ***\n" ) );
tess_error_callback( tobj, GLU_OUT_OF_MEMORY, NULL );
return;
}
COPY_3V( tobj->current_contour->plane.normal, tobj->plane.normal );
tobj->current_contour->plane.dist = tobj->plane.dist;
tobj->current_contour->vertex_count = 0;
tobj->current_contour->vertices =
tobj->current_contour->last_vertex = NULL;
tobj->current_contour->reflex_vertices = NULL;
tobj->current_contour->cross_vertices = hashtable_init( HT_DEFAULT_SIZE );
tobj->current_contour->orientation = GLU_UNKNOWN;
tobj->current_contour->area = 0.0;
tobj->current_contour->label = 0;
CLEAR_BBOX_2DV( tobj->current_contour->mins,
tobj->current_contour->maxs );
tobj->current_contour->rotx = tobj->current_contour->roty = 0.0;
cleanup:
DEBUGP( 3, ( " <- gluTessBeginContour( tobj:%p )\n", tobj ) );
return;
}
/*****************************************************************************
* gluTessVertex
*****************************************************************************/
void GLAPIENTRY gluTessVertex( GLUtesselator *tobj, GLdouble coords[3],
void *vertex_data )
{
tess_contour_t *current = tobj->current_contour;
tess_vertex_t *last_vertex;
DEBUGP( 3, ( " -> gluTessVertex( tobj:%p coords:(%.2f,%.2f,%.2f) )\n", tobj, coords[0], coords[1], coords[2] ) );
TESS_CHECK_ERRORS( tobj );
if ( current == NULL )
{
/* gluTessBeginContour was not called. */
DEBUGP( 0, ( "*** error 2 ***\n" ) );
tess_error_callback( tobj, GLU_TESS_ERROR2, NULL );
return;
}
tobj->vertex_count++;
last_vertex = current->last_vertex;
if ( last_vertex == NULL )
{
if ( ( last_vertex = (tess_vertex_t *)
malloc( sizeof(tess_vertex_t) ) ) == NULL )
{
DEBUGP( 0, ( "*** memory error ***\n" ) );
tess_error_callback( tobj, GLU_OUT_OF_MEMORY, NULL );
return;
}
current->vertices = last_vertex;
current->last_vertex = last_vertex;
last_vertex->index = -1;
last_vertex->data = vertex_data;
last_vertex->coords[X] = coords[X];
last_vertex->coords[Y] = coords[Y];
last_vertex->coords[Z] = coords[Z];
last_vertex->next = NULL;
last_vertex->previous = NULL;
current->vertex_count++;
}
else
{
tess_vertex_t *vertex;
if ( ( vertex = (tess_vertex_t *)
malloc( sizeof(tess_vertex_t) ) ) == NULL )
{
DEBUGP( 0, ( "*** memory error ***\n" ) );
tess_error_callback( tobj, GLU_OUT_OF_MEMORY, NULL );
return;
}
vertex->index = -1;
vertex->data = vertex_data;
vertex->coords[X] = coords[X];
vertex->coords[Y] = coords[Y];
vertex->coords[Z] = coords[Z];
vertex->next = NULL;
vertex->previous = last_vertex;
current->vertex_count++;
last_vertex->next = vertex;
current->last_vertex = vertex;
}
cleanup:
DEBUGP( 3, ( " <- gluTessVertex( tobj:%p )\n", tobj ) );
return;
}
/*****************************************************************************
* gluTessEndContour
*****************************************************************************/
void GLAPIENTRY gluTessEndContour( GLUtesselator *tobj )
{
DEBUGP( 3, ( " -> gluTessEndContour( tobj:%p )\n", tobj ) );
TESS_CHECK_ERRORS( tobj );
if ( tobj->current_contour == NULL )
{
/* gluTessBeginContour was not called. */
DEBUGP( 0, ( "*** error 2 ***\n" ) );
tess_error_callback( tobj, GLU_TESS_ERROR2, NULL );
return;
}
if ( tobj->current_contour->vertex_count > 0 )
{
inspect_current_contour( tobj );
}
else
{
delete_current_contour( tobj );
}
cleanup:
DEBUGP( 3, ( " <- gluTessEndContour( tobj:%p )\n", tobj ) );
return;
}
/*****************************************************************************
* gluTessEndPolygon
*****************************************************************************/
void GLAPIENTRY gluTessEndPolygon( GLUtesselator *tobj )
{
DEBUGP( 3, ( "-> gluTessEndPolygon( tobj:%p )\n", tobj ) );
TESS_CHECK_ERRORS( tobj );
if ( tobj->current_contour != NULL )
{
/* gluTessBeginPolygon was not called. */
DEBUGP( 0, ( "*** error 1 ***\n" ) );
tess_error_callback( tobj, GLU_TESS_ERROR1, NULL );
return;
}
TESS_CHECK_ERRORS( tobj );
/*
* Ensure we have at least one contour to tessellate. If we have none,
* clean up and exit gracefully.
*/
if ( tobj->contour_count == 0 )
{
tess_cleanup( tobj );
return;
}
/* Wrap the contour list. */
tobj->last_contour->next = tobj->contours;
tobj->contours->previous = tobj->last_contour;
/* tess_find_contour_hierarchies(tobj); */
TESS_CHECK_ERRORS( tobj );
/* tess_handle_holes(tobj); */
TESS_CHECK_ERRORS( tobj );
/*
* Before we tessellate the contours, ensure we have the appropriate
* callbacks registered. We at least need the begin, vertex and end
* callbacks to do any meaningful work.
*/
if ( ( ( tobj->callbacks.begin != NULL ) ||
( tobj->callbacks.beginData != NULL ) ) &&
( ( tobj->callbacks.vertex != NULL ) ||
( tobj->callbacks.vertexData != NULL ) ) &&
( ( tobj->callbacks.end != NULL ) ||
( tobj->callbacks.endData != NULL ) ) )
{
if ( ( tobj->callbacks.edgeFlag == NULL ) &&
( tobj->callbacks.edgeFlagData == NULL ) )
{
fist_tessellation( tobj );
}
else
{
fist_tessellation( tobj );
}
}
cleanup:
delete_all_contours( tobj );
DEBUGP( 3, ( "<- gluTessEndPolygon( tobj:%p )\n", tobj ) );
}
/*****************************************************************************
* gluTessCallback
*****************************************************************************/
void GLAPIENTRY gluTessCallback( GLUtesselator *tobj, GLenum which,
void (GLCALLBACK *fn)() )
{
switch ( which )
{
/* Register the begin callbacks. */
case GLU_TESS_BEGIN:
tobj->callbacks.begin = (void (GLCALLBACK*)(GLenum)) fn;
break;
case GLU_TESS_BEGIN_DATA:
tobj->callbacks.beginData = (void (GLCALLBACK*)(GLenum, void *)) fn;
break;
/* Register the edge flag callbacks. */
case GLU_TESS_EDGE_FLAG:
tobj->callbacks.edgeFlag = (void (GLCALLBACK*)(GLboolean)) fn;
break;
case GLU_TESS_EDGE_FLAG_DATA:
tobj->callbacks.edgeFlagData =
(void (GLCALLBACK*)(GLboolean, void *)) fn;
break;
/* Register the vertex callbacks. */
case GLU_TESS_VERTEX:
tobj->callbacks.vertex = (void (GLCALLBACK*)(void *)) fn;
break;
case GLU_TESS_VERTEX_DATA:
tobj->callbacks.vertexData = (void (GLCALLBACK*)(void *, void *)) fn;
break;
/* Register the end callbacks. */
case GLU_TESS_END:
tobj->callbacks.end = (void (GLCALLBACK*)(void)) fn;
break;
case GLU_TESS_END_DATA:
tobj->callbacks.endData = (void (GLCALLBACK*)(void *)) fn;
break;
/* Register the error callbacks. */
case GLU_TESS_ERROR:
tobj->callbacks.error = (void (GLCALLBACK*)(GLenum)) fn;
break;
case GLU_TESS_ERROR_DATA:
tobj->callbacks.errorData = (void (GLCALLBACK*)(GLenum, void *)) fn;
break;
/* Register the combine callbacks. */
case GLU_TESS_COMBINE:
tobj->callbacks.combine =
(void (GLCALLBACK*)(GLdouble[3], void *[4],
GLfloat [4], void **)) fn;
break;
case GLU_TESS_COMBINE_DATA:
tobj->callbacks.combineData =
(void (GLCALLBACK*)(GLdouble[3], void *[4], GLfloat [4],
void **, void *)) fn;
break;
default:
DEBUGP( 0, ( " gluTessCallback( tobj:%p which:%d ) invalid enum\n", tobj, which ) );
tobj->error = GLU_INVALID_ENUM;
break;
}
}
/*****************************************************************************
* gluTessProperty
*
* Set the current value of the given property.
*****************************************************************************/
void GLAPIENTRY gluTessProperty( GLUtesselator *tobj, GLenum which,
GLdouble value )
{
switch ( which )
{
case GLU_TESS_BOUNDARY_ONLY:
tobj->boundary_only = (GLboolean) value;
break;
case GLU_TESS_TOLERANCE:
tobj->tolerance = value;
break;
case GLU_TESS_WINDING_RULE:
tobj->winding_rule = (GLenum) value;
break;
default:
DEBUGP( 0, ( " gluTessProperty( tobj:%p which:%d ) invalid enum\n", tobj, which ) );
tobj->error = GLU_INVALID_ENUM;
break;
}
}
/*****************************************************************************
* gluGetTessProperty
*
* Return the current value of the given property.
*****************************************************************************/
void GLAPIENTRY gluGetTessProperty( GLUtesselator *tobj, GLenum which,
GLdouble *value )
{
switch ( which )
{
case GLU_TESS_BOUNDARY_ONLY:
*value = tobj->boundary_only;
break;
case GLU_TESS_TOLERANCE:
*value = tobj->tolerance;
break;
case GLU_TESS_WINDING_RULE:
*value = tobj->winding_rule;
break;
default:
DEBUGP( 0, ( " gluGetTessProperty( tobj:%p which:%d ) invalid enum\n", tobj, which ) );
tobj->error = GLU_INVALID_ENUM;
break;
}
}
/*****************************************************************************
* gluTessNormal
*
* Set the current tessellation normal.
*****************************************************************************/
void GLAPIENTRY gluTessNormal( GLUtesselator *tobj, GLdouble x,
GLdouble y, GLdouble z )
{
DEBUGP( 3, ( " gluTessNormal( tobj:%p n:(%.2f,%.2f,%.2f)\n", tobj, x, y, z ) );
tobj->plane.normal[X] = x;
tobj->plane.normal[Y] = y;
tobj->plane.normal[Z] = z;
}
/*****************************************************************************
*
* OBSOLETE TESSELLATION FUNCTIONS
*
*****************************************************************************/
void GLAPIENTRY gluBeginPolygon( GLUtesselator *tobj )
{
gluTessBeginPolygon( tobj, NULL );
gluTessBeginContour( tobj );
}
void GLAPIENTRY gluNextContour( GLUtesselator *tobj, GLenum type )
{
gluTessEndContour( tobj );
gluTessBeginContour( tobj );
}
void GLAPIENTRY gluEndPolygon( GLUtesselator *tobj )
{
gluTessEndContour( tobj );
gluTessEndPolygon( tobj );
}
/*****************************************************************************
* tess_error_callback
*
* Internal error handler. Call the user-registered error callback.
*****************************************************************************/
void tess_error_callback( GLUtesselator *tobj, GLenum errno, void *data )
{
if ( tobj->error == GLU_NO_ERROR )
{
tobj->error = errno;
}
if ( tobj->callbacks.errorData != NULL )
{
( tobj->callbacks.errorData )( errno, data );
}
else if ( tobj->callbacks.error != NULL )
{
( tobj->callbacks.error )( errno );
}
}
/*****************************************************************************
*
* INTERNAL FUNCTIONS
*
*****************************************************************************/
/*****************************************************************************
* init_callbacks
*****************************************************************************/
static void init_callbacks( tess_callbacks_t *callbacks )
{
callbacks->begin = ( void (GLCALLBACK*)(GLenum) ) NULL;
callbacks->beginData = ( void (GLCALLBACK*)(GLenum, void *) ) NULL;
callbacks->edgeFlag = ( void (GLCALLBACK*)(GLboolean) ) NULL;
callbacks->edgeFlagData = ( void (GLCALLBACK*)(GLboolean, void *) ) NULL;
callbacks->vertex = ( void (GLCALLBACK*)(void *) ) NULL;
callbacks->vertexData = ( void (GLCALLBACK*)(void *, void *) ) NULL;
callbacks->end = ( void (GLCALLBACK*)(void) ) NULL;
callbacks->endData = ( void (GLCALLBACK*)(void *) ) NULL;
callbacks->error = ( void (GLCALLBACK*)(GLenum) ) NULL;
callbacks->errorData = ( void (GLCALLBACK*)(GLenum, void *) ) NULL;
callbacks->combine = ( void (GLCALLBACK*)(GLdouble [3], void *[4],
GLfloat [4], void **) ) NULL;
callbacks->combineData = ( void (GLCALLBACK*)(GLdouble [3], void *[4],
GLfloat [4], void **,
void *) ) NULL;
}
/*****************************************************************************
* tess_cleanup
*****************************************************************************/
static void tess_cleanup( GLUtesselator *tobj )
{
DEBUGP( 3, ( " -> tess_cleanup( tobj:%p )\n", tobj ) );
if ( tobj->current_contour != NULL )
{
delete_current_contour( tobj );
}
if ( tobj->contours != NULL )
{
delete_all_contours( tobj );
}
DEBUGP( 3, ( " <- tess_cleanup( tobj:%p )\n", tobj ) );
}
/*****************************************************************************
* inspect_current_contour
*****************************************************************************/
static GLenum find_normal( GLUtesselator *tobj );
static void project_current_contour( GLUtesselator *tobj );
static GLenum save_current_contour( GLUtesselator *tobj );
static void inspect_current_contour( GLUtesselator *tobj )
{
tess_contour_t *current = tobj->current_contour;
GLdouble origin[3] = { 0.0, 0.0, 0.0 };
DEBUGP( 3, ( " -> inspect_current_contour( tobj:%p )\n", tobj ) );
if ( current->vertex_count < 3 )
{
DEBUGP( 3, ( " count %d < 3, deleting\n", current->vertex_count ) );
delete_current_contour( tobj );
return;
}
current->last_vertex->next = current->vertices;
current->vertices->previous = current->last_vertex;
if ( ( tobj->contours == NULL ) &&
( COMPARE_3DV( current->plane.normal, origin ) ) )
{
/* We haven't been given a normal, so let's take a guess. */
if ( find_normal( tobj ) == GLU_ERROR ) {
return;
}
COPY_3V( tobj->plane.normal, current->plane.normal );
tobj->plane.dist = current->plane.dist;
}
else
{
DEBUGP( 3, ( " normal: (%.2f,%.2f,%.2f)\n", tobj->plane.normal[X], tobj->plane.normal[Y], tobj->plane.normal[Z] ) );
}
project_current_contour( tobj );
if ( save_current_contour( tobj ) == GLU_ERROR ) {
return;
}
DEBUGP( 3, ( " <- inspect_current_contour( tobj:%p )\n", tobj ) );
}
/*****************************************************************************
* find_normal
*****************************************************************************/
static GLenum find_normal( GLUtesselator *tobj )
{
tess_contour_t *contour = tobj->current_contour;
tess_vertex_t *va, *vb, *vc;
GLdouble a[3], b[3], c[3];
DEBUGP( 3, ( " -> find_normal( tobj:%p )\n", tobj ) );
if ( contour == NULL ) { return GLU_ERROR; }
va = contour->vertices;
vb = va->next;
/* If va and vb are the same point, keep looking for a different vertex. */
while ( COMPARE_3DV( va->coords, vb->coords ) && ( vb != va ) ) {
vb = vb->next;
}
if ( vb == va ) {
DEBUGP( 0, ( "*** error 7 ***\n" ) );
tess_error_callback( tobj, GLU_TESS_ERROR7, NULL );
}
SUB_3V( a, vb->coords, va->coords );
for ( vc = vb->next; vc != va; vc = vc->next )
{
SUB_3V( b, vc->coords, va->coords );
CROSS3( c, a, b );
if ( ( ABSD( c[X] ) > EQUAL_EPSILON ) ||
( ABSD( c[Y] ) > EQUAL_EPSILON ) ||
( ABSD( c[Z] ) > EQUAL_EPSILON ) )
{
COPY_3V( contour->plane.normal, c );
NORMALIZE_3DV( contour->plane.normal );
contour->plane.dist = - DOT3( contour->plane.normal, va->coords );
DEBUGP( 3, ( " <- find_normal( tobj:%p ) n: (%.2f,%.2f,%.2f)\n", tobj, contour->plane.normal[X], contour->plane.normal[Y], contour->plane.normal[Z] ) );
return GLU_NO_ERROR;
}
}
DEBUGP( 0, ( "*** error 7 ***\n" ) );
tess_error_callback( tobj, GLU_TESS_ERROR7, NULL );
return GLU_ERROR;
}
/*****************************************************************************
* project_current_contour
*****************************************************************************/
static GLdouble twice_contour_area( tess_vertex_t *vertex,
tess_vertex_t *last_vertex );
static void project_current_contour( GLUtesselator *tobj )
{
tess_contour_t *current = tobj->current_contour;
tess_vertex_t *vertex;
GLdouble area;
GLdouble zaxis[3] = { 0.0, 0.0, 1.0 }, znormal[3], xnormal[3];
GLdouble dot, rotx, roty;
GLuint i;
DEBUGP( 3, ( " -> project_current_contour( tobj:%p )\n", tobj ) );
if ( current == NULL ) { return; }
/* Rotate the plane normal around the y-axis. */
znormal[X] = current->plane.normal[X];
znormal[Y] = 0.0;
znormal[Z] = current->plane.normal[Z];
dot = DOT3( znormal, zaxis );
current->roty = roty = acos( dot );
/* Rotate the plane normal around the x-axis. */
xnormal[X] = cos( roty ) * znormal[X] - sin( roty ) * znormal[Z];
xnormal[Y] = znormal[Y];
xnormal[Z] = sin( roty ) * znormal[X] + cos( roty ) * znormal[Z];
dot = DOT3( xnormal, zaxis );
current->rotx = rotx = acos( dot );
for ( vertex = current->vertices, i = 0;
i < current->vertex_count; vertex = vertex->next, i++ )
{
tess_plane_t *plane = &current->plane;
GLdouble proj[3], yrot[3], xrot[3];
/* FIXME: This needs a cleanup, 'cos I'm sure it's inefficient. */
proj[X] = vertex->coords[X] - plane->dist * plane->normal[X];
proj[Y] = vertex->coords[Y] - plane->dist * plane->normal[Y];
proj[Z] = vertex->coords[Z] - plane->dist * plane->normal[Z];
yrot[X] = cos( roty ) * proj[X] - sin( roty ) * proj[Z];
yrot[Y] = proj[Y];
yrot[Z] = sin( roty ) * proj[X] + cos( roty ) * proj[Z];
xrot[X] = yrot[X];
xrot[Y] = cos( rotx ) * yrot[Y] - sin( rotx ) * yrot[Z];
xrot[Z] = sin( rotx ) * yrot[Y] + cos( rotx ) * yrot[Z];
vertex->v[X] = xrot[X];
vertex->v[Y] = xrot[Y];
ACC_BBOX_2V( vertex->v, tobj->mins, tobj->maxs );
ACC_BBOX_2V( vertex->v, current->mins, current->maxs );
}
area = twice_contour_area( current->vertices,
current->last_vertex );
if ( area >= 0.0 )
{
current->orientation = GLU_CCW;
current->area = area;
}
else
{
current->orientation = GLU_CW;
current->area = -area;
}
DEBUGP( 3, ( " <- project_current_contour( tobj:%p )\n", tobj ) );
}
/*****************************************************************************
* twice_contour_area
*****************************************************************************/
static GLdouble twice_contour_area( tess_vertex_t *vertex,
tess_vertex_t *last_vertex )
{
tess_vertex_t *next;
GLdouble area, x, y;
area = 0.0;
x = vertex->v[X];
y = vertex->v[Y];
vertex = vertex->next;
while ( vertex != last_vertex )
{
next = vertex->next;
area +=
(vertex->v[X] - x) * (next->v[Y] - y) -
(vertex->v[Y] - y) * (next->v[X] - x);
vertex = vertex->next;
}
return area;
}
/*****************************************************************************
* save_current_contour
*****************************************************************************/
static GLenum save_current_contour( GLUtesselator *tobj )
{
tess_contour_t *current = tobj->current_contour;
tess_vertex_t *vertex;
GLuint i;
if ( current == NULL ) { return GLU_ERROR; }
if ( tobj->contours == NULL )
{
tobj->contours = tobj->last_contour = current;
current->next = current->previous = NULL;
}
else
{
current->previous = tobj->last_contour;
tobj->last_contour->next = current;
tobj->last_contour = current;
current->next = NULL;
}
for ( vertex = current->vertices, i = 0;
i < current->vertex_count; vertex = vertex->next, i++ )
{
vertex->shadow_vertex = NULL;
vertex->edge_flag = GL_TRUE;
}
current->type = GLU_UNKNOWN;
tobj->contour_count++;
tobj->current_contour = NULL;
return GLU_NO_ERROR;
}
/*****************************************************************************
* delete_current_contour
*****************************************************************************/
static void delete_current_contour( GLUtesselator *tobj )
{
tess_contour_t *current = tobj->current_contour;
tess_vertex_t *vertex, *next;
GLuint i;
if ( current == NULL ) { return; }
for ( vertex = current->vertices, i = 0; i < current->vertex_count; i++)
{
next = vertex->next;
free( vertex );
vertex = next;
}
free( current );
tobj->current_contour = NULL;
}
/*****************************************************************************
* delete_all_contours
*****************************************************************************/
static void delete_all_contours( GLUtesselator *tobj )
{
tess_contour_t *current = tobj->current_contour, *next_contour;
tess_vertex_t *vertex, *next_vertex;
GLuint i;
if ( current != NULL )
{
delete_current_contour( tobj );
}
for ( current = tobj->contours, i = 0; i < tobj->contour_count; i++ )
{
vertex = current->vertices;
while ( vertex != current->last_vertex )
{
next_vertex = vertex->next;
free( vertex );
vertex = next_vertex;
}
free( vertex );
next_contour = current->next;
free( current );
current = next_contour;
}
tobj->contour_count = tobj->vertex_count = 0;
tobj->contours = tobj->last_contour = NULL;
CLEAR_BBOX_2DV( tobj->mins, tobj->maxs );
ZERO_3V( tobj->plane.normal );
tobj->plane.dist = 0.0;
}
/*****************************************************************************
* Debugging output
*****************************************************************************/
#ifdef DEBUG
int tess_debug_level = 0;
int vdebugstr( char *format_str, ... )
{
va_list ap;
va_start( ap, format_str );
vfprintf( stderr, format_str, ap );
va_end( ap );
return 0;
}
#endif