-/* $Id: tessdemo.c,v 1.5 2000/01/24 22:54:05 gareth Exp $ */
/*
* A demo of the GLU polygon tesselation functions written by Bogdan Sikorski.
- * This demo isn't built by the Makefile because it needs GLUT. After you've
- * installed GLUT you can try this demo.
- * Here's the command for IRIX, for example:
- cc -g -ansi -prototypes -fullwarn -float -I../include -DSHM tess_demo.c -L../lib -lglut -lMesaGLU -lMesaGL -lm -lX11 -lXext -lXmu -lfpe -lXext -o tess_demo
+ * Updated for GLU 1.3 tessellation by Gareth Hughes <gareth@valinux.com>
*/
-/*
- * Updated for GLU 1.3 tessellation by Gareth Hughes <garethh@bell-labs.com>
- */
-
-/*
- * $Log: tessdemo.c,v $
- * Revision 1.5 2000/01/24 22:54:05 gareth
- * Removed '#if 0' from second pass.
- *
- * Revision 1.4 2000/01/23 21:25:39 gareth
- * Merged 3.2 updates, namely combine callback for intersecting
- * contours.
- *
- * Revision 1.3.2.1 1999/11/16 11:09:09 gareth
- * Added combine callback. Converted vertices from ints to floats.
- *
- * Revision 1.3 1999/11/04 04:00:42 gareth
- * Updated demo for new GLU 1.3 tessellation. Added optimized rendering
- * by saving the output of the tessellation into display lists.
- *
- * Revision 1.2 1999/09/19 20:09:00 tanner
- *
- * lots of autoconf updates
- *
- * Revision 1.1.1.1 1999/08/19 00:55:40 jtg
- * Imported sources
- *
- * Revision 3.5 1999/03/28 18:24:37 brianp
- * minor clean-up
- *
- * Revision 3.4 1999/02/14 03:37:07 brianp
- * fixed callback problem
- *
- * Revision 3.3 1998/07/26 01:25:26 brianp
- * removed include of gl.h and glu.h
- *
- * Revision 3.2 1998/06/29 02:37:30 brianp
- * minor changes for Windows (Ted Jump)
- *
- * Revision 3.1 1998/06/09 01:53:49 brianp
- * main() should return an int
- *
- * Revision 3.0 1998/02/14 18:42:29 brianp
- * initial rev
- *
- */
-
-
#include <GL/glut.h>
#include <stdio.h>
#include <stdlib.h>
#endif
#endif
+#ifdef GLU_VERSION_1_2
+
typedef enum{ QUIT, TESSELATE, CLEAR } menu_entries;
typedef enum{ DEFINE, TESSELATED } mode_type;
static GLfloat edge_color[3];
-static struct
-{
+static struct {
GLfloat p[MAX_POINTS][2];
GLuint point_cnt;
} contours[MAX_CONTOURS];
-static struct
-{
+static struct {
GLsizei no;
GLfloat p[3][2];
GLclampf color[3][3];
-void GLCALLBACK error_callback( GLenum err )
+static void GLCALLBACK error_callback( GLenum err )
{
int len, i;
char const *str;
}
}
-void GLCALLBACK begin_callback( GLenum mode )
+static void GLCALLBACK begin_callback( GLenum mode )
{
/* Allow multiple triangles to be output inside the begin/end pair. */
triangle_cnt = 0;
triangles[triangle_cnt].no = 0;
}
-void GLCALLBACK edge_callback( GLenum flag )
+static void GLCALLBACK edge_callback( GLenum flag )
{
/* Persist the edge flag across triangles. */
- if ( flag == GL_TRUE )
- {
+ if ( flag == GL_TRUE ) {
edge_color[0] = 1.0;
edge_color[1] = 1.0;
edge_color[2] = 0.5;
- }
- else
- {
+ } else {
edge_color[0] = 1.0;
edge_color[1] = 0.0;
edge_color[2] = 0.0;
}
}
-void GLCALLBACK end_callback()
+static void GLCALLBACK end_callback()
{
- GLint i;
+ GLuint i;
glBegin( GL_LINES );
/* Output the three edges of each triangle as lines colored
according to their edge flag. */
- for ( i = 0 ; i < triangle_cnt ; i++ )
- {
+ for ( i = 0 ; i < triangle_cnt ; i++ ) {
glColor3f( triangles[i].color[0][0],
triangles[i].color[0][1],
triangles[i].color[0][2] );
glEnd();
}
-void GLCALLBACK vertex_callback( void *data )
+static void GLCALLBACK vertex_callback( void *data )
{
GLsizei no;
GLfloat *p;
triangles[triangle_cnt].color[no][2] = edge_color[2];
/* After every three vertices, initialize the next triangle. */
- if ( ++(triangles[triangle_cnt].no) == 3 )
- {
+ if ( ++(triangles[triangle_cnt].no) == 3 ) {
triangle_cnt++;
triangles[triangle_cnt].no = 0;
}
}
-void GLCALLBACK combine_callback( GLdouble coords[3],
- GLdouble *vertex_data[4],
- GLfloat weight[4], void **data )
+static void GLCALLBACK combine_callback( GLdouble coords[3],
+ GLdouble *vertex_data[4],
+ GLfloat weight[4], void **data )
{
GLfloat *vertex;
- int i;
vertex = (GLfloat *) malloc( 2 * sizeof(GLfloat) );
}
-void set_screen_wh( GLsizei w, GLsizei h )
+static void set_screen_wh( GLsizei w, GLsizei h )
{
width = w;
height = h;
}
-void tesse( void )
+typedef void (GLAPIENTRY *callback_t)();
+
+static void tesse( void )
{
GLUtesselator *tobj;
GLdouble data[3];
tobj = gluNewTess();
- if ( tobj != NULL )
- {
+ if ( tobj != NULL ) {
gluTessNormal( tobj, 0.0, 0.0, 1.0 );
- gluTessCallback( tobj, GLU_TESS_BEGIN, glBegin );
- gluTessCallback( tobj, GLU_TESS_VERTEX, glVertex2fv );
- gluTessCallback( tobj, GLU_TESS_END, glEnd );
- gluTessCallback( tobj, GLU_TESS_ERROR, error_callback );
- gluTessCallback( tobj, GLU_TESS_COMBINE, combine_callback );
+ gluTessCallback( tobj, GLU_TESS_BEGIN, (callback_t) glBegin );
+ gluTessCallback( tobj, GLU_TESS_VERTEX, (callback_t) glVertex2fv );
+ gluTessCallback( tobj, GLU_TESS_END, (callback_t) glEnd );
+ gluTessCallback( tobj, GLU_TESS_ERROR, (callback_t) error_callback );
+ gluTessCallback( tobj, GLU_TESS_COMBINE, (callback_t) combine_callback );
glNewList( list_start, GL_COMPILE );
gluBeginPolygon( tobj );
- for ( j = 0 ; j <= contour_cnt ; j++ )
- {
+ for ( j = 0 ; j <= contour_cnt ; j++ ) {
point_cnt = contours[j].point_cnt;
gluNextContour( tobj, GLU_UNKNOWN );
- for ( i = 0 ; i < point_cnt ; i++ )
- {
+ for ( i = 0 ; i < point_cnt ; i++ ) {
data[0] = (GLdouble)( contours[j].p[i][0] );
data[1] = (GLdouble)( contours[j].p[i][1] );
data[2] = 0.0;
gluEndPolygon( tobj );
glEndList();
- gluTessCallback( tobj, GLU_TESS_BEGIN, begin_callback );
- gluTessCallback( tobj, GLU_TESS_VERTEX, vertex_callback );
- gluTessCallback( tobj, GLU_TESS_END, end_callback );
- gluTessCallback( tobj, GLU_TESS_EDGE_FLAG, edge_callback );
+ gluTessCallback( tobj, GLU_TESS_BEGIN, (callback_t) begin_callback );
+ gluTessCallback( tobj, GLU_TESS_VERTEX, (callback_t) vertex_callback );
+ gluTessCallback( tobj, GLU_TESS_END, (callback_t) end_callback );
+ gluTessCallback( tobj, GLU_TESS_EDGE_FLAG, (callback_t) edge_callback );
glNewList( list_start + 1, GL_COMPILE );
gluBeginPolygon( tobj );
- for ( j = 0 ; j <= contour_cnt ; j++ )
- {
+ for ( j = 0 ; j <= contour_cnt ; j++ ) {
point_cnt = contours[j].point_cnt;
gluNextContour( tobj, GLU_UNKNOWN );
- for ( i = 0 ; i < point_cnt ; i++ )
- {
+ for ( i = 0 ; i < point_cnt ; i++ ) {
data[0] = (GLdouble)( contours[j].p[i][0] );
data[1] = (GLdouble)( contours[j].p[i][1] );
data[2] = 0.0;
}
}
-void left_down( int x1, int y1 )
+static void left_down( int x1, int y1 )
{
GLfloat P[2];
GLuint point_cnt;
glBegin( GL_LINES );
- if ( point_cnt )
- {
+ if ( point_cnt ) {
glVertex2fv( contours[contour_cnt].p[point_cnt-1] );
glVertex2fv( P );
- }
- else
- {
+ } else {
glVertex2fv( P );
glVertex2fv( P );
}
contours[contour_cnt].point_cnt++;
}
-void middle_down( int x1, int y1 )
+static void middle_down( int x1, int y1 )
{
GLuint point_cnt;
(void) x1;
point_cnt = contours[contour_cnt].point_cnt;
- if ( point_cnt > 2 )
- {
+ if ( point_cnt > 2 ) {
glBegin( GL_LINES );
glVertex2fv( contours[contour_cnt].p[0] );
}
}
-void mouse_clicked( int button, int state, int x, int y )
+static void mouse_clicked( int button, int state, int x, int y )
{
x -= x%10;
y -= y%10;
- switch ( button )
- {
+ switch ( button ) {
case GLUT_LEFT_BUTTON:
if ( state == GLUT_DOWN ) {
left_down( x, y );
}
}
-void display( void )
+static void display( void )
{
GLuint i,j;
+ GLsizei ii, jj;
GLuint point_cnt;
glClear( GL_COLOR_BUFFER_BIT );
- switch ( mode )
- {
+ switch ( mode ) {
case DEFINE:
/* draw grid */
glColor3f( 0.6, 0.5, 0.5 );
glBegin( GL_LINES );
- for ( i = 0 ; i < width ; i += 10 )
- {
- for ( j = 0 ; j < height ; j += 10 )
- {
- glVertex2i( 0, j );
- glVertex2i( width, j );
- glVertex2i( i, height );
- glVertex2i( i, 0 );
+ for ( ii = 0 ; ii < width ; ii += 10 ) {
+ for ( jj = 0 ; jj < height ; jj += 10 ) {
+ glVertex2i( 0, jj );
+ glVertex2i( width, jj );
+ glVertex2i( ii, height );
+ glVertex2i( ii, 0 );
}
}
+ glEnd();
+
glColor3f( 1.0, 1.0, 0.0 );
- for ( i = 0 ; i <= contour_cnt ; i++ )
- {
+ for ( i = 0 ; i <= contour_cnt ; i++ ) {
point_cnt = contours[i].point_cnt;
glBegin( GL_LINES );
- switch ( point_cnt )
- {
+ switch ( point_cnt ) {
case 0:
break;
case 1:
break;
default:
--point_cnt;
- for ( j = 0 ; j < point_cnt ; j++ )
- {
+ for ( j = 0 ; j < point_cnt ; j++ ) {
glVertex2fv( contours[i].p[j] );
glVertex2fv( contours[i].p[j+1] );
}
- if ( contours[i].p[j+1][0] == -1 )
- {
+ if ( contours[i].p[j+1][0] == -1 ) {
glVertex2fv( contours[i].p[0] );
glVertex2fv( contours[i].p[j] );
}
glColor3f( 1.0, 1.0, 0.0 );
}
-void clear( void )
+static void clear( void )
{
contour_cnt = 0;
contours[0].point_cnt = 0;
list_start = 0;
}
-void quit( void )
+static void quit( void )
{
exit( 0 );
}
-void menu_selected( int entry )
+static void menu_selected( int entry )
{
- switch ( entry )
- {
+ switch ( entry ) {
case CLEAR:
clear();
break;
glutPostRedisplay();
}
-void key_pressed( unsigned char key, int x, int y )
+static void key_pressed( unsigned char key, int x, int y )
{
(void) x;
(void) y;
- switch ( key )
- {
+ switch ( key ) {
case 'c':
case 'C':
clear();
case 'T':
tesse();
break;
+ case 27:
case 'q':
case 'Q':
quit();
glutPostRedisplay();
}
-void myinit( void )
+static void myinit( void )
{
/* clear background to gray */
glClearColor( 0.4, 0.4, 0.4, 0.0 );
set_screen_wh( w, h );
}
+#endif
+
static void usage( void )
{
}
-/*
- * Main Loop
- * Open window with initial window size, title bar,
- * RGBA display mode, and handle input events.
- */
int main( int argc, char **argv )
{
- usage();
+ const char *version = (const char *) gluGetString( GLU_VERSION );
+ printf( "GLU version string: %s\n", version );
+ if ( strstr( version, "1.0" ) || strstr( version, "1.1" ) ) {
+ fprintf( stderr, "Sorry, this demo reqiures GLU 1.2 or later.\n" );
+ exit( 1 );
+ }
- glutInit( &argc, argv );
- glutInitDisplayMode( GLUT_SINGLE | GLUT_RGB );
- glutInitWindowSize( 400, 400 );
- glutCreateWindow( argv[0] );
+ usage();
- myinit();
+ glutInit( &argc, argv );
+ glutInitDisplayMode( GLUT_SINGLE | GLUT_RGB );
+ glutInitWindowSize( 400, 400 );
+ glutCreateWindow( argv[0] );
- glutDisplayFunc( display );
- glutReshapeFunc( reshape );
+ /* GH: Bit of a hack...
+ */
+#ifdef GLU_VERSION_1_2
+ myinit();
- glutMainLoop();
+ glutDisplayFunc( display );
+ glutReshapeFunc( reshape );
+
+ glutMainLoop();
+#endif
- return 0;
+ return 0;
}