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-rw-r--r--progs/demos/tessdemo.c592
1 files changed, 343 insertions, 249 deletions
diff --git a/progs/demos/tessdemo.c b/progs/demos/tessdemo.c
index 2e02b9027e..3648ebd084 100644
--- a/progs/demos/tessdemo.c
+++ b/progs/demos/tessdemo.c
@@ -1,331 +1,410 @@
-/* $Id: tessdemo.c,v 1.8 2000/07/11 14:11:58 brianp Exp $ */
+/* $Id: tessdemo.c,v 1.9 2001/03/21 02:43:14 gareth Exp $ */
/*
* A demo of the GLU polygon tesselation functions written by Bogdan Sikorski.
+ * Updated for GLU 1.3 tessellation by Gareth Hughes <gareth@valinux.com>
*/
-
#include <GL/glut.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
-#define MAX_POINTS 200
-#define MAX_CONTOURS 50
+#define MAX_POINTS 256
+#define MAX_CONTOURS 32
+#define MAX_TRIANGLES 256
-static int menu;
-typedef enum
-{ QUIT, TESSELATE, CLEAR }
-menu_entries;
+#ifndef GLCALLBACK
+#ifdef CALLBACK
+#define GLCALLBACK CALLBACK
+#else
+#define GLCALLBACK
+#endif
+#endif
-typedef enum
-{ DEFINE, TESSELATED }
-mode_type;
+#ifdef GLU_VERSION_1_2
-struct
-{
- GLint p[MAX_POINTS][2];
- GLuint point_cnt;
-}
-contours[MAX_CONTOURS];
+typedef enum{ QUIT, TESSELATE, CLEAR } menu_entries;
+typedef enum{ DEFINE, TESSELATED } mode_type;
-static GLuint contour_cnt;
-static GLsizei width, height;
-static mode_type mode;
+static GLsizei width, height;
+static GLuint contour_cnt;
+static GLuint triangle_cnt;
-struct
-{
- GLsizei no;
- GLfloat color[3];
- GLint p[3][2];
- GLclampf p_color[3][3];
-}
-triangle;
+static mode_type mode;
+static int menu;
+static GLuint list_start;
-static void GLCALLBACK
-my_error(GLenum err)
-{
- int len, i;
- char const *str;
-
- glColor3f(0.9, 0.9, 0.9);
- glRasterPos2i(5, 5);
- str = (const char *) gluErrorString(err);
- len = strlen(str);
- for (i = 0; i < len; i++)
- glutBitmapCharacter(GLUT_BITMAP_9_BY_15, str[i]);
-}
+static GLfloat edge_color[3];
+static struct {
+ GLfloat p[MAX_POINTS][2];
+ GLuint point_cnt;
+} contours[MAX_CONTOURS];
-static void GLCALLBACK
-begin_callback(GLenum mode)
+static struct {
+ GLsizei no;
+ GLfloat p[3][2];
+ GLclampf color[3][3];
+} triangles[MAX_TRIANGLES];
+
+
+
+static void GLCALLBACK error_callback( GLenum err )
{
- triangle.no = 0;
+ int len, i;
+ char const *str;
+
+ glColor3f( 0.9, 0.9, 0.9 );
+ glRasterPos2i( 5, 5 );
+
+ str = (const char *) gluErrorString( err );
+ len = strlen( str );
+
+ for ( i = 0 ; i < len ; i++ ) {
+ glutBitmapCharacter( GLUT_BITMAP_9_BY_15, str[i] );
+ }
}
+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;
+}
-static void GLCALLBACK
-edge_callback(GLenum flag)
+static void GLCALLBACK edge_callback( GLenum flag )
{
- if (flag == GL_TRUE) {
- triangle.color[0] = 1.0;
- triangle.color[1] = 1.0;
- triangle.color[2] = 0.5;
- }
- else {
- triangle.color[0] = 1.0;
- triangle.color[1] = 0.0;
- triangle.color[2] = 0.0;
+ /* Persist the edge flag across triangles. */
+ if ( flag == GL_TRUE ) {
+ edge_color[0] = 1.0;
+ edge_color[1] = 1.0;
+ edge_color[2] = 0.5;
+ } else {
+ edge_color[0] = 1.0;
+ edge_color[1] = 0.0;
+ edge_color[2] = 0.0;
}
}
-
-static void GLCALLBACK
-end_callback()
+static void GLCALLBACK end_callback()
{
- glBegin(GL_LINES);
- glColor3f(triangle.p_color[0][0], triangle.p_color[0][1],
- triangle.p_color[0][2]);
- glVertex2i(triangle.p[0][0], triangle.p[0][1]);
- glVertex2i(triangle.p[1][0], triangle.p[1][1]);
- glColor3f(triangle.p_color[1][0], triangle.p_color[1][1],
- triangle.p_color[1][2]);
- glVertex2i(triangle.p[1][0], triangle.p[1][1]);
- glVertex2i(triangle.p[2][0], triangle.p[2][1]);
- glColor3f(triangle.p_color[2][0], triangle.p_color[2][1],
- triangle.p_color[2][2]);
- glVertex2i(triangle.p[2][0], triangle.p[2][1]);
- glVertex2i(triangle.p[0][0], triangle.p[0][1]);
+ GLint 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++ ) {
+ glColor3f( triangles[i].color[0][0],
+ triangles[i].color[0][1],
+ triangles[i].color[0][2] );
+
+ glVertex2f( triangles[i].p[0][0], triangles[i].p[0][1] );
+ glVertex2f( triangles[i].p[1][0], triangles[i].p[1][1] );
+
+ glColor3f( triangles[i].color[1][0],
+ triangles[i].color[1][1],
+ triangles[i].color[1][2] );
+
+ glVertex2f( triangles[i].p[1][0], triangles[i].p[1][1] );
+ glVertex2f( triangles[i].p[2][0], triangles[i].p[2][1] );
+
+ glColor3f( triangles[i].color[2][0],
+ triangles[i].color[2][1],
+ triangles[i].color[2][2] );
+
+ glVertex2f( triangles[i].p[2][0], triangles[i].p[2][1] );
+ glVertex2f( triangles[i].p[0][0], triangles[i].p[0][1] );
+ }
+
glEnd();
}
+static void GLCALLBACK vertex_callback( void *data )
+{
+ GLsizei no;
+ GLfloat *p;
+
+ p = (GLfloat *) data;
+ no = triangles[triangle_cnt].no;
+
+ triangles[triangle_cnt].p[no][0] = p[0];
+ triangles[triangle_cnt].p[no][1] = p[1];
+
+ triangles[triangle_cnt].color[no][0] = edge_color[0];
+ triangles[triangle_cnt].color[no][1] = edge_color[1];
+ triangles[triangle_cnt].color[no][2] = edge_color[2];
-static void GLCALLBACK
-vertex_callback(void *data)
+ /* After every three vertices, initialize the next triangle. */
+ if ( ++(triangles[triangle_cnt].no) == 3 ) {
+ triangle_cnt++;
+ triangles[triangle_cnt].no = 0;
+ }
+}
+
+static void GLCALLBACK combine_callback( GLdouble coords[3],
+ GLdouble *vertex_data[4],
+ GLfloat weight[4], void **data )
{
- GLsizei no;
- GLint *p;
-
- p = (GLint *) data;
- no = triangle.no;
- triangle.p[no][0] = p[0];
- triangle.p[no][1] = p[1];
- triangle.p_color[no][0] = triangle.color[0];
- triangle.p_color[no][1] = triangle.color[1];
- triangle.p_color[no][2] = triangle.color[2];
- ++(triangle.no);
+ GLfloat *vertex;
+
+ vertex = (GLfloat *) malloc( 2 * sizeof(GLfloat) );
+
+ vertex[0] = (GLfloat) coords[0];
+ vertex[1] = (GLfloat) coords[1];
+
+ *data = vertex;
}
-static void
-set_screen_wh(GLsizei w, GLsizei h)
+static void set_screen_wh( GLsizei w, GLsizei h )
{
width = w;
height = h;
}
-
-static void
-tesse(void)
+static void tesse( void )
{
- GLUtriangulatorObj *tobj;
- GLdouble data[3];
- GLuint i, j, point_cnt;
+ GLUtesselator *tobj;
+ GLdouble data[3];
+ GLuint i, j, point_cnt;
+
+ list_start = glGenLists( 2 );
tobj = gluNewTess();
- if (tobj != NULL) {
- glClear(GL_COLOR_BUFFER_BIT);
- glColor3f(0.7, 0.7, 0.0);
- gluTessCallback(tobj, GLU_BEGIN, glBegin);
- gluTessCallback(tobj, GLU_END, glEnd);
- gluTessCallback(tobj, GLU_ERROR, my_error);
- gluTessCallback(tobj, GLU_VERTEX, glVertex2iv);
- gluBeginPolygon(tobj);
- for (j = 0; j <= contour_cnt; j++) {
+
+ 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 );
+
+ glNewList( list_start, GL_COMPILE );
+ gluBeginPolygon( tobj );
+
+ for ( j = 0 ; j <= contour_cnt ; j++ ) {
point_cnt = contours[j].point_cnt;
- gluNextContour(tobj, GLU_UNKNOWN);
- for (i = 0; i < point_cnt; i++) {
- data[0] = (GLdouble) (contours[j].p[i][0]);
- data[1] = (GLdouble) (contours[j].p[i][1]);
+ gluNextContour( tobj, GLU_UNKNOWN );
+
+ 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;
- gluTessVertex(tobj, data, contours[j].p[i]);
+ gluTessVertex( tobj, data, contours[j].p[i] );
}
}
- gluEndPolygon(tobj);
- glLineWidth(2.0);
- gluTessCallback(tobj, GLU_BEGIN, begin_callback);
- gluTessCallback(tobj, GLU_END, end_callback);
- gluTessCallback(tobj, GLU_VERTEX, vertex_callback);
- gluTessCallback(tobj, GLU_EDGE_FLAG, edge_callback);
- gluBeginPolygon(tobj);
- for (j = 0; j <= contour_cnt; j++) {
+
+ 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 );
+
+ glNewList( list_start + 1, GL_COMPILE );
+ gluBeginPolygon( tobj );
+
+ for ( j = 0 ; j <= contour_cnt ; j++ ) {
point_cnt = contours[j].point_cnt;
- gluNextContour(tobj, GLU_UNKNOWN);
- for (i = 0; i < point_cnt; i++) {
- data[0] = (GLdouble) (contours[j].p[i][0]);
- data[1] = (GLdouble) (contours[j].p[i][1]);
+ gluNextContour( tobj, GLU_UNKNOWN );
+
+ 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;
- gluTessVertex(tobj, data, contours[j].p[i]);
+ gluTessVertex( tobj, data, contours[j].p[i] );
}
}
- gluEndPolygon(tobj);
- gluDeleteTess(tobj);
- glutMouseFunc(NULL);
- glColor3f(1.0, 1.0, 0.0);
- glLineWidth(1.0);
+
+ gluEndPolygon( tobj );
+ glEndList();
+
+ gluDeleteTess( tobj );
+
+ glutMouseFunc( NULL );
mode = TESSELATED;
}
}
-
-static void
-left_down(int x1, int y1)
+static void left_down( int x1, int y1 )
{
- GLint P[2];
- GLuint point_cnt;
+ GLfloat P[2];
+ GLuint point_cnt;
/* translate GLUT into GL coordinates */
+
P[0] = x1;
P[1] = height - y1;
+
point_cnt = contours[contour_cnt].point_cnt;
+
contours[contour_cnt].p[point_cnt][0] = P[0];
contours[contour_cnt].p[point_cnt][1] = P[1];
- glBegin(GL_LINES);
- if (point_cnt) {
- glVertex2iv(contours[contour_cnt].p[point_cnt - 1]);
- glVertex2iv(P);
- }
- else {
- glVertex2iv(P);
- glVertex2iv(P);
+
+ glBegin( GL_LINES );
+
+ if ( point_cnt ) {
+ glVertex2fv( contours[contour_cnt].p[point_cnt-1] );
+ glVertex2fv( P );
+ } else {
+ glVertex2fv( P );
+ glVertex2fv( P );
}
+
glEnd();
glFinish();
- ++(contours[contour_cnt].point_cnt);
-}
+ contours[contour_cnt].point_cnt++;
+}
-static void
-middle_down(int x1, int y1)
+static void middle_down( int x1, int y1 )
{
- GLuint point_cnt;
+ GLuint point_cnt;
+ (void) x1;
+ (void) y1;
point_cnt = contours[contour_cnt].point_cnt;
- if (point_cnt > 2) {
- glBegin(GL_LINES);
- glVertex2iv(contours[contour_cnt].p[0]);
- glVertex2iv(contours[contour_cnt].p[point_cnt - 1]);
+
+ if ( point_cnt > 2 ) {
+ glBegin( GL_LINES );
+
+ glVertex2fv( contours[contour_cnt].p[0] );
+ glVertex2fv( contours[contour_cnt].p[point_cnt-1] );
+
contours[contour_cnt].p[point_cnt][0] = -1;
+
glEnd();
glFinish();
+
contour_cnt++;
contours[contour_cnt].point_cnt = 0;
}
}
-
-static 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) {
+ x -= x%10;
+ y -= y%10;
+
+ switch ( button ) {
case GLUT_LEFT_BUTTON:
- if (state == GLUT_DOWN)
- left_down(x, y);
+ if ( state == GLUT_DOWN ) {
+ left_down( x, y );
+ }
break;
case GLUT_MIDDLE_BUTTON:
- if (state == GLUT_DOWN)
- middle_down(x, y);
+ if ( state == GLUT_DOWN ) {
+ middle_down( x, y );
+ }
break;
}
}
-
-static void
-display(void)
+static void display( void )
{
- GLuint i, j;
+ GLuint i,j;
GLuint point_cnt;
- glClear(GL_COLOR_BUFFER_BIT);
- switch (mode) {
+ glClear( GL_COLOR_BUFFER_BIT );
+
+ 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);
+ 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 );
}
+ }
+
glEnd();
- glColor3f(1.0, 1.0, 0.0);
- for (i = 0; i <= contour_cnt; i++) {
+
+ glColor3f( 1.0, 1.0, 0.0 );
+
+ for ( i = 0 ; i <= contour_cnt ; i++ ) {
point_cnt = contours[i].point_cnt;
- glBegin(GL_LINES);
- switch (point_cnt) {
+
+ glBegin( GL_LINES );
+
+ switch ( point_cnt ) {
case 0:
break;
case 1:
- glVertex2iv(contours[i].p[0]);
- glVertex2iv(contours[i].p[0]);
+ glVertex2fv( contours[i].p[0] );
+ glVertex2fv( contours[i].p[0] );
break;
case 2:
- glVertex2iv(contours[i].p[0]);
- glVertex2iv(contours[i].p[1]);
+ glVertex2fv( contours[i].p[0] );
+ glVertex2fv( contours[i].p[1] );
break;
default:
--point_cnt;
- for (j = 0; j < point_cnt; j++) {
- glVertex2iv(contours[i].p[j]);
- glVertex2iv(contours[i].p[j + 1]);
+ 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) {
- glVertex2iv(contours[i].p[0]);
- glVertex2iv(contours[i].p[j]);
+ if ( contours[i].p[j+1][0] == -1 ) {
+ glVertex2fv( contours[i].p[0] );
+ glVertex2fv( contours[i].p[j] );
}
break;
}
+
glEnd();
}
+
glFinish();
break;
+
case TESSELATED:
- /* draw lines */
- tesse();
+ /* draw triangles */
+ glColor3f( 0.7, 0.7, 0.0 );
+ glCallList( list_start );
+
+ glLineWidth( 2.0 );
+ glCallList( list_start + 1 );
+ glLineWidth( 1.0 );
+
+ glFlush();
break;
}
- glColor3f(1.0, 1.0, 0.0);
+ glColor3f( 1.0, 1.0, 0.0 );
}
-
-static void
-clear(void)
+static void clear( void )
{
contour_cnt = 0;
contours[0].point_cnt = 0;
- glutMouseFunc(mouse_clicked);
+ triangle_cnt = 0;
+
+ glutMouseFunc( mouse_clicked );
+
mode = DEFINE;
- display();
-}
+ glDeleteLists( list_start, 2 );
+ list_start = 0;
+}
-static void
-quit(void)
+static void quit( void )
{
- exit(0);
+ exit( 0 );
}
-
-static void
-menu_selected(int entry)
+static void menu_selected( int entry )
{
- switch (entry) {
+ switch ( entry ) {
case CLEAR:
clear();
break;
@@ -336,87 +415,102 @@ menu_selected(int entry)
quit();
break;
}
-}
+ glutPostRedisplay();
+}
-static void
-key_pressed(unsigned char key, int x, int y)
+static void key_pressed( unsigned char key, int x, int y )
{
- switch (key) {
+ (void) x;
+ (void) y;
+
+ switch ( key ) {
+ case 'c':
+ case 'C':
+ clear();
+ break;
case 't':
case 'T':
tesse();
- glFinish();
break;
case 'q':
case 'Q':
quit();
break;
- case 'c':
- case 'C':
- clear();
- break;
}
-}
+ glutPostRedisplay();
+}
-static void
-myinit(void)
+static void myinit( void )
{
-/* clear background to gray */
- glClearColor(0.4, 0.4, 0.4, 0.0);
- glShadeModel(GL_FLAT);
-
- menu = glutCreateMenu(menu_selected);
- glutAddMenuEntry("clear", CLEAR);
- glutAddMenuEntry("tesselate", TESSELATE);
- glutAddMenuEntry("quit", QUIT);
- glutAttachMenu(GLUT_RIGHT_BUTTON);
- glutMouseFunc(mouse_clicked);
- glutKeyboardFunc(key_pressed);
+ /* clear background to gray */
+ glClearColor( 0.4, 0.4, 0.4, 0.0 );
+ glShadeModel( GL_FLAT );
+ glPolygonMode( GL_FRONT, GL_FILL );
+
+ menu = glutCreateMenu( menu_selected );
+
+ glutAddMenuEntry( "clear", CLEAR );
+ glutAddMenuEntry( "tesselate", TESSELATE );
+ glutAddMenuEntry( "quit", QUIT );
+
+ glutAttachMenu( GLUT_RIGHT_BUTTON );
+
+ glutMouseFunc( mouse_clicked );
+ glutKeyboardFunc( key_pressed );
+
contour_cnt = 0;
- glPolygonMode(GL_FRONT, GL_FILL);
mode = DEFINE;
}
-
-static void
-reshape(GLsizei w, GLsizei h)
+static void reshape( GLsizei w, GLsizei h )
{
- glViewport(0, 0, w, h);
- glMatrixMode(GL_PROJECTION);
+ glViewport( 0, 0, w, h );
+
+ glMatrixMode( GL_PROJECTION );
glLoadIdentity();
- glOrtho(0.0, (GLdouble) w, 0.0, (GLdouble) h, -1.0, 1.0);
- glMatrixMode(GL_MODELVIEW);
+ glOrtho( 0.0, (GLdouble)w, 0.0, (GLdouble)h, -1.0, 1.0 );
+
+ glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
- set_screen_wh(w, h);
+
+ set_screen_wh( w, h );
}
-static void
-usage(void)
+static void usage( void )
{
- printf("Use left mouse button to place vertices.\n");
- printf("Press middle mouse button when done.\n");
- printf("Select tesselate from the pop-up menu.\n");
+ printf( "Use left mouse button to place vertices.\n" );
+ printf( "Press middle mouse button when done.\n" );
+ printf( "Select tesselate from the pop-up menu.\n" );
}
+#endif
-/* Main Loop
- * Open window with initial window size, title bar,
- * RGBA display mode, and handle input events.
- */
-int
-main(int argc, char **argv)
+
+int main( int argc, char **argv )
{
+ 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 );
+ }
+
usage();
- glutInit(&argc, argv);
- glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
- glutInitWindowSize(400, 400);
- glutCreateWindow(argv[0]);
+
+ glutInit( &argc, argv );
+ glutInitDisplayMode( GLUT_SINGLE | GLUT_RGB );
+ glutInitWindowSize( 400, 400 );
+ glutCreateWindow( argv[0] );
+
myinit();
- glutDisplayFunc(display);
- glutReshapeFunc(reshape);
+
+ glutDisplayFunc( display );
+ glutReshapeFunc( reshape );
+
glutMainLoop();
+
return 0;
}
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