+++ /dev/null
-/*
- * Copyright (c) 1993-1997, Silicon Graphics, Inc.
- * ALL RIGHTS RESERVED
- * Permission to use, copy, modify, and distribute this software for
- * any purpose and without fee is hereby granted, provided that the above
- * copyright notice appear in all copies and that both the copyright notice
- * and this permission notice appear in supporting documentation, and that
- * the name of Silicon Graphics, Inc. not be used in advertising
- * or publicity pertaining to distribution of the software without specific,
- * written prior permission.
- *
- * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
- * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
- * FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
- * GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
- * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
- * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
- * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
- * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN
- * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
- * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
- * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
- *
- * US Government Users Restricted Rights
- * Use, duplication, or disclosure by the Government is subject to
- * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
- * (c)(1)(ii) of the Rights in Technical Data and Computer Software
- * clause at DFARS 252.227-7013 and/or in similar or successor
- * clauses in the FAR or the DOD or NASA FAR Supplement.
- * Unpublished-- rights reserved under the copyright laws of the
- * United States. Contractor/manufacturer is Silicon Graphics,
- * Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311.
- *
- * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
- */
-
-/*
- * select.c
- * This is an illustration of the selection mode and
- * name stack, which detects whether objects which collide
- * with a viewing volume. First, four triangles and a
- * rectangular box representing a viewing volume are drawn
- * (drawScene routine). The green triangle and yellow
- * triangles appear to lie within the viewing volume, but
- * the red triangle appears to lie outside it. Then the
- * selection mode is entered (selectObjects routine).
- * Drawing to the screen ceases. To see if any collisions
- * occur, the four triangles are called. In this example,
- * the green triangle causes one hit with the name 1, and
- * the yellow triangles cause one hit with the name 3.
- */
-#include <GL/glut.h>
-#include <stdlib.h>
-#include <stdio.h>
-
-/* draw a triangle with vertices at (x1, y1), (x2, y2)
- * and (x3, y3) at z units away from the origin.
- */
-static void drawTriangle (GLfloat x1, GLfloat y1, GLfloat x2,
- GLfloat y2, GLfloat x3, GLfloat y3, GLfloat z)
-{
- glBegin (GL_TRIANGLES);
- glVertex3f (x1, y1, z);
- glVertex3f (x2, y2, z);
- glVertex3f (x3, y3, z);
- glEnd ();
-}
-
-/* draw a rectangular box with these outer x, y, and z values */
-static void drawViewVolume (GLfloat x1, GLfloat x2, GLfloat y1,
- GLfloat y2, GLfloat z1, GLfloat z2)
-{
- glColor3f (1.0, 1.0, 1.0);
- glBegin (GL_LINE_LOOP);
- glVertex3f (x1, y1, -z1);
- glVertex3f (x2, y1, -z1);
- glVertex3f (x2, y2, -z1);
- glVertex3f (x1, y2, -z1);
- glEnd ();
-
- glBegin (GL_LINE_LOOP);
- glVertex3f (x1, y1, -z2);
- glVertex3f (x2, y1, -z2);
- glVertex3f (x2, y2, -z2);
- glVertex3f (x1, y2, -z2);
- glEnd ();
-
- glBegin (GL_LINES); /* 4 lines */
- glVertex3f (x1, y1, -z1);
- glVertex3f (x1, y1, -z2);
- glVertex3f (x1, y2, -z1);
- glVertex3f (x1, y2, -z2);
- glVertex3f (x2, y1, -z1);
- glVertex3f (x2, y1, -z2);
- glVertex3f (x2, y2, -z1);
- glVertex3f (x2, y2, -z2);
- glEnd ();
-}
-
-/* drawScene draws 4 triangles and a wire frame
- * which represents the viewing volume.
- */
-static void drawScene (void)
-{
- glMatrixMode (GL_PROJECTION);
- glLoadIdentity ();
- gluPerspective (40.0, 4.0/3.0, 1.0, 100.0);
-
- glMatrixMode (GL_MODELVIEW);
- glLoadIdentity ();
- gluLookAt (7.5, 7.5, 12.5, 2.5, 2.5, -5.0, 0.0, 1.0, 0.0);
- glColor3f (0.0, 1.0, 0.0); /* green triangle */
- drawTriangle (2.0, 2.0, 3.0, 2.0, 2.5, 3.0, -5.0);
- glColor3f (1.0, 0.0, 0.0); /* red triangle */
- drawTriangle (2.0, 7.0, 3.0, 7.0, 2.5, 8.0, -5.0);
- glColor3f (1.0, 1.0, 0.0); /* yellow triangles */
- drawTriangle (2.0, 2.0, 3.0, 2.0, 2.5, 3.0, 0.0);
- drawTriangle (2.0, 2.0, 3.0, 2.0, 2.5, 3.0, -10.0);
- drawViewVolume (0.0, 5.0, 0.0, 5.0, 0.0, 10.0);
-}
-
-/* processHits prints out the contents of the selection array
- */
-static void processHits (GLint hits, GLuint buffer[])
-{
- GLint i;
- GLuint j, names, *ptr;
-
- printf ("hits = %d\n", hits);
- ptr = (GLuint *) buffer;
- for (i = 0; i < hits; i++) { /* for each hit */
- names = *ptr;
- printf (" number of names for hit = %d\n", names); ptr++;
- printf(" z1 is %g;", (float) *ptr/0x7fffffff); ptr++;
- printf(" z2 is %g\n", (float) *ptr/0x7fffffff); ptr++;
- printf (" the name is ");
- for (j = 0; j < names; j++) { /* for each name */
- printf ("%d ", *ptr); ptr++;
- }
- printf ("\n");
- }
-}
-
-/* selectObjects "draws" the triangles in selection mode,
- * assigning names for the triangles. Note that the third
- * and fourth triangles share one name, so that if either
- * or both triangles intersects the viewing/clipping volume,
- * only one hit will be registered.
- */
-#define BUFSIZE 512
-
-static void selectObjects(void)
-{
- GLuint selectBuf[BUFSIZE];
- GLint hits;
-
- glSelectBuffer (BUFSIZE, selectBuf);
- (void) glRenderMode (GL_SELECT);
-
- glInitNames();
- glPushName(0);
-
- glPushMatrix ();
- glMatrixMode (GL_PROJECTION);
- glLoadIdentity ();
- glOrtho (0.0, 5.0, 0.0, 5.0, 0.0, 10.0);
- glMatrixMode (GL_MODELVIEW);
- glLoadIdentity ();
- glLoadName(1);
- drawTriangle (2.0, 2.0, 3.0, 2.0, 2.5, 3.0, -5.0);
- glLoadName(2);
- drawTriangle (2.0, 7.0, 3.0, 7.0, 2.5, 8.0, -5.0);
- glLoadName(3);
- drawTriangle (2.0, 2.0, 3.0, 2.0, 2.5, 3.0, 0.0);
- drawTriangle (2.0, 2.0, 3.0, 2.0, 2.5, 3.0, -10.0);
- glPopMatrix ();
- glFlush ();
-
- hits = glRenderMode (GL_RENDER);
- processHits (hits, selectBuf);
-}
-
-static void init (void)
-{
- glEnable(GL_DEPTH_TEST);
- glShadeModel(GL_FLAT);
-}
-
-static void display(void)
-{
- glClearColor (0.0, 0.0, 0.0, 0.0);
- glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
- drawScene ();
- selectObjects ();
- glFlush();
-}
-
-/* ARGSUSED1 */
-static void keyboard(unsigned char key, int x, int y)
-{
- switch (key) {
- case 27:
- exit(0);
- break;
- }
-}
-
-/* Main Loop */
-int main(int argc, char** argv)
-{
- glutInit(&argc, argv);
- glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
- glutInitWindowSize (200, 200);
- glutInitWindowPosition (100, 100);
- glutCreateWindow (argv[0]);
- init();
- glutDisplayFunc(display);
- glutKeyboardFunc(keyboard);
- glutMainLoop();
- return 0;
-}
projects / mesa.git / blobdiff