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Diffstat (limited to 'progs/trivial/tri-z.c')
| -rw-r--r-- | progs/trivial/tri-z.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/progs/trivial/tri-z.c b/progs/trivial/tri-z.c new file mode 100644 index 0000000000..014aaa071a --- /dev/null +++ b/progs/trivial/tri-z.c @@ -0,0 +1,204 @@ +/* + * 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 + * Unpublished-- rights reserved under the copyright laws of the + * United States.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. + */ + +#include <GL/glut.h> +#include <stdlib.h> +#include <stdio.h> + +static int leftFirst = GL_TRUE; + +static struct { GLenum func; const char *str; } funcs[] = + { + { GL_LESS, "GL_LESS" }, + { GL_LEQUAL, "GL_LEQUAL" }, + { GL_GREATER, "GL_GREATER" }, + { GL_GEQUAL, "GL_GEQUAL" }, + { GL_EQUAL, "GL_EQUAL" }, + { GL_NOTEQUAL, "GL_NOTEQUAL" }, + { GL_ALWAYS, "GL_ALWAYS" }, + { GL_NEVER, "GL_NEVER" }, + }; + +#define NUM_FUNCS (sizeof(funcs) / sizeof(funcs[0])) + +static int curFunc = 0; +static double clearVal = 1.0; +static float minZ = 0.0; +static float maxZ = 1.0; + +static void usage(void) +{ + printf("t - toggle rendering order of triangles\n"); + printf("c - toggle Z clear value between 0, 1\n"); + printf("f - cycle through depth test functions\n"); + printf("n/N - decrease/increase depthrange minZ\n"); + printf("x/X - decrease/increase depthrange maxZ\n"); + printf("spc - reset\n"); + printf("z - set to reverse-direction (ztrick) mode\n"); + fflush(stdout); +} + + +static void init(void) +{ + glEnable(GL_DEPTH_TEST); + glClearColor (1.0, 0.0, 0.0, 0.0); +} + +static void drawLeftTriangle(void) +{ + /* draw yellow triangle on LHS of screen */ + glBegin (GL_TRIANGLES); + glColor4f(1.0, 1.0, 0.0, 0.75); + glVertex3f(0.1, 0.9, -1.0); + glVertex3f(0.1, 0.1, -1.0); + glVertex3f(0.8, 0.5, 1.0); + glEnd(); +} + +static void drawRightTriangle(void) +{ + /* draw cyan triangle on RHS of screen */ + glBegin (GL_TRIANGLES); + glColor4f(0.0, 1.0, 1.0, 0.75); + glVertex3f(0.9, 0.9, 0.0); + glVertex3f(0.2, 0.5, 0.0); + glVertex3f(0.9, 0.1, 0.0); + glEnd(); +} + +void display(void) +{ + printf("GL_CLEAR_DEPTH = %.2f, GL_DEPTH_FUNC = %s, DepthRange(%.1f, %.1f)\n", + clearVal, funcs[curFunc].str, minZ, maxZ); + fflush(stdout); + glClearDepth(clearVal); + glDepthRange(minZ, maxZ); + glDepthFunc(funcs[curFunc].func); + + glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); + + if (leftFirst) { + drawLeftTriangle(); + drawRightTriangle(); + } + else { + drawRightTriangle(); + drawLeftTriangle(); + } + + glFlush(); +} + +void reshape(int w, int h) +{ + glViewport(0, 0, (GLsizei) w, (GLsizei) h); + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + if (w <= h) + gluOrtho2D (0.0, 1.0, 0.0, 1.0*(GLfloat)h/(GLfloat)w); + else + gluOrtho2D (0.0, 1.0*(GLfloat)w/(GLfloat)h, 0.0, 1.0); +} + +/* ARGSUSED1 */ +void keyboard(unsigned char key, int x, int y) +{ + switch (key) { + case 'n': + minZ -= .1; + break; + case 'N': + minZ += .1; + break; + case 'x': + maxZ -= .1; + break; + case 'X': + maxZ += .1; + break; + case 'c': + case 'C': + clearVal = 1.0 - clearVal; + break; + case 'f': + case 'F': + curFunc = (curFunc + 1) % NUM_FUNCS; + break; + case 't': + case 'T': + leftFirst = !leftFirst; + break; + case ' ': + curFunc = 0; + clearVal = 1.0; + minZ = 0.0; + maxZ = 1.0; + break; + case 'z': + curFunc = 2; + clearVal = 0.0; + minZ = 1.0; + maxZ = 0.0; + break; + case 27: /* Escape key */ + exit(0); + break; + default: + return; + } + glutPostRedisplay(); +} + +/* Main Loop + * Open window with initial window size, title bar, + * RGBA display mode, and handle input events. + */ +int main(int argc, char** argv) +{ + glutInit(&argc, argv); + glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH); + glutInitWindowSize (200, 200); + glutCreateWindow (argv[0]); + glutReshapeFunc (reshape); + glutKeyboardFunc (keyboard); + glutDisplayFunc (display); + init(); + usage(); + glutMainLoop(); + return 0; +} |