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Diffstat (limited to 'progs/redbook/texgen.c')
-rw-r--r-- | progs/redbook/texgen.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/progs/redbook/texgen.c b/progs/redbook/texgen.c new file mode 100644 index 0000000000..7c1802a3be --- /dev/null +++ b/progs/redbook/texgen.c @@ -0,0 +1,207 @@ +/* + * 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 + * Unpublished-- rights reserved under the copyright laws of the + * United States.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. + */ + +/* texgen.c + * This program draws a texture mapped teapot with + * automatically generated texture coordinates. The + * texture is rendered as stripes on the teapot. + * Initially, the object is drawn with texture coordinates + * based upon the object coordinates of the vertex + * and distance from the plane x = 0. Pressing the 'e' + * key changes the coordinate generation to eye coordinates + * of the vertex. Pressing the 'o' key switches it back + * to the object coordinates. Pressing the 's' key + * changes the plane to a slanted one (x + y + z = 0). + * Pressing the 'x' key switches it back to x = 0. + */ + +#include <GL/glut.h> +#include <stdlib.h> +#include <stdio.h> + +#define stripeImageWidth 32 +GLubyte stripeImage[4*stripeImageWidth]; + +#ifdef GL_VERSION_1_1 +static GLuint texName; +#endif + +void makeStripeImage(void) +{ + int j; + + for (j = 0; j < stripeImageWidth; j++) { + stripeImage[4*j] = (GLubyte) ((j<=4) ? 255 : 0); + stripeImage[4*j+1] = (GLubyte) ((j>4) ? 255 : 0); + stripeImage[4*j+2] = (GLubyte) 0; + stripeImage[4*j+3] = (GLubyte) 255; + } +} + +/* planes for texture coordinate generation */ +static GLfloat xequalzero[] = {1.0, 0.0, 0.0, 0.0}; +static GLfloat slanted[] = {1.0, 1.0, 1.0, 0.0}; +static GLfloat *currentCoeff; +static GLenum currentPlane; +static GLint currentGenMode; + +void init(void) +{ + glClearColor (0.0, 0.0, 0.0, 0.0); + glEnable(GL_DEPTH_TEST); + glShadeModel(GL_SMOOTH); + + makeStripeImage(); + glPixelStorei(GL_UNPACK_ALIGNMENT, 1); + +#ifdef GL_VERSION_1_1 + glGenTextures(1, &texName); + glBindTexture(GL_TEXTURE_1D, texName); +#endif + glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_REPEAT); + glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); + glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); +#ifdef GL_VERSION_1_1 + glTexImage1D(GL_TEXTURE_1D, 0, GL_RGBA, stripeImageWidth, 0, + GL_RGBA, GL_UNSIGNED_BYTE, stripeImage); +#else + glTexImage1D(GL_TEXTURE_1D, 0, 4, stripeImageWidth, 0, + GL_RGBA, GL_UNSIGNED_BYTE, stripeImage); +#endif + + glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); + currentCoeff = xequalzero; + currentGenMode = GL_OBJECT_LINEAR; + currentPlane = GL_OBJECT_PLANE; + glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, currentGenMode); + glTexGenfv(GL_S, currentPlane, currentCoeff); + + glEnable(GL_TEXTURE_GEN_S); + glEnable(GL_TEXTURE_1D); + glEnable(GL_CULL_FACE); + glEnable(GL_LIGHTING); + glEnable(GL_LIGHT0); + glEnable(GL_AUTO_NORMAL); + glEnable(GL_NORMALIZE); + glFrontFace(GL_CW); + glCullFace(GL_BACK); + glMaterialf (GL_FRONT, GL_SHININESS, 64.0); +} + +void display(void) +{ + glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); + + glPushMatrix (); + glRotatef(45.0, 0.0, 0.0, 1.0); +#ifdef GL_VERSION_1_1 + glBindTexture(GL_TEXTURE_1D, texName); +#endif + glutSolidTeapot(2.0); + glPopMatrix (); + glFlush(); +} + +void reshape(int w, int h) +{ + glViewport(0, 0, (GLsizei) w, (GLsizei) h); + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + if (w <= h) + glOrtho (-3.5, 3.5, -3.5*(GLfloat)h/(GLfloat)w, + 3.5*(GLfloat)h/(GLfloat)w, -3.5, 3.5); + else + glOrtho (-3.5*(GLfloat)w/(GLfloat)h, + 3.5*(GLfloat)w/(GLfloat)h, -3.5, 3.5, -3.5, 3.5); + glMatrixMode(GL_MODELVIEW); + glLoadIdentity(); +} + +/* ARGSUSED1 */ +void keyboard (unsigned char key, int x, int y) +{ + switch (key) { + case 'e': + case 'E': + currentGenMode = GL_EYE_LINEAR; + currentPlane = GL_EYE_PLANE; + glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, currentGenMode); + glTexGenfv(GL_S, currentPlane, currentCoeff); + glutPostRedisplay(); + break; + case 'o': + case 'O': + currentGenMode = GL_OBJECT_LINEAR; + currentPlane = GL_OBJECT_PLANE; + glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, currentGenMode); + glTexGenfv(GL_S, currentPlane, currentCoeff); + glutPostRedisplay(); + break; + case 's': + case 'S': + currentCoeff = slanted; + glTexGenfv(GL_S, currentPlane, currentCoeff); + glutPostRedisplay(); + break; + case 'x': + case 'X': + currentCoeff = xequalzero; + glTexGenfv(GL_S, currentPlane, currentCoeff); + glutPostRedisplay(); + break; + case 27: + exit(0); + break; + default: + break; + } +} + +int main(int argc, char** argv) +{ + glutInit(&argc, argv); + glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH); + glutInitWindowSize(256, 256); + glutInitWindowPosition(100, 100); + glutCreateWindow (argv[0]); + init (); + glutDisplayFunc(display); + glutReshapeFunc(reshape); + glutKeyboardFunc(keyboard); + glutMainLoop(); + return 0; +} |