380 lines
13 KiB
C
380 lines
13 KiB
C
/*
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* Copyright (c) 1993-2003, Silicon Graphics, Inc.
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* All Rights Reserved
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose and without fee is hereby granted, provided that the above
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* copyright notice appear in all copies and that both the copyright
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* notice and this permission notice appear in supporting documentation,
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* and that the name of Silicon Graphics, Inc. not be used in
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* advertising or publicity pertaining to distribution of the software
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* without specific, written prior permission.
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*
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* THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS" AND
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* WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
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* INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
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* FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
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* GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
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* SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
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* OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION, LOSS OF
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* PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF THIRD
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* PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN ADVISED OF
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* THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE POSSESSION, USE
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* OR PERFORMANCE OF THIS SOFTWARE.
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*
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* US Government Users Restricted Rights
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* Use, duplication, or disclosure by the Government is subject to
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* restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
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* (c)(1)(ii) of the Rights in Technical Data and Computer Software
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* clause at DFARS 252.227-7013 and/or in similar or successor clauses
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* in the FAR or the DOD or NASA FAR Supplement. Unpublished - rights
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* reserved under the copyright laws of the United States.
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*
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* Contractor/manufacturer is:
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* Silicon Graphics, Inc.
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* 1500 Crittenden Lane
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* Mountain View, CA 94043
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* United State of America
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*
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* OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
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*/
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/* combiner.c
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* This program renders a variety of quads showing different
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* effects of texture combiner functions.
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*
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* The first row renders an untextured polygon (so you can
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* compare the fragment colors) and then the 2 textures.
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* The second row shows several different combiner functions
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* on a single texture: replace, modulate, add, add-signed,
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* and subtract.
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* The third row shows the interpolate combiner function
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* on a single texture with a constant color/alpha value,
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* varying the amount of interpolation.
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* The fourth row uses multitexturing with two textures
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* and different combiner functions.
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* The fifth row are some combiner experiments: using the
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* scaling factor and reversing the order of subtraction
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* for a combination function.
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*/
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#include <GL/glew.h>
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#include <GL/glut.h>
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#include <stdlib.h>
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#include <stdio.h>
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#define imageWidth 8
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#define imageHeight 8
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/* arrays for two textures */
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static GLubyte image0[imageHeight][imageWidth][4];
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static GLubyte image1[imageHeight][imageWidth][4];
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static GLuint texName[4];
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static void makeImages(void)
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{
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int i, j, c;
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for (i = 0; i < imageHeight; i++) {
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for (j = 0; j < imageWidth; j++) {
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c = ((i&2)==0)*255; /* horiz b & w stripes */
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image0[i][j][0] = (GLubyte) c;
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image0[i][j][1] = (GLubyte) c;
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image0[i][j][2] = (GLubyte) c;
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image0[i][j][3] = (GLubyte) 255;
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c = ((j&4)!=0)*128; /* wider vertical 50% cyan and black stripes */
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image1[i][j][0] = (GLubyte) 0;
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image1[i][j][1] = (GLubyte) c;
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image1[i][j][2] = (GLubyte) c;
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image1[i][j][3] = (GLubyte) 255;
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}
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}
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}
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static void init(void)
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{
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glClearColor (0.0, 0.0, 0.0, 0.0);
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glShadeModel(GL_SMOOTH);
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makeImages();
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glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
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glGenTextures(4, texName);
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glBindTexture(GL_TEXTURE_2D, texName[0]);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
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glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, imageWidth, imageHeight,
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0, GL_RGBA, GL_UNSIGNED_BYTE, image0);
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glBindTexture(GL_TEXTURE_2D, texName[1]);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
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glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, imageWidth, imageHeight,
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0, GL_RGBA, GL_UNSIGNED_BYTE, image1);
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/* smooth-shaded polygon with multiple texture coordinates */
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glNewList (1, GL_COMPILE);
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glBegin(GL_QUADS);
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glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 0.0, 0.0);
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glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0, 0.0);
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glColor3f (0.5, 1.0, 0.25);
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glVertex3f(0.0, 0.0, 0.0);
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glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 0.0, 2.0);
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glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0, 2.0);
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glColor3f (1.0, 1.0, 1.0);
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glVertex3f(0.0, 1.0, 0.0);
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glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 2.0, 2.0);
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glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 2.0, 2.0);
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glColor3f (1.0, 1.0, 1.0);
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glVertex3f(1.0, 1.0, 0.0);
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glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 2.0, 0.0);
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glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 2.0, 0.0);
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glColor3f (1.0, 0.5, 0.25);
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glVertex3f(1.0, 0.0, 0.0);
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glEnd();
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glEndList ();
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}
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static void display(void)
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{
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static GLfloat constColor[4] = {0.0, 0.0, 0.0, 0.0}; /* for use as constant texture color */
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glClear(GL_COLOR_BUFFER_BIT);
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glDisable(GL_TEXTURE_2D); /* untextured polygon--see the "fragment" colors */
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glPushMatrix();
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glTranslatef(0.0, 5.0, 0.0);
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glCallList(1);
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glPopMatrix();
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glEnable(GL_TEXTURE_2D);
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/* draw ordinary textured polys; 1 texture unit; combine mode disabled */
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glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
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glPushMatrix();
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glBindTexture(GL_TEXTURE_2D, texName[0]);
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glTranslatef(1.0, 5.0, 0.0);
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glCallList(1);
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glPopMatrix();
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glPushMatrix();
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glBindTexture(GL_TEXTURE_2D, texName[1]);
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glTranslatef(2.0, 5.0, 0.0);
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glCallList(1);
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glPopMatrix();
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/* different combine modes enabled; 1 texture unit
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* defaults are:
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* glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE);
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* glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);
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* glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB);
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* glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);
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*/
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glBindTexture(GL_TEXTURE_2D, texName[0]);
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glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB);
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_REPLACE);
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glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE);
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glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);
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glPushMatrix();
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glTranslatef(1.0, 4.0, 0.0);
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glCallList(1);
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glPopMatrix();
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_MODULATE);
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glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB);
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glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);
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glPushMatrix();
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glTranslatef(2.0, 4.0, 0.0);
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glCallList(1);
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glPopMatrix();
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_ADD);
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glPushMatrix();
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glTranslatef(3.0, 4.0, 0.0);
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glCallList(1);
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glPopMatrix();
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_ADD_SIGNED_ARB);
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glPushMatrix();
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glTranslatef(4.0, 4.0, 0.0);
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glCallList(1);
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glPopMatrix();
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_SUBTRACT_ARB);
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glPushMatrix();
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glTranslatef(5.0, 4.0, 0.0);
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glCallList(1);
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glPopMatrix();
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/* interpolate combine with constant color; 1 texture unit
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* use different alpha values for constant color
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* defaults are:
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* glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE);
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* glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);
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* glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB);
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* glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);
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* glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE2_RGB_ARB, GL_CONSTANT_ARB);
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* glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND2_RGB_ARB, GL_SRC_ALPHA);
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*/
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constColor[3] = 0.2;
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glTexEnvfv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, constColor);
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glBindTexture(GL_TEXTURE_2D, texName[0]);
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glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB);
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_INTERPOLATE_ARB);
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glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE);
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glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);
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glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB);
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glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);
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glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE2_RGB_ARB, GL_CONSTANT_ARB);
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glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND2_RGB_ARB, GL_SRC_ALPHA);
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glPushMatrix();
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glTranslatef(1.0, 3.0, 0.0);
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glCallList(1);
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glPopMatrix();
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constColor[3] = 0.4;
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glTexEnvfv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, constColor);
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glPushMatrix();
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glTranslatef(2.0, 3.0, 0.0);
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glCallList(1);
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glPopMatrix();
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constColor[3] = 0.6;
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glTexEnvfv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, constColor);
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glPushMatrix();
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glTranslatef(3.0, 3.0, 0.0);
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glCallList(1);
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glPopMatrix();
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constColor[3] = 0.8;
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glTexEnvfv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, constColor);
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glPushMatrix();
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glTranslatef(4.0, 3.0, 0.0);
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glCallList(1);
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glPopMatrix();
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/* combine textures 0 & 1
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* defaults are:
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* glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE);
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* glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);
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* glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB);
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* glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);
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*/
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glActiveTextureARB (GL_TEXTURE0_ARB);
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glEnable (GL_TEXTURE_2D);
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glBindTexture(GL_TEXTURE_2D, texName[0]);
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glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
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glActiveTextureARB (GL_TEXTURE1_ARB);
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glEnable (GL_TEXTURE_2D);
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glBindTexture(GL_TEXTURE_2D, texName[1]);
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glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB);
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_REPLACE);
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glPushMatrix();
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glTranslatef(1.0, 2.0, 0.0);
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glCallList(1);
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glPopMatrix();
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/* try different combiner modes of texture unit 1 */
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_MODULATE);
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glPushMatrix();
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glTranslatef(2.0, 2.0, 0.0);
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glCallList(1);
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glPopMatrix();
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_ADD);
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glPushMatrix();
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glTranslatef(3.0, 2.0, 0.0);
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glCallList(1);
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glPopMatrix();
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_ADD_SIGNED_ARB);
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glPushMatrix();
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glTranslatef(4.0, 2.0, 0.0);
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glCallList(1);
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glPopMatrix();
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_SUBTRACT_ARB);
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glPushMatrix();
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glTranslatef(5.0, 2.0, 0.0);
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glCallList(1);
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glPopMatrix();
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/* some experiments */
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/* see the effect of RGB_SCALE */
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glTexEnvf(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, 2.0);
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_REPLACE);
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glPushMatrix();
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glTranslatef(1.0, 1.0, 0.0);
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glCallList(1);
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glPopMatrix();
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_MODULATE);
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glPushMatrix();
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glTranslatef(2.0, 1.0, 0.0);
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glCallList(1);
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glPopMatrix();
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glTexEnvf(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, 1.0);
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/* using SOURCE0 and SOURCE1, reverse the order of subtraction Arg1-Arg0 */
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glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB);
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glTexEnvf(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_SUBTRACT_ARB);
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glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_PREVIOUS_ARB);
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glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB, GL_SRC_COLOR);
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glTexEnvf(GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_TEXTURE);
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glTexEnvf(GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB, GL_SRC_COLOR);
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glPushMatrix();
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glTranslatef(5.0, 1.0, 0.0);
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glCallList(1);
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glPopMatrix();
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glActiveTextureARB (GL_TEXTURE1_ARB); /* deactivate multitexturing */
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glDisable (GL_TEXTURE_2D);
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glActiveTextureARB (GL_TEXTURE0_ARB); /* activate single texture unit */
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glFlush();
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}
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static void reshape(int w, int h)
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{
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glViewport(0, 0, (GLsizei) w, (GLsizei) h);
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glMatrixMode(GL_PROJECTION);
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glLoadIdentity();
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gluOrtho2D(0.0, 7.0, 0.0, 7.0);
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glMatrixMode(GL_MODELVIEW);
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glLoadIdentity();
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}
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static void keyboard (unsigned char key, int x, int y)
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{
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switch (key) {
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case 27:
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exit(0);
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break;
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default:
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break;
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}
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}
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int main(int argc, char** argv)
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{
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glutInit(&argc, argv);
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glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
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glutInitWindowSize(400, 400);
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glutInitWindowPosition(100, 100);
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glutCreateWindow(argv[0]);
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glewInit();
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init();
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glutDisplayFunc(display);
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glutReshapeFunc(reshape);
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glutKeyboardFunc(keyboard);
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glutMainLoop();
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return 0;
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}
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