477 lines
12 KiB
C
477 lines
12 KiB
C
/*
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* GL_ARB_texture_cube_map demo
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*
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* Brian Paul
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* May 2000
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*
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*
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* Copyright (C) 2000 Brian Paul All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included
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* in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
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* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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/*
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* This is a pretty minimalistic demo for now. Eventually, use some
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* interesting cube map textures and 3D objects.
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* For now, we use 6 checkerboard "walls" and a sphere (good for
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* verification purposes).
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*/
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#include <assert.h>
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#include <math.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "GL/glut.h"
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#include "readtex.h"
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static GLfloat Xrot = 0, Yrot = 0;
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static GLfloat EyeDist = 10;
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static GLboolean use_vertex_arrays = GL_FALSE;
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static GLboolean anim = GL_TRUE;
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#define eps1 0.99
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#define br 20.0 /* box radius */
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static const GLfloat tex_coords[] = {
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/* +X side */
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1.0, -eps1, -eps1,
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1.0, -eps1, eps1,
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1.0, eps1, eps1,
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1.0, eps1, -eps1,
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/* -X side */
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-1.0, eps1, -eps1,
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-1.0, eps1, eps1,
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-1.0, -eps1, eps1,
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-1.0, -eps1, -eps1,
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/* +Y side */
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-eps1, 1.0, -eps1,
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-eps1, 1.0, eps1,
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eps1, 1.0, eps1,
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eps1, 1.0, -eps1,
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/* -Y side */
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-eps1, -1.0, -eps1,
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-eps1, -1.0, eps1,
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eps1, -1.0, eps1,
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eps1, -1.0, -eps1,
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/* +Z side */
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eps1, -eps1, 1.0,
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-eps1, -eps1, 1.0,
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-eps1, eps1, 1.0,
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eps1, eps1, 1.0,
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/* -Z side */
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eps1, eps1, -1.0,
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-eps1, eps1, -1.0,
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-eps1, -eps1, -1.0,
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eps1, -eps1, -1.0,
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};
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static const GLfloat vtx_coords[] = {
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/* +X side */
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br, -br, -br,
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br, -br, br,
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br, br, br,
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br, br, -br,
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/* -X side */
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-br, br, -br,
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-br, br, br,
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-br, -br, br,
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-br, -br, -br,
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/* +Y side */
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-br, br, -br,
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-br, br, br,
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br, br, br,
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br, br, -br,
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/* -Y side */
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-br, -br, -br,
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-br, -br, br,
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br, -br, br,
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br, -br, -br,
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/* +Z side */
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br, -br, br,
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-br, -br, br,
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-br, br, br,
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br, br, br,
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/* -Z side */
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br, br, -br,
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-br, br, -br,
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-br, -br, -br,
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br, -br, -br,
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};
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static void draw_skybox( void )
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{
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if ( use_vertex_arrays ) {
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glTexCoordPointer( 3, GL_FLOAT, 0, tex_coords );
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glVertexPointer( 3, GL_FLOAT, 0, vtx_coords );
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glEnableClientState( GL_TEXTURE_COORD_ARRAY );
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glEnableClientState( GL_VERTEX_ARRAY );
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glDrawArrays( GL_QUADS, 0, 24 );
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glDisableClientState( GL_TEXTURE_COORD_ARRAY );
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glDisableClientState( GL_VERTEX_ARRAY );
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}
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else {
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unsigned i;
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glBegin(GL_QUADS);
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for ( i = 0 ; i < 24 ; i++ ) {
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glTexCoord3fv( & tex_coords[ i * 3 ] );
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glVertex3fv ( & vtx_coords[ i * 3 ] );
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}
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glEnd();
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}
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}
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static void draw( void )
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{
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glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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glPushMatrix(); /*MODELVIEW*/
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glTranslatef( 0.0, 0.0, -EyeDist );
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/* skybox */
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glDisable(GL_TEXTURE_GEN_S);
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glDisable(GL_TEXTURE_GEN_T);
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glDisable(GL_TEXTURE_GEN_R);
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glMatrixMode(GL_MODELVIEW);
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glPushMatrix();
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glRotatef(Xrot, 1, 0, 0);
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glRotatef(Yrot, 0, 1, 0);
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draw_skybox();
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glPopMatrix();
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/* sphere */
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glMatrixMode(GL_TEXTURE);
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glLoadIdentity();
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glRotatef(-Yrot, 0, 1, 0);
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glRotatef(-Xrot, 1, 0, 0);
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glEnable(GL_TEXTURE_GEN_S);
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glEnable(GL_TEXTURE_GEN_T);
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glEnable(GL_TEXTURE_GEN_R);
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glutSolidSphere(2.0, 20, 20);
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glLoadIdentity(); /* texture */
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glMatrixMode(GL_MODELVIEW);
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glPopMatrix();
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glutSwapBuffers();
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}
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static void idle(void)
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{
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GLfloat t = 0.05 * glutGet(GLUT_ELAPSED_TIME);
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Yrot = t;
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glutPostRedisplay();
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}
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static void set_mode(GLuint mode)
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{
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if (mode == 0) {
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glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_REFLECTION_MAP_ARB);
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glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_REFLECTION_MAP_ARB);
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glTexGeni(GL_R, GL_TEXTURE_GEN_MODE, GL_REFLECTION_MAP_ARB);
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printf("GL_REFLECTION_MAP_ARB mode\n");
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}
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else if (mode == 1) {
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glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_NORMAL_MAP_ARB);
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glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_NORMAL_MAP_ARB);
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glTexGeni(GL_R, GL_TEXTURE_GEN_MODE, GL_NORMAL_MAP_ARB);
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printf("GL_NORMAL_MAP_ARB mode\n");
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}
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}
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static void key(unsigned char k, int x, int y)
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{
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static GLuint mode = 0;
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(void) x;
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(void) y;
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switch (k) {
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case ' ':
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anim = !anim;
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if (anim)
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glutIdleFunc(idle);
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else
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glutIdleFunc(NULL);
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break;
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case 'm':
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mode = !mode;
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set_mode(mode);
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break;
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case 'v':
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use_vertex_arrays = ! use_vertex_arrays;
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printf( "Vertex arrays are %sabled\n",
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(use_vertex_arrays) ? "en" : "dis" );
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break;
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case 'z':
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EyeDist -= 0.5;
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if (EyeDist < 6.0)
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EyeDist = 6.0;
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break;
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case 'Z':
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EyeDist += 0.5;
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if (EyeDist > 90.0)
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EyeDist = 90;
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break;
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case 27:
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exit(0);
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}
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glutPostRedisplay();
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}
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static void specialkey(int key, int x, int y)
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{
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GLfloat step = 5;
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(void) x;
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(void) y;
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switch (key) {
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case GLUT_KEY_UP:
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Xrot += step;
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break;
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case GLUT_KEY_DOWN:
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Xrot -= step;
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break;
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case GLUT_KEY_LEFT:
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Yrot -= step;
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break;
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case GLUT_KEY_RIGHT:
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Yrot += step;
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break;
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}
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glutPostRedisplay();
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}
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/* new window size or exposure */
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static void reshape(int width, int height)
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{
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GLfloat ar = (float) width / (float) height;
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glViewport(0, 0, (GLint)width, (GLint)height);
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glMatrixMode(GL_PROJECTION);
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glLoadIdentity();
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glFrustum( -2.0*ar, 2.0*ar, -2.0, 2.0, 4.0, 100.0 );
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glMatrixMode(GL_MODELVIEW);
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glLoadIdentity();
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}
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static void init_checkers( void )
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{
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#define CUBE_TEX_SIZE 64
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GLubyte image[CUBE_TEX_SIZE][CUBE_TEX_SIZE][3];
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static const GLubyte colors[6][3] = {
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{ 255, 0, 0 }, /* face 0 - red */
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{ 0, 255, 255 }, /* face 1 - cyan */
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{ 0, 255, 0 }, /* face 2 - green */
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{ 255, 0, 255 }, /* face 3 - purple */
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{ 0, 0, 255 }, /* face 4 - blue */
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{ 255, 255, 0 } /* face 5 - yellow */
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};
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static const GLenum targets[6] = {
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GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB,
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GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB,
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GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB,
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GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB,
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GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB,
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GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB
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};
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GLint i, j, f;
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glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
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/* make colored checkerboard cube faces */
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for (f = 0; f < 6; f++) {
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for (i = 0; i < CUBE_TEX_SIZE; i++) {
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for (j = 0; j < CUBE_TEX_SIZE; j++) {
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if ((i/4 + j/4) & 1) {
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image[i][j][0] = colors[f][0];
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image[i][j][1] = colors[f][1];
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image[i][j][2] = colors[f][2];
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}
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else {
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image[i][j][0] = 255;
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image[i][j][1] = 255;
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image[i][j][2] = 255;
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}
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}
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}
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glTexImage2D(targets[f], 0, GL_RGB, CUBE_TEX_SIZE, CUBE_TEX_SIZE, 0,
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GL_RGB, GL_UNSIGNED_BYTE, image);
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}
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}
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static void load(GLenum target, const char *filename,
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GLboolean flipTB, GLboolean flipLR)
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{
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GLint w, h;
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GLenum format;
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GLubyte *img = LoadRGBImage( filename, &w, &h, &format );
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if (!img) {
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printf("Error: couldn't load texture image %s\n", filename);
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exit(1);
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}
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assert(format == GL_RGB);
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/* <sigh> the way the texture cube mapping works, we have to flip
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* images to make things look right.
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*/
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if (flipTB) {
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const int stride = 3 * w;
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GLubyte temp[3*1024];
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int i;
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for (i = 0; i < h / 2; i++) {
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memcpy(temp, img + i * stride, stride);
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memcpy(img + i * stride, img + (h - i - 1) * stride, stride);
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memcpy(img + (h - i - 1) * stride, temp, stride);
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}
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}
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if (flipLR) {
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const int stride = 3 * w;
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GLubyte temp[3];
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GLubyte *row;
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int i, j;
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for (i = 0; i < h; i++) {
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row = img + i * stride;
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for (j = 0; j < w / 2; j++) {
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int k = w - j - 1;
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temp[0] = row[j*3+0];
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temp[1] = row[j*3+1];
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temp[2] = row[j*3+2];
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row[j*3+0] = row[k*3+0];
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row[j*3+1] = row[k*3+1];
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row[j*3+2] = row[k*3+2];
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row[k*3+0] = temp[0];
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row[k*3+1] = temp[1];
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row[k*3+2] = temp[2];
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}
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}
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}
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gluBuild2DMipmaps(target, GL_RGB, w, h, format, GL_UNSIGNED_BYTE, img);
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free(img);
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}
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static void load_envmaps(void)
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{
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load(GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB, "right.rgb", GL_TRUE, GL_FALSE);
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load(GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB, "left.rgb", GL_TRUE, GL_FALSE);
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load(GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB, "top.rgb", GL_FALSE, GL_TRUE);
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load(GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB, "bottom.rgb", GL_FALSE, GL_TRUE);
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load(GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB, "front.rgb", GL_TRUE, GL_FALSE);
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load(GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB, "back.rgb", GL_TRUE, GL_FALSE);
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}
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static void init( GLboolean useImageFiles )
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{
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GLenum filter;
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/* check for extension */
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{
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char *exten = (char *) glGetString(GL_EXTENSIONS);
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if (!strstr(exten, "GL_ARB_texture_cube_map")) {
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printf("Sorry, this demo requires GL_ARB_texture_cube_map\n");
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exit(0);
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}
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}
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printf("GL_RENDERER: %s\n", (char *) glGetString(GL_RENDERER));
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if (useImageFiles) {
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load_envmaps();
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filter = GL_LINEAR;
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}
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else {
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init_checkers();
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filter = GL_NEAREST;
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}
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glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER, filter);
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glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER, filter);
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glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
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glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
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glEnable(GL_TEXTURE_CUBE_MAP_ARB);
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glEnable(GL_DEPTH_TEST);
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glClearColor(.3, .3, .3, 0);
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glColor3f( 1.0, 1.0, 1.0 );
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set_mode(0);
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}
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static void usage(void)
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{
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printf("keys:\n");
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printf(" SPACE - toggle animation\n");
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printf(" CURSOR KEYS - rotation\n");
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printf(" m - toggle texgen reflection mode\n");
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printf(" z/Z - change viewing distance\n");
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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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glutInitWindowPosition(0, 0);
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glutInitWindowSize(600, 500);
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glutInitDisplayMode( GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE );
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glutCreateWindow("Texture Cube Mapping");
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if (argc > 1 && strcmp(argv[1] , "-i") == 0)
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init( 1 );
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else
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init( 0 );
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glutReshapeFunc( reshape );
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glutKeyboardFunc( key );
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glutSpecialFunc( specialkey );
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glutDisplayFunc( draw );
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if (anim)
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glutIdleFunc(idle);
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usage();
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glutMainLoop();
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return 0;
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}
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