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