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mesa/progs/demos/cubemap.c

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/*
* 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[] )
{
glutInit(&argc, 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;
}
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