added skybox and options to load real images

This commit is contained in:
Brian Paul 2002-10-25 17:20:26 +00:00
parent 92c195211a
commit a4f0b6884c

View file

@ -1,4 +1,4 @@
/* $Id: cubemap.c,v 1.3 2000/06/27 17:04:43 brianp Exp $ */
/* $Id: cubemap.c,v 1.4 2002/10/25 17:20:26 brianp Exp $ */
/*
* GL_ARB_texture_cube_map demo
@ -36,25 +36,100 @@
*/
#include <assert.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "GL/glut.h"
#include "../util/readtex.c" /* a hack */
static GLfloat Xrot = 0, Yrot = 0;
static GLfloat EyeDist = 10;
static void draw_skybox( void )
{
const GLfloat eps1 = 0.99;
const GLfloat br = 20.0; /* box radius */
glBegin(GL_QUADS);
/* +X side */
glTexCoord3f(1.0, -eps1, -eps1); glVertex3f(br, -br, -br);
glTexCoord3f(1.0, -eps1, eps1); glVertex3f(br, -br, br);
glTexCoord3f(1.0, eps1, eps1); glVertex3f(br, br, br);
glTexCoord3f(1.0, eps1, -eps1); glVertex3f(br, br, -br);
/* -X side */
glTexCoord3f(-1.0, eps1, -eps1); glVertex3f(-br, br, -br);
glTexCoord3f(-1.0, eps1, eps1); glVertex3f(-br, br, br);
glTexCoord3f(-1.0, -eps1, eps1); glVertex3f(-br, -br, br);
glTexCoord3f(-1.0, -eps1, -eps1); glVertex3f(-br, -br, -br);
/* +Y side */
glTexCoord3f(-eps1, 1.0, -eps1); glVertex3f(-br, br, -br);
glTexCoord3f(-eps1, 1.0, eps1); glVertex3f(-br, br, br);
glTexCoord3f( eps1, 1.0, eps1); glVertex3f( br, br, br);
glTexCoord3f( eps1, 1.0, -eps1); glVertex3f( br, br, -br);
/* -Y side */
glTexCoord3f(-eps1, -1.0, -eps1); glVertex3f(-br, -br, -br);
glTexCoord3f(-eps1, -1.0, eps1); glVertex3f(-br, -br, br);
glTexCoord3f( eps1, -1.0, eps1); glVertex3f( br, -br, br);
glTexCoord3f( eps1, -1.0, -eps1); glVertex3f( br, -br, -br);
/* +Z side */
glTexCoord3f( eps1, -eps1, 1.0); glVertex3f( br, -br, br);
glTexCoord3f(-eps1, -eps1, 1.0); glVertex3f(-br, -br, br);
glTexCoord3f(-eps1, eps1, 1.0); glVertex3f(-br, br, br);
glTexCoord3f( eps1, eps1, 1.0); glVertex3f( br, br, br);
/* -Z side */
glTexCoord3f( eps1, eps1, -1.0); glVertex3f( br, br, -br);
glTexCoord3f(-eps1, eps1, -1.0); glVertex3f(-br, br, -br);
glTexCoord3f(-eps1, -eps1, -1.0); glVertex3f(-br, -br, -br);
glTexCoord3f( eps1, -eps1, -1.0); glVertex3f( br, -br, -br);
glEnd();
}
static void draw( void )
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_TEXTURE);
glLoadIdentity();
glRotatef(Xrot, 1, 0, 0);
glRotatef(Yrot, 0, 1, 0);
glutSolidSphere(2.0, 20, 20);
glMatrixMode(GL_MODELVIEW);
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();
}
@ -62,7 +137,8 @@ static void draw( void )
static void idle(void)
{
Yrot += 5.0;
GLfloat t = 0.05 * glutGet(GLUT_ELAPSED_TIME);
Yrot = t;
glutPostRedisplay();
}
@ -81,9 +157,6 @@ static void set_mode(GLuint mode)
glTexGeni(GL_R, GL_TEXTURE_GEN_MODE, GL_NORMAL_MAP_ARB);
printf("GL_NORMAL_MAP_ARB mode\n");
}
glEnable(GL_TEXTURE_GEN_S);
glEnable(GL_TEXTURE_GEN_T);
glEnable(GL_TEXTURE_GEN_R);
}
@ -105,6 +178,16 @@ static void key(unsigned char k, int x, int y)
mode = !mode;
set_mode(mode);
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);
}
@ -114,15 +197,15 @@ static void key(unsigned char k, int x, int y)
static void specialkey(int key, int x, int y)
{
GLfloat step = 10;
GLfloat step = 5;
(void) x;
(void) y;
switch (key) {
case GLUT_KEY_UP:
Xrot -= step;
Xrot += step;
break;
case GLUT_KEY_DOWN:
Xrot += step;
Xrot -= step;
break;
case GLUT_KEY_LEFT:
Yrot -= step;
@ -138,17 +221,17 @@ static void specialkey(int key, int x, int y)
/* 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, 2.0, -2.0, 2.0, 6.0, 20.0 );
glFrustum( -2.0*ar, 2.0*ar, -2.0, 2.0, 4.0, 100.0 );
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef( 0.0, 0.0, -8.0 );
}
static void init( void )
static void init_checkers( void )
{
#define CUBE_TEX_SIZE 64
GLubyte image[CUBE_TEX_SIZE][CUBE_TEX_SIZE][3];
@ -171,16 +254,6 @@ static void init( void )
GLint i, j, f;
/* 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);
}
}
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
/* make colored checkerboard cube faces */
@ -203,18 +276,102 @@ static void init( void )
glTexImage2D(targets[f], 0, GL_RGB, CUBE_TEX_SIZE, CUBE_TEX_SIZE, 0,
GL_RGB, GL_UNSIGNED_BYTE, image);
}
}
#if 1
glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
#else
glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
#endif
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 );
@ -229,16 +386,21 @@ static void usage(void)
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(300, 300);
glutInitWindowSize(600, 500);
glutInitDisplayMode( GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE );
glutCreateWindow("Texture Cube Maping");
init();
if (argc > 1 && strcmp(argv[1] , "-i") == 0)
init( 1 );
else
init( 0 );
glutReshapeFunc( reshape );
glutKeyboardFunc( key );
glutSpecialFunc( specialkey );