/* * 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 "../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); 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 GLboolean anim = GL_TRUE; 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 '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 ); glutIdleFunc( idle ); glutDisplayFunc( draw ); usage(); glutMainLoop(); return 0; }