| /* |
| * 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; |
| } |