/***************************************************************** tex3d.cpp by Dave Pape 15 April 2003 This program demonstrates the creation of a 3D texture, and applies it to the teapot using texgen for all 3 coordinates (S, T, & R). *****************************************************************/ #include #include #include #include #include #include #include using namespace dms; void createTexture(void); void drawEverything(void); void key(unsigned char k, int x, int y); void specialkey(int k, int x, int y); void idle(void); PerspCamera camera; Light light; Material *material; GLuint textureID, textureID_2D; bool texture3D=false; int main(int argc, char *argv[]) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); glutInitWindowSize(512,512); glutCreateWindow(argv[0]); material = new Material(Color::White); glutDisplayFunc(drawEverything); glutKeyboardFunc(key); glutSpecialFunc(specialkey); glutIdleFunc(idle); camera.setPosition(0, 0, 10); light.setInfinitePosition(-5, 4, 1); createTexture(); glutMainLoop(); return 0; } /*************** CODE OF INTEREST ******************************/ /* The texture image is now a 3D array of colors. */ /* */ #define TEX_HEIGHT 16 #define TEX_WIDTH 16 #define TEX_DEPTH 16 struct _color { GLubyte r,g,b; }; struct _color textureImage[TEX_DEPTH][TEX_HEIGHT][TEX_WIDTH]; void createTexture(void) { /*************** CODE OF INTEREST ******************************/ /* Fill in the 3D image array with red & white pixels that will*/ /* produce a brick-like pattern. */ /* */ int i,j,k; for (i = 0; i < TEX_WIDTH; i++) for (j = 0; j < TEX_HEIGHT; j++) for (k = 0; k < TEX_DEPTH; k++) { if ((j % 8 == 7) || (k % 8 == 7) || ((j%16 < 8) && (i%8 == 7)) || ((j%16 >= 8) && ((i+4)%8 == 7))) { textureImage[k][j][i].r = 255; textureImage[k][j][i].g = 255; textureImage[k][j][i].b = 255; } else { textureImage[k][j][i].r = 255; textureImage[k][j][i].g = 0; textureImage[k][j][i].b = 0; } } /*************** CODE OF INTEREST ******************************/ /* Define the 3D texture. This is similar to defining a 2D */ /* texture, but using the target GL_TEXTURE_3D and the */ /* glTexImage3D function. */ /* */ glGenTextures(1, &textureID); glBindTexture(GL_TEXTURE_3D, textureID); glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_REPEAT); glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_REPEAT); glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexImage3D(GL_TEXTURE_3D, 0, GL_RGB, TEX_WIDTH, TEX_HEIGHT, TEX_DEPTH, 0, GL_RGB, GL_UNSIGNED_BYTE, textureImage); glBindTexture(GL_TEXTURE_3D, 0); /*************** CODE OF INTEREST ******************************/ /* For comparison, we also create a 2D texture using the same */ /* data. This texture will just use the first "plane" of */ /* image data. */ /* */ glGenTextures(1, &textureID_2D); glBindTexture(GL_TEXTURE_2D, textureID_2D); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, TEX_WIDTH, TEX_HEIGHT, 0, GL_RGB, GL_UNSIGNED_BYTE, textureImage); glBindTexture(GL_TEXTURE_2D, 0); } void drawEverything(void) { glClearColor(0.5, 0.7, 1.0, 0.0); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glEnable(GL_DEPTH_TEST); camera.apply(); light.apply(); material->apply(); glRotatef(currentTime() * 2, 1, 1, 1); /*************** CODE OF INTEREST ******************************/ /* To apply a 3D texture, we now need 3 coordinates - S, T, & R*/ /* These will all be generated using texgen in this case. */ /* A program can also explicitly set the coordinates using */ /* the function glTexCoord3f(). */ /* */ if (texture3D) { glEnable(GL_TEXTURE_3D); glBindTexture(GL_TEXTURE_3D, textureID); glEnable(GL_TEXTURE_GEN_S); glEnable(GL_TEXTURE_GEN_T); glEnable(GL_TEXTURE_GEN_R); GLfloat SplaneCoefficients[4] = { 1, 0, 0, 0 }; GLfloat TplaneCoefficients[4] = { 0, 1, 0, 0 }; GLfloat RplaneCoefficients[4] = { 0, 0, 1, 0 }; glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR); glTexGenfv(GL_S, GL_EYE_PLANE, SplaneCoefficients); glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR); glTexGenfv(GL_T, GL_EYE_PLANE, TplaneCoefficients); glTexGeni(GL_R, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR); glTexGenfv(GL_R, GL_EYE_PLANE, RplaneCoefficients); } else { glEnable(GL_TEXTURE_2D); glBindTexture(GL_TEXTURE_2D, textureID_2D); } glutSolidTeapot(2.0); glDisable(GL_TEXTURE_3D); glDisable(GL_TEXTURE_2D); glDisable(GL_TEXTURE_GEN_S); glDisable(GL_TEXTURE_GEN_T); glDisable(GL_TEXTURE_GEN_R); glutSwapBuffers(); checkGLError("end-of-frame"); } void key(unsigned char k, int x, int y) { if (k == 27) exit(0); else if (k == ' ') texture3D = !texture3D; } void specialkey(int k, int x, int y) { if (k == GLUT_KEY_LEFT) camera.turn(3); else if (k == GLUT_KEY_RIGHT) camera.turn(-3); else if (k == GLUT_KEY_UP) camera.pitch(2); else if (k == GLUT_KEY_DOWN) camera.pitch(-2); else if (k == GLUT_KEY_HOME) camera.moveForward(0.25); else if (k == GLUT_KEY_END) camera.moveForward(-0.25); else if (k == GLUT_KEY_PAGE_UP) camera.zoom(-1); else if (k == GLUT_KEY_PAGE_DOWN) camera.zoom(1); } void idle(void) { glutPostRedisplay(); }