#include #include #include #include #include #include GLfloat viewRotY = 0, viewRotX = 0; #define SPOT_DIRECTION 1 #define SPOT_CUTOFF 2 #define SPOT_EXPONENT 3 GLfloat lightPos[4] = { 0, 4, 10, 1 }; GLfloat spotDirection[] = { 0, 0, -1 }; GLfloat spotCutoff = 30; GLfloat spotExponent = 0.0; int mouseMode = SPOT_DIRECTION; void drawEverything(void); void defineLight(void); void drawSpotlight(void); void drawFloorMesh(int columns,int rows); void drawPedestal(void); void drawTeapot(void); void drawBall(void); float currentTime(void); void checkGLError(char *); void idle(void); void key(unsigned char k, int x, int y); void specialkey(int k, int x, int y); void mousebutton(int button, int state, int x, int y); void mousemotion(int x, int y); int main(int argc, char *argv[]) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); glutInitWindowSize(512, 512); glutCreateWindow("example"); glutDisplayFunc(drawEverything); glutKeyboardFunc(key); glutSpecialFunc(specialkey); glutMouseFunc(mousebutton); glutMotionFunc(mousemotion); glutIdleFunc(idle); glutMainLoop(); return 0; } void drawEverything(void) { glClearColor(0.5, 0.8, 1.0, 0.0); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glEnable(GL_DEPTH_TEST); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(50.0, 1.0, 1.0, 100.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glTranslatef(0.0, 0.0, -25.0); glRotatef(viewRotX, 1.0, 0.0, 0.0); glRotatef(viewRotY, 0.0, 1.0, 0.0); defineLight(); glEnable(GL_LIGHTING); drawFloorMesh(32,32); drawTeapot(); drawPedestal(); drawBall(); glDisable(GL_LIGHTING); glutSwapBuffers(); checkGLError("end-of-frame"); } void defineLight(void) { GLfloat white[4] = { 1, 1, 1, 1 }; glEnable(GL_LIGHT0); glLightfv(GL_LIGHT0, GL_DIFFUSE, white); glLightfv(GL_LIGHT0, GL_POSITION, lightPos); glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, spotDirection); glLightf(GL_LIGHT0, GL_SPOT_CUTOFF, spotCutoff); glLightf(GL_LIGHT0, GL_SPOT_EXPONENT, spotExponent); drawSpotlight(); } void drawSpotlight(void) { glColor3f(1.0, 1.0, 0.0); glPointSize(12.0); glBegin(GL_POINTS); glVertex3fv(lightPos); glEnd(); glBegin(GL_LINES); glVertex3fv(lightPos); glVertex3f(spotDirection[0]*100, spotDirection[1]*100, spotDirection[2]*100); glEnd(); } void drawFloorMesh(int columns,int rows) { int i,j; GLfloat x,z; GLfloat green[4] = { 0, 0.8, 0.1, 1 }; GLfloat black[4] = { 0, 0, 0, 1 }; glMaterialfv(GL_FRONT, GL_AMBIENT, green); glMaterialfv(GL_FRONT, GL_DIFFUSE, green); glMaterialfv(GL_FRONT, GL_SPECULAR, black); glNormal3f(0.0, 1.0, 0.0); for (j = 0; j < rows; j++) { glBegin(GL_TRIANGLE_STRIP); for (i = 0; i < columns; i++) { x = (((float)i) / columns) * 40.0 - 20.0; z = (((float)j) / rows) * 40.0 - 20.0; glVertex3f(x, -2.0, z); z = (((float)j+1) / rows) * 40.0 - 20.0; glVertex3f(x, -2.0, z); } glEnd(); } } void drawTeapot(void) { GLfloat red[4] = { 0.8, 0, 0, 1 }; GLfloat white[4] = { 1, 1, 1, 1 }; glMaterialfv(GL_FRONT, GL_AMBIENT, red); glMaterialfv(GL_FRONT, GL_DIFFUSE, red); glMaterialfv(GL_FRONT, GL_SPECULAR, white); glMaterialf(GL_FRONT, GL_SHININESS, 90.0); glPushMatrix(); glTranslatef(2.0, 4.0, -1.0); glRotatef(currentTime() * 30.0, 0.0, 1.0, 0.0); glutSolidTeapot(2.0); glPopMatrix(); } void drawPedestal(void) { static GLUquadricObj * quadric = NULL; GLfloat grey[4] = { 0.6, 0.6, 0.6, 1 }; GLfloat white[4] = { 1, 1, 1, 1 }; if (!quadric) quadric = gluNewQuadric(); glMaterialfv(GL_FRONT, GL_AMBIENT, grey); glMaterialfv(GL_FRONT, GL_DIFFUSE, grey); glMaterialfv(GL_FRONT, GL_SPECULAR, white); glMaterialf(GL_FRONT, GL_SHININESS, 30.0); glPushMatrix(); glTranslatef(2.0, -2.0, -1.0); glRotatef(-90.0, 1.0, 0.0, 0.0); gluCylinder(quadric, 4.0, 4.0, 4.0, 16, 1); glTranslatef(0.0, 0.0, 4.0); gluDisk(quadric, 0.0, 4.0, 16, 1); glPopMatrix(); } void drawBall(void) { GLfloat cyan[4] = { 0, 1, 1, 1 }; GLfloat black[4] = { 0, 0, 0, 1 }; glMaterialfv(GL_FRONT, GL_AMBIENT, cyan); glMaterialfv(GL_FRONT, GL_DIFFUSE, cyan); glMaterialfv(GL_FRONT, GL_SPECULAR, black); glPushMatrix(); glTranslatef(-10.0, fabs(sin(currentTime())) * 3.0, -15.0); glutSolidSphere(2.0, 16, 8); glPopMatrix(); } float currentTime(void) { static struct timeval startTime; static int firstCall=1; struct timeval t; if (firstCall) { firstCall = 0; gettimeofday(&startTime, NULL); } gettimeofday(&t,NULL); return (t.tv_sec-startTime.tv_sec) + (t.tv_usec - startTime.tv_usec) / 1000000.0; } void checkGLError(char *prefix) { GLenum err = glGetError(); if (err != GL_NO_ERROR) printf("%s GL error '%s'\n",prefix,gluErrorString(err)); } void idle(void) { glutPostRedisplay(); } void key(unsigned char k, int x, int y) { if (k == 27) exit(0); } void specialkey(int k, int x, int y) { if (k == GLUT_KEY_LEFT) viewRotY += 3; else if (k == GLUT_KEY_RIGHT) viewRotY -= 3; else if (k == GLUT_KEY_UP) viewRotX += 3; else if (k == GLUT_KEY_DOWN) viewRotX -= 3; } void mousebutton(int button, int state, int x, int y) { if ((button == GLUT_LEFT_BUTTON) && (state == GLUT_DOWN)) mouseMode = SPOT_DIRECTION; else if ((button == GLUT_MIDDLE_BUTTON) && (state == GLUT_DOWN)) mouseMode = SPOT_CUTOFF; else if ((button == GLUT_RIGHT_BUTTON) && (state == GLUT_DOWN)) mouseMode = SPOT_EXPONENT; } void mousemotion(int x, int y) { if (mouseMode == SPOT_DIRECTION) { spotDirection[0] = (float)x / glutGet(GLUT_WINDOW_WIDTH) * 2.0 - 1.0; spotDirection[1] = 1.0 - (float)y / glutGet(GLUT_WINDOW_HEIGHT) * 2.0; } else if (mouseMode == SPOT_CUTOFF) { spotCutoff = (float)x / glutGet(GLUT_WINDOW_WIDTH) * 90.0; if (spotCutoff < 0) spotCutoff = 0; else if (spotCutoff > 90) spotCutoff = 90; } else if (mouseMode == SPOT_EXPONENT) { spotExponent = (float)x / glutGet(GLUT_WINDOW_WIDTH) * 10.0; if (spotExponent < 0) spotExponent = 0; } printf("direction = %.3f %.3f %.3f\t cutoff = %f\t exponent = %f\n", spotDirection[0], spotDirection[1], spotDirection[2], spotCutoff, spotExponent); }