Lighthouse3d.com >> GLUT Tutorial >> Avoiding the Idle Func >> The Code So Far VIII
以下代码用glutPostRedisplay函数代替了原来的空闲函数的回调.
#include <stdio.h> #include <stdlib.h> #include <math.h> #ifdef __APPLE__ #include <GLUT/glut.h> #else #include <GL/glut.h> #endif // angle of rotation for the camera direction float angle = 0.0f; // actual vector representing the camera's direction float lx=0.0f,lz=-1.0f, ly = 0.0f; // XZ position of the camera float x=0.0f, z=5.0f, y = 1.75f; // the key states. These variables will be zero //when no key is being presses float deltaAngle = 0.0f; float deltaMove = 0; int xOrigin = -1; // width and height of the window int h,w; // variables to compute frames per second int frame; long time, timebase; char s[50]; // variables to hold window identifiers int mainWindow, subWindow1,subWindow2,subWindow3; //border between subwindows int border = 6; void setProjection(int w1, int h1) { float ratio; // Prevent a divide by zero, when window is too short // (you cant make a window of zero width). ratio = 1.0f * w1 / h1; // Reset the coordinate system before modifying glMatrixMode(GL_PROJECTION); glLoadIdentity(); // Set the viewport to be the entire window glViewport(0, 0, w1, h1); // Set the clipping volume gluPerspective(45,ratio,0.1,1000); glMatrixMode(GL_MODELVIEW); } void changeSize(int w1,int h1) { if(h1 == 0) h1 = 1; // we're keeping these values cause we'll need them latter w = w1; h = h1; // set subwindow 1 as the active window glutSetWindow(subWindow1); // resize and reposition the sub window glutPositionWindow(border,border); glutReshapeWindow(w-2*border, h/2 - border*3/2); setProjection(w-2*border, h/2 - border*3/2); // set subwindow 2 as the active window glutSetWindow(subWindow2); // resize and reposition the sub window glutPositionWindow(border,(h+border)/2); glutReshapeWindow(w/2-border*3/2, h/2 - border*3/2); setProjection(w/2-border*3/2,h/2 - border*3/2); // set subwindow 3 as the active window glutSetWindow(subWindow3); // resize and reposition the sub window glutPositionWindow((w+border)/2,(h+border)/2); glutReshapeWindow(w/2-border*3/2,h/2 - border*3/2); setProjection(w/2-border*3/2,h/2 - border*3/2); } void drawSnowMan() { glColor3f(1.0f, 1.0f, 1.0f); // Draw Body glTranslatef(0.0f ,0.75f, 0.0f); glutSolidSphere(0.75f,20,20); // Draw Head glTranslatef(0.0f, 1.0f, 0.0f); glutSolidSphere(0.25f,20,20); // Draw Eyes glPushMatrix(); glColor3f(0.0f,0.0f,0.0f); glTranslatef(0.05f, 0.10f, 0.18f); glutSolidSphere(0.05f,10,10); glTranslatef(-0.1f, 0.0f, 0.0f); glutSolidSphere(0.05f,10,10); glPopMatrix(); // Draw Nose glColor3f(1.0f, 0.5f, 0.5f); glRotatef(0.0f,1.0f, 0.0f, 0.0f); glutSolidCone(0.08f,0.5f,10,2); glColor3f(1.0f, 1.0f, 1.0f); } void renderBitmapString( float x, float y, float z, void *font, char *string) { char *c; glRasterPos3f(x, y,z); for (c=string; *c != ' '; c++) { glutBitmapCharacter(font, *c); } } void restorePerspectiveProjection() { glMatrixMode(GL_PROJECTION); // restore previous projection matrix glPopMatrix(); // get back to modelview mode glMatrixMode(GL_MODELVIEW); } void setOrthographicProjection() { // switch to projection mode glMatrixMode(GL_PROJECTION); // save previous matrix which contains the //settings for the perspective projection glPushMatrix(); // reset matrix glLoadIdentity(); // set a 2D orthographic projection gluOrtho2D(0, w, h, 0); // switch back to modelview mode glMatrixMode(GL_MODELVIEW); } void computePos(float deltaMove) { x += deltaMove * lx * 0.1f; z += deltaMove * lz * 0.1f; } // Common Render Items for all subwindows void renderScene2() { // Draw ground glColor3f(0.9f, 0.9f, 0.9f); glBegin(GL_QUADS); glVertex3f(-100.0f, 0.0f, -100.0f); glVertex3f(-100.0f, 0.0f, 100.0f); glVertex3f( 100.0f, 0.0f, 100.0f); glVertex3f( 100.0f, 0.0f, -100.0f); glEnd(); // Draw 36 SnowMen for(int i = -3; i < 3; i++) for(int j=-3; j < 3; j++) { glPushMatrix(); glTranslatef(i*10.0f, 0.0f, j * 10.0f); drawSnowMan(); glPopMatrix(); } } // Display func for main window void renderScene() { glutSetWindow(mainWindow); glClear(GL_COLOR_BUFFER_BIT); glutSwapBuffers(); } // Display func for sub window 1 void renderScenesw1() { glutSetWindow(subWindow1); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); gluLookAt(x, y, z, x + lx,y + ly,z + lz, 0.0f,1.0f,0.0f); renderScene2(); // display fps in the top window frame++; time=glutGet(GLUT_ELAPSED_TIME); if (time - timebase > 1000) { sprintf(s,"Lighthouse3D - FPS:%4.2f", frame*1000.0/(time-timebase)); timebase = time; frame = 0; } setOrthographicProjection(); glPushMatrix(); glLoadIdentity(); renderBitmapString(5,30,0,GLUT_BITMAP_HELVETICA_12,s); glPopMatrix(); restorePerspectiveProjection(); glutSwapBuffers(); } // Display func for sub window 2 void renderScenesw2() { glutSetWindow(subWindow2); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); gluLookAt(x, y+15, z, x ,y - 1,z, lx,0,lz); // Draw red cone at the location of the main camera glPushMatrix(); glColor3f(1.0,0.0,0.0); glTranslatef(x,y,z); glRotatef(180-(angle+deltaAngle)*180.0/3.14,0.0,1.0,0.0); glutSolidCone(0.2,0.8f,4,4); glPopMatrix(); renderScene2(); glutSwapBuffers(); } // Display func for sub window 3 void renderScenesw3() { glutSetWindow(subWindow3); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); gluLookAt(x-lz*10 , y, z+lx*10, x ,y ,z , 0.0f,1.0f,0.0f); // Draw red cone at the location of the main camera glPushMatrix(); glColor3f(1.0,0.0,0.0); glTranslatef(x,y,z); glRotatef(180-(angle+deltaAngle)*180.0/3.14,0.0,1.0,0.0); glutSolidCone(0.2,0.8f,4,4); glPopMatrix(); renderScene2(); glutSwapBuffers(); } // Global render func void renderSceneAll() { // check for keyboard movement if (deltaMove) { computePos(deltaMove); glutSetWindow(mainWindow); glutPostRedisplay(); } renderScene(); renderScenesw1(); renderScenesw2(); renderScenesw3(); } // ----------------------------------- // KEYBOARD // ----------------------------------- void processNormalKeys(unsigned char key, int xx, int yy) { if (key == 27) { glutDestroyWindow(mainWindow); exit(0); } } void pressKey(int key, int xx, int yy) { switch (key) { case GLUT_KEY_UP : deltaMove = 0.5f; break; case GLUT_KEY_DOWN : deltaMove = -0.5f; break; } glutSetWindow(mainWindow); glutPostRedisplay(); } void releaseKey(int key, int x, int y) { switch (key) { case GLUT_KEY_UP : case GLUT_KEY_DOWN : deltaMove = 0;break; } } // ----------------------------------- // MOUSE // ----------------------------------- void mouseMove(int x, int y) { // this will only be true when the left button is down if (xOrigin >= 0) { // update deltaAngle deltaAngle = (x - xOrigin) * 0.001f; // update camera's direction lx = sin(angle + deltaAngle); lz = -cos(angle + deltaAngle); glutSetWindow(mainWindow); glutPostRedisplay(); } } void mouseButton(int button, int state, int x, int y) { // only start motion if the left button is pressed if (button == GLUT_LEFT_BUTTON) { // when the button is released if (state == GLUT_UP) { angle += deltaAngle; deltaAngle = 0.0f; xOrigin = -1; } else {// state = GLUT_DOWN xOrigin = x; } } } // ----------------------------------- // MAIN and INIT // ----------------------------------- void init() { glClearColor(0.0, 0.0, 0.0, 0.0); glEnable(GL_DEPTH_TEST); glEnable(GL_CULL_FACE); // register callbacks glutIgnoreKeyRepeat(1); glutKeyboardFunc(processNormalKeys); glutSpecialFunc(pressKey); glutSpecialUpFunc(releaseKey); glutMouseFunc(mouseButton); glutMotionFunc(mouseMove); } int main(int argc, char **argv) { // init GLUT and create main window glutInit(&argc, argv); glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA); glutInitWindowPosition(100,100); glutInitWindowSize(800,800); mainWindow = glutCreateWindow("Lighthouse3D - GLUT Tutorial"); // callbacks for main window glutDisplayFunc(renderSceneAll); glutReshapeFunc(changeSize); // Removing the idle function to save CPU and GPU //glutIdleFunc(renderSceneAll); init(); // sub windows subWindow1 = glutCreateSubWindow(mainWindow, border,border,w-2*border, h/2 - border*3/2); glutDisplayFunc(renderScenesw1); init(); subWindow2 = glutCreateSubWindow(mainWindow, border,(h+border)/2,w/2-border*3/2, h/2 - border*3/2); glutDisplayFunc(renderScenesw2); init(); subWindow3 = glutCreateSubWindow(mainWindow, (w+border)/2,(h+border)/2,w/2-border*3/2,h/2 - border*3/2); glutDisplayFunc(renderScenesw3); init(); // enter GLUT event processing cycle glutMainLoop(); return 1; }