Lighthouse3d.com >> GLUT Tutorial >> Extras >> The Code So Far V
该代码与位图字体的代码类似.区别是用了笔划字体来显示每个雪人上的数字,然后雪人是用正交投影来显示,还有一段用位图字体显示的文本.后面包含了每秒帧数的文本不受镜头移动的影响,它一直停留在屏幕的相同位置.
字体菜单也改成了用笔划字体代替位图字体.
#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; // XZ position of the camera float x=0.0f, z=5.0f; // the key states. These variables will be zero //when no key is being presses float deltaAngle = 0.0f; float deltaMove = 0; int xOrigin = -1; // Constant definitions for Menus #define RED 1 #define GREEN 2 #define BLUE 3 #define ORANGE 4 #define FILL 1 #define LINE 2 // Pop up menu identifiers int fillMenu, fontMenu, mainMenu, colorMenu; // color for the nose float red = 1.0f, blue=0.5f, green=0.5f; // scale of snowman float scale = 1.0f; // menu status int menuFlag = 0; // default font void *font = GLUT_STROKE_ROMAN; // width and height of the window int h,w; // variables to compute frames per second int frame; long time, timebase; char s[50]; void changeSize(int ww, int hh) { h = hh; w = ww; // Prevent a divide by zero, when window is too short // (you cant make a window of zero width). if (h == 0) h = 1; float ratio = w * 1.0 / h; // Use the Projection Matrix glMatrixMode(GL_PROJECTION); // Reset Matrix glLoadIdentity(); // Set the viewport to be the entire window glViewport(0, 0, w, h); // Set the correct perspective. gluPerspective(45.0f, ratio, 0.1f, 100.0f); // Get Back to the Modelview glMatrixMode(GL_MODELVIEW); } void drawSnowMan() { glScalef(scale, scale, scale); 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(red, green, blue); 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 renderStrokeFontString( float x, float y, float z, void *font, char *string) { char *c; glPushMatrix(); glTranslatef(x, y,z); glScalef(0.002f, 0.002f, 0.002f); for (c=string; *c != ' '; c++) { glutStrokeCharacter(font, *c); } glPopMatrix(); } 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; } void renderScene(void) { if (deltaMove) computePos(deltaMove); // Clear Color and Depth Buffers glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Reset transformations glLoadIdentity(); // Set the camera gluLookAt( x, 1.0f, z, x+lx, 1.0f, z+lz, 0.0f, 1.0f, 0.0f); // 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 char number[3]; 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(); sprintf(number,"%d",(i+3)*6+(j+3)); renderStrokeFontString(0.0f, 0.5f, 0.0f, (void *)font ,number); glPopMatrix(); } // Code to compute frames per second 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; } // Code to display a string (fps) with bitmap fonts setOrthographicProjection(); glPushMatrix(); glLoadIdentity(); renderBitmapString(5,30,0,GLUT_BITMAP_HELVETICA_18,s); glPopMatrix(); restorePerspectiveProjection(); glutSwapBuffers(); } // ----------------------------------- // KEYBOARD // ----------------------------------- void processNormalKeys(unsigned char key, int xx, int yy) { switch (key) { case 27: glutDestroyMenu(mainMenu); glutDestroyMenu(fillMenu); glutDestroyMenu(colorMenu); glutDestroyMenu(fontMenu); exit(0); break; } } 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; } } 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); } } 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; xOrigin = -1; } else {// state = GLUT_DOWN xOrigin = x; } } } // ----------------------------------- // MENUS // ----------------------------------- void processMenuStatus(int status, int x, int y) { if (status == GLUT_MENU_IN_USE) menuFlag = 1; else menuFlag = 0; } void processMainMenu(int option) { // nothing to do in here // all actions are for submenus } void processFillMenu(int option) { switch (option) { case FILL: glPolygonMode(GL_FRONT, GL_FILL); break; case LINE: glPolygonMode(GL_FRONT, GL_LINE); break; } } void processFontMenu(int option) { switch (option) { case 1: font = GLUT_STROKE_ROMAN; break; case 2: font = GLUT_STROKE_MONO_ROMAN; break; } } void processColorMenu(int option) { switch (option) { case RED : red = 1.0f; green = 0.0f; blue = 0.0f; break; case GREEN : red = 0.0f; green = 1.0f; blue = 0.0f; break; case BLUE : red = 0.0f; green = 0.0f; blue = 1.0f; break; case ORANGE : red = 1.0f; green = 0.5f; blue = 0.5f; break; } } void createPopupMenus() { fontMenu = glutCreateMenu(processFontMenu); glutAddMenuEntry("STROKE_ROMAN",1 ); glutAddMenuEntry("STROKE_MONO_ROMAN",2 ); fillMenu = glutCreateMenu(processFillMenu); glutAddMenuEntry("Fill",FILL); glutAddMenuEntry("Line",LINE); colorMenu = glutCreateMenu(processColorMenu); glutAddMenuEntry("Red",RED); glutAddMenuEntry("Blue",BLUE); glutAddMenuEntry("Green",GREEN); glutAddMenuEntry("Orange",ORANGE); mainMenu = glutCreateMenu(processMainMenu); glutAddSubMenu("Polygon Mode", fillMenu); glutAddSubMenu("Color", colorMenu); glutAddSubMenu("Font",fontMenu); // attach the menu to the right button glutAttachMenu(GLUT_RIGHT_BUTTON); // this will allow us to know if the menu is active glutMenuStatusFunc(processMenuStatus); } // ----------------------------------- // MAIN // ----------------------------------- int main(int argc, char **argv) { // init GLUT and create window glutInit(&argc, argv); glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA); glutInitWindowPosition(100,100); glutInitWindowSize(320,320); glutCreateWindow("Lighthouse3D - GLUT Tutorial"); // register callbacks glutDisplayFunc(renderScene); glutReshapeFunc(changeSize); glutIdleFunc(renderScene); glutIgnoreKeyRepeat(1); glutKeyboardFunc(processNormalKeys); glutSpecialFunc(pressKey); glutSpecialUpFunc(releaseKey); // here are the two new functions glutMouseFunc(mouseButton); glutMotionFunc(mouseMove); // OpenGL init glEnable(GL_DEPTH_TEST); glEnable(GL_CULL_FACE); // init Menus createPopupMenus(); // enter GLUT event processing cycle glutMainLoop(); return 1; }