[译]GLUT教程 - 整合代码2

Lighthouse3d.com >> GLUT Tutorial >> Input >> The Code So Far II

 

以下是前面几节的完整整合代码:

#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;



void changeSize(int w, int h) {



    // 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() {



    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);

}



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



    for(int i = -3; i < 3; i++)

        for(int j=-3; j < 3; j++) {

                     glPushMatrix();

                     glTranslatef(i*10.0,0,j * 10.0);

                     drawSnowMan();

                     glPopMatrix();

               }

        glutSwapBuffers();

} 



void processNormalKeys(unsigned char key, int xx, int yy) {     



        if (key == 27)

              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;

       }

} 



void releaseKey(int key, int x, int y) {     



        switch (key) {

             case GLUT_KEY_UP :

             case GLUT_KEY_DOWN : deltaMove = 0;break;

        }

} 



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;

        }

    }

}



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);



    // enter GLUT event processing cycle

    glutMainLoop();



    return 1;

}