[译]GLUT教程

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

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;

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 computeDir(float deltaAngle) {

    angle += deltaAngle;
    lx = sin(angle);
    lz = -cos(angle);
}

void renderScene(void) {

    if (deltaMove)
        computePos(deltaMove);
    if (deltaAngle)
        computeDir(deltaAngle);

    // 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 pressKey(int key, int xx, int yy) {

    switch (key) {
        case GLUT_KEY_LEFT : deltaAngle = -0.01f; break;
        case GLUT_KEY_RIGHT : deltaAngle = 0.01f; break;
        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_LEFT :
        case GLUT_KEY_RIGHT : deltaAngle = 0.0f;break;
        case GLUT_KEY_UP :
        case GLUT_KEY_DOWN : deltaMove = 0;break;
    }
}

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);

    glutSpecialFunc(pressKey);

    // here are the new entries
    glutIgnoreKeyRepeat(1);
    glutSpecialUpFunc(releaseKey);

    // OpenGL init
    glEnable(GL_DEPTH_TEST);

    // enter GLUT event processing cycle
    glutMainLoop();

    return 1;
}