Week 14 宋侑恩

Week 14 Part 1 - Projection

到 http://jsyeh.org/3d 下載 data.zip、windows.zip、glut32.dll

把windows.zip解壓縮，皆將data資料夾和glut32.dll丟進wondows資料夾

將projection.exe打開

gluLookAt(0.00 , 0.00 , 2.00,   ←eye          (相機的位置)

                   0.00 , 0.00 , 0.00,   ←center      (中心位置)

                   0.00 , 1.00 , 0.00); ←up            (相機上方的位置)

Week 14 Part 2 - 了解glut專案中的main.cpp程式

開啟一個新的glut專案

打開專案裡的main.cpp一行一行看程式碼

#ifdef __APPLE__

#include <GLUT/glut.h>

#else

#include <GL/glut.h>

#endif

#include <stdlib.h>

static int slices = 16;

static int stacks = 16;

static void resize(int width, int height) ///glutReshapeFunc(resize);

{

    const float ar = (float) width / (float) height;

    glViewport(0, 0, width, height);

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    glFrustum(-ar, ar, -1.0, 1.0, 2.0, 100.0);

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity() ;

    gluLookAt(0.3,10,0.3,0,0,-6,0,1,0);

}

static void display(void)

{

    const double t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;

    const double a = t*90.0;

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glColor3d(1,0,0);

    glPushMatrix();

        glTranslated(-2.4,1.2,-6);

        glRotated(60,1,0,0);

        glRotated(a,0,0,1);

        glutSolidSphere(1,slices,stacks);

    glPopMatrix();

    glPushMatrix();

        glTranslated(0,1.2,-6);

        glRotated(60,1,0,0);

        glRotated(a,0,0,1);

        glutSolidCone(1,1,slices,stacks);

    glPopMatrix();

    glPushMatrix();

        glTranslated(2.4,1.2,-6);

        glRotated(60,1,0,0);

        glRotated(a,0,0,1);

        glutSolidTorus(0.2,0.8,slices,stacks);

    glPopMatrix();

    glPushMatrix();

        glTranslated(-2.4,-1.2,-6);

        glRotated(60,1,0,0);

        glRotated(a,0,0,1);

        glutWireSphere(1,slices,stacks);

    glPopMatrix();

    glPushMatrix();

        glTranslated(0,-1.2,-6);

        glRotated(60,1,0,0);

        glRotated(a,0,0,1);

        glutWireCone(1,1,slices,stacks);

    glPopMatrix();

    glPushMatrix();

        glTranslated(2.4,-1.2,-6);

        glRotated(60,1,0,0);

        glRotated(a,0,0,1);

        glutWireTorus(0.2,0.8,slices,stacks);

    glPopMatrix();

    glutSwapBuffers();

}

static void key(unsigned char key, int x, int y)

{

    switch (key)

    {

        case 27 :

        case 'q':

            exit(0);

            break;

        case '+':

            slices++;

            stacks++;

            break;

        case '-':

            if (slices>3 && stacks>3)

            {

                slices--;

                stacks--;

            }

            break;

    }

    glutPostRedisplay();

}

static void idle(void)

{

    glutPostRedisplay();

}

const GLfloat light_ambient[]  = { 0.0f, 0.0f, 0.0f, 1.0f };

const GLfloat light_diffuse[]  = { 1.0f, 1.0f, 1.0f, 1.0f };

const GLfloat light_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };

const GLfloat light_position[] = { 2.0f, 5.0f, 5.0f, 0.0f };

const GLfloat mat_ambient[]    = { 0.7f, 0.7f, 0.7f, 1.0f };

const GLfloat mat_diffuse[]    = { 0.8f, 0.8f, 0.8f, 1.0f };

const GLfloat mat_specular[]   = { 1.0f, 1.0f, 1.0f, 1.0f };

const GLfloat high_shininess[] = { 100.0f };

int main(int argc, char *argv[])

{

    glutInit(&argc, argv);

    glutInitWindowSize(640,480);

    glutInitWindowPosition(10,10);

    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("GLUT Shapes");

    glutReshapeFunc(resize);///攝影機、投影矩陣的設定。 resize(int width,int height)

    glutDisplayFunc(display);

    glutKeyboardFunc(key);

    glutIdleFunc(idle);

    glClearColor(1,1,1,1);///背景顏色設定

    glEnable(GL_CULL_FACE);///較特別：有些面提早決定不要畫

    glCullFace(GL_BACK);///容易設定錯誤

    glEnable(GL_DEPTH_TEST);///3D的深度測試(決定前後，誰近誰遠)

    glDepthFunc(GL_LESS);

    glEnable(GL_LIGHT0);///打光，Light 0 開

    glEnable(GL_NORMALIZE);///打光，裡面的法向 長度 要讓電腦OpenGL重算成1

    glEnable(GL_COLOR_MATERIAL);///打光，material開起來

    glEnable(GL_LIGHTING);///打光，lighting開起來

    glLightfv(GL_LIGHT0, GL_AMBIENT,  light_ambient);///打光，把光設定好

    glLightfv(GL_LIGHT0, GL_DIFFUSE,  light_diffuse);

    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);

    glLightfv(GL_LIGHT0, GL_POSITION, light_position);

    glMaterialfv(GL_FRONT, GL_AMBIENT,   mat_ambient);///打光，把material設定好

    glMaterialfv(GL_FRONT, GL_DIFFUSE,   mat_diffuse);

    glMaterialfv(GL_FRONT, GL_SPECULAR,  mat_specular);

    glMaterialfv(GL_FRONT, GL_SHININESS, high_shininess);

    glutMainLoop();///主要迴圈

    return EXIT_SUCCESS;

}

Week 14 Part 2 - 利用滑鼠來運鏡

加上motion函式，執行過後發現可以利用滑鼠來控制攝影機的方向

#include <math.h>///為了cos和sin

void motion(int x,int y)

{

    float angle = x*3.1415926/180.0;

    float cameraY = (y-300)/100.0;

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity() ;

    gluLookAt(5*cos(angle),cameraY,5*sin(angle)-6,0,0,-6,0,1,0);

    glutPostRedisplay();///每次設定好重畫一次

}