2020電腦圖學A: 2020/06/03-天氣晴

Week16

1.下載3dcg10的data win32 glut.dll
開啟Projection(投影) 了解參數代表的意義並嘗試設定

fov : feild of view
野視
fovy : y方向視野
aspect ratio : 長寬比例
zNear : z方向近的面
zFar : z方向遠的面

2.練習新的函數 : glFrustum

調整左右下上近遠

3.試著用gluPerspective()函式

4.修改專案檔resize裡的程式碼將平行投影改寫成透視投影
glFrustum()=>gluPerspective()

將長寬比改為ar 讓物體大小不會隨著視窗改變而變形
gluPerspective()裡面的aspect ratio用 ar=寬度除高度, 便可順利做出來

5.使用glOrtho()函式

6.試著操作glLookAt()函式
eye : 鏡頭角度
center : 中心點位置(keypoint:要對到物體)
up : 高度

7.改寫專案檔秀出茶壺
#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif

#include <stdlib.h>

static int slices = 16;
static int stacks = 16;

/* GLUT callback Handlers */
float eyeX=0, eyeY=0, eyeZ=1; ///TODO3 for gluLookAt()
float centerX=0, centerY=0, centerZ=0;///TODO3 for gluLookAt()
static void resize(int width, int height)
{
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);
gluPerspective( 60, ar, 0.001, 1000 );///TODO3
///glOrtho(-1,+1, -1,+1, -1,+1);///預設值,很限制
///glOrtho(-3.4, +3.4, -2.2, +2.2, -6.0, +16.0);///TODO2

glMatrixMode(GL_MODELVIEW);
glLoadIdentity() ;///TODO3 for gluLookAt()
gluLookAt(eyeX,eyeY,eyeZ, centerX,centerY,centerZ, 0,1,0);
}

static void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glutSolidTeapot(0.3);///TODO3,只放我們的Teapot

glutSwapBuffers();
}

///key全刪....

static void idle(void)
{
///TODO3: 等一下要在這裡做動作....
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 };

/* Program entry point */

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);
glutDisplayFunc(display);
///glutKeyboardFunc(key);
glutIdleFunc(idle);

glClearColor(1,1,1,1);

glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);

glEnable(GL_LIGHT0);
glEnable(GL_NORMALIZE);
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_LIGHTING);

glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
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);
glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
glMaterialfv(GL_FRONT, GL_SHININESS, high_shininess);

glutMainLoop();

return EXIT_SUCCESS;

}

8.滑鼠移動改變鏡頭位置
加上motion函式
#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif

#include <stdlib.h>

static int slices = 16;
static int stacks = 16;

/* GLUT callback Handlers */
float eyeX=0, eyeY=0, eyeZ=1; ///TODO3 for gluLookAt()
float centerX=0, centerY=0, centerZ=0;///TODO3 for gluLookAt()
static void resize(int width, int height)
{
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);
gluPerspective( 60, ar, 0.001, 1000 );///TODO3
///glOrtho(-1,+1, -1,+1, -1,+1);///預設值,很限制
///glOrtho(-3.4, +3.4, -2.2, +2.2, -6.0, +16.0);///TODO2

glMatrixMode(GL_MODELVIEW);
glLoadIdentity() ;///TODO3 for gluLookAt()
gluLookAt(eyeX,eyeY,eyeZ, centerX,centerY,centerZ, 0,1,0);
}

static void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glutSolidTeapot(0.3);///TODO3,只放我們的Teapot

glutSwapBuffers();
}

///key全刪....

static void idle(void)
{
///TODO3: 等一下要在這裡做動作....
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 };

void motion(int x,int y)
{
eyeX=(x-320)/320.0;
eyeY=(y-240)/240.0;
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(eyeX,eyeY,eyeZ,centerX,centerY,centerZ,0,1,0);
}

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);
glutDisplayFunc(display);
///glutKeyboardFunc(key);
glutIdleFunc(idle);
glutMotionFunc(motion);

glClearColor(1,1,1,1);

glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);

glEnable(GL_LIGHT0);
glEnable(GL_NORMALIZE);
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_LIGHTING);

glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
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);
glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
glMaterialfv(GL_FRONT, GL_SHININESS, high_shininess);

glutMainLoop();

return EXIT_SUCCESS;

}