Week 04

 Week 04

    去https://jsyeh.org/3dcg10/下載data和win32，把data解壓縮後放進win32的解壓縮，然後打開transform.exe

    glRotatef(  0.0,  0.00,  0.00,  0.00)

                     角度, x軸,  y軸,    z軸

        第一個為控制角度

     為1.00時X軸為旋轉軸

    為1.00時Y軸為旋轉軸

    為1.00時Z軸為旋轉軸

    

    現在我們把茶壺一直旋轉

#include <GL/glut.h>

float angle = 0;

void display()

{

glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );///清理背景不清會有殘影

glPushMatrix();///備份矩陣

        glRotatef(angle,0,1,0);

        glutSolidTeapot( 0.3 );

    glPopMatrix();/// 還原矩陣

glutSwapBuffers();

angle++;///把角度++

}

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

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("GLUT Shapes");

    glutDisplayFunc(display);

    glutIdleFunc(display);///清畫面

    glutMainLoop();

}

現在把茶壺打光

#include <GL/glut.h>

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 myLight(){

    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);

}

float angle = 0;

void display()

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

    glRotatef(angle,0,1,0);

    glutSolidTeapot(0.3);

    glPopMatrix();

    glutSwapBuffers();

    angle++;

}

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

{

glutInit(&argc, argv);

glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

glutCreateWindow("GLUT Shapes");

glutDisplayFunc(display);

glutIdleFunc(display);

myLight();

glutMainLoop();

}

現在我們把旋轉茶壺加顏色和清掉背景

#include <GL/glut.h>

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 myLight(){

    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);

}

float angle = 0;

void display()

{

    glClearColor(1,1,1,1); ///用來清理背景

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

    glRotatef(angle,0,1,0);

    glColor3f(1,1,0);///加色彩

    glutSolidTeapot(0.3);

    glPopMatrix();

    glutSwapBuffers();

    angle++;

}

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

{

glutInit(&argc, argv);

glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

glutCreateWindow("GLUT Shapes");

glutDisplayFunc(display);

glutIdleFunc(display);

myLight();

glutMainLoop();

}

現在我們來了解一下win32裡面transformation.exe的旋轉原理

glTranslatef識字轉平面線錄影機一樣動，而glRotate是會繞車子公轉

現在來理解一夏glTranslatef和glRotate先後 跑的結果

#include <GL/glut.h>

float angle = 0;///宣告 global 全域變數 angle

void display()

{

    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); ///清背景

    glPushMatrix(); ///備份矩陣

        glTranslatef( 0.6, 0, 0);///平面轉

        glRotatef(angle, 0, 1, 0);///公轉

        glColor3f(1,1,0);

        glutSolidTeapot( 0.3 );

    glPopMatrix(); ///還原矩陣

    glPushMatrix(); ///備份矩陣

        glRotatef(angle, 0, 1, 0);///公轉

        glTranslatef( 0.6, 0, 0);///平面轉

        glColor3f(1,0,0);

        glutSolidTeapot( 0.3 );

    glPopMatrix(); ///還原矩陣

    glutSwapBuffers();

    angle++;

}

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

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE|GLUT_DEPTH);

    glutCreateWindow("week04");

    glutDisplayFunc(display);

    glutIdleFunc(display);///有空idle時,就重畫畫面

    glutMainLoop();

}