ClassNote_Week04 移動 & 旋轉 & 縮放 & 滑鼠移動

1. 移動

。以下程式碼為例
glPushMatrix();
 glTranslated(-2.4,1.2,-6);  /// 移動(X,Y,Z)  d表double
 glRotated(60,1,0,0);
 glRotated(a,0,0,1);
 glScalef(1,1,1);
 glutSolidSphere(1,slices,stacks);
glPopMatrix();

2. 旋轉

。以下程式碼為例
glPushMatrix();
 glTranslated(-2.4,1.2,-6);
 /// 旋轉(度數,X,Y,Z)  X,Y,Z軸表向量
 glRotated(60,1,0,0);  /// 沿著x軸轉動60度
 glRotated(a,0,0,1);    /// 沿著z軸每秒轉動90度
 glScalef(1,1,1);
 glutSolidSphere(1,slices,stacks);
glPopMatrix();

✤依照右手座標系統旋轉

3. 縮放

。以下程式碼為例
glPushMatrix();
 glTranslated(-2.4,1.2,-6);
 glRotated(60,1,0,0);
 glRotated(a,0,0,1);
 glScalef(1,1,1);  /// 縮放比率(X,Y,Z)
 glutSolidSphere(1,slices,stacks);
glPopMatrix();

4. 用滑鼠移動

。以下程式碼為例
#include <GL/glut.h>
#include <stdio.h>
float dx=0.0,dy=0.0,dz=0.0;
int oldX=0,oldY=0,oldZ=0;

void display(){
 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 glPushMatrix();
 glTranslated(dx,dy,dz);
 glutSolidTeapot(0.3);
 glPopMatrix();
 glutSwapBuffers();
}

void mouse(int button, int state, int x, int y){
 if(state==GLUT_DOWN){  /// 如果按下滑鼠
  oldX=x;
  oldY=y;
 }
}

void motion(int x, int y){
 dx += (x-oldX)/150.0;
 dy += -(y-oldY)/150.0;         /// Y座標上下顛倒所以要加負號
 oldX = x;
 oldY = y;
 glutPostRedisplay();             /// 畫面刷新
}

int main(int argc, char *argv[]){
 glutInit(&argc, argv);
 glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 glutCreateWindow("week 04");
 glutDisplayFunc(display);
 glutMouseFunc(mouse);
 glutMotionFunc(motion);
 glutMainLoop();
 return EXIT_SUCCESS;
}