OpenGL programming based on MFC Part 5 transformations

OpenGL programming based on MFC Part 5 transformations-rotations,translations and scaling

Transformations-translation, Rotation and scaling

Translation is no but moving along an arbitrary axis. Rotation is spinning about a arbitrary axis. Scaling is increase or decrease in size along a arbitrary axis. One important point to remember is this OpenGL uses a right hand coordinate system where z-ve in the screen. An object said to is undergoing a transformation could be undergoing a translation, rotation and/or. Understanding different types of transformations work together is very important.

This article will model the Earth around the sun, and it will also have the moon accompanying, and in the following will be added to the mouse and keyboard event response mechanism.

Drawing code

void CCY457OpenGLView::RenderScene ()
{//绘制函数
　　　　//Draw Sun
　　glTranslatef(0.0f,0.0f,-5.0f);
　　glRotatef(6,1.0f,0.0f,0.0f);
　　glutWireSphere(1.0f,20,20);
　　//Draw Planet
　　glPushMatrix();
　　　　glTranslatef(-1.2f,-0.5f,-2.0f);
　　　　glRotatef(6,1.0f,0.0f,0.0f);
　　　　glutWireSphere(0.5f,20,20);
　　　　//Draw Moon
　　　　glPushMatrix();
　　　　　　glTranslatef(-1.2f,-0.5f,-2.0f);
　　　　　　glRotatef(6,1.0f,0.0f,0.0f);
　　　　　　glutWireSphere(0.05f,20,20);
　　　　glPopMatrix();
　　glPopMatrix();
}