OpenGL学习笔记4_2（透视相关）

蓝宝书 第四章

正交投影

在ChangeSize函数中使用glOrtho函数调整

glOrtho参考：点击打开链接

正交投影ChangeSize代码参考

void ChangeSize(GLsizei w, GLsizei h){GLfloat nRange = 100.0f;// Prevent a divide by zero  if (h == 0)h = 1;// Set Viewport to window dimensions  glViewport(0, 0, w, h);// Reset projection matrix stack  glMatrixMode(GL_PROJECTION);glLoadIdentity();// Establish clipping volume (left, right, bottom, top, near, far)  if (w <= h)glOrtho(-nRange, nRange, -nRange*h / w, nRange*h / w, -nRange, nRange);elseglOrtho(-nRange*w / h, nRange*w / h, -nRange, nRange, -nRange, nRange);// Reset Model view matrix stack  glMatrixMode(GL_MODELVIEW);glLoadIdentity();}

透视投影

在ChangeSize函数中使用gluPerspective函数调整

gluPerspective参考：点击打开链接

透视投影ChangeSize代码参考

void ChangeSize(GLsizei w, GLsizei h){GLfloat fAspect;// Prevent a divide by zeroif (h == 0)h = 1;// Set viewport to window dimensionsglViewport(0, 0, w, h);fAspect = (GLfloat)w / (GLfloat)h;// Reset coordinate systemglMatrixMode(GL_PROJECTION);glLoadIdentity();// Produce the perspective projectiongluPerspective(60.0f, fAspect, 1.0, 400.0);glMatrixMode(GL_MODELVIEW);glLoadIdentity();}

glOrtho函数和gluPerspective的作用是在整个世界中勾出一个视线可以达到的范围

例4.3 太阳地球月亮模型

光源参考：点击打开链接

#include <windows.h>  #include <math.h>  #include <GL\GL.h>  #include <GL\GLU.h>  #include <GL\glut.h>   void RenderScene(void){static float fMoonRot = 0.0f;static float fEarthRot = 0.0f;glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);glMatrixMode(GL_MODELVIEW);glPushMatrix();glTranslatef(0.0f, 0.0f, -300.0f);//sunglColor3ub(255, 255, 0);glDisable(GL_LIGHTING);glutSolidSphere(15.0f, 15, 15);glEnable(GL_LIGHTING);GLfloat lightPos[] = { 0.0f, 0.0f, 0.0f, 1.0f};glLightfv(GL_LIGHT0, GL_POSITION, lightPos);glRotatef(fEarthRot, 0.0f, 1.0f, 0.0f);glColor3ub(0, 0, 255);glTranslatef(105.0f, 0.0f, 0.0f);glutSolidSphere(15.0f, 15, 15);glColor3ub(200, 200, 200);glRotatef(fMoonRot, 0.0f, 1.0f, 0.0f);glTranslatef(30.0f, 0.0f, 0.0f);fMoonRot += 15.0f;if (fMoonRot > 360.0f)fMoonRot = 0.0f;glutSolidSphere(6.0f, 15, 15);glPopMatrix(); // Modelview matrixfEarthRot += 5.0f;if (fEarthRot > 360.0f)fEarthRot = 0.0f;// Show the imageglutSwapBuffers();}void SetupRC(){glEnable(GL_DEPTH_TEST);glFrontFace(GL_CCW);glEnable(GL_CULL_FACE);glEnable(GL_LIGHTING);glEnable(GL_LIGHT0);glEnable(GL_COLOR_MATERIAL);// Black backgroundglClearColor(0.0f, 0.0f, 0.0f, 1.0f);}void timerProc(int id){RenderScene();glutTimerFunc(100, timerProc, 1);}void ChangeSize(GLsizei w, GLsizei h){GLfloat fAspect;// Prevent a divide by zeroif (h == 0)h = 1;// Set viewport to window dimensionsglViewport(0, 0, w, h);fAspect = (GLfloat)w / (GLfloat)h;// Reset coordinate systemglMatrixMode(GL_PROJECTION);glLoadIdentity();// Produce the perspective projectiongluPerspective(45.0f, fAspect, 1.0, 425.0);glMatrixMode(GL_MODELVIEW);glLoadIdentity();}int main(int argc, char* argv[]){glutInit(&argc, argv);glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);glutInitWindowSize(800, 600);glutCreateWindow("Earth & Moon & Sun System");glutDisplayFunc(RenderScene);//显示回调函数  glutReshapeFunc(ChangeSize);//窗口大小变形回调函数  glutTimerFunc(100, timerProc, 1);SetupRC();glutMainLoop();return 0;}