Lane-学习OpenGL(4)-4个进阶例子

运行环境:

(1)Windows 7

(2)CodeBlocks

(3)GLUT

(4)Author:Lane

2014-12-19

1.经过纹理贴图的棋盘

#include <windows.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>

#include <cstdlib>
#include <cstdio>
#include <cmath>

#define checkImageWidth 64
#define checkImageHeight 64
static GLubyte checkImage[checkImageHeight][checkImageWidth][4];

static GLuint texName;

void makeCheckImage(void){
    int i,j,c;
    for(i = 0; i < checkImageHeight; i++){
        for(j = 0; j < checkImageWidth; j++){
            c = (((i&0x8)==0)^((j&0x8))==0)*255;
            checkImage[i][j][0] = (GLubyte)c;
            checkImage[i][j][1] = (GLubyte)c;
            checkImage[i][j][2] = (GLubyte)c;
            checkImage[i][j][3] = (GLubyte)255;
        }
    }
}

void init(void){
    glClearColor(0.0,0.0,0.0,0.0);
    glShadeModel(GL_FLAT);
    glEnable(GL_DEPTH_TEST);
    makeCheckImage();
    glPixelStorei(GL_UNPACK_ALIGNMENT,1);
    glGenTextures(1,&texName);
    glBindTexture(GL_TEXTURE_2D,texName);

    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
    glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,checkImageWidth,checkImageHeight,0,GL_RGBA,GL_UNSIGNED_BYTE,checkImage);
}

void display(void){
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glEnable(GL_TEXTURE_2D);
    glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_REPLACE);
    glBindTexture(GL_TEXTURE_2D,texName);
    glBegin(GL_QUADS);
        glTexCoord2f(0.0,0.0);
        glVertex3f(-2.0,-1.0,0.0);
        glTexCoord2f(0.0,1.0);
        glVertex3f(-2.0,1.0,0.0);
        glTexCoord2f(1.0,1.0);
        glVertex3f(0.0,1.0,0.0);
        glTexCoord2f(1.0,0.0);
        glVertex3f(0.0,-1.0,0.0);

        glTexCoord2f(0.0,0.0);
        glVertex3f(1.0,-1.0,0.0);
        glTexCoord2f(0.0,1.0);
        glVertex3f(1.0,1.0,0.0);
        glTexCoord2f(1.0,1.0);
        glVertex3f(2.41421,1.0,-1.41421);
        glTexCoord2f(1.0,0.0);
        glVertex3f(2.41421,-1.0,-1.41421);
    glEnd();
    glFlush();
    glDisable(GL_TEXTURE_2D);
}

void reshape(int w,int h){
    glViewport(0,0,(GLsizei)w,(GLsizei)h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(60.0,(GLfloat)w/(GLfloat)h,1.0,30.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glTranslatef(0.0,0.0,-3.6);
}

int main(int argc,char** argv){
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB|GLUT_DEPTH);
    glutInitWindowSize(256,256);
    glutInitWindowPosition(100,100);
    glutCreateWindow(argv[0]);
    init();
    glutDisplayFunc(display);
    glutReshapeFunc(reshape);
    //glutKeyboardFunc(keyboard);
    glutMainLoop();
    return 0;
}

2.替换纹理子图像

#include <windows.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>

#include <cstdlib>
#include <cstdio>
#include <cmath>

#define checkImageWidth 64
#define checkImageHeight 64

#define subImageWidth 16
#define subImageHeight 16

static GLubyte checkImage[checkImageHeight][checkImageWidth][4];

static GLubyte subImage[subImageHeight][subImageWidth][4];

static GLuint texName;

void makeCheckImage(void){
    int i,j,c;
    for(i = 0; i < checkImageHeight; i++){
        for(j = 0; j < checkImageWidth; j++){
            c = (((i&0x8)==0)^((j&0x8))==0)*255;
            checkImage[i][j][0] = (GLubyte)c;
            checkImage[i][j][1] = (GLubyte)c;
            checkImage[i][j][2] = (GLubyte)c;
            checkImage[i][j][3] = (GLubyte)255;
        }
    }

    for(i = 0; i < subImageHeight; i++){
        for(j = 0; j < subImageWidth; j++){
            c = (((i&0x4)==0)^((j&0x4)==0)*255);
            subImage[i][j][0] = (GLubyte)c;
            subImage[i][j][1] = (GLubyte)0;
            subImage[i][j][2] = (GLubyte)0;
            subImage[i][j][3] = (GLubyte)255;
        }
    }
}

void keyboard(unsigned char key,int x,int y){
    switch(key){
        case 's':
        case 'S':
            glBindTexture(GL_TEXTURE_2D,texName);
            glTexSubImage2D(GL_TEXTURE_2D,0,12,44,
                            subImageWidth,subImageHeight,GL_RGBA,
                            GL_UNSIGNED_BYTE,subImage);
            glutPostRedisplay();
            break;
        case 'r':
        case 'R':
            glBindTexture(GL_TEXTURE_2D,texName);
            glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,
                         checkImageWidth,checkImageHeight,0,
                         GL_RGBA,GL_UNSIGNED_BYTE,checkImage);
            glutPostRedisplay();
            break;
        case 27:
            exit(0);
            break;
        default:
            break;
    }
}

void init(void){
    glClearColor(0.0,0.0,0.0,0.0);
    glShadeModel(GL_FLAT);
    glEnable(GL_DEPTH_TEST);
    makeCheckImage();
    glPixelStorei(GL_UNPACK_ALIGNMENT,1);
    glGenTextures(1,&texName);
    glBindTexture(GL_TEXTURE_2D,texName);

    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
    glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,checkImageWidth,checkImageHeight,0,GL_RGBA,GL_UNSIGNED_BYTE,checkImage);
}

void display(void){
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glEnable(GL_TEXTURE_2D);
    glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_REPLACE);
    glBindTexture(GL_TEXTURE_2D,texName);
    glBegin(GL_QUADS);
        glTexCoord2f(0.0,0.0);
        glVertex3f(-2.0,-1.0,0.0);
        glTexCoord2f(0.0,1.0);
        glVertex3f(-2.0,1.0,0.0);
        glTexCoord2f(1.0,1.0);
        glVertex3f(0.0,1.0,0.0);
        glTexCoord2f(1.0,0.0);
        glVertex3f(0.0,-1.0,0.0);

        glTexCoord2f(0.0,0.0);
        glVertex3f(1.0,-1.0,0.0);
        glTexCoord2f(0.0,1.0);
        glVertex3f(1.0,1.0,0.0);
        glTexCoord2f(1.0,1.0);
        glVertex3f(2.41421,1.0,-1.41421);
        glTexCoord2f(1.0,0.0);
        glVertex3f(2.41421,-1.0,-1.41421);
    glEnd();
    glFlush();
    glDisable(GL_TEXTURE_2D);
}

void reshape(int w,int h){
    glViewport(0,0,(GLsizei)w,(GLsizei)h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(60.0,(GLfloat)w/(GLfloat)h,1.0,30.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glTranslatef(0.0,0.0,-3.6);
}

int main(int argc,char** argv){
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB|GLUT_DEPTH);
    glutInitWindowSize(256,256);
    glutInitWindowPosition(100,100);
    glutCreateWindow(argv[0]);
    init();
    glutDisplayFunc(display);
    glutReshapeFunc(reshape);
    glutKeyboardFunc(keyboard);
    glutMainLoop();
    return 0;
}

3.使用求值器进行纹理处理

#include <windows.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>

#include <cstdlib>
#include <cstdio>
#include <cmath>

GLfloat ctrlpoints[4][4][3] = {
    {{-1.5,-1.5,4.0},{-0.5,-1.5,2.0},
     {0.5,-1.5,-1.0},{1.5,-1.5,2.0}},
    {{-1.5,-0.5,1.0},{-0.5,-0.5,3.0},
     {0.5,-0.5,0.0},{1.5,-0.5,-1.0}},
    {{-1.5,0.5,4.0},{-0.5,0.5,0.0},
     {0.5,0.5,3.0},{1.5,0.5,4.0}},
    {{-1.5,-1.5,-2.0},{-0.5,1.5,-2.0},
     {0.5,1.5,0.0},{1.5,1.5,-1.0}}
};
GLfloat texpts[2][2][2]={{{0.0,0.0},{0.0,1.0}},{{1.0,0.0},{1.0,1.0}}};

void display(void){
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glColor3f(1.0,1.0,1.0);
    glEvalMesh2(GL_FILL,0,20,0,20);
    glFlush();
}

#define imageWidth 64
#define imageHeight 64

GLubyte image[3*imageWidth*imageHeight];
void makeImage(void){
    int i,j;
    float ti,tj;

    for(i = 0; i < imageWidth;i++){
        ti = 2.0 * 3.14159265*i/imageWidth;
        for(j = 0; j < imageHeight; j++){
            tj = 2.0 * 3.14169265*j/imageHeight;
            image[3*(imageHeight*i+j)]=(GLubyte)127*(1.0+sin(ti));
            image[3*(imageHeight*i+j)]=(GLubyte)127*(1.0+cos(2*tj));
            image[3*(imageHeight*i+j)+2]=(GLubyte)127*(1.0+cos(ti+tj));
        }
    }
}

void init(void){
    glMap2f(GL_MAP2_VERTEX_3,0,1,3,4,0,1,12,4,&ctrlpoints[0][0][0]);
    glMap2f(GL_MAP2_TEXTURE_COORD_2,0,1,2,2,0,1,4,2,&texpts[0][0][0]);
    glEnable(GL_MAP2_TEXTURE_COORD_2);
    glEnable(GL_MAP2_VERTEX_3);
    glMapGrid2f(20,0.0,1.0,20,0.0,1.0);
    makeImage();
    glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_DECAL);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
    glTexImage2D(GL_TEXTURE_2D,0,3,imageWidth,imageHeight,0,GL_RGB,GL_UNSIGNED_BYTE,image);
    glEnable(GL_TEXTURE_2D);
    glEnable(GL_DEPTH_TEST);
    glShadeModel(GL_FLAT);
}

void reshape(int w,int h){
    glViewport(0,0,(GLsizei)w,(GLsizei)h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if(w <= h)
        glOrtho(-4.0,4.0,-4.0*(GLfloat)h/(GLfloat)w,4.0*(GLfloat)h/(GLfloat)w,-4.0,4.0);
    else
        glOrtho(-4.0*(GLfloat)w/(GLfloat)h,4.0*(GLfloat)w/(GLfloat)h,-4.0,4.0,-4.0,4.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glRotatef(35.0,1.0,1.0,1.0);
}

int main(int argc,char** argv){
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB|GLUT_DEPTH);
    glutInitWindowSize(500,500);
    glutInitWindowPosition(100,100);
    glutCreateWindow(argv[0]);
    init();
    glutDisplayFunc(display);
    glutReshapeFunc(reshape);
    glutMainLoop();
    return 0;
}

4.NURBS表面

#include <windows.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>

#include <cstdlib>
#include <cstdio>
#include <cmath>

#ifdef CALLBACK
#define CALLBACK
#endif // CALLBACK

GLfloat ctlpoints[4][4][3];
int showPoints = 0;

GLUnurbsObj *theNurb;

void init_surface(void){
    int u,v;
    for(u=0;u<4;u++){
        for(v=0;v<4;v++){
            ctlpoints[u][v][0]=2.0*((GLfloat)u-1.5);
            ctlpoints[u][v][1]=2.0*((GLfloat)v-1.5);
            if((u==1||u==2)&&(v==1||v==2))
                ctlpoints[u][v][2]=3.0;
            else
                ctlpoints[u][v][2]=-3.0;
        }
    }
}

void CALLBACK nurbsError(GLenum errorCode){
    const GLubyte *estring;
    estring = gluErrorString(errorCode);
    fprintf(stderr,"Nurbs Error:%s \n ",estring);
    exit(0);
}

void init(void){
    GLfloat mat_diffuse[] = {0.7,0.7,0.7,1.0};
    GLfloat mat_specular[] = {1.0,1.0,1.0,1.0};
    GLfloat mat_shininess[] = {100.0};

    glClearColor(0.0,0.0,0.0,0.0);
    glMaterialfv(GL_FRONT,GL_DIFFUSE,mat_diffuse);
    glMaterialfv(GL_FRONT,GL_SPECULAR,mat_specular);
    glMaterialfv(GL_FRONT,GL_SHININESS,mat_shininess);

    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_AUTO_NORMAL);
    glEnable(GL_NORMALIZE);

    init_surface();
    theNurb = gluNewNurbsRenderer();
    gluNurbsProperty(theNurb,GLU_SAMPLING_TOLERANCE,25.0);
    gluNurbsProperty(theNurb,GLU_DISPLAY_MODE,GLU_FILL);
    gluNurbsCallback(theNurb,GLU_ERROR,(void (__stdcall *)(void))nurbsError);
}

void display(void){
    GLfloat knots[8]={0.0,0.0,0.0,0.0,1.0,1.0,1.0,1.0};
    int i,j;

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glPushMatrix();
    glRotatef(330.0,1.0,0.0,0.0);
    glScalef(0.5,0.5,0.5);

    gluBeginSurface(theNurb);
    gluNurbsSurface(theNurb,8,knots,8,knots,4*3,8,&ctlpoints[0][0][0],4,4,GL_MAP2_VERTEX_3);
    gluEndSurface(theNurb);

    if(showPoints){
        glPointSize(5.0);
        glDisable(GL_LIGHTING);
        glColor3f(1.0,1.0,0.0);
        glBegin(GL_POINTS);
        for(i=0;i<4;i++){
            for(j=0;j<4;j++){
                glVertex3f(ctlpoints[i][j][0],ctlpoints[i][j][1],ctlpoints[i][j][2]);
            }
        }
        glEnd();
        glEnable(GL_LIGHTING);
    }
    glPopMatrix();
    glFlush();
}

void reshape(int w,int h){
    glViewport(0,0,(GLsizei)w,(GLsizei)h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.0,(GLdouble)w/(GLdouble)h,3.0,8.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glTranslatef(0.0,0.0,-5.0);
}

void keyboard(unsigned char key,int x,int y){
    switch(key){
        case 'c':
        case 'C':
            showPoints = !showPoints;
            glutPostRedisplay();
            break;
        case 27:
            exit(0);
            break;
        default:
            break;
    }
}

int main(int argc,char** argv){
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB|GLUT_DEPTH);
    glutInitWindowSize(500,500);
    glutInitWindowPosition(100,100);
    glutCreateWindow(argv[0]);
    init();
    glutReshapeFunc(reshape);
    glutDisplayFunc(display);
    glutKeyboardFunc(keyboard);
    glutMainLoop();
    return 0;
}

时间： 2024-10-26 05:42:02

Lane-学习OpenGL(4)-4个进阶例子的相关文章

从零开始学习OpenGL ES之一 – 基本概念

我曾写过一些文章介绍iPhone OpenGL ES编程,但大部分针对的是已经至少懂得一些3D编程知识的人.作为起点,请下载我的OpenGL Xcode项目模板,而不要使用Apple提供的模板.你可以解压到下面位置安装此模板:/Developer/Platforms/iPhoneOS.platform/Developer/Library/Xcode/Project Templates/Application/ 已经有大量有关OpenGL的好教程和书籍.但是,却没有多少是关于OpenGL ES,而

Lane-学习OpenGL(1)-七个简单例子

在看了许多实例之后, 准备沿着OpenGL编程指南(第七版)学习OpenGL. 运行环境: (1)Windows 7 (2)CodeBlocks (3)GLUT (4)Author:Lane 2014-12-02 1.黑色背景加白色矩形 #include <windows.h> #include <GL/gl.h> #include <GL/glu.h> #include <GL/glut.h> #include <cstdlib> #inclu

cocos2D-X源码讲解之从cocos2D-X学习OpenGL（1）----cocos2D-X渲染结构

 个人原创,欢迎转载,转载请注明原文地址http://blog.csdn.net/bill_man 从本篇文章开始,将分析cocos2D-X 3.0源代码,第一部分是从cocos2D-X学习OpenGL,也就是分析cocos2D-X 3.0的渲染代码,本篇首先介绍cocos2D-X 3.0的渲染结构,使用的是3.0正式版. void DisplayLinkDirector::mainLoop() { if (_purgeDirectorInNextLoop) { //只有一种情况会调用到这里来,

基于Cocos2d-x学习OpenGL ES 2.0系列——编写自己的shader（2）

在上篇文章中,我给大家介绍了如何在Cocos2d-x里面绘制一个三角形,当时我们使用的是Cocos2d-x引擎自带的shader和一些辅助函数.在本文中,我将演示一下如何编写自己的shader,同时,我们还会介绍VBO(顶点缓冲区对象)和VAO(顶点数组对象)的基本用法. 在编写自己的shader之前,我觉得有必要提一下OpenGL渲染管线. 理解OpenGL渲染管线,对于学习OpenGL非常重要.下面是OpenGL渲染管线的示意图:(图中淡蓝色区域是可以编程的阶段) 此图是从wiki中拿过来的

Android中关于JNI 的学习（零）简单的例子，简单地入门

Android中JNI的作用,就是让Java能够去调用由C/C++实现的代码,为了实现这个功能,需要用到Anrdoid提供的NDK工具包,在这里不讲如何配置了,好麻烦,配置了好久... 本质上,Java去调用C/C++的代码其实就是去调用C/C++提供的方法,所以,第一步,我们要创建一个类,并且定义一个Native方法,如下: JniTest类: public class JniTest { public native String getTestString(); } 可以看到,在这个方法的前

cocos2D-X源码分析之从cocos2D-X学习OpenGL（3）----BATCH_COMMAND

个人原创,欢迎转载,转载请注明原文地址http://blog.csdn.net/bill_man 上一篇介绍了QUAD_COMMAND渲染命令,顺带介绍了VAO和VBO,这一篇介绍批处理渲染命令BatchCommand,批处理命令的处理在Render中比较简单 else if(commandType == RenderCommand::Type:: BATCH_COMMAND) { //将之前缓存的绘制 flush(); auto cmd = static_cast<BatchCommand*>

Android中关于JNI 的学习（四）简单的例子，温故而知新

在第零篇文章简单地介绍了JNI编程的模式之后,后面两三篇文章,我们又针对JNI中的一些概念做了一些简单的介绍,也不知道我到底说的清楚没有,但相信很多童鞋跟我一样,在刚开始学习一个东西的时候,入门最好的方式就是一个现成的例子来参考,慢慢研究,再学习概念,再回过来研究代码,加深印象,从而开始慢慢掌握. 今天我们就再来做一个小Demo,这个例子会比前面稍微复杂一点,但是如果阅读过前面几篇文章的话,理解起来也还是很简单的.很多东西就是这样,未知的时候很可怕,理解了就很简单了. 1)我们首先定义一个Jav

学习Tensorflow的LSTM的RNN例子

学习Tensorflow的LSTM的RNN例子 基于TensorFlow一次简单的RNN实现 极客学院-递归神经网络 如何使用TensorFlow构建.训练和改进循环神经网络

emberjs学习一(环境和第一个例子)

code { margin: 0; padding: 0; white-space: pre; border: none; background: transparent; } code, pre tt { background-color: transparent; border: none; } --> emberjs学习一(环境和第一个例子) 博客:http://www.cnblogs.com/xiangbing/p/emberjs-test.html 案例:http://www.love