OpenGL立方体在世界坐标系中_缩放_旋转_平移_顶点片源着色器_光照作用_棋盘纹理贴图

读取bmp等图片格式中的像素还有难度，就先用这个棋盘图象素来弄了

代码打错一个就一直First-chance exception ，貌似还有一个要用q或者Q才能成功退出，不知道缺少哪句，我用窗口红叉退出也会First-chance exception

glTexParameterf写错成glTextureParameteri

随手来个链接https://www.opengl.org/sdk/docs/man/html/glTexParameter.xhtml

//
// 绘制一个旋转的OpenGL立方体在世界坐标系中_缩放_旋转_平移_顶点片源着色器_光照作用
// 使用空闲回调函数增加旋转的角度
//  立方体的旋转角度被发送到用于实现立方体旋转的顶点着色器中

#include "Angel.h"
#pragma comment(lib, "glew32.lib")

typedef Angel::vec4  color4;
typedef Angel::vec4  point4;

const int NumVertices = ; //(6 faces)(2 triangles/face)(3 vertices/triangle)

point4 points[NumVertices];
vec3 normals[NumVertices];//法向量标记

// Vertices of a unit cube centered at origin, sides aligned with axes
point4 vertices[] = {
    point4(-0.5, -0.5, 0.5, 1.0),
    point4(-0.5, 0.5, 0.5, 1.0),
    point4(0.5, 0.5, 0.5, 1.0),
    point4(0.5, -0.5, 0.5, 1.0),
    point4(-0.5, -0.5, -0.5, 1.0),
    point4(-0.5, 0.5, -0.5, 1.0),
    point4(0.5, 0.5, -0.5, 1.0),
    point4(0.5, -0.5, -0.5, 1.0)
};

const int texturesize = ; //新增或有更改
GLuint textureloc;//新增或有更改
GLubyte imageRBG[texturesize][texturesize][];//新增或有更改
vec2 tex_coords[NumVertices];//新增或有更改

void imageinit()//新增或有更改
{
    for (int i = ; i < ; i++)
    {
        for (int j = ; j < ; j++)
        {
            GLubyte c = (((i & 0x8) == ) ^ ((j & 0x8) == ) )*;
            imageRBG[i][j][] = imageRBG[i][j][] = imageRBG[i][j][] = c;
        }
    }
    glGenTextures(, &textureloc);//产生一个纹理对象标志符并存在地址textureloc中

    glBindTexture(GL_TEXTURE_2D, textureloc);
    glTexImage2D(GL_TEXTURE_2D, , GL_RGB, texturesize, texturesize, , GL_RGB, GL_UNSIGNED_BYTE, imageRBG);
    //target90FL_TEXTURE_[1,2,3]D或者GL_TEXTURE_CUBE_MAP;level,iformat,width,height,border,format,type,&textureeloc;

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);//写错成glTextureParameteri
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glActiveTexture(GL_TEXTURE1);
    glBindTexture(GL_TEXTURE_2D, textureloc);

}//新增或有更改

// Array of rotation angles (in degrees) for each coordinate axis
//enum { Xaxis = 0, Yaxis = 1, Zaxis = 2, NumAxes = 3 };
//enum { Xdist = 0, Ydist = 1, Zdist = 2, NumAxes1 = 3 };
color4 gr = color4(1.0, 1.0, 1.0, 1.0);
color4 onecolor = color4(1.0, 0.0, 0.0, 1.0);
color4 light_ex;
int      Axi = ;//Xaxis;
GLfloat  Thet[] = { 0.0, 0.0, 0.0 };
//GLfloat  Atha[3] = { 0.0, 0.0, 0.0 };
GLfloat Disx = ;
GLfloat Dis = ;
GLfloat fd = ;

GLuint  thet;  // The location of the "theta" shader uniform variable
GLuint atha;
GLuint direct;
GLuint f;
GLuint vam;
//----------------------------------------------------------------------------

// quad generates two triangles for each face and assigns colors
//    to the vertices
int Index = ;
void
quad(int a, int b, int c, int d)
{
    vec4 u = vertices[b] - vertices[a];
    vec4 v = vertices[c] - vertices[b];
    vec3 normal = normalize(cross(u, v));//normalize叉乘得到法向量
    normals[Index] = normal; points[Index] = vertices[a]; tex_coords[Index] = vec2(0.0, 0.0); Index++;////新增或有更改
    normals[Index] = normal; points[Index] = vertices[b]; tex_coords[Index] = vec2(0.0, 1.0); Index++;////新增或有更改
    normals[Index] = normal; points[Index] = vertices[c]; tex_coords[Index] = vec2(1.0, 1.0); Index++;////新增或有更改
    normals[Index] = normal; points[Index] = vertices[a]; tex_coords[Index] = vec2(0.0, 0.0); Index++;////新增或有更改
    normals[Index] = normal; points[Index] = vertices[c]; tex_coords[Index] = vec2(1.0, 1.0); Index++;////新增或有更改
    normals[Index] = normal; points[Index] = vertices[d]; tex_coords[Index] = vec2(1.0, 0.0); Index++;////新增或有更改
}

//----------------------------------------------------------------------------

// generate 12 triangles: 36 vertices and 36 colors
void
colorcube()
{
    quad(, , , );
    quad(, , , );
    quad(, , , );
    quad(, , , );
    quad(, , , );
    quad(, , , );
}

//----------------------------------------------------------------------------

// OpenGL initialization
void
init()
{
    colorcube();//新增或有更改
    imageinit();//新增或有更改

    // Create a vertex array object
    GLuint vao;
    glGenVertexArrays(, &vao);
    glBindVertexArray(vao);

    // Create and initialize a buffer object
    GLuint buffer;
    glGenBuffers(, &buffer);

    glBindBuffer(GL_ARRAY_BUFFER, buffer);
    glBufferData(GL_ARRAY_BUFFER, sizeof(points) + sizeof(normals) + sizeof(tex_coords), NULL, GL_STATIC_DRAW);//

    glBufferSubData(GL_ARRAY_BUFFER, , sizeof(points), points);
    glBufferSubData(GL_ARRAY_BUFFER, sizeof(points), sizeof(normals), normals);
    glBufferSubData(GL_ARRAY_BUFFER, sizeof(points) + sizeof(normals), sizeof(tex_coords), tex_coords);//新增或有更改

    // Load shaders and use the resulting shader program
    GLuint program = InitShader("vshader.glsl", "fshader.glsl");
    glUseProgram(program);

    // set up vertex arrays
    GLuint vPosition = glGetAttribLocation(program, "vPosition");
    glEnableVertexAttribArray(vPosition);
    glVertexAttribPointer(vPosition, , GL_FLOAT, GL_FALSE, ,BUFFER_OFFSET());

    GLuint vNormal = glGetAttribLocation(program, "vNormal");
    glEnableVertexAttribArray(vNormal);
    glVertexAttribPointer(vNormal, , GL_FLOAT, GL_FALSE, , BUFFER_OFFSET(sizeof(points)));

    GLuint vTexCoord = glGetAttribLocation(program, "vtexCoord");////新增或有更改
    glEnableVertexAttribArray(vTexCoord);////新增或有更改
    glVertexAttribPointer(vTexCoord, , GL_FLOAT, GL_FALSE, , BUFFER_OFFSET(sizeof(points) + sizeof(normals)));////新增或有更改

    //初始化光照参数la,ld,ls环境，漫反射，镜面反射
    point4 light_position(0.0, 0.0, 2.0,-0.0);
    //color4 light_ambient(1.0,0.0,0.0,1.0);//R红_G绿_B蓝
    color4 light_diffuse(1.0, 1.0, 1.0, 1.0);
    color4 light_specular(1.0, 1.0, 1.0, 1.0);

    color4 material_ambient(1.0, 0.0, 1.0, 1.0);
    color4 material_diffuse(1.0, 0.8, 0.0, 1.0);
    color4 material_specular(1.0, 0.8, 0.0, 1.0);
    float material_shininess = 20.0;//高光系数 高金属 低塑料

    light_ex = material_ambient;
    //color4 ambient_product = light_ambient*material_ambient;
    color4 diffuse_product = light_diffuse*material_diffuse;
    color4 specular_product = light_specular*material_specular;

    glUniform4fv(glGetUniformLocation(program, "DiffuseProduct"), , diffuse_product);
    glUniform4fv(glGetUniformLocation(program, "SpecularProduct"), , specular_product);
    glUniform4fv(glGetUniformLocation(program, "LightPosition"), , light_position);
    glUniform1f(glGetUniformLocation(program,"Shininess"),material_shininess);

    vam = glGetUniformLocation(program, "AmbientProduct");
    thet = glGetUniformLocation(program, "theta");
    atha = glGetUniformLocation(program, "athat");
    direct = glGetUniformLocation(program, "direct");
    f = glGetUniformLocation(program, "ff");

    glUniform1i(glGetUniformLocation(program, "texture"), );//新增或有更改
    //texture在vshader里面，后面的1对应glActiveTexture(GL_TEXTURE1);
    //如果0，那么对应glActiveTexture(GL_TEXTURE0);
    //如果3，那么对应glActiveTexture(GL_TEXTURE3);

    glEnable(GL_DEPTH_TEST);///开启深度缓存测试
    glEnable(GL_CULL_FACE);///启动多边形剔除功能

    //glOrtho(1.0, 0.0, 0.0, 1.0, 0.0, 1.0);

}

//----------------------------------------------------------------------------

void
display(void)
{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    //glMatrixMode(GL_PROJECTION);
    //glMatrixMode(GL_MODELVIEW);
    //glLoadIdentity();
    //gluLookAt(1.0, 1.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.1, 0.0);
    glUniform4fv(vam, , light_ex*onecolor);
    glUniform3fv(thet, , Thet);
    glUniform1f(atha, Disx);
    glUniform1f(direct, Dis);//传递单个的
    glUniform1f(f, fd);
    glDrawArrays(GL_TRIANGLES, , NumVertices);
    glClearColor(gr[], gr[], gr[], gr[]);
    glFlush();
}

void ProcessMenu(int value)
{
    if (value == )
        exit();

    if (value == )
    {
        gr = vec4(1.0f, 1.0f, 1.0f, 1.0f);
        onecolor = vec4(1.0, 0.0, 1.0, 1.0);
    }
    else{

        switch (value)
        {
        case :gr = vec4(0.75f, 0.0f, 1.0f, 1.0f); break;
        case :gr = vec4(0.75f, 0.75f, 1.0f, 1.0f); break;
        case :gr = vec4(1.75f, 1.75f, 0.75f, 1.0f); break;
        case :gr = vec4(1.75f, 1.0f, 1.55f, 1.0f); break;
        case :gr = vec4(0.0f, 1.0f, 0.75f, 0.0f); break;
        case :onecolor = color4(0.0, 0.0, 0.0, 1.0); break;//黑色
        case :onecolor = color4(0.0, 0.0, 1.0, 1.0); break;//蓝色
        case :onecolor = color4(1.0, 0.0, 1.0, 1.0); break;//品红色
        case :onecolor = color4(0.0, 1.0, 1.0, 1.0); break;//青色
        }
    }
    glutSwapBuffers();
    glutPostRedisplay();
}

//----------------------------------------------------------------------------

void
keyboard(unsigned char key, int x, int y)
{
    switch (key) {
    case 'x':    Axi = ; break; //Xaxis;  break;
    case 'y':    Axi = ; break;//Yaxis;  break;
    case 'z':    Axi = ; break;//Zaxis;  break;选择对应的x，y，z旋转角度来变化
    case 'f':fd += 0.1; break;//Xdist; break;
    case 's':fd -= 0.1; break;//Ydist; break;
    case : // Escape Key
    case 'q': case 'Q':
        exit(EXIT_SUCCESS);
        break;
    }
    if (fd == )fd = 0.1;
}
void SpecialKeys(int key, int x, int y)
{
    switch (key) {
    case GLUT_KEY_UP:Dis += 0.01;  break;
    case GLUT_KEY_DOWN:Dis -= 0.01;  break;//Ydist; break;
    case GLUT_KEY_LEFT:Disx -= 0.01;   break;
    case GLUT_KEY_RIGHT:Disx += 0.01;   break;//Xdist; break;
    case : // Escape Key
    case 'q': case 'Q':
        exit(EXIT_SUCCESS);
        break;
    }
}

//----------------------------------------------------------------------------

//----------------------------------------------------------------------------

void
idle(void)
{
    Thet[Axi] += 0.01;

    if (Thet[Axi] > 360.0) {
        Thet[Axi] -= 360.0;
    }
    glutSwapBuffers();
    glutPostRedisplay();
}

//----------------------------------------------------------------------------

int
main(int argc, char **argv)
{

    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH);
    glutInitWindowSize(, );
    glutInitContextVersion(, );
    //这里在舍友的电脑上用3，2可以用，在我的电脑上会出现
    //freeglut（dll地址）：unableto create OpenGL3.2 context（flags 0， profile 1）
    //我改成3，1就可以了。不知道会不会是版本问题。这里用的是比较旧的版本freeglut。

    glutInitContextProfile(GLUT_CORE_PROFILE);
    glutCreateWindow("Color Cube");

    glewExperimental = true;
    glewInit();
    int nGlutColorMenu1 = glutCreateMenu(ProcessMenu);
    glutAddMenuEntry("black", );
    glutAddMenuEntry("blue", );
    glutAddMenuEntry("magenta", );
    glutAddMenuEntry("cyan", );

    int nGlutColorMenu2 = glutCreateMenu(ProcessMenu);
    glutAddMenuEntry("background1", );
    glutAddMenuEntry("background2", );
    glutAddMenuEntry("background3", );
    glutAddMenuEntry("background4", );
    glutAddMenuEntry("background5", );

    int nGlutColorMenu3 = glutCreateMenu(ProcessMenu);
    glutAddMenuEntry("return", );

    int nGlutColorMenu = glutCreateMenu(ProcessMenu);
    glutAddSubMenu("coclor", nGlutColorMenu1);
    glutAddSubMenu("background", nGlutColorMenu2);
    glutAddSubMenu("return", nGlutColorMenu3);
    glutAttachMenu(GLUT_RIGHT_BUTTON);
    init();
    glutDisplayFunc(display);
    glutSpecialFunc(SpecialKeys);
    glutKeyboardFunc(keyboard);
    //glutMouseFunc(mouse);
    glutIdleFunc(idle);

    glutMainLoop();
    return ;
}

vshader.glsl

#version 

in vec2 vtexCoord;////新增或有更改
in  vec4 vPosition;
in vec3 vNormal;

out vec2 texCoord;////新增或有更改
out vec4 color;

uniform vec4 AmbientProduct,DiffuseProduct,SpecularProduct;
uniform vec4 LightPosition;
uniform float Shininess;
uniform vec3 theta;
uniform float athat;
uniform float direct;
uniform float ff;
void main()
{
   texCoord=vtexCoord;////新增或有更改
    vec3 angles = radians( theta );
    vec3 c = cos( angles );
    vec3 s = sin( angles );

     mat4 rx = mat4( 1.0,  0.0,  0.0, 0.0,
            0.0,  c.x,  s.x, 0.0,
            0.0, -s.x,  c.x, 0.0,
            0.0,  0.0,  0.0, 1.0 );

    mat4 ry = mat4( c.y, 0.0, -s.y, 0.0,
            0.0, 1.0,  0.0, 0.0,
            s.y, 0.0,  c.y, 0.0,
            0.0, 0.0,  0.0, 1.0 );

    // Workaround for bug in ATI driver
    ry[][] = 0.0;
    ry[][] = 1.0;

    mat4 rz = mat4( c.z, s.z, 0.0, 0.0,
            -s.z,  c.z, 0.0, 0.0,
            0.0,  0.0, 1.0, 0.0,
            0.0,  0.0, 0.0, 1.0 );

    // Workaround for bug in ATI driver
    rz[][] = 1.0;

    //color = vColor;
    mat4 t=mat4(1.0,0.0,0.0,0.0,
    0.0,1.0,0.0,0.0,
    0.0,0.0,1.0,0.0,
    athat,direct,0.0,1.0); 

    mat4 sf=mat4(ff,0.0,,,
    0.0,ff,0.0,0.0,
    0.0,0.0,ff,0.0,
    0.0,0.0,0.0,1.0);
    mat4 modeview=t*rx*rz*ry;
    vec3 pos=(modeview*vPosition).xyz;

    vec3 L=normalize(LightPosition.xyz-pos);
    vec3 E=normalize(-pos);
    vec3 H=normalize(L+E);

    vec3 N=normalize(modeview*vec4(vNormal,0.0)).xyz;

    vec4 ambient=AmbientProduct;

    float Kd=max(dot(L,N),0.0);
    vec4 diffuse=Kd*DiffuseProduct;
       float Ks=pow(max(dot(N,H),0.0),Shininess);
       vec4 specular=Ks*SpecularProduct;
    if(dot(L,N)<0.0)

     specular=vec4(0.0,0.0,0.0,1.0);
    gl_Position =modeview*sf*vPosition;
    color=ambient+diffuse+specular;
    color.a=1.0;
} 

fshader.glsl

#version
in vec2 texCoord;////新增或有更改
in  vec4 color;
out vec4 fColor;

uniform sampler2D texture;////新增或有更改
void main()
{ 

    fColor = color*texture2D(texture,texCoord);////新增或有更改
} 

InitShader.cpp

#include "Angel.h"

namespace Angel {

// Create a NULL-terminated string by reading the provided file
static char*
readShaderSource(const char* shaderFile)
{
    //FILE* fp = fopen(shaderFile, "r");
    //由于vs甚么安全性的原因，不让使用fopen，用下面的fopen_s代替；
    FILE *fp;
    fopen_s(&fp, shaderFile, "r");

    if ( fp == NULL ) { return NULL; }

    fseek(fp, 0L, SEEK_END);
    long size = ftell(fp);

    fseek(fp, 0L, SEEK_SET);
    char* buf = new char[size + ];
    fread(buf, , size, fp);

    buf[size] = '\0';
    fclose(fp);

    return buf;
}

// Create a GLSL program object from vertex and fragment shader files
GLuint
InitShader(const char* vShaderFile, const char* fShaderFile)
{
    struct Shader {
    const char*  filename;
    GLenum       type;
    GLchar*      source;
    }  shaders[] = {
    { vShaderFile, GL_VERTEX_SHADER, NULL },
    { fShaderFile, GL_FRAGMENT_SHADER, NULL }
    };

    GLuint program = glCreateProgram();

    for ( int i = ; i < ; ++i ) {
    Shader& s = shaders[i];
    s.source = readShaderSource( s.filename );
    if ( shaders[i].source == NULL ) {
        std::cerr << "Failed to read " << s.filename << std::endl;
        exit( EXIT_FAILURE );
    }

    GLuint shader = glCreateShader( s.type );
    glShaderSource( shader, , (const GLchar**) &s.source, NULL );
    glCompileShader( shader );

    GLint  compiled;
    glGetShaderiv( shader, GL_COMPILE_STATUS, &compiled );
    if ( !compiled ) {
        std::cerr << s.filename << " failed to compile:" << std::endl;
        GLint  logSize;
        glGetShaderiv( shader, GL_INFO_LOG_LENGTH, &logSize );
        char* logMsg = new char[logSize];
        glGetShaderInfoLog( shader, logSize, NULL, logMsg );
        std::cerr << logMsg << std::endl;
        delete [] logMsg;

        exit( EXIT_FAILURE );
    }

    delete [] s.source;

    glAttachShader( program, shader );
    }

    /* link  and error check */
    glLinkProgram(program);

    GLint  linked;
    glGetProgramiv( program, GL_LINK_STATUS, &linked );
    if ( !linked ) {
    std::cerr << "Shader program failed to link" << std::endl;
    GLint  logSize;
    glGetProgramiv( program, GL_INFO_LOG_LENGTH, &logSize);
    char* logMsg = new char[logSize];
    glGetProgramInfoLog( program, logSize, NULL, logMsg );
    std::cerr << logMsg << std::endl;
    delete [] logMsg;

    exit( EXIT_FAILURE );
    }

    /* use program object */
    glUseProgram(program);

    return program;
}

}  // Close namespace Angel block