使用 OpenGL 对具有不同图像的立方体进行纹理处理

Question

我目前正在从事一个学校项目，我需要对一个仅显示 3 个面的非旋转立方体进行纹理处理。我试过自己做，但我只能在所有 3 张脸上得到一张图像。我不知道是我的方法错误还是我加载剩余两张图像的方式。我非常感谢任何人的帮助。

这就是我加载纹理的方式

GLuint VAO, VBO;
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);

glBindVertexArray(VAO);

glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

// position attribute
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
// texture coord attribute
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
glEnableVertexAttribArray(1);

// this is for texture coords

//Load Image
//int width, height; // width1, height1;
//unsigned char* image = SOIL_load_image("res/images/image1.jpg", &width, &height, 0, SOIL_LOAD_RGBA);

GLuint texture1, texture2, texture3;
// texture 1
// ---------
glGenTextures(1, &texture1);
glBindTexture(GL_TEXTURE_2D, texture1);
// set the texture wrapping parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
// set texture filtering parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// load image, create texture and generate mipmaps
int width, height;
stbi_set_flip_vertically_on_load(true); // tell stb_image.h to flip loaded texture's on the y-axis.
unsigned char* image = SOIL_load_image("res/images/image1.jpg", &width, &height, 0, SOIL_LOAD_RGBA);

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, image);
glGenerateMipmap(GL_TEXTURE_2D);

SOIL_free_image_data(image);
glBindTexture(GL_TEXTURE_2D, 0);
// texture 2
// ---------
glGenTextures(1, &texture2);
glBindTexture(GL_TEXTURE_2D, texture2);
// set the texture wrapping parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
// set texture filtering parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// load image, create texture and generate mipmaps
int width1, height1;
unsigned char* image1 = SOIL_load_image("res/images/image2.jpg", &width1, &height1, 0, SOIL_LOAD_RGBA);

// note that the awesomeface.png has transparency and thus an alpha channel, so make sure to tell OpenGL the data type is of GL_RGBA
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width1, height1, 0, GL_RGBA, GL_UNSIGNED_BYTE, image1);
glGenerateMipmap(GL_TEXTURE_2D);

SOIL_free_image_data(image1);
glBindTexture(GL_TEXTURE_2D, 1);

// texture 3
// ---------
glGenTextures(1, &texture3);
glBindTexture(GL_TEXTURE_2D, texture3);
// set the texture wrapping parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
// set texture filtering parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// load image, create texture and generate mipmaps
int width2, height2;
unsigned char* image2 = SOIL_load_image("res/images/image3.jpg", &width2, &height2, 0, SOIL_LOAD_RGBA);

// note that the awesomeface.png has transparency and thus an alpha channel, so make sure to tell OpenGL the data type is of GL_RGBA
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width2, height2, 0, GL_RGBA, GL_UNSIGNED_BYTE, image2);
glGenerateMipmap(GL_TEXTURE_2D);

SOIL_free_image_data(image2);
glBindTexture(GL_TEXTURE_2D, 2);

// tell opengl for each sampler to which texture unit it belongs to (only has to be done once)
// -------------------------------------------------------------------------------------------
shader.Use();
shader.setInt("texture0", 0); // Function to get UniformLocation
shader.setInt("texture1", 0);
shader.setInt("texture2", 2);

这是我在渲染循环中激活和绑定纹理时的代码

shader.Use();
glActiveTexture(GL_TEXTURE0);
glBindVertexArray(VAO);

glBindTexture(GL_TEXTURE_2D, texture1);

glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(0);

glActiveTexture(GL_TEXTURE1);
glBindVertexArray(VAO);
glBindTexture(GL_TEXTURE_2D, texture2);

glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(0);

glActiveTexture(GL_TEXTURE2);
glBindVertexArray(VAO);
glBindTexture(GL_TEXTURE_2D, texture2);

glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(0);

这是我的程序片段着色器。我真的不知道如何使用我在这里创建的 3 个 sampler2D 变量

#version 330 core
in vec2 textCoords;
//in vec2 textCoords2;
//in vec3 ourColor;

out vec4 color1;
out vec4 color2;

uniform sampler2D texture0;
uniform sampler2D texture1;
uniform sampler2D texture2;

void main()
{
   // color = vec4(ourColor, 1.0f);
    color1 = texture(texture0,textCoords) ;   
    //color2 = texture(texture1,textCoords2);

}

这是我现在使用这段代码得到的结果，但我想要三个面上的不同图像：

Answer 1

您没有正确绑定纹理...

1. 您绑定 txr1 并渲染整个立方体
2. 然后绑定 txr2 并渲染整个立方体
3. 然后绑定 txr3 并渲染整个立方体

所以根据深度测试，您看到的只有 txr1 或 txr3 或一些 z 战斗混乱......

您需要将具有相同纹理的单独面分成单独的 VAO/VBO（而不是将整个立方体放在一个中）

或使用 texture "atlas"（将所有纹理放入单个图像中）并校正纹理坐标...例如这样的：

在新版本中也有可能使用无绑定 teturing（从未使用过，但它应该只是将纹理 id 传递给着色器的问题）

[Edit1] 纹理图集

好的，让我们有一些纹理图集，例如这个（我刚刚编译）：

您可以看到它的 7x7 方形纹理，因此每个纹理 i = 0,1,2,...,7*7-1 都从纹理坐标开始：

x = (i%7)/7.0;
y = (i/7)/7.0;

所以您只需将x,y 添加到每个面的每个顶点的纹理坐标中，其中i 是所选纹理，并将坐标标准化为单个纹理的大小，因此：

x = ((i%7)+x0)/7.0;
y = ((i/7)+y0)/7.0;

x0,y0 是普通纹理的纹理坐标（就像你现在得到的那样），i 是选定的纹理。如果您有不同的图集布局，则只需更改 7 以获取图集中每个轴的纹理 xcount。

我修改了我的complete GL+GLSL+VAO/VBO C++ example 并为立方体添加了纹理：

//---------------------------------------------------------------------------
//--- GL simple ver: 1.002 --------------------------------------------------
//---------------------------------------------------------------------------
// [complete GL+GLSL+VAO/VBO C++ example](https://stackoverflow.com/a/31913542/2521214)
//---------------------------------------------------------------------------
#define GLEW_STATIC
#include "glew.c"
#include <gl\gl.h>
#include <gl\glu.h>
//---------------------------------------------------------------------------
//--- OpenGL GL example -----------------------------------------------------
//---------------------------------------------------------------------------
int     xs,ys;      // screen size
HDC     hdc=NULL;   // device context
HGLRC   hrc=NULL;   // rendering context
int  gl_inicialized=0;
int  gl_init(HWND Handle);
void gl_exit();
void gl_draw();
void gl_resize(int _xs,int _ys);
//---------------------------------------------------------------------------
//--- OpenGL GLSL example ---------------------------------------------------
//---------------------------------------------------------------------------
GLint prog_id=0,    // whole program
      vert_id=0,    // vertex shader
      geom_id=0,    // geometry shader
      frag_id=0;    // fragment shader
char  glsl_log[4096];// compile/link GLSL log
int   glsl_logs=0;
void  glsl_init(char *vert,char *frag);     // create/compile/link GLSL program
void  glsl_exit();
//---------------------------------------------------------------------------
//--- OpenGL VAO example ----------------------------------------------------
//---------------------------------------------------------------------------
#pragma pack(1)
// #define vao_indices
GLuint vbo[5]={-1,-1,-1,-1,-1};
GLuint vao[5]={-1,-1,-1,-1,-1};
const GLfloat vao_pos[]=
    {
//  x    y    z     //ix
    -1.0,+1.0,-1.0, //0
    +1.0,+1.0,-1.0, //1
    +1.0,-1.0,-1.0, //2
    -1.0,-1.0,-1.0, //3

    -1.0,-1.0,+1.0, //4
    +1.0,-1.0,+1.0, //5
    +1.0,+1.0,+1.0, //6
    -1.0,+1.0,+1.0, //7

    #ifndef vao_indices
    -1.0,-1.0,-1.0, //3
    +1.0,-1.0,-1.0, //2
    +1.0,-1.0,+1.0, //5
    -1.0,-1.0,+1.0, //4

    +1.0,-1.0,-1.0, //2
    +1.0,+1.0,-1.0, //1
    +1.0,+1.0,+1.0, //6
    +1.0,-1.0,+1.0, //5

    +1.0,+1.0,-1.0, //1
    -1.0,+1.0,-1.0, //0
    -1.0,+1.0,+1.0, //7
    +1.0,+1.0,+1.0, //6

    -1.0,+1.0,-1.0, //0
    -1.0,-1.0,-1.0, //3
    -1.0,-1.0,+1.0, //4
    -1.0,+1.0,+1.0, //7
    #endif
    };

const GLfloat vao_txr[]=
    {
//  x    y      //ix
    (0.0+0.0)/7.0,(5.0+1.0)/7.0, //0
    (0.0+1.0)/7.0,(5.0+1.0)/7.0, //1
    (0.0+1.0)/7.0,(5.0+0.0)/7.0, //2
    (0.0+0.0)/7.0,(5.0+0.0)/7.0, //3

    (5.0+0.0)/7.0,(5.0+0.0)/7.0, //4
    (5.0+1.0)/7.0,(5.0+0.0)/7.0, //5
    (5.0+1.0)/7.0,(5.0+1.0)/7.0, //6
    (5.0+0.0)/7.0,(5.0+1.0)/7.0, //7

    #ifndef vaices
    (5.0+0.0)/7.0,(4.0+0.0)/7.0, //3
    (5.0+1.0)/7.0,(4.0+0.0)/7.0, //2
    (5.0+1.0)/7.0,(4.0+1.0)/7.0, //5
    (5.0+0.0)/7.0,(4.0+1.0)/7.0, //4

    (3.0+1.0)/7.0,(2.0+0.0)/7.0, //2
    (3.0+1.0)/7.0,(2.0+1.0)/7.0, //1
    (3.0+0.0)/7.0,(2.0+1.0)/7.0, //6
    (3.0+0.0)/7.0,(2.0+0.0)/7.0, //5

    (0.0+1.0)/7.0,(6.0+1.0)/7.0, //1
    (0.0+0.0)/7.0,(6.0+1.0)/7.0, //0
    (0.0+0.0)/7.0,(6.0+0.0)/7.0, //7
    (0.0+1.0)/7.0,(6.0+0.0)/7.0, //6

    (2.0+1.0)/7.0,(6.0+1.0)/7.0, //0
    (2.0+1.0)/7.0,(6.0+0.0)/7.0, //3
    (2.0+0.0)/7.0,(6.0+0.0)/7.0, //4
    (2.0+0.0)/7.0,(6.0+1.0)/7.0, //7
    #endif
    };

const GLfloat vao_col[]=
    {
//  r   g   b    //ix
    0.0,0.0,0.0, //0
    1.0,0.0,0.0, //1
    1.0,1.0,0.0, //2
    0.0,1.0,0.0, //3
    0.0,0.0,1.0, //4
    1.0,0.0,1.0, //5
    1.0,1.0,1.0, //6
    0.0,1.0,1.0, //7

    #ifndef vao_indices
    0.0,0.0,0.0, //0
    1.0,0.0,0.0, //1
    1.0,0.0,1.0, //5
    0.0,0.0,1.0, //4

    1.0,0.0,0.0, //1
    1.0,1.0,0.0, //2
    1.0,1.0,1.0, //6
    1.0,0.0,1.0, //5

    1.0,1.0,0.0, //2
    0.0,1.0,0.0, //3
    0.0,1.0,1.0, //7
    1.0,1.0,1.0, //6

    0.0,1.0,0.0, //3
    0.0,0.0,0.0, //0
    0.0,0.0,1.0, //4
    0.0,1.0,1.0, //7
    #endif
    };

#ifndef vao_indices
const GLfloat vao_nor[]=
    {
//   nx   ny   nz   //ix
     0.0, 0.0,-1.0, //0
     0.0, 0.0,-1.0, //1
     0.0, 0.0,-1.0, //2
     0.0, 0.0,-1.0, //3

     0.0, 0.0,+1.0, //4
     0.0, 0.0,+1.0, //5
     0.0, 0.0,+1.0, //6
     0.0, 0.0,+1.0, //7

     0.0,-1.0, 0.0, //0
     0.0,-1.0, 0.0, //1
     0.0,-1.0, 0.0, //5
     0.0,-1.0, 0.0, //4

    +1.0, 0.0, 0.0, //1
    +1.0, 0.0, 0.0, //2
    +1.0, 0.0, 0.0, //6
    +1.0, 0.0, 0.0, //5

     0.0,+1.0, 0.0, //2
     0.0,+1.0, 0.0, //3
     0.0,+1.0, 0.0, //7
     0.0,+1.0, 0.0, //6

    -1.0, 0.0, 0.0, //3
    -1.0, 0.0, 0.0, //0
    -1.0, 0.0, 0.0, //4
    -1.0, 0.0, 0.0, //7
    };
#endif

#ifdef vao_indices
const GLuint vao_ix[]=
    {
    0,1,2,3,
    4,5,6,7,
    3,2,5,4,
    2,1,6,5,
    1,0,7,6,
    0,3,4,7,
    };
#endif

#pragma pack()
void vao_init();
void vao_exit();
void vao_draw();
//---------------------------------------------------------------------------
//--- bodies: ---------------------------------------------------------------
//---------------------------------------------------------------------------
int gl_init(HWND Handle)
    {
    if (gl_inicialized) return 1;
    hdc = GetDC(Handle);            // get device context
    PIXELFORMATDESCRIPTOR pfd;
    ZeroMemory( &pfd, sizeof( pfd ) );      // set the pixel format for the DC
    pfd.nSize = sizeof( pfd );
    pfd.nVersion = 1;
    pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
    pfd.iPixelType = PFD_TYPE_RGBA;
    pfd.cColorBits = 24;
    pfd.cDepthBits = 24;
    pfd.iLayerType = PFD_MAIN_PLANE;
    SetPixelFormat(hdc,ChoosePixelFormat(hdc, &pfd),&pfd);
    hrc = wglCreateContext(hdc);            // create current rendering context
    if(hrc == NULL)
            {
            ShowMessage("Could not initialize OpenGL Rendering context !!!");
            gl_inicialized=0;
            return 0;
            }
    if(wglMakeCurrent(hdc, hrc) == false)
            {
            ShowMessage("Could not make current OpenGL Rendering context !!!");
            wglDeleteContext(hrc);          // destroy rendering context
            gl_inicialized=0;
            return 0;
            }
    gl_resize(1,1);
    glEnable(GL_DEPTH_TEST);                // Zbuf
    glDisable(GL_CULL_FACE);                // vynechavaj odvratene steny
    glDisable(GL_TEXTURE_2D);               // pouzivaj textury, farbu pouzivaj z textury
    glDisable(GL_BLEND);                    // priehladnost
    glShadeModel(GL_SMOOTH);                // gourard shading
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);   // background color
    gl_inicialized=1;
    glewInit();
    return 1;
    }
//---------------------------------------------------------------------------
void gl_exit()
    {
    if (!gl_inicialized) return;
    wglMakeCurrent(NULL, NULL);     // release current rendering context
    wglDeleteContext(hrc);          // destroy rendering context
    gl_inicialized=0;
    }
//---------------------------------------------------------------------------
void gl_resize(int _xs,int _ys)
    {
    xs=_xs;
    ys=_ys;
    if (xs<=0) xs = 1;                  // Prevent a divide by zero
    if (ys<=0) ys = 1;
    if (!gl_inicialized) return;
    glViewport(0,0,xs,ys);              // Set Viewport to window dimensions
    glMatrixMode(GL_PROJECTION);        // operacie s projekcnou maticou
    glLoadIdentity();                   // jednotkova matica projekcie
    gluPerspective(30,float(xs)/float(ys),0.1,100.0); // matica=perspektiva,120 stupnov premieta z viewsize do 0.1
    glMatrixMode(GL_TEXTURE);           // operacie s texturovou maticou
    glLoadIdentity();                   // jednotkova matica textury
    glMatrixMode(GL_MODELVIEW);         // operacie s modelovou maticou
    glLoadIdentity();                   // jednotkova matica modelu (objektu)
    }
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void glsl_init(char *vert,char *geom,char *frag)
    {
    const int _size=1024;
    GLint status,siz=0,i;
    const char * VS = vert;
    const char * GS = geom;
    const char * FS = frag;
    glsl_logs=0;
    if (prog_id<=0) prog_id=glCreateProgram();

    if (vert_id<=0) vert_id=glCreateShader(GL_VERTEX_SHADER); else glDetachShader(prog_id,vert_id);
    if (vert)
        {
        glShaderSource(vert_id, 1, &VS,NULL);
        glCompileShader(vert_id);
        glAttachShader(prog_id,vert_id);
        glGetShaderiv(vert_id,GL_COMPILE_STATUS,&status);
        const char t[]="[Vertex]\r\n"; for (i=0;t[i];i++) { glsl_log[glsl_logs]=t[i]; glsl_logs++; }
        glGetShaderInfoLog(vert_id,_size,&siz,glsl_log+glsl_logs);
        glsl_logs+=siz;
        }
    if (geom_id<=0) geom_id=glCreateShader(GL_GEOMETRY_SHADER); else glDetachShader(prog_id,geom_id);
    if (geom)
        {
        glShaderSource(geom_id, 1, &GS,NULL);
        glCompileShader(geom_id);
        glAttachShader(prog_id,geom_id);
        glGetShaderiv(geom_id,GL_COMPILE_STATUS,&status);
        const char t[]="[Geometry]\r\n"; for (i=0;t[i];i++) { glsl_log[glsl_logs]=t[i]; glsl_logs++; }
        glGetShaderInfoLog(geom_id,_size,&siz,glsl_log+glsl_logs);
        glsl_logs+=siz;
        }
    if (frag_id<=0) frag_id=glCreateShader(GL_FRAGMENT_SHADER); else glDetachShader(prog_id,frag_id);
    if (frag)
        {
        glShaderSource(frag_id, 1, &FS,NULL);
        glCompileShader(frag_id);
        glAttachShader(prog_id,frag_id);
        glGetShaderiv(frag_id,GL_COMPILE_STATUS,&status);
        const char t[]="[Fragment]\r\n"; for (i=0;t[i];i++) { glsl_log[glsl_logs]=t[i]; glsl_logs++; }
        glGetShaderInfoLog(frag_id,_size,&siz,glsl_log+glsl_logs);
        glsl_logs+=siz;
        }
    glLinkProgram(prog_id);
    glGetProgramiv(prog_id,GL_LINK_STATUS,&status);
    const char t[]="[Program]\r\n"; for (i=0;t[i];i++) { glsl_log[glsl_logs]=t[i]; glsl_logs++; }
    glGetProgramInfoLog(prog_id,_size,&siz,glsl_log+glsl_logs);
    glsl_logs+=siz;

    glReleaseShaderCompiler();
    glsl_log[glsl_logs]=0;
    }
//------------------------------------------------------------------------------
void glsl_exit()
    {
    glUseProgram(0);
    if (vert_id>0) { glDetachShader(prog_id,vert_id); glDeleteShader(vert_id); }
    if (geom_id>0) { glDetachShader(prog_id,geom_id); glDeleteShader(geom_id); }
    if (frag_id>0) { glDetachShader(prog_id,frag_id); glDeleteShader(frag_id); }
    if (prog_id>0) {                                  glDeleteShader(prog_id); }
    glsl_log[0]=0;
    }
//---------------------------------------------------------------------------
//------------------------------------------------------------------------------
void vao_init()
    {
    GLuint i;
    glGenVertexArrays(4,vao);
    glGenBuffers(4,vbo);
    glBindVertexArray(vao[0]);
    i=0; // vertex
    glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
    glBufferData(GL_ARRAY_BUFFER,sizeof(vao_pos),vao_pos,GL_STATIC_DRAW);
    glEnableVertexAttribArray(i);
    glVertexAttribPointer(i,3,GL_FLOAT,GL_FALSE,0,0);
    i=1; // indices
    #ifdef vao_indices
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,vbo[i]);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(vao_ix),vao_ix,GL_STATIC_DRAW);
    glEnableVertexAttribArray(i);
    glVertexAttribIPointer(i,4,GL_UNSIGNED_INT,0,0);
    #endif
    i=2; // normal
    #ifndef vao_indices
    glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
    glBufferData(GL_ARRAY_BUFFER,sizeof(vao_nor),vao_nor,GL_STATIC_DRAW);
    glEnableVertexAttribArray(i);
    glVertexAttribPointer(i,3,GL_FLOAT,GL_FALSE,0,0);
    #endif
    i=3; // color
    glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
    glBufferData(GL_ARRAY_BUFFER,sizeof(vao_col),vao_col,GL_STATIC_DRAW);
    glEnableVertexAttribArray(i);
    glVertexAttribPointer(i,3,GL_FLOAT,GL_FALSE,0,0);
    i=4; // textures
    glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
    glBufferData(GL_ARRAY_BUFFER,sizeof(vao_txr),vao_txr,GL_STATIC_DRAW);
    glEnableVertexAttribArray(i);
    glVertexAttribPointer(i,2,GL_FLOAT,GL_FALSE,0,0);

    glBindVertexArray(0);
    glBindBuffer(GL_ARRAY_BUFFER,0);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0);
    glDisableVertexAttribArray(0);
    glDisableVertexAttribArray(1);
    glDisableVertexAttribArray(2);
    glDisableVertexAttribArray(3);
    glDisableVertexAttribArray(4);
    }
//---------------------------------------------------------------------------
void vao_exit()
    {
    glDeleteVertexArrays(5,vao);
    glDeleteBuffers(5,vbo);
    }
//---------------------------------------------------------------------------
void vao_draw()
    {
    glBindVertexArray(vao[0]);
    #ifndef vao_indices
    glDrawArrays(GL_QUADS,0,sizeof(vao_pos)/sizeof(vao_pos[0]));                    // QUADS ... no indices
    #endif
    #ifdef vao_indices
    glDrawElements(GL_QUADS,sizeof(vao_ix)/sizeof(vao_ix[0]),GL_UNSIGNED_INT,0);    // indices (choose just one line not both !!!)
    #endif
    glBindVertexArray(0);
    }
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------

您需要将纹理添加到着色器并将采样器单元与纹理坐标一起传递。这也不适用于启用索引，因为该示例不是为此而构建的，我懒得重新编码它。这里重要的是：

const GLfloat vao_txr[]=
    {
//  x    y      //ix
    (0.0+0.0)/7.0,(5.0+1.0)/7.0, //0
    (0.0+1.0)/7.0,(5.0+1.0)/7.0, //1
    (0.0+1.0)/7.0,(5.0+0.0)/7.0, //2
    (0.0+0.0)/7.0,(5.0+0.0)/7.0, //3

    (5.0+0.0)/7.0,(5.0+0.0)/7.0, //4
    (5.0+1.0)/7.0,(5.0+0.0)/7.0, //5
    (5.0+1.0)/7.0,(5.0+1.0)/7.0, //6
    (5.0+0.0)/7.0,(5.0+1.0)/7.0, //7

    #ifndef vaices
    (5.0+0.0)/7.0,(4.0+0.0)/7.0, //3
    (5.0+1.0)/7.0,(4.0+0.0)/7.0, //2
    (5.0+1.0)/7.0,(4.0+1.0)/7.0, //5
    (5.0+0.0)/7.0,(4.0+1.0)/7.0, //4

    (3.0+1.0)/7.0,(2.0+0.0)/7.0, //2
    (3.0+1.0)/7.0,(2.0+1.0)/7.0, //1
    (3.0+0.0)/7.0,(2.0+1.0)/7.0, //6
    (3.0+0.0)/7.0,(2.0+0.0)/7.0, //5

    (0.0+1.0)/7.0,(6.0+1.0)/7.0, //1
    (0.0+0.0)/7.0,(6.0+1.0)/7.0, //0
    (0.0+0.0)/7.0,(6.0+0.0)/7.0, //7
    (0.0+1.0)/7.0,(6.0+0.0)/7.0, //6

    (2.0+1.0)/7.0,(6.0+1.0)/7.0, //0
    (2.0+1.0)/7.0,(6.0+0.0)/7.0, //3
    (2.0+0.0)/7.0,(6.0+0.0)/7.0, //4
    (2.0+0.0)/7.0,(6.0+1.0)/7.0, //7
    #endif
    };

如您所见，坐标的形式为start_of_texture+texture_coordinate，我从图集中为每张脸选择了 6 种不同的纹理...

这里预览（禁用颜色以便纹理颜色更明显）：

为了完整起见，着色器（但是您的纹理可以正常工作，因此无需更改您的）：

// Fragment
#version 400 core
#extension GL_ARB_explicit_uniform_location : enable
layout(location =64) uniform vec3 lt_pnt_pos;// point light source position [GCS]
layout(location =67) uniform vec3 lt_pnt_col;// point light source color&strength
layout(location =70) uniform vec3 lt_amb_col;// ambient light source color&strength
layout(location =73) uniform sampler2D txr;
in vec3 pixel_pos;      // fragment position [GCS]
in vec3 pixel_col;      // fragment surface color
in vec3 pixel_nor;      // fragment surface normal [GCS]
in vec2 pixel_txr;      // fragment texture coord
out vec4 col;
void main()
    {
    float li;
    vec3 c,lt_dir;
    lt_dir=normalize(lt_pnt_pos-pixel_pos); // vector from fragment to point light source in [GCS]
    li=dot(pixel_nor,lt_dir);
    if (li<0.0) li=0.0;
    c =texture(txr,pixel_txr).rgb;
//  c*=pixel_col;
    c*=(lt_amb_col+(lt_pnt_col*li));
    col=vec4(c,1.0);
    }

// Vertex
#version 400 core
#extension GL_ARB_explicit_uniform_location : enable
layout(location = 0) in vec3 pos;
layout(location = 2) in vec3 nor;
layout(location = 3) in vec3 col;
layout(location = 4) in vec2 txr;
layout(location = 0) uniform mat4 m_model;  // model matrix
layout(location =16) uniform mat4 m_normal; // model matrix with origin=(0,0,0)
layout(location =32) uniform mat4 m_view;   // inverse of camera matrix
layout(location =48) uniform mat4 m_proj;   // projection matrix
out vec3 pixel_pos;     // fragment position [GCS]
out vec3 pixel_col;     // fragment surface color
out vec3 pixel_nor;     // fragment surface normal [GCS]
out vec2 pixel_txr;     // fragment texture coord
void main()
    {
    pixel_col=col;
    pixel_pos=(m_model*vec4(pos,1)).xyz;
    pixel_nor=(m_normal*vec4(nor,1)).xyz;
    pixel_txr=txr;
    gl_Position=m_proj*m_view*m_model*vec4(pos,1);
    }

这里是我的窗口的 C++/VCL 代码：

//---------------------------------------------------------------------------
#include <vcl.h>
#include <jpeg.hpp>
#pragma hdrstop
#include "Unit1.h"
#include "gl_simple.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
GLfloat lt_pnt_pos[3]={+2.5,+2.5,+2.5};
GLfloat lt_pnt_col[3]={0.8,0.8,0.8};
GLfloat lt_amb_col[3]={0.2,0.2,0.2};
GLuint  txrid=0;
//---------------------------------------------------------------------------
void gl_draw()
    {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnable(GL_CULL_FACE);

    // load values into shader
    GLint i,id;
    GLfloat m[16];
    glUseProgram(prog_id);
/*
    id=glGetUniformLocation(prog_id,"lt_pnt_pos"); glUniform3fv(id,1,lt_pnt_pos);
    id=glGetUniformLocation(prog_id,"lt_pnt_col"); glUniform3fv(id,1,lt_pnt_col);
    id=glGetUniformLocation(prog_id,"lt_amb_col"); glUniform3fv(id,1,lt_amb_col);
    glGetFloatv(GL_MODELVIEW_MATRIX,m);
    id=glGetUniformLocation(prog_id,"m_model"   ); glUniformMatrix4fv(id,1,GL_FALSE,m);
    m[12]=0.0; m[13]=0.0; m[14]=0.0;
    id=glGetUniformLocation(prog_id,"m_normal"  ); glUniformMatrix4fv(id,1,GL_FALSE,m);
    for (i=0;i<16;i++) m[i]=0.0; m[0]=1.0; m[5]=1.0; m[10]=1.0; m[15]=1.0;
    id=glGetUniformLocation(prog_id,"m_view"    ); glUniformMatrix4fv(id,1,GL_FALSE,m);
    glGetFloatv(GL_PROJECTION_MATRIX,m);
    id=glGetUniformLocation(prog_id,"m_proj"    ); glUniformMatrix4fv(id,1,GL_FALSE,m);
*/
    id=64; glUniform3fv(id,1,lt_pnt_pos);
    id=67; glUniform3fv(id,1,lt_pnt_col);
    id=70; glUniform3fv(id,1,lt_amb_col);
    id=73; glUniform1i(id,0);   // texture unit
    glGetFloatv(GL_MODELVIEW_MATRIX,m);
    id=0; glUniformMatrix4fv(id,1,GL_FALSE,m);
    m[12]=0.0; m[13]=0.0; m[14]=0.0;
    id=16; glUniformMatrix4fv(id,1,GL_FALSE,m);
    for (i=0;i<16;i++) m[i]=0.0; m[0]=1.0; m[5]=1.0; m[10]=1.0; m[15]=1.0;
    id=32; glUniformMatrix4fv(id,1,GL_FALSE,m);
    glGetFloatv(GL_PROJECTION_MATRIX,m);
    id=48; glUniformMatrix4fv(id,1,GL_FALSE,m);


    // draw VAO cube
    glEnable(GL_TEXTURE_2D);
    glBindTexture(GL_TEXTURE_2D,txrid);
    vao_draw();
    glBindTexture(GL_TEXTURE_2D,0);
    glDisable(GL_TEXTURE_2D);
    // turn of shader
    glUseProgram(0);

    // render the cube in old style GL
    if (0)
        {
        glEnable(GL_LIGHTING);
        glEnable(GL_LIGHT0);
        glEnable(GL_COLOR_MATERIAL);
        #ifndef vao_indices
        glBegin(GL_QUADS);
        for (int i=0;i<6*4*3;i+=3)
            {
            glNormal3fv(vao_nor+i);
            glColor3fv (vao_col+i);
            glVertex3fv(vao_pos+i);
            }
        glEnd();
        #else
        int i,j,k;
        const GLfloat vao_nor[]=
            {
        //   nx   ny   nz
             0.0, 0.0,-1.0,
             0.0, 0.0,+1.0,
             0.0,-1.0, 0.0,
            +1.0, 0.0, 0.0,
             0.0,+1.0, 0.0,
            -1.0, 0.0, 0.0,
            };
        glBegin(GL_QUADS);
        for (j=0;j<6*4;j++)
            {
            i=vao_ix[j]; i+=i+i;
            k=j>>2; k+=k+k;
            glNormal3fv(vao_nor+k);
            glColor3fv (vao_col+i);
            glVertex3fv(vao_pos+i);
            }
        glEnd();
        #endif
        glDisable(GL_COLOR_MATERIAL);
        glDisable(GL_LIGHTING);
        glDisable(GL_LIGHT0);
        }


    // rotate the cube to see animation
    glMatrixMode(GL_MODELVIEW);
    glRotatef(1.0,0.0,1.0,0.0);
    glRotatef(1.0,1.0,0.0,0.0);

    // render point light source in [GCS]
    glMatrixMode(GL_MODELVIEW);
    glPushMatrix();
    glLoadIdentity();
    GLfloat x,y,z,d=0.25;
    x=lt_pnt_pos[0];
    y=lt_pnt_pos[1];
    z=lt_pnt_pos[2];
    glBegin(GL_LINES);
    glColor3fv(lt_pnt_col);
    glVertex3f(x-d,y,z);
    glVertex3f(x+d,y,z);
    glVertex3f(x,y-d,z);
    glVertex3f(x,y+d,z);
    glVertex3f(x,y,z-d);
    glVertex3f(x,y,z+d);
    glEnd();
    glMatrixMode(GL_MODELVIEW);
    glPopMatrix();

    glFlush();
    SwapBuffers(hdc);
    }
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner):TForm(Owner)
    {
    gl_init(Handle);

    // load shaders
    int hnd,siz; char vertex[4096],fragment[4096];
    hnd=FileOpen("normal_shading.glsl_vert",fmOpenRead); siz=FileSeek(hnd,0,2); FileSeek(hnd,0,0); FileRead(hnd,vertex  ,siz); vertex  [siz]=0; FileClose(hnd);
    hnd=FileOpen("normal_shading.glsl_frag",fmOpenRead); siz=FileSeek(hnd,0,2); FileSeek(hnd,0,0); FileRead(hnd,fragment,siz); fragment[siz]=0; FileClose(hnd);
    glsl_init(vertex,NULL,fragment);
    hnd=FileCreate("GLSL.txt"); FileWrite(hnd,glsl_log,glsl_logs); FileClose(hnd);

    // load texture atlas
    Byte q;
    unsigned int *pp;
    int xs,ys,x,y,adr,*txr;
    union { unsigned int c32; Byte db[4]; } c;
    TJPEGImage *jpg=new TJPEGImage;
    Graphics::TBitmap *bmp=new Graphics::TBitmap;
    if (bmp)
        {
        if (jpg)
            {
            jpg->LoadFromFile("textures128x128.jpg");
            bmp->Assign(jpg);
            delete jpg;
            }
        glGenTextures(1,&txrid);
        bmp->HandleType=bmDIB;      // allow direct access to pixels
        bmp->PixelFormat=pf32bit;   // set pixel to 32bit so int is the same size as pixel
        xs=bmp->Width;              // resolution should be power of 2
        ys=bmp->Height;
        txr=new int[xs*ys];         // create linear framebuffer
        for(adr=0,y=0;y<ys;y++)
            {
            pp=(unsigned int*)bmp->ScanLine[y];
            for(x=0;x<xs;x++,adr++)
                {
                // rgb2bgr and copy bmp -> txr[]
                    c.c32=pp[x];
                q      =c.db[2];
                c.db[2]=c.db[0];
                c.db[0]=q;
                txr[adr]=c.c32;
                }
            }
        glEnable(GL_TEXTURE_2D);    // copy it to gfx card
        glBindTexture(GL_TEXTURE_2D,txrid);
        glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,GL_CLAMP);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,GL_CLAMP);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR);
        glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,GL_MODULATE);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, xs, ys, 0, GL_RGBA, GL_UNSIGNED_BYTE, txr);
        glDisable(GL_TEXTURE_2D);
        delete[] txr;
        delete bmp;
        }
    vao_init();
    }
//---------------------------------------------------------------------------
void __fastcall TForm1::FormDestroy(TObject *Sender)
    {
    glDeleteTextures(1,&txrid);
    gl_exit();
    glsl_exit();
    vao_exit();
    }
//---------------------------------------------------------------------------
void __fastcall TForm1::FormResize(TObject *Sender)
    {
    gl_resize(ClientWidth,ClientHeight);
    glMatrixMode(GL_PROJECTION);
    glTranslatef(0,0,-15.0);
    }
//---------------------------------------------------------------------------
void __fastcall TForm1::FormPaint(TObject *Sender)
    {
    gl_draw();
    }
//---------------------------------------------------------------------------
void __fastcall TForm1::Timer1Timer(TObject *Sender)
    {
    gl_draw();
    }
//---------------------------------------------------------------------------
void __fastcall TForm1::FormMouseWheel(TObject *Sender, TShiftState Shift, int WheelDelta, TPoint &MousePos, bool &Handled)
    {
    GLfloat dz=2.0;
    if (WheelDelta<0) dz=-dz;
    glMatrixMode(GL_PROJECTION);
    glTranslatef(0,0,dz);
    gl_draw();
    }
//---------------------------------------------------------------------------

同样，大部分代码并不重要，您只需查找与 vao_ 相关的代码即可。