opengl cube不能正常显示

Question

我试图呈现立方体的正面，但它没有做到我想要的。它显示了它的正面和底面，我不认为顶点有问题，我只是想不出来，请帮帮我

这是我所有的代码：

#include <iostream> 
#include <Windows.h> 
#include <SFML\Window.hpp> 
#include <SFML\Graphics.hpp> 
#include <GL\glew.h> 
#include <glm\glm.hpp> 
#include <glm\gtc\matrix_transform.hpp> 

using namespace std; 
using namespace sf; 
using namespace glm; 

const GLchar* vertexSource = 
"#version 430\r\n" 
"in vec3 position;" 
"in vec3 color;" 
"uniform mat4 fullMatrix;" 
"out vec3 theColor;" 
"void main()" 
"{" 
"vec4 v = vec4(position, 1.0);" 
"gl_Position = fullMatrix * v;" 
"theColor = color;" 
"}"; 

const GLchar* fragmentSource = 
"#version 430\r\n" 
"in vec3 theColor;" 
"out vec4 daColor;" 
"void main()" 
"{" 
" daColor = vec4(theColor, 1.0);" 
"}"; 

int main() { 
    Window window(VideoMode(800, 600), "OpenGL", Style::Close); 
    window.setFramerateLimit(60); 
    glewExperimental = GL_TRUE; 
    glewInit(); 
    glEnable(GL_DEPTH_TEST); 

struct vertex { 
    vec3 position; 
    vec3 color; 
}; 

vertex vert[] = { 
    vec3(-1.0f, +1.0f, +1.0f), // 0 
    vec3(+1.0f, +0.0f, +0.0f), 

    vec3(+1.0f, +1.0f, +1.0f), // 1 
    vec3(+0.0f, +1.0f, +0.0f), 

    vec3(+1.0f, +1.0f, -1.0f), // 2 
    vec3(+0.0f, +0.0f, +1.0f), 

    vec3(-1.0f, +1.0f, -1.0f), // 3 
    vec3(+1.0f, +1.0f, +1.0f), 

    vec3(-1.0f, +1.0f, -1.0f), // 4 
    vec3(+1.0f, +0.0f, +1.0f), 

    vec3(+1.0f, +1.0f, -1.0f), // 5 
    vec3(+0.0f, +0.5f, +0.2f), 

    vec3(+1.0f, -1.0f, -1.0f), // 6 
    vec3(+0.8f, +0.6f, +0.4f), 

    vec3(-1.0f, -1.0f, -1.0f), // 7 
    vec3(+0.3f, +1.0f, +0.5f), 

    vec3(+1.0f, +1.0f, -1.0f), // 8 
    vec3(+0.2f, +0.5f, +0.2f), 

    vec3(+1.0f, +1.0f, +1.0f), // 9 
    vec3(+0.9f, +0.3f, +0.7f), 

    vec3(+1.0f, -1.0f, +1.0f), // 10 
    vec3(+0.3f, +0.7f, +1.0f), 

    vec3(+1.0f, -1.0f, -1.0f), // 11 
    vec3(+0.5f, +0.7f, +0.5f), 

    vec3(-1.0f, +1.0f, +1.0f), // 12 
    vec3(+0.7f, +0.8f, +0.2f), 

    vec3(-1.0f, +1.0f, -1.0f), // 13 
    vec3(+0.5f, +0.7f, +0.3f), 

    vec3(-1.0f, -1.0f, -1.0f), // 14 
    vec3(+0.4f, +0.7f, +0.7f), 

    vec3(-1.0f, -1.0f, +1.0f), // 15 
    vec3(+0.2f, +0.5f, +1.0f), 

    vec3(+1.0f, +1.0f, +1.0f), // 16 
    vec3(+0.6f, +1.0f, +0.7f), 

    vec3(-1.0f, +1.0f, +1.0f), // 17 
    vec3(+0.6f, +0.4f, +0.8f), 

    vec3(-1.0f, -1.0f, +1.0f), // 18 
    vec3(+0.2f, +0.8f, +0.7f), 

    vec3(+1.0f, -1.0f, +1.0f), // 19 
    vec3(+0.2f, +0.7f, +1.0f), 

    vec3(+1.0f, -1.0f, -1.0f), // 20 
    vec3(+0.8f, +0.3f, +0.7f), 

    vec3(-1.0f, -1.0f, -1.0f), // 21 
    vec3(+0.8f, +0.9f, +0.5f), 

    vec3(-1.0f, -1.0f, +1.0f), // 22 
    vec3(+0.5f, +0.8f, +0.5f), 

    vec3(+1.0f, -1.0f, +1.0f), // 23 
    vec3(+0.9f, +1.0f, +0.2f), 
}; 

GLuint numVertices = sizeof(vert)/sizeof(*vert); 

GLuint vboBuffer; 
glGenBuffers(1, &vboBuffer); 
glBindBuffer(GL_ARRAY_BUFFER, vboBuffer); 
glBufferData(GL_ARRAY_BUFFER, sizeof(vert), vert, GL_STATIC_DRAW); 
glEnableVertexAttribArray(0); 
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(float) * 6, 0); 
glEnableVertexAttribArray(1); 
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(float) * 6, (void*)(sizeof(float) * 3)); 

GLushort indi[] = { 
    0, 1, 2, 0, 2, 3, // Top 
    4, 5, 6, 4, 6, 7, // Front 
    8, 9, 10, 8, 10, 11, // Right 
    12, 13, 14, 12, 14, 15, // Left 
    16, 17, 18, 16, 18, 19, // Back 
    20, 22, 21, 20, 23, 22, // Bottom 
}; 

GLuint numIndices = sizeof(indi)/sizeof(*indi); 

GLuint indiBuffer; 
glGenBuffers(1, &indiBuffer); 
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indiBuffer); 
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indi), indi, GL_STATIC_DRAW); 

GLuint vertexShaderID = glCreateShader(GL_VERTEX_SHADER); 
GLuint fragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER); 
GLuint programID = glCreateProgram(); 

glShaderSource(vertexShaderID, 1, &vertexSource, 0); 
glShaderSource(fragmentShaderID, 1, &fragmentSource, 0); 
glCompileShader(vertexShaderID); 
glCompileShader(fragmentShaderID); 

glAttachShader(programID, vertexShaderID); 
glAttachShader(programID, fragmentShaderID); 
glLinkProgram(programID); 
glUseProgram(programID); 

bool running = true; 
while (running) 
{ 
    Event event; 
    while (window.pollEvent(event)) 
    { 
     if (event.type == Event::Closed) { 
      running = false; 
     } 
     else if (event.type == Event::KeyPressed && event.key.code == Keyboard::Escape) { 
      running = false; 
     } 
    } 

    glClearColor(0, 0, 0, 1); 
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 

    mat4 transformMatrix = translate(mat4(), vec3(0.0f, 0.0f, -3.0f)); 
    mat4 projectionMatrix = perspective(45.0f, (float)800/600, 0.1f, 10.0f); 
    mat4 fullMatrix = projectionMatrix * transformMatrix; 

    GLint fullLocation = glGetUniformLocation(programID, "fullMatrix"); 

    glUniformMatrix4fv(fullLocation, 1, GL_FALSE, &fullMatrix[0][0]); 

    glDrawElements(GL_TRIANGLES, numIndices, GL_UNSIGNED_SHORT, 0); 

    window.display(); 
} 
} 

它显示了这个图像

但我不想底面露面

Answer 1

由于深度测试已经被启用（glEnable(GL_DEPTH_TEST），但显然是不工作时，似乎该窗口没有深度缓冲区。从SFML文档看起来好像一个人到手动请求：

sf::ContextSettings settings; 
settings.depthBits = 24;   //<-- This is the important line 
settings.stencilBits = 8; 
settings.antialiasingLevel = 4; 
settings.majorVersion = 3; 
settings.minorVersion = 0; 

sf::Window window(sf::VideoMode(800, 600), "OpenGL", sf::Style::Default, settings); 

您可能需要OpenGL的版本等适应您的需求，但要确保不设置depthBits为零。