C++ / OpenGL 3.3+:未渲染顶点

我想这是同类型的第一百万个问题。我正在使用OpenGL 3.3核心配置文件和C++并尝试渲染三角形。

我已经阅读了以下两页，包括键入和复制粘贴正在讨论的代码。下面我发布了重要的部分。我已经渲染了一个三角形，但显然我更改了一些小细节并搞砸了它。GLFW和GLEW正在初始化，使用glClearColor进行清除工作正常。

正在使用的框架：用于窗口的GLFW，GLEW和GLM。

问题：我的代码中有什么错误，为什么没有呈现任何内容？

期望：白色三角形应该可见。

结果：未呈现任何内容。窗口充满了glClearColor

游戏.cpp

const float vertex_data[9] = {
-1.0f, -1.0f, 0.0f,
1.0f, -1.0f, 0.0f,
0.0f,  1.0f, 0.0f,
};
void Game::init()
{
shader = ShaderProgram();
shader.attachShader(readTextFromFile("data/shaders/main.vs"), GL_VERTEX_SHADER);
shader.attachShader(readTextFromFile("data/shaders/main.fs"), GL_FRAGMENT_SHADER);
shader.linkProgram();
mesh = Mesh(vertex_data);
}
void Game::render()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
shader.bind();
{
mesh.render();
}
shader.unbind();
}

网格.cpp

uint32_t vao;
uint32_t vertex_buffer;
Mesh::Mesh(const float vertex_data[])
{
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
glGenBuffers(1, &vertex_buffer);
glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_data), vertex_data, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (void*) 0);
}
void Mesh::render()
{
glBindVertexArray(vao);
glEnableVertexAttribArray(0);
{
// Is this actually necessary for every draw-call?
glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer); 
glDrawArrays(GL_TRIANGLES, 0, 3);
}
glDisableVertexAttribArray(0);
}

着色器程序.cpp

uint32 id = 0;
bool linked = false;
uint32 vertex_shader = 0;
uint32 fragment_shader = 0;
ShaderProgram::~ShaderProgram()
{
unbind();
if (vertex_shader > 0)
{
glDetachShader(id, vertex_shader);
glDeleteShader(vertex_shader);
}
if (fragment_shader > 0)
{
glDetachShader(id, fragment_shader);
glDeleteShader(fragment_shader);
}
if (id > 0 && linked)
{
glDeleteProgram(id);
}
}
void ShaderProgram::attachShader(std::string source, int32 type)
{
assert(type == GL_VERTEX_SHADER || type == GL_FRAGMENT_SHADER);
assert(id == 0);
const char* code = source.c_str();
switch (type)
{
case GL_VERTEX_SHADER:
assert(vertex_shader == 0);
vertex_shader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertex_shader, 1, &code, NULL);
glCompileShader(vertex_shader);
int32 vresult;
glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &vresult);
if (vresult != GL_TRUE)
{
int32 infolength;
glGetShaderiv(vertex_shader, GL_INFO_LOG_LENGTH, &infolength);
GLchar* infolog = new GLchar[infolength + 1];
glGetShaderInfoLog(vertex_shader, infolength + 1, NULL, infolog);
std::stringstream ss;
ss << "Shader compilation failed for Vertex Shader: " << infolog << std::endl;
std::cout << ss.str() << std::endl;
throw std::runtime_error(ss.str());
}
break;
case GL_FRAGMENT_SHADER:
assert(fragment_shader == 0);
fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragment_shader, 1, &code, NULL);
glCompileShader(fragment_shader);
int32 fresult;
glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &fresult);
if (fresult != GL_TRUE)
{
int32 infolength;
glGetShaderiv(fragment_shader, GL_INFO_LOG_LENGTH, &infolength);
int32 infosize = infolength + 1;
GLchar* infolog = new GLchar[infosize];
glGetShaderInfoLog(fragment_shader, infosize, NULL, infolog);
std::stringstream ss;
ss << "Shader compilation failed for Fragment Shader: " << infolog << std::endl;
std::cout << ss.str() << std::endl;
throw std::runtime_error(ss.str());
}
break;
default:
throw std::invalid_argument("Unknown Shader-Type specified");
}
}
void ShaderProgram::linkProgram()
{
assert(id == 0);
assert(vertex_shader > 0);
assert(fragment_shader > 0);
id = glCreateProgram();
glAttachShader(id, vertex_shader);
glAttachShader(id, fragment_shader);
glLinkProgram(id);
int32 result;
glGetProgramiv(id, GL_LINK_STATUS, &result);
if (result != GL_TRUE)
{
int32 infolength;
glGetProgramiv(id, GL_INFO_LOG_LENGTH, &infolength);
int32 infosize = infolength + 1;
GLchar* infolog = new GLchar[infosize];
glGetProgramInfoLog(id, infosize, NULL, infolog);
std::stringstream ss;
ss << "Shader Program Linking failed: " << infolog << std::endl;
throw std::runtime_error(ss.str());
}
linked = true;
}
void ShaderProgram::bind()
{
assert(id > 0);
assert(linked);
glUseProgram(id);
}
void ShaderProgram::unbind()
{
int32 current;
glGetIntegerv(GL_CURRENT_PROGRAM, &current);
if (current == id)
{
glUseProgram(0);
}
}
bool ShaderProgram::isLinked()
{
return linked;
}

顶点着色器："main.vs">

#version 330
layout(location = 0) in vec3 VertexPosition;
void main()
{
gl_Position = vec4(VertexPosition.xyz, 1.0);
}

片段着色器 "main.fs"：

#version 330
out vec4 FinalColor;
void main()
{
FinalColor = vec4(1.0, 1.0, 1.0, 1.0);
}