C++ OpenGL在以下教程之后不渲染任何内容
我最近开始关注TheCherno在youtube上的OpenGL教程系列。C++ OpenGL在以下教程之后不渲染任何内容,c++,opengl,glsl,shader,glfw,C++,Opengl,Glsl,Shader,Glfw,我最近开始关注TheCherno在youtube上的OpenGL教程系列。 这是我的密码: #include <GL/glew.h> #include <GLFW/glfw3.h> #include <iostream> #include <fstream> #include <string> #include <sstream> struct ShaderProgramSource { std::string
这是我的密码:
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
struct ShaderProgramSource {
std::string VertexSource;
std::string FragmentSource;
};
static ShaderProgramSource ParseShader(const std::string& filepath) {
std::ifstream stream(filepath);
enum class ShaderType {
NONE = -1, VERTEX = 0, FRAGMENT = 1
};
std::string line;
std::stringstream ss[2];
ShaderType type = ShaderType::NONE;
while (getline(stream, line)) {
if (line.find("#shader") != std::string::npos) {
if (line.find("vertex") != std::string::npos)
type = ShaderType::VERTEX;
else if (line.find("fragment") != std::string::npos)
type = ShaderType::FRAGMENT;
} else {
ss[(int)type] << line << '\n';
}
}
return { ss[0].str(), ss[1].str() };
}
static unsigned int CompileShader(unsigned int type, const std::string& source) {
std::cout << "Compiling " << (type == GL_VERTEX_SHADER ? "vertex" : "fragment") << " shader..." << std::endl;
unsigned int id = glCreateShader(type);
const char* src = source.c_str();
glShaderSource(id, 1, &src, nullptr);
std::cout << glGetError() << std::endl;
glCompileShader(id);
std::cout << glGetError() << std::endl;
int result;
glGetShaderiv(id, GL_COMPILE_STATUS, &result);
std::cout << glGetError() << std::endl;
if (result == GL_FALSE) {
int length;
glGetShaderiv(id, GL_INFO_LOG_LENGTH, &length);
std::cout << glGetError() << std::endl;
char* message = (char*)alloca(length * sizeof(char));
glGetShaderInfoLog(id, length, &length, message);
std::cout << glGetError() << std::endl;
std::cout << "Failed to compile" << (type == GL_VERTEX_SHADER ? "vertex" : "fragment") << " shader!" << std::endl;
std::cout << message << std::endl;
glDeleteShader(id);
std::cout << glGetError() << std::endl;
return 0;
}
std::cout << "Successfully compiled " << (type == GL_VERTEX_SHADER ? "vertex" : "fragment") << " shader!" << std::endl << std::endl;
return id;
}
static unsigned int CreateShader(const std::string& vertexShader, const std::string& fragmentShader) {
std::cout << "Creating shader..." << std::endl << std::endl;
unsigned int program = glCreateProgram();
unsigned int vs = CompileShader(GL_VERTEX_SHADER, vertexShader);
unsigned int fs = CompileShader(GL_FRAGMENT_SHADER, fragmentShader);
glAttachShader(program, vs);
std::cout << glGetError() << std::endl;
std::cout << "Attached vertex shader" << std::endl;
glAttachShader(program, fs);
std::cout << glGetError() << std::endl;
std::cout << "Attached fragment shader" << std::endl;
glLinkProgram(program);
std::cout << glGetError() << std::endl;
glValidateProgram(program);
std::cout << glGetError() << std::endl;
std::cout << "Linked and validated program" << std::endl;
glDeleteShader(vs);
std::cout << glGetError() << std::endl;
std::cout << "Deleted vertex shader" << std::endl;
glDeleteShader(fs);
std::cout << glGetError() << std::endl;
std::cout << "Deleted fragment shader" << std::endl;
std::cout << "Succesfully created shader!" << std::endl << std::endl;
return program;
}
int main(void)
{
GLFWwindow* window;
/* Initialize the library */
if (!glfwInit())
return -1;
/* Create a windowed mode window and its OpenGL context */
window = glfwCreateWindow(640, 480, "Hello World", NULL, NULL);
if (!window)
{
glfwTerminate();
return -1;
}
/* Make the window's context current */
glfwMakeContextCurrent(window);
if (glewInit() != GLEW_OK) {
std::cout << "Error!" << std::endl;
}
std::cout << glGetString(GL_VERSION) << std::endl;
float positions[6] = {
-0.5f, -0.5f,
0.0f, 0.5f,
0.5f, -0.5f
};
unsigned int buffer;
glGenBuffers(1, &buffer);
std::cout << glGetError() << std::endl;
glBindBuffer(GL_ARRAY_BUFFER, buffer);
std::cout << glGetError() << std::endl;
glBufferData(GL_ARRAY_BUFFER, 6*sizeof(float), positions, GL_STATIC_DRAW);
std::cout << glGetError() << std::endl;
glDisableVertexAttribArray(0);
std::cout << glGetError() << std::endl;
glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(float)*2, 0);
std::cout << glGetError() << std::endl;
glBindBuffer(GL_ARRAY_BUFFER, 0);
std::cout << glGetError() << std::endl;
ShaderProgramSource source = ParseShader("res/shaders/Basic.shader");
std::cout << "VERTEX" << std::endl;
std::cout << source.VertexSource << std::endl;
std::cout << "FRAGMENT" << std::endl;
std::cout << source.FragmentSource << std::endl;
//unsigned int shader = CreateShader(vertexShader, fragmentShader);
///glUseProgram(shader);
// render loop
while (!glfwWindowShouldClose(window))
{
/* Render here */
glClear(GL_COLOR_BUFFER_BIT);
glDrawArrays(GL_TRIANGLES, 0, 3);
/* Swap front and back buffers */
glfwSwapBuffers(window);
/* Poll for and process events */
glfwPollEvents();
}
//glDeleteProgram(shader);
glfwTerminate();
return 0;
}
我尝试过使用
glGetError
,但它没有输出任何错误。您需要启用通用顶点属性数组,而不是禁用它(请参阅):
glDisableVertexAttributeArray(0)代码>
GlenableVertexAttributeArray(0);
此外,编译、链接和安装sahder的代码被注释掉:
//unsigned int shader=CreateShader(vertexShader,fragmentShader)代码>
///glUseProgram(着色器)代码>
unsigned int shader=CreateShader(source.VertexSource,source.FragmentSource);
glUseProgram(着色器);
我相信@rabbi76的答案是正确的。如果仍然不起作用,请确保使用兼容的OpenGL上下文或创建VAO来保存状态
可通过以下方式设置兼容的OpenGL上下文:
//在glfwCreateWindow调用之前,在glfwInit之后
glfwWindowHint(GLFW_OPENGL_配置文件、GLFW_OPENGL_COMPAT_配置文件);
默认值为GLFW\u OPENGL\u ANY\u PROFILE
,如果COMPAT
不可用,这可能意味着CORE
。这样可以确保默认对象始终存在并被绑定。这意味着您的glvertexattributepointer
调用实际上有一个存储该信息的位置。我没有看到这些Cherno的教程,很可能在未来的教程中会介绍VAO。在CORE
中不会有一个,它可能不会画任何东西
在这里,精确地设置所需的最小OpenGL版本并不是一个坏主意。如果由于某种原因,该窗口在目标计算机上不可用,则窗口创建将失败。在调用不受支持的函数时,这比获得“随机”seg错误更可取
glfwWindowHint(GLFW\u CONTEXT\u VERSION\u MAJOR,3);
glfwWindowHint(GLFW_上下文_版本_小调,3);
我的首选方法是创建一个实际的VAO,并使用GLFW\u OPENGL\u CORE\u PROFILE
。但是请随意使用教程,我从他那里看到的教程都是高质量的
//将这些放在顶点缓冲区初始化之前
int VAO;
glGenVertexArrays(1和VAO);
glBindVertexArray(VAO);
非常感谢您!被评论掉的原因是因为他在视频中出于某种原因这样做了。