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帧缓冲不完整!使用OpenGL

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我克隆了以下示例:

https://github.com/JoeyDeVries/LearnOpenGL/tree/master/src/5.advanced_lighting/6.hdr

git clone https://github.com/JoeyDeVries/LearnOpenGL
cd LearnOpenGL
echo "static char const * logl_root = \".\";" > includes/learnopengl/root_directory.h
cp -avr resources src/5.advanced_lighting/6.hdr
cd src/5.advanced_lighting/6.hdr
g++ -std=c++11 hdr.cpp -lglut -lGL -lGLU -lGLEW -lm -lglfw3 -lpthread -lX11 -lXrandr -lXinerama -lXi -lXxf86vm -lXcursor -lGL -ldl -lSOIL -lassimp  -I ../../../includes

编译好 . 但它在跑步方面存在问题 . 命令行窗口中的输出是

./a.out
Framebuffer not complete!
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1
exposure: 1

输出是一个黑暗的窗口 .

我应该怎么解决?

我不遵循安装指南,因为它们会导致其他一些错误,最后它们会停止 . 到目前为止,许多例子都是通过手工构建为我工作的 . 但是这个HDR示例有 Framebuffer not complete! 问题 .

Link to hdr.cpp

hdr.cpp

// GLEW
#define GLEW_STATIC
#include <GL/glew.h>

// GLFW
#include <GLFW/glfw3.h>

// GL includes
#include <learnopengl/shader.h>
#include <learnopengl/camera.h>

// GLM Mathemtics
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>

// Other Libs
#include <SOIL.h>
#include <learnopengl/filesystem.h>

// Properties
const GLuint SCR_WIDTH = 800, SCR_HEIGHT = 600;

// Function prototypes
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode);
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
void mouse_callback(GLFWwindow* window, double xpos, double ypos);
void Do_Movement();
GLuint loadTexture(GLchar const * path);
void RenderScene(Shader &shader);
void RenderCube();
void RenderQuad();

// Camera
Camera camera(glm::vec3(0.0f, 0.0f, 5.0f));

// Delta
GLfloat deltaTime = 0.0f;
GLfloat lastFrame = 0.0f;

// Options
GLboolean hdr = true; // Change with 'Space'
GLfloat exposure = 1.0f; // Change with Q and E

// Global variables
GLuint woodTexture;

// The MAIN function, from here we start our application and run our Game loop
int main()
{
    // Init GLFW
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);

    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", nullptr, nullptr); // Windowed
    glfwMakeContextCurrent(window);

    // Set the required callback functions
    glfwSetKeyCallback(window, key_callback);
    glfwSetCursorPosCallback(window, mouse_callback);
    glfwSetScrollCallback(window, scroll_callback);

    // Options
    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);

    // Initialize GLEW to setup the OpenGL Function pointers
    glewExperimental = GL_TRUE;
    glewInit();

    // Define the viewport dimensions
    glViewport(0, 0, SCR_WIDTH, SCR_HEIGHT);

    // Setup some OpenGL options
    glEnable(GL_DEPTH_TEST);

    // Setup and compile our shaders
    Shader shader("lighting.vs", "lighting.frag");
    Shader hdrShader("hdr.vs", "hdr.frag");

    // Light sources
    // - Positions
    std::vector<glm::vec3> lightPositions;
    lightPositions.push_back(glm::vec3(0.0f, 0.0f, 49.5f)); // back light
    lightPositions.push_back(glm::vec3(-1.4f, -1.9f, 9.0f));
    lightPositions.push_back(glm::vec3(0.0f, -1.8f, 4.0f));
    lightPositions.push_back(glm::vec3(0.8f, -1.7f, 6.0f));
    // - Colors
    std::vector<glm::vec3> lightColors;
    lightColors.push_back(glm::vec3(200.0f, 200.0f, 200.0f));
    lightColors.push_back(glm::vec3(0.1f, 0.0f, 0.0f));
    lightColors.push_back(glm::vec3(0.0f, 0.0f, 0.2f));
    lightColors.push_back(glm::vec3(0.0f, 0.1f, 0.0f));

    // Load textures
    woodTexture = loadTexture(FileSystem::getPath("resources/textures/wood.png").c_str());

    // Set up floating point framebuffer to render scene to
    GLuint hdrFBO;
    glGenFramebuffers(1, &hdrFBO);
    // - Create floating point color buffer
    GLuint colorBuffer;
    glGenTextures(1, &colorBuffer);
    glBindTexture(GL_TEXTURE_2D, colorBuffer);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, SCR_WIDTH, SCR_HEIGHT, 0, GL_RGB, GL_FLOAT, NULL);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    // - Create depth buffer (renderbuffer)
    GLuint rboDepth;
    glGenRenderbuffers(1, &rboDepth);
    glBindRenderbuffer(GL_RENDERBUFFER, rboDepth);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, SCR_WIDTH, SCR_HEIGHT);
    // - Attach buffers
    glBindFramebuffer(GL_FRAMEBUFFER, hdrFBO);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colorBuffer, 0);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rboDepth);
    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
        std::cout << "Framebuffer not complete!" << std::endl;
    glBindFramebuffer(GL_FRAMEBUFFER, 0);

    glClearColor(0.1f, 0.1f, 0.1f, 1.0f);

    // Game loop
    while (!glfwWindowShouldClose(window))
    {
        // Set frame time
        GLfloat currentFrame = glfwGetTime();
        deltaTime = currentFrame - lastFrame;
        lastFrame = currentFrame;

        // Check and call events
        glfwPollEvents();
        Do_Movement();

        // 1. Render scene into floating point framebuffer
        glBindFramebuffer(GL_FRAMEBUFFER, hdrFBO);
            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
            glm::mat4 projection = glm::perspective(camera.Zoom, (GLfloat)SCR_WIDTH / (GLfloat)SCR_HEIGHT, 0.1f, 100.0f);
            glm::mat4 view       = camera.GetViewMatrix();
            glm::mat4 model;
            shader.Use();
            glUniformMatrix4fv(glGetUniformLocation(shader.Program, "projection"), 1, GL_FALSE, glm::value_ptr(projection));
            glUniformMatrix4fv(glGetUniformLocation(shader.Program, "view"),       1, GL_FALSE, glm::value_ptr(view));
            glActiveTexture(GL_TEXTURE0);
            glBindTexture(GL_TEXTURE_2D, woodTexture);
            // - set lighting uniforms
            for (GLuint i = 0; i < lightPositions.size(); i++)
            {
                glUniform3fv(glGetUniformLocation(shader.Program, ("lights[" + std::to_string(i) + "].Position").c_str()), 1, &lightPositions[i][0]);
                glUniform3fv(glGetUniformLocation(shader.Program, ("lights[" + std::to_string(i) + "].Color").c_str()), 1, &lightColors[i][0]);
            }
            glUniform3fv(glGetUniformLocation(shader.Program, "viewPos"), 1, &camera.Position[0]);
            // - render tunnel
            model = glm::mat4();
            model = glm::translate(model, glm::vec3(0.0f, 0.0f, 25.0));
            model = glm::scale(model, glm::vec3(5.0f, 5.0f, 55.0f));
            glUniformMatrix4fv(glGetUniformLocation(shader.Program, "model"), 1, GL_FALSE, glm::value_ptr(model));
            glUniform1i(glGetUniformLocation(shader.Program, "inverse_normals"), GL_TRUE);
            RenderCube();
        glBindFramebuffer(GL_FRAMEBUFFER, 0);      

        // 2. Now render floating point color buffer to 2D quad and tonemap HDR colors to default framebuffer's (clamped) color range
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);        
        hdrShader.Use();
        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D, colorBuffer);
        glUniform1i(glGetUniformLocation(hdrShader.Program, "hdr"), hdr);
        glUniform1f(glGetUniformLocation(hdrShader.Program, "exposure"), exposure);
        RenderQuad();       

        std::cout << "exposure: " << exposure << std::endl;

        // Swap the buffers
        glfwSwapBuffers(window);
    }

    glfwTerminate();
    return 0;
}


// RenderQuad() Renders a 1x1 quad in NDC, best used for framebuffer color targets
// and post-processing effects.
GLuint quadVAO = 0;
GLuint quadVBO;
void RenderQuad()
{
    if (quadVAO == 0)
    {
        GLfloat quadVertices[] = {
            // Positions        // Texture Coords
            -1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
            -1.0f, -1.0f, 0.0f, 0.0f, 0.0f,
            1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
            1.0f, -1.0f, 0.0f, 1.0f, 0.0f,
        };
        // Setup plane VAO
        glGenVertexArrays(1, &quadVAO);
        glGenBuffers(1, &quadVBO);
        glBindVertexArray(quadVAO);
        glBindBuffer(GL_ARRAY_BUFFER, quadVBO);
        glBufferData(GL_ARRAY_BUFFER, sizeof(quadVertices), &quadVertices, GL_STATIC_DRAW);
        glEnableVertexAttribArray(0);
        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)0);
        glEnableVertexAttribArray(1);
        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)(3 * sizeof(GLfloat)));
    }
    glBindVertexArray(quadVAO);
    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
    glBindVertexArray(0);
}

// RenderCube() Renders a 1x1 3D cube in NDC.
GLuint cubeVAO = 0;
GLuint cubeVBO = 0;
void RenderCube()
{
    // Initialize (if necessary)
    if (cubeVAO == 0)
    {
        GLfloat vertices[] = {
            // Back face
            -0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, // Bottom-left
            0.5f, 0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 1.0f, 1.0f, // top-right
            0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 1.0f, 0.0f, // bottom-right         
            0.5f, 0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 1.0f, 1.0f,  // top-right
            -0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f,  // bottom-left
            -0.5f, 0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f,// top-left
            // Front face
            -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, // bottom-left
            0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f,  // bottom-right
            0.5f, 0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f,  // top-right
            0.5f, 0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, // top-right
            -0.5f, 0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f,  // top-left
            -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f,  // bottom-left
            // Left face
            -0.5f, 0.5f, 0.5f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-right
            -0.5f, 0.5f, -0.5f, -1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top-left
            -0.5f, -0.5f, -0.5f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f,  // bottom-left
            -0.5f, -0.5f, -0.5f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom-left
            -0.5f, -0.5f, 0.5f, -1.0f, 0.0f, 0.0f, 0.0f, 0.0f,  // bottom-right
            -0.5f, 0.5f, 0.5f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-right
            // Right face
            0.5f, 0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-left
            0.5f, -0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom-right
            0.5f, 0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top-right         
            0.5f, -0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f,  // bottom-right
            0.5f, 0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f,  // top-left
            0.5f, -0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, // bottom-left     
            // Bottom face
            -0.5f, -0.5f, -0.5f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f, // top-right
            0.5f, -0.5f, -0.5f, 0.0f, -1.0f, 0.0f, 1.0f, 1.0f, // top-left
            0.5f, -0.5f, 0.5f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f,// bottom-left
            0.5f, -0.5f, 0.5f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, // bottom-left
            -0.5f, -0.5f, 0.5f, 0.0f, -1.0f, 0.0f, 0.0f, 0.0f, // bottom-right
            -0.5f, -0.5f, -0.5f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f, // top-right
            // Top face
            -0.5f, 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f,// top-left
            0.5f, 0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // bottom-right
            0.5f, 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, // top-right     
            0.5f, 0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // bottom-right
            -0.5f, 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f,// top-left
            -0.5f, 0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f // bottom-left        
        };
        glGenVertexArrays(1, &cubeVAO);
        glGenBuffers(1, &cubeVBO);
        // Fill buffer
        glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
        // Link vertex attributes
        glBindVertexArray(cubeVAO);
        glEnableVertexAttribArray(0);
        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (GLvoid*)0);
        glEnableVertexAttribArray(1);
        glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (GLvoid*)(3 * sizeof(GLfloat)));
        glEnableVertexAttribArray(2);
        glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (GLvoid*)(6 * sizeof(GLfloat)));
        glBindBuffer(GL_ARRAY_BUFFER, 0);
        glBindVertexArray(0);
    }
    // Render Cube
    glBindVertexArray(cubeVAO);
    glDrawArrays(GL_TRIANGLES, 0, 36);
    glBindVertexArray(0);
}

// This function loads a texture from file. Note: texture loading functions like these are usually 
// managed by a 'Resource Manager' that manages all resources (like textures, models, audio). 
// For learning purposes we'll just define it as a utility function.
GLuint loadTexture(GLchar const * path)
{
    // Generate texture ID and load texture data 
    GLuint textureID;
    glGenTextures(1, &textureID);
    int width, height;
    unsigned char* image = SOIL_load_image(path, &width, &height, 0, SOIL_LOAD_RGB);
    // Assign texture to ID
    glBindTexture(GL_TEXTURE_2D, textureID);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
    glGenerateMipmap(GL_TEXTURE_2D);

    // Parameters
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glBindTexture(GL_TEXTURE_2D, 0);
    SOIL_free_image_data(image);
    return textureID;

}

bool keys[1024];
bool keysPressed[1024];
// Moves/alters the camera positions based on user input
void Do_Movement()
{
    // Camera controls
    if (keys[GLFW_KEY_W])
        camera.ProcessKeyboard(FORWARD, deltaTime);
    if (keys[GLFW_KEY_S])
        camera.ProcessKeyboard(BACKWARD, deltaTime);
    if (keys[GLFW_KEY_A])
        camera.ProcessKeyboard(LEFT, deltaTime);
    if (keys[GLFW_KEY_D])
        camera.ProcessKeyboard(RIGHT, deltaTime);

    if (keys[GLFW_KEY_SPACE] && !keysPressed[GLFW_KEY_SPACE])
    {
        hdr = !hdr;
        keysPressed[GLFW_KEY_SPACE] = true;
    }

    // Change parallax height scale
    if (keys[GLFW_KEY_Q])
        exposure -= 0.5 * deltaTime;
    else if (keys[GLFW_KEY_E])
        exposure += 0.5 * deltaTime;
}

GLfloat lastX = 400, lastY = 300;
bool firstMouse = true;
// Is called whenever a key is pressed/released via GLFW
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode)
{
    if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
        glfwSetWindowShouldClose(window, GL_TRUE);

    if (key >= 0 && key <= 1024)
    {
        if (action == GLFW_PRESS)
            keys[key] = true;
        else if (action == GLFW_RELEASE)
        {
            keys[key] = false;
            keysPressed[key] = false;
        }
    }
}

void mouse_callback(GLFWwindow* window, double xpos, double ypos)
{
    if (firstMouse)
    {
        lastX = xpos;
        lastY = ypos;
        firstMouse = false;
    }

    GLfloat xoffset = xpos - lastX;
    GLfloat yoffset = lastY - ypos;

    lastX = xpos;
    lastY = ypos;

    camera.ProcessMouseMovement(xoffset, yoffset);
}

void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
{
    camera.ProcessMouseScroll(yoffset);
}

1 回答

  • 1

    这里没有足够的信息来诊断问题,所以你需要做一些调试 . 第一个疑问是你的OpenGL实现是否支持使用 GL_RGB16F 纹理作为帧缓冲附件 . 您可以尝试将其更改为 GL_RGBA16F 并查看是否有效 .

    除此之外,我建议在初始化期间添加一些额外的日志记录......

    就在之前

    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colorBuffer, 0);
    

    std::cout << "Color buffer: " << colorBuffer << std::endl;
    std::cout << "Depth buffer: " << rboDepth << std::endl;
    

    这样您就可以在帧缓冲附件出现之前验证颜色缓冲区和深度缓冲区是否有效(非零) . 另外,我会改变

    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
        std::cout << "Framebuffer not complete!" << std::endl;
    

    auto fboStatus = glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if (fboStatus != GL_FRAMEBUFFER_COMPLETE)
        std::cout << "Framebuffer not complete: " << fboStatus << std::endl;
    

    这样您就可以看到实际的帧缓冲状态,这可能会为您提供问题的线索 .

    当你学习在每次OpenGL调用之后调用glGetError()以确保没有生成错误时,这也是一个好主意...

    {
        auto glstatus = glGetError();
        if (glstatus != GL_NO_ERROR) { std::cout << "Error in GL call: << glstatus << std::endl; } 
    }
    

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