Opengl 3D多維數據集在Windows上無法正確呈現

Question

我正在關注有關Udemy-Modern Opengl 3.0的教程。 我設法到達了基礎教程的第5部分“投影和坐標系”。 這在具有相同代碼的Mac上完美運行，但是我無法在Windows上運行。 我什至重新開始了本教程，以確保我不會錯過任何內容，並且所有先前的教程都可以使用，但是我得到的結果相同。 只是無法正確渲染。 我是在Windows的Visual Studio 2015上執行此操作的。 在Mac上，我可以通過使用vim和Makefile來使用它...您會認為，使用為您編譯的IDE會更容易，但顯然沒有。

這就是我的屏幕上顯示的內容，只有它閃爍得非常快並且移動很多，而不是我應該得到的旋轉立方體。

這是代碼：

Shader.h：

#ifndef SHADER_H
#define SHADER_H

#include <string>
#include <fstream>
#include <sstream>
#include <iostream>

#include <GL/glew.h>

class Shader
{
public:
    GLuint Program;
    // Constructor generates the shader on the fly
    Shader(const GLchar *vertexPath, const GLchar *fragmentPath)
    {
        // 1. Retrieve the vertex/fragment source code from filePath
        std::string vertexCode;
        std::string fragmentCode;
        std::ifstream vShaderFile;
        std::ifstream fShaderFile;
        // ensures ifstream objects can throw exceptions:
        vShaderFile.exceptions(std::ifstream::badbit);
        fShaderFile.exceptions(std::ifstream::badbit);
        try
        {
            // Open files
            vShaderFile.open(vertexPath);
            fShaderFile.open(fragmentPath);
            std::stringstream vShaderStream, fShaderStream;
            // Read file's buffer contents into streams
            vShaderStream << vShaderFile.rdbuf();
            fShaderStream << fShaderFile.rdbuf();
            // close file handlers
            vShaderFile.close();
            fShaderFile.close();
            // Convert stream into string
            vertexCode = vShaderStream.str();
            fragmentCode = fShaderStream.str();
        }
        catch (std::ifstream::failure e)
        {
            std::cout << "ERROR::SHADER::FILE_NOT_SUCCESFULLY_READ" << std::endl;
        }
        const GLchar *vShaderCode = vertexCode.c_str();
        const GLchar *fShaderCode = fragmentCode.c_str();
        // 2. Compile shaders
        GLuint vertex, fragment;
        GLint success;
        GLchar infoLog[512];
        // Vertex Shader
        vertex = glCreateShader(GL_VERTEX_SHADER);
        glShaderSource(vertex, 1, &vShaderCode, NULL);
        glCompileShader(vertex);
        // Print compile errors if any
        glGetShaderiv(vertex, GL_COMPILE_STATUS, &success);
        if (!success)
        {
            glGetShaderInfoLog(vertex, 512, NULL, infoLog);
            std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
        }
        // Fragment Shader
        fragment = glCreateShader(GL_FRAGMENT_SHADER);
        glShaderSource(fragment, 1, &fShaderCode, NULL);
        glCompileShader(fragment);
        // Print compile errors if any
        glGetShaderiv(fragment, GL_COMPILE_STATUS, &success);
        if (!success)
        {
            glGetShaderInfoLog(fragment, 512, NULL, infoLog);
            std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
        }
        // Shader Program
        this->Program = glCreateProgram();
        glAttachShader(this->Program, vertex);
        glAttachShader(this->Program, fragment);
        glLinkProgram(this->Program);
        // Print linking errors if any
        glGetProgramiv(this->Program, GL_LINK_STATUS, &success);
        if (!success)
        {
            glGetProgramInfoLog(this->Program, 512, NULL, infoLog);
            std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
        }
        // Delete the shaders as they're linked into our program now and no longer necessery
        glDeleteShader(vertex);
        glDeleteShader(fragment);

    }
    // Uses the current shader
    void Use()
    {
        glUseProgram(this->Program);
    }
};

#endif

core.frag：

#version 330 core
in vec2 TexCoord;

out vec4 color;

uniform sampler2D ourTexture1;

void main()
{
    color = texture(ourTexture1, TexCoord);
}

core.vs：

#version 330 core
layout (location = 0) in vec3 position;
layout (location = 2) in vec2 texCoord;

out vec2 TexCoord;

uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;

void main()
{
    gl_Position = projection * view * model * vec4(position, 1.0f);
    TexCoord = vec2(texCoord.x, 1.0 - texCoord.y);
}

main.cpp：

#include <iostream>

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

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

// Other Libs
#include "SOIL2/SOIL2.h"

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

// Other includes
#include "Shader.h"

// Window dimensions
const GLuint WIDTH = 800, HEIGHT = 600;

// The MAIN function, from here we start the application and run the game loop
int main()
{
    // Init GLFW
    glfwInit();

    // Set all the required options for GLFW
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);

    glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);

    // Create a GLFWwindow object that we can use for GLFW's functions
    GLFWwindow *window = glfwCreateWindow(WIDTH, HEIGHT, "LearnOpenGL", nullptr, nullptr);

    int screenWidth, screenHeight;
    glfwGetFramebufferSize(window, &screenWidth, &screenHeight);

    if (nullptr == window)
    {
        std::cout << "Failed to create GLFW window" << std::endl;
        glfwTerminate();

        return EXIT_FAILURE;
    }

    glfwMakeContextCurrent(window);

    // Set this to true so GLEW knows to use a modern approach to retrieving function pointers and extensions
    glewExperimental = GL_TRUE;
    // Initialize GLEW to setup the OpenGL Function pointers
    if (GLEW_OK != glewInit())
    {
        std::cout << "Failed to initialize GLEW" << std::endl;
        return EXIT_FAILURE;
    }

    // Define the viewport dimensions
    glViewport(0, 0, screenWidth, screenHeight);

    glEnable(GL_DEPTH_TEST);
    // enable alpha support
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);//enables jpegs and alphas

    // Build and compile our shader program
    Shader ourShader("res/shaders/core.vs", "res/shaders/core.frag");

    // use with Perspective Projection
    GLfloat vertices[] = {
        //x     y       z      normalized texture coordinates 
        -0.5f, -0.5f, -0.5f,  0.0f, 0.0f,
        0.5f, -0.5f, -0.5f,  1.0f, 0.0f,
        0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
        0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
        -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, 0.0f,

        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
        0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
        0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
        0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
        -0.5f,  0.5f,  0.5f,  0.0f, 1.0f,
        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,

        -0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
        -0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
        -0.5f,  0.5f,  0.5f,  1.0f, 0.0f,

        0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
        0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
        0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
        0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
        0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
        0.5f,  0.5f,  0.5f,  1.0f, 0.0f,

        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
        0.5f, -0.5f, -0.5f,  1.0f, 1.0f,
        0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
        0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,

        -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
        0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
        0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
        0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
        -0.5f,  0.5f,  0.5f,  0.0f, 0.0f,
        -0.5f,  0.5f, -0.5f,  0.0f, 1.0f
    };

    GLuint VBO, VAO;//Vertex Buffer Object, Vertex Array Object
    glGenVertexArrays(1, &VAO);
    glGenBuffers(1, &VBO);

    // Bind the Vertex Array Object first, then bind and set vertex buffer(s) and attribute pointer(s).
    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(GLfloat), (GLvoid *)0);
    glEnableVertexAttribArray(0);
    // TexCoord attribute
    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid *)(3 * sizeof(GLfloat)));
    glEnableVertexAttribArray(2);

    glBindVertexArray(0); // Unbind VAO

    // Load and create a texture
    GLuint texture;

    int width, height;

    glGenTextures(1, &texture);
    glBindTexture(GL_TEXTURE_2D, texture);
    // Set our texture parameters
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    // Set texture filtering
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    // Load, create texture and generate mipmaps
    unsigned char *image = SOIL_load_image("res/images/image1.jpg", &width, &height, 0, SOIL_LOAD_RGBA);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, image);
    glGenerateMipmap(GL_TEXTURE_2D);
    SOIL_free_image_data(image);
    glBindTexture(GL_TEXTURE_2D, 0);


    glm::mat4 projection;
    projection = glm::perspective(45.0f, (GLfloat)screenWidth / (GLfloat)screenHeight, 0.1f, 1000.0f); 

    // Game loop
    while (!glfwWindowShouldClose(window))
    {
        // Check if any events have been activiated (key pressed, mouse moved etc.) and call corresponding response functions
        glfwPollEvents();

        // Render
        // Clear the colorbuffer
        glClearColor(0.9f, 0.5f, 0.3f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);


        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D, texture);
        glUniform1i(glGetUniformLocation(ourShader.Program, "ourTexture"), 0);
        ourShader.Use();

        glm::mat4 model;
        glm::mat4 view;
        model = glm::rotate(model, (GLfloat)glfwGetTime() * 1.0f, glm::vec3(0.5f, 1.0f, 0.0f));
        view = glm::translate(view, glm::vec3(0.0f, 0.0f, -3.0f));

        GLint modelLoc = glGetUniformLocation(ourShader.Program, "model");
        GLint viewLoc = glGetUniformLocation(ourShader.Program, "view");
        GLint projLoc = glGetUniformLocation(ourShader.Program, "projection");

        glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
        glUniformMatrix4fv(viewLoc, 1, GL_FALSE, glm::value_ptr(view));
        glUniformMatrix4fv(projLoc, 1, GL_FALSE, glm::value_ptr(projection));

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

        // Swap the screen buffers
        glfwSwapBuffers(window);
    }    

    // Properly de-allocate all resources once they've outlived their purpose
    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);

    // Terminate GLFW, clearing any resources allocated by GLFW.
    glfwTerminate();

    return EXIT_SUCCESS;
}

Answer 1

在片段着色器中，紋理采樣器統一的名稱為"ourTexture1" ：

uniform sampler2D ourTexture1;

但是，當您嘗試獲取紋理采樣器統一的位置時，請使用名稱"ourTexture" ：

glGetUniformLocation(ourShader.Program, "ourTexture")

第二個問題是，在程序成為當前渲染狀態的一部分之前，將紋理采樣器設置為ourTexture1統一。

glUniform1i(glGetUniformLocation(ourShader.Program, "ourTexture"), 0);
ourShader.Use();

鏈接程序后（ glGetUniformLocation ），可以隨時檢索制服的位置（ glLinkProgram ）。

glLinkProgram( ourShader.Program );

GLint modelLoc = glGetUniformLocation( ourShader.Program, "model" );
GLint viewLoc  = glGetUniformLocation( ourShader.Program, "view" );
GLint projLoc  = glGetUniformLocation( ourShader.Program, "projection" );
GLint texLoc   = glGetUniformLocation( ourShader.Program, "ourTexture1" );

但制服不能設定（ glUniform ）直到程序是活動程序（ glUseProgram ）。

glUseProgram( ourShader.Program );

glUniformMatrix4fv( modelLoc, 1, GL_FALSE, glm::value_ptr(model) );
glUniformMatrix4fv( viewLoc, 1, GL_FALSE, glm::value_ptr(view) );
glUniformMatrix4fv( projLoc, 1, GL_FALSE, glm::value_ptr(projection) );
glUniform1i( texLoc, 0 );

Answer 2

您在激活着色器之前在着色器上設置了統一，這似乎是錯誤的。