如何让我的 OpenGL 立方体着色器正确渲染？

问题描述

我正在尝试在我的 OpenGL 项目中制作一个立方体。由于某种原因，我的代码没有呈现，我不知道为什么。我试图将 glm::mat4 更改为 glm::mat4(1)；但是，它仍然不起作用。即使没有绘制，我也没有收到任何错误或警告。我看到的只是一个空白屏幕，但没有立方体。

main.cpp

#include <iostream>
#define GLEW_STATIC
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include "Shader.h"
#include "SOIL2/SOIL2.h"
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>

using namespace std;

const GLint WIDTH = 800;
const GLint HEIGHT = 600;

nt main() {
    glfwInit();
    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_TRUE );

    GLFWwindow* window = glfwCreateWindow(WIDTH,HEIGHT,"Pemdas",nullptr,nullptr);
    
    int screenWidth;
    int screenHeight;
    glfwGetFramebufferSize(window,&screenWidth,&screenWidth);
    
    if(nullptr == window) {
        cout << "Falled to create the window.";
        glfwTerminate();
        return -1;
    }
    
    glfwMakeContextCurrent(window);
    glewExperimental = GL_TRUE;
    
    if(GLEW_OK != glewInit()) {
        std::cout << "Failed to initialize window" << std::endl;
        return -1;
    }
    
    glViewport(0,screenWidth,screenHeight);
    
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
    
    Shader ourShader("Resources/Shaders/core.vs","Resources/Shaders/core.frag");
    
    GLfloat vertices[] =
    {
        -0.5f,-0.5f,0.0f,0.5f,1.0f,1.0f
    };
    
    GLint VAO;
    glGenVertexArrays( 1,&VAO );
    
    GLint VBO;
    glGenBuffers( 1,&VBO );   
    
    glBindVertexArray( VAO );
    
    glBindBuffer(GL_ARRAY_BUFFER,VBO);
    glBufferData(GL_ARRAY_BUFFER,sizeof( vertices ),vertices,GL_STATIC_DRAW);

    glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,5 * sizeof(GLfloat),(GLvoid*)0);
    glEnabLevertexAttribArray(0);
    
    glVertexAttribPointer(2,2,(GLvoid*)(3 * sizeof(GLfloat)));
    glEnabLevertexAttribArray(2);
    
    glBindVertexArray(0);
    
    gluint texture;
    glGenTextures(1,&texture);
    glBindTexture(GL_TEXTURE_2D,texture);
    
    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);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
    
    int width;
    int height;
    unsigned char* image = SOIL_load_image("Resources/Shaders/pexels-adrien-olichon-2931270.jpg",&width,&hight,SOIL_LOAD_RGBA);
    
    glTexImage2D( GL_TEXTURE_2D,GL_RGBA,width,hight,GL_UNSIGNED_BYTE,image);
    glGenerateMipmap(GL_TEXTURE_2D);
    SOIL_free_image_data(image);
    glBindTexture(GL_TEXTURE_2D,0);
    
    glm::mat4 projection(1);
    projection = glm::perspective(45.0f,(GLfloat)screenWidth / (GLfloat)screenHeight,0.1f,1000.0f);
    
    while(!glfwWindowShouldClose(window)) {
        glfwPollEvents();
        
        glClearColor(0.2f,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(1);
        glm::mat4 view(1);
        model = glm::rotate(model,(GLfloat)glfwGetTime() * 1.0f,glm::vec3(0.5f,0.0f));
        view = glm::translate(view,glm::vec3(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,glm::value_ptr(model));
        gluniformMatrix4fv(viewLoc,glm::value_ptr(view));
        gluniformMatrix4fv(projLoc,glm::value_ptr(projection));
        
        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES,36);
        glBindVertexArray(0);
        
        glfwSwapBuffers(window);
    }
    
    glDeleteVertexArrays(1,&VAO );
    glDeleteBuffers(1,&VBO);
    
   
    glfwTerminate();
    return 0;
}

core.vs

#version 400 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 = model * view * projection * vec4(position,1.0f);

    TexCoord = vec2(texCoord.x,1.0 - texCoord.y);
}

core.frag

#version 400 core

in vec2 TexCoord;

out vec4 color;

uniform sampler2D texture1;

void main() {
    color = texture(texture1,TexCoord);
}

解决方法

如评论中所述，变换顺序与矩阵乘法顺序相反。同样在您的顶点着色器中，您会在 color 中获得一个名为 location=1 的输入属性，但我在任何地方都看不到 glEnableVertexAttribArray(1);。

我还建议您像这样检查着色器中的编译错误：

glGetShaderiv(vertex,GL_COMPILE_STATUS,&success);
        if (!success)
        {
            glGetShaderInfoLog(vertex,512,NULL,infoLog);
            std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
        };