Question

我的OpenGL项目中的着色器无法编译。我有Ubuntu 16.04 LTS，使用CLion。没有找到任何解决方案，这就是为什么要问这里。

这是我的错误列表：

ATTENTION: default value of option force_s3tc_enable overridden by environment.
ERROR::SHADER::VERTEX::COMPILATION_FAILED
0:1(1): error: syntax error, unexpected $end

ERROR::SHADER::FRAGMENT::COMPILATION_FAILED
0:1(1): error: syntax error, unexpected $end

ERROR::SHADER::PROGRAM::LINKING_FAILED
error: linking with uncompiled shadererror: linking with uncompiled shader

这是我的main.cpp代码：

#include <iostream>

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

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

// 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 );

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


    // Set up vertex data (and buffer(s)) and attribute pointers
    GLfloat vertices[] =
            {
                    // Positions         // Colors
                    0.5f, -0.5f, 0.0f,   1.0f, 0.0f, 0.0f,  // Bottom Right
                    -0.5f, -0.5f, 0.0f,   0.0f, 1.0f, 0.0f,  // Bottom Left
                    0.0f,  0.5f, 0.0f,   0.0f, 0.0f, 1.0f   // Top
            };
    GLuint VBO, VAO;
    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, 6 * sizeof( GLfloat ), ( GLvoid * ) 0 );
    glEnableVertexAttribArray( 0 );
    // Color attribute
    glVertexAttribPointer( 1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof( GLfloat ), ( GLvoid * )( 3 * sizeof( GLfloat ) ) );
    glEnableVertexAttribArray( 1 );

    glBindVertexArray( 0 ); // Unbind VAO

    // 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( 0.2f, 0.3f, 0.3f, 1.0f );
        glClear( GL_COLOR_BUFFER_BIT );

        // Draw the triangle
        ourShader.Use( );
        glBindVertexArray( VAO );
        glDrawArrays( GL_TRIANGLES, 0, 3 );
        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;
}

Shader.h代码：

#ifndef SHADER_H
#define SHADER_H

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

#include <GL/glew.h>
#include <cstring>

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

这是我的core.vs：

#version 330 core
layout (location = 0) in vec3 position;
layout (location = 1) in vec3 color;
layout (location = 2) in vec2 texCoord;

out vec3 ourColor;
out vec2 TexCoord;

void main()
{
    gl_Position = vec4(position, 1.0f);
    ourColor = color;
    // We swap the y-axis by substracing our coordinates from 1. This is done because most images have the top y-axis inversed with OpenGL's top y-axis.
    // TexCoord = texCoord;
    TexCoord = vec2(texCoord.x, 1.0 - texCoord.y);
}

...和core.frag：

#version 330 core
in vec3 ourColor;
in vec2 TexCoord;

out vec4 color;

// Texture samplers
uniform sampler2D ourTexture1;

void main()
{
// Linearly interpolate between both textures (second texture is only slightly combined)
color = texture(ourTexture1, TexCoord);
}

我还附上了我的CMakeLists.txt。希望它有所帮助：

cmake_minimum_required(VERSION 3.9)
project(STUDY_GL)

set(CMAKE_CXX_STANDARD 11)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14 -pthread -fpermissive")

find_package (OpenGL REQUIRED)
find_package (GLUT REQUIRED)
find_package (glfw3 REQUIRED)
find_library (glew REQUIRED)
find_library (glad REQUIRED)


include_directories(${/usr/include/GLFW/})
include_directories(${/usr/include/GL/})


file(GLOB SOURCE_FILES
        *.cpp
        *.h
        )

add_executable(main.cpp ${SOURCE_FILES} Shader.h)

target_link_libraries (main.cpp ${OPENGL_LIBRARIES} ${GLUT_LIBRARIES} ${GLFW3_LIBRARIES} -lGL -lglfw -lglut -lGLEW)

我在项目中有一个SOIL2目录。这是它的link。

Answer 1

一般来说，您的代码很好，但您必须将std::ifstream::failbit传递给std::ios::exceptions，因为如果std::ifstream::open失败，则设置failbit状态标志。

vShaderFile.exceptions ( std::ifstream::failbit | std::ifstream::badbit );
fShaderFile.exceptions ( std::ifstream::failbit | std::ifstream::badbit );
try
{
   vShaderFile.open( vertexPath );
   fShaderFile.open( fragmentPath );
   .....
}
catch ( std::ifstream::failure e )
{
    std::cout << "ERROR::SHADER::FILE_NOT_SUCCESFULLY_READ" << std::endl;
}

我打赌你的工作目录没有正确设置。出于调试原因，请使用着色器文件的绝对文件路径如果无法访问着色器源文件，并且您的代码没有抛出任何异常，那么您尝试编译空字符串。这会导致错误消息。

顺便说一下，由于您在问题中发布的代码段中没有使用任何纹理，因此您应该对片段着色器进行以下更改：

// color = texture(ourTexture1, TexCoord); <--- skip
color = vec4(ourColor,1.0);                <--- add

Answer 2

当您在没有指定源字符串长度的情况下将没有空终结符的着色器源传递给glShaderSource时，通常会发生错误。由于典型文件通常不包含空终止符，因此OpenGL将读取超过源字符串末尾的内容。

解决方案是传递着色器源字符串的确切长度。

OpenGL着色器无法编译

2 个答案: