Question

我正在关注arcsynthesis的OpenGL教程。第一部分没有提供使演示工作所需的所有代码，所以我不得不即兴发挥。无论如何，看起来一切正常，除了我的顶点和片段着色器没有编译。这些是我用glGetShaderInfoLog获得的错误：

ERROR: 0:1: error(#132) Syntax error: "test" parse error
ERROR: error(#273) 1 compilation errors.  No code generated

这是我的OpenGL代码：

#include <GL/glew.h>
#include <GL/freeglut.h>
#include <cstdio>
#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

const float vertexPositions[] = {
  0.75f, 0.75f, 0.0f, 1.0f,
  0.75f, -0.75f, 0.0f, 1.0f,
  -0.75f, -0.75f, 0.0f, 1.0f
};

const string strVertexShader = "test.vert";
const string strFragmentShader = "test.frag";

GLuint positionBufferObject;
GLuint theProgram;
GLuint create_shader(GLenum, const string &);

GLuint create_program(const vector<GLuint>&);

void init_program()
{
    vector<GLuint> shaderList;

    shaderList.push_back(create_shader(GL_VERTEX_SHADER, strVertexShader));
    shaderList.push_back(create_shader(GL_FRAGMENT_SHADER, strFragmentShader));

    theProgram = create_program(shaderList);

    for_each(shaderList.begin(), shaderList.end(), glDeleteShader);
}

GLuint create_shader(GLenum eShaderType, const std::string &strShaderFile)
{
    GLuint shader = glCreateShader(eShaderType);
    const char *strFileData = strShaderFile.c_str();
    glShaderSource(shader, 1, &strFileData, NULL);

    glCompileShader(shader);

    GLint status;
    glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
    if (status == GL_FALSE)
    {
        GLint infoLogLength;
        glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &infoLogLength);

        GLchar *strInfoLog = new GLchar[infoLogLength + 1];
        glGetShaderInfoLog(shader, infoLogLength, NULL, strInfoLog);

        const char *strShaderType = NULL;
        switch(eShaderType)
        {
        case GL_VERTEX_SHADER: strShaderType = "vertex"; break;
        case GL_GEOMETRY_SHADER: strShaderType = "geometry"; break;
        case GL_FRAGMENT_SHADER: strShaderType = "fragment"; break;
        }

        fprintf(stderr, "Compile failure in %s shader:\n%s\n", strShaderType, strInfoLog);
        delete[] strInfoLog;
    }

  return shader;
}

GLuint create_program(const std::vector<GLuint> &shaderList)
{
    GLuint program = glCreateProgram();

    for(size_t iLoop = 0; iLoop < shaderList.size(); iLoop++)
      glAttachShader(program, shaderList[iLoop]);

    glLinkProgram(program);

    GLint status;
    glGetProgramiv (program, GL_LINK_STATUS, &status);
    if (status == GL_FALSE)
    {
        GLint infoLogLength;
        glGetProgramiv(program, GL_INFO_LOG_LENGTH, &infoLogLength);

        GLchar *strInfoLog = new GLchar[infoLogLength + 1];
        glGetProgramInfoLog(program, infoLogLength, NULL, strInfoLog);
        fprintf(stderr, "Linker failure: %s\n", strInfoLog);
        delete[] strInfoLog;
    }

    for(size_t iLoop = 0; iLoop < shaderList.size(); iLoop++)
        glDetachShader(program, shaderList[iLoop]);

    return program;
}

void init(void)
{
  init_program();  

  glGenBuffers(1, &positionBufferObject);

  glBindBuffer(GL_ARRAY_BUFFER, positionBufferObject);
  glBufferData(GL_ARRAY_BUFFER, sizeof(vertexPositions), vertexPositions, GL_STATIC_DRAW);

  glBindBuffer(GL_ARRAY_BUFFER, 0);
}

void display(void)
{
  glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
  glClear(GL_COLOR_BUFFER_BIT);

  glUseProgram(theProgram);

  glBindBuffer(GL_ARRAY_BUFFER, positionBufferObject);
  glEnableVertexAttribArray(0);
  glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, 0);

  glDrawArrays(GL_TRIANGLES, 0, 3);

  glDisableVertexAttribArray(0);
  glUseProgram(0);

  glutSwapBuffers();
}

int main(int argc, char** argv)
{
  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_RGBA);
  glutInitWindowSize(512, 512);
  glutInitContextVersion(3, 3);
  glutInitContextProfile(GLUT_CORE_PROFILE);
  glutCreateWindow(argv[0]);

  if (glewInit()) {
    cerr << "Unable to initialize GLEW ... exiting" << endl;
    exit(EXIT_FAILURE);
  }

  init();

  glutDisplayFunc(display);

  glutMainLoop();
}

我的顶点着色器“test.vert”：

#version 330

layout(location = 0) in vec4 position;

void main()
{
  gl_Position = position;
}

我的片段着色为“test.frag”：

#version 330

out vec4 outputColor;

void main()
{
  outputColor = vec4(1.0f, 1.0f, 1.0f, 1.0f);
}

Answer 1

OpenGL不会为您加载文件，它根本不知道文件的概念。 glShaderSource期望源代码为字符串（或一系列单独的字符串）。您只需提供一个文件名，现在解释为GLSL源代码，当然不是有效的程序。

请注意，arcsynthesis教程附带full source code，因此无需即兴创作。

GLSL编译错误＃132

1 个答案: