c++ - EXC_BAD_ACCESS glGetShaderInfoLog - 如何进行？

Question

我正在使用 Marmalade C++ 和 Open GL ES 2.0。我正在学习几个教程，但总是遇到同样的错误:

调用 glGetShaderInfo() 时出现 EXC_BAD_ACCESS

这是我的代码。在这种情况下我该如何处理？

static int eglInit()
{
    if (!IwGLInit() )
    {
        s3eDebugErrorShow(S3E_MESSAGE_CONTINUE, "eglInit failed");
        return 1;
    }
    return 0;
}

const char* vShaderStr =
    "attribute vec4 vPosition;\n"
    "void main()\n"
    "{\n"
    "gl_Position = vPosition;\n"
    "};\n";

const char* fShaderStr =
    "precision mediump float;\n"
    "void main()\n"
    "{\n"
    "gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);\n"
    "}\n";

GLuint LoadShader(GLenum type, const char *shaderSrc)
{
    GLuint shader;
    GLint compiled;

    // Create the shader object
    shader = glCreateShader(type);

    if (shader == 0)
        return 0;

    // Load the shader source
    glShaderSource(shader, 1, &shaderSrc, NULL);

    // Compile the shader
    glCompileShader(shader);

    glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);

    if (!compiled)
    {
        GLint infoLen = 0;
        glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &infoLen);
        if (infoLen > 1)
        {
            char* infoLog = (char*)malloc(sizeof(char) * infoLen);

            glGetShaderInfoLog(shader, infoLen, NULL, infoLog);
            printf("Error compiling shader:\n%s\n", infoLog);

            free(infoLog);
        }

        glDeleteShader(shader);
        return 0;
    }

    return shader;
}

int main()
{
    if (eglInit())
        return 1;
    printf("Screen BPP: %d\n", s3eSurfaceGetInt(S3E_SURFACE_PIXEL_TYPE) & S3E_SURFACE_PIXEL_SIZE_MASK);
    printf("\n");
    printf( "Vendor     : %s\n", (char*)glGetString(GL_VENDOR));
    printf( "Renderer   : %s\n", (char*)glGetString(GL_RENDERER));
    printf( "Version    : %s\n", (char*)glGetString(GL_VERSION));
    printf( "Extensions : %s\n", (char*)glGetString(GL_EXTENSIONS));
    printf("\n");

    GLuint vertexShader;
    vertexShader = LoadShader(GL_VERTEX_SHADER, vShaderStr);

    bool quit = false;
    int numFrames = 0;
    while (!quit) {
        s3eKeyboardUpdate();
        s3eDeviceYield(0);
        if (s3eDeviceCheckQuitRequest())
            quit = 1;
        if (s3eKeyboardGetState(s3eKeyEsc) & S3E_KEY_STATE_PRESSED)
            quit = 1;
        numFrames++;
    }
    //Shutdown GL system
    IwGLTerminate();
    return 0;
}

Answer 1

在:

glGetShaderInfoLog(shader, infoLen, NULL, infoLog);

您传递的是 NULL 作为第三个参数，它应该接受 GLsizei*。这个参数(第三个)is populated具有信息日志的实际长度，因此应该是一个有效的指针。

要解决您可以做的问题:

GLsizei info_length = 0;
glGetShaderInfoLog(shader, infoLen, &info_length, infoLog);