Question

我编写了一个使用FreeType将文本渲染到窗口的应用程序。我已经构建了调试和发布版本，它们都可以从visual studio 2015运行良好。我已经设置了我的运行时库来链接到/ MDd。我还在资源文件中包含了字体OCRAEXT.TTF。

以下是使用FreeType的代码：

TextRenderer::TextRenderer(GLuint width, GLuint height)
{
    //Load and configure shader
    this->TextShader = ResourceManager::LoadShader("VertexText.vert", "FragmentText.frag", nullptr, "text");
    this->TextShader.SetMatrix4("projection", glm::ortho(0.0f, static_cast<GLfloat>(width), static_cast<GLfloat>(height), 0.0f), GL_TRUE);
    this->TextShader.SetInteger("text", 0);

    //configure VAO/VBO for texture quads
    glGenVertexArrays(1, &this->VAO);
    glGenBuffers(1, &this->VBO);
    glBindVertexArray(this->VAO);
    glBindBuffer(GL_ARRAY_BUFFER, this->VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 6 * 4, NULL, GL_DYNAMIC_DRAW);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 4 * sizeof(GLfloat), 0);
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindVertexArray(0);
}


void TextRenderer::Load(std::string font, GLuint fontSize)
{
    //first clear the previously loaded characters
    this->Characters.clear();

    //then initialise and load the Freetype library
    FT_Library ft;
    if (FT_Init_FreeType(&ft))  //All functions return a value different than 0 whenever an error occurred
        std::cout << "ERROR::FREETYPE: Could not init freetype library" << std::endl;

    //Load font as face
    FT_Face face;
    if (FT_New_Face(ft, font.c_str(), 0, &face))
        std::cout << "ERROR::FREETYPE: Failed to load font" << std::endl;

    //set size to load glyphs as
    FT_Set_Pixel_Sizes(face, 0, fontSize);

    //disable byte-alignment restriction
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

    //then for the first 128 ASCII characters, pre-load/compile their characters and store them
    for (GLubyte c = 0; c < 128; c++)
    {
        //Load character glyph
        if (FT_Load_Char(face, c, FT_LOAD_RENDER))
        {
            std::cout << "ERROR::FREETYPE: Failed to load glyph" << std::endl;
            continue;
        }

        //generate texture
        GLuint texture;
        glGenTextures(1, &texture);
        glBindTexture(GL_TEXTURE_2D, texture);
        glTexImage2D(
            GL_TEXTURE_2D,
            0,
            GL_RED,
            face->glyph->bitmap.width,
            face->glyph->bitmap.rows,
            0,
            GL_RED,
            GL_UNSIGNED_BYTE,
            face->glyph->bitmap.buffer
            );

        //set texture options
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

        //Now store character for later use
        Character character =
        {
            texture,
            glm::ivec2(face->glyph->bitmap.width, face->glyph->bitmap.rows),
            glm::ivec2(face->glyph->bitmap_left, face->glyph->bitmap_top),
            face->glyph->advance.x,
        };
        Characters.insert(std::pair<GLchar, Character>(c, character));

    }
    glBindTexture(GL_TEXTURE_2D, 0);

    //destroy FreeType once we're finished
    FT_Done_Face(face);
    FT_Done_FreeType(ft);
}

在我的Game类中，我有一个初始化函数，其中包含以下代码行：

Text = new TextRenderer(this->Width, this->Height);
    Text->Load("fonts/OCRAEXT.TTF", 24);

问题是，当我尝试运行独立的.exe时，我收到消息“ERROR :: FREETYPE：无法加载字体”和.exe。停止运行。我试图调试这个，我收到一条消息，说“Game.exe中0x00730072处未处理的异常.0xC0000005：访问冲突执行位置0x00730072。”

断点指向这行代码：

FT_Set_Pixel_Sizes(face, 0, fontSize);

我已经尝试逐步解决问题，但很少有道理。有人可以解释一下可能出现的问题吗？

Answer 1

FT_New_Face需要文件系统中的路径。 PE资源不在文件系统中，因此尝试查找文件失败并且您收到此错误。

您必须使用FT_New_Memory_Face;可以使用Resource API (link to MSDN)检索资源的内存位置。而不是使用LoadLibrary使用GetModuleHandle(NULL)来检索进程的PE映像的句柄。

为什么Freetype不能在我的.exe中加载字体

1 个答案: