如何在OpenGL中显示unicode文本？

#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <ft2build.h>
#include FT_FREETYPE_H

// 加载字体
FT_Library ft;
FT_Face face;
if (FT_Init_FreeType(&ft))
    std::cout << "ERROR::FREETYPE: Could not init FreeType Library"<< std::endl;
if (FT_New_Face(ft, "path/to/font.ttf", 0, &face))
    std::cout << "ERROR::FREETYPE: Failed to load font"<< std::endl;

// 设置字体大小
FT_Set_Pixel_Sizes(face, 0, 48);

// 加载字符
wchar_t text[] = L"Hello, Unicode!";
for (wchar_t c : text)
{
    if (FT_Load_Char(face, c, FT_LOAD_RENDER))
    {
        std::cout << "ERROR::FREETYTPE: Failed to load Glyph"<< std::endl;
        continue;
    }
    // 创建纹理
    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
    );
    // 设置纹理参数
    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);
    // 存储字符信息
    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<char, Character>(c, character));
}

// 渲染文本
std::string text = "Hello, Unicode!";
for (char c : text)
{
    Character ch = Characters[c];
    float xpos = x + ch.Bearing.x * scale;
    float ypos = y - (ch.Size.y - ch.Bearing.y) * scale;

    float w = ch.Size.x * scale;
    float h = ch.Size.y * scale;
    // 更新VBO
    GLfloat vertices[6][4] = {
        { xpos,     ypos + h,   0.0, 0.0 },
        { xpos,     ypos,       0.0, 1.0 },
        { xpos + w, ypos,       1.0, 1.0 },

        { xpos,     ypos + h,   0.0, 0.0 },
        { xpos + w, ypos,       1.0, 1.0 },
        { xpos + w, ypos + h,   1.0, 0.0 }
    };
    // 绘制文本
    glBindTexture(GL_TEXTURE_2D, ch.TextureID);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices);
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glDrawArrays(GL_TRIANGLES, 0, 6);
    // 更新位置
    x += (ch.Advance >> 6) * scale;
}