textrenderer.hpp

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#pragma once
 
#include <vertexbuffer.hpp>
#include <vertexbufferlayout.hpp>
#include <vertexarray.hpp>
#include <shader.hpp>
 
#include <ft2build.h>
#include FT_FREETYPE_H
 
inline constexpr unsigned int CH_LIMIT=400;
inline constexpr unsigned int CH_NUM=128;
 
class TextRenderer{
public:
    TextRenderer(): m_Loaded(false),m_Characters(nullptr),m_Transforms(nullptr),m_ToRender(nullptr),m_FontPath(100,'\0'),m_GlyphSize(0),m_Fixed(false){}
    TextRenderer(const std::string &font_path,float glyph_size,bool fixed);
    TextRenderer(const std::string &font_path,float glyph_size,bool fixed,uint32_t id);
    ~TextRenderer();
 
    void DrawText(const std::string &text,float x,float y,float scale,int layer,Vec3 color);
 
    void _DrawText(const std::string &text,float x,float y,float scale,Vec3 color);
    std::pair<float,float> GetTextSize(std::string text,float scale); 
 
    inline void UpdateProjMat(glm::mat4 &proj){
        if(m_Loaded){
            m_Shader.Bind();
            m_Shader.SetUniformMat4fv("u_PM",glm::value_ptr(proj),1);
        }
    }
 
private:
    friend class SceneSerializer;
    friend class FontManager;
 
    struct Character{
        unsigned int TexID;     // ID of the glyph texture       
        glm::ivec2 Size;       // Size of glyph
        glm::ivec2 Bearing;     // Offset from baseline to left/top of glyph
        unsigned int Advance;   // Horizontal offset to advance to next glyph
    };
 
    FT_Library m_FT;
    FT_Face m_Face;
 
    VertexBuffer m_VBO;
    VertexArray m_VAO;
    VertexBufferLayout m_VBL;
    Shader m_Shader;
 
    unsigned int m_TextureArrayID;
    Character *m_Characters;
    glm::mat4 *m_Transforms;
    int *m_ToRender;
 
    std::string m_LoadedFontPath;
    float m_LoadedGlyphSize;
 
    bool m_Loaded;
 
    void Init(const std::string &font_path,float glyph_size,bool fixed);
    void Render(int num_characters);  
 
public:
    uint32_t m_ID;
    std::string m_FontPath;
    float m_GlyphSize;
    bool m_Fixed;
};