text.hpp

// SPDX-License-Identifier: MIT
// Author:  Giovanni Santini
// Mail:    giovanni.santini@proton.me
// Github:  @San7o
 
#pragma once
 
#include <brenta/buffer.hpp>
#include <brenta/shader.hpp>
#include <brenta/vao.hpp>
#include <brenta/subsystem.hpp>
 
#include <ft2build.h>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
 
#include <map>
#include <string>
 
#include FT_FREETYPE_H
 
namespace brenta
{
 
namespace types
{
 
struct character
{
  unsigned int texture_id; // ID handle of the glyph texture
  glm::ivec2 size;         // Size of glyph
  glm::ivec2 bearing;      // Offset from baseline to left/top of glyph
  unsigned int advance;    // Offset to advance to next glyph
};
 
} // namespace types
 
class text : public subsystem
{
public:
  
  static std::map<char, types::character> characters;
 
  class config;
  class builder;
 
  static const std::string subsystem_name;
  static const text::config default_config;
  static text::config init_config;
 
  // Subsystem interface
  std::expected<void, subsystem::error> initialize() override;
 
  std::expected<void, subsystem::error> terminate() override;
  std::string name() override;
  bool is_initialized() override;
 
  // Constructors / destructors
  text() = default;
  ~text() = default;
  
  // Member functions
  
  static text &instance();
 
  static void load(std::string font_name, int font_size = 48);
  
  static void render_text(std::string text, float x, float y,
                          float scale, glm::vec3 color);
 
private:
  
  static shader::name_t shader_name;
  static types::vao vao;
  static types::buffer vbo;
  static bool initialized;
  
};
 
struct text::config
{
  std::string font_path;
  int font_size;
};
  
class text::builder : public subsystem::builder
{
private:
 
  text::config conf = text::default_config;
  
public:
 
  builder() = default;
  ~builder() = default;
 
  builder &font(const std::string &font_path);
  builder &size(int font_size);
  
  brenta::subsystem &build() override;
  
};
 
  
} // namespace brenta