font_resource.hpp

// Copyright [2015] Albert Huang

#ifndef SCENEVIEW_FONT_RESOURCE_HPP__
#define SCENEVIEW_FONT_RESOURCE_HPP__

#include <memory>

#include <QFont>

class QOpenGLTexture;

namespace sv {

class FontResource {
  public:
    struct CharData {
      // Texture left coordinate
      float u0;

      // Texture top coordinate
      float v0;

      // Texture right coordinate
      float u1;

      // Texture bottom coordinate
      float v1;

      // Character width, relative to line height
      float width_to_height;

      // Vertex left offset (relative to line height)
      float x0;

      // Vertex top offset (relative to line height)
      float y0;

      // Vertex right offset (relative to line height)
      float x1;

      // Vertex bottom offset (relative to line height)
      float y1;
    };

  public:
    typedef std::shared_ptr<FontResource> Ptr;

    const std::shared_ptr<QOpenGLTexture>& Texture() { return texture_; }

    const CharData& GetCharData(int c) {
      return char_data_[c];
    }

  private:
    friend class ResourceManager;

    static Ptr Create(const QFont& font);

    explicit FontResource(const QFont& font);

    void Build(const QFont& font);

    int num_rows_;
    int num_cols_;
    int block_size_;

    CharData char_data_[256];

    std::shared_ptr<QOpenGLTexture> texture_;
};

}  // namespace sv

#endif  // SCENEVIEW_FONT_RESOURCE_HPP__