project_misth/include/window/window.h

#ifndef WINDOW_H
#define WINDOW_H

#include "pch.h"
#include "utils.h"

using ImageID = uint32_t;
using FontID = uint32_t;
using TextID = uint32_t;

struct Font {
  TTF_Font *font;
  bool pixel_art;
};

struct Event {
  enum Type {
    NONE,
    QUIT,
    KEY_UP,
    KEY_DOWN,
    TEXT_INPUT,
    SCROLL,
    MOUSE_BUTTON_UP,
    MOUSE_BUTTON_DOWN,
    MOUSE_MOVE
  } type;

  union {
    struct {
      uint32_t key;
    } key;

    struct {
      char *text;
      uint32_t length;
    } text_input;

    struct {
      float x, y;
    } scroll;

    struct {
      uint8_t button;
      Vec2<float> position;
    } mouse_button;

    struct {
      Vec2<float> position;
      Vec2<float> delta;
    } mouse_move;
  };
};

struct Window {
public:
  // title can be free'd by the caller after the window is created, as it's copied internally.
  Window(Vec2<float> size, const char *title);

  ~Window();

  // Rendering functions

  ImageID load_image(const char *path, bool pixel_art = false);
  void unload_image(ImageID image_id);

  FontID load_font(const char *path, int font_size, bool bold = false, bool italic = false, bool underline = false, bool pixel_art = false);
  void unload_font(FontID font_id);

  // text is copied internally, so it can be free'd by the caller after the text is created.
  TextID create_text(FontID font_id, const char *text, uint32_t length, Color color);
  void unload_text(TextID text_id);

  bool write(TextID text_id, Vec2<float> position, float z, float angle = 0.0f, Vec2<float> scale = {1.0f, 1.0f});

  bool draw(ImageID image_id, Vec2<float> position, float z, float angle = 0.0f, Vec2<float> scale = {1.0f, 1.0f}, float alpha = 1.0f);

  bool draw_rect(Rect rect, Color color, float z, float angle = 0.0f);

  void render(); // the rest of the calls only build the instruction list, this actually renders everything added to the screen (following z order)

  void clear(); // clears the instruction list

  // Event handling

  bool poll(Event &event); // returns true if an event was polled, false otherwise

  // consumes an event, (mostly for text input, to free the text input buffer)
  // but also so the user can decide when they're done with the event explicitly.
  void consume(Event &event);

  // Text input
  // Starts accepting Unicode text input events, and stops acceptong normal key down/up events for those keys.

  void start_text_input();
  void stop_text_input();

  // Clipboard get

  // To be free'd by the caller after use.
  const char *paste();

  // Time

  uint64_t get_time();   // returns the time in milliseconds since the window was created
  uint64_t delta_time(); // returns the time in milliseconds since the last render call

private:
  // internal data and functions
  SDL_Window *window;
  SDL_Renderer *renderer;

  Vec2<float> real_size;
  Vec2<float> virtual_size;
  Vec2<float> offset;
  float scale;

  // White pixel texture for drawing colored rectangles
  SDL_Texture *white_tex;

  // Image pool
  std::vector<SDL_Texture *> images;
  std::vector<int> free_image_indices;

  // Font pool
  std::vector<struct Font> fonts;
  std::vector<int> free_font_indices;

  // Text pool
  std::vector<SDL_Texture *> texts;
  std::vector<int> free_text_indices;

  struct RenderInstruction {
    enum Type {
      DRAW_IMAGE,
      DRAW_TEXT,
      DRAW_RECT
    } type;

    float z;
    float angle;
    Vec2<float> scale;

    union {
      struct {
        ImageID image_id;
        Vec2<float> position;
        float alpha;
      } draw_image;

      struct {
        TextID text_id;
        Vec2<float> position;
      } draw_text;

      struct {
        Rect rect;
        Color color;
      } draw_rect;
    };
  };

  std::vector<struct RenderInstruction> render_instructions;

  bool text_input_active;

  void compute_transform();

  bool mouse_in_window(const Vec2<float> real_position, Vec2<float> &virtual_position);

  void draw_letterbox();
};

#endif