//
// GLUT emulation header file for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2023 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
//     https://www.fltk.org/bugs.php
//

// Emulation of GLUT using fltk.

// GLUT is Copyright (c) Mark J. Kilgard, 1994, 1995, 1996:
// "This program is freely distributable without licensing fees  and is
// provided without guarantee or warrantee expressed or  implied. This
// program is -not- in the public domain."

// Although I have copied the GLUT API, none of my code is based on
// any GLUT implementation details and is therefore covered by the LGPL.

// Commented out lines indicate parts of GLUT that are not emulated.

// Notes: as pointed out in STR #3458 the current GLUT window,
// i.e. the global static variable 'glut_window' can be NULL ...
//  (a) if not (yet) initialized
//  (b) if the current GLUT window is deleted at any time.
// The FLTK implementation silently ignores function calls if the current
// window is NULL to avoid dereferencing a NULL pointer. This is obviously
// compatible with GLUT version 3.7 according to comment #5 on STR #3458.
// According to the same comment FreeGLUT 3.0 would issue an error message
// and quit.
// Albrecht-S, Oct 2023

#ifndef _FL_glut_H_
#  define _FL_glut_H_

#  include "gl.h"


#  include "Fl.H"
#  include "Fl_Gl_Window.H"

/**
  GLUT is emulated using this window class and these static variables
  (plus several more static variables hidden in glut_compatibility.cxx):
*/
class FL_EXPORT Fl_Glut_Window : public Fl_Gl_Window {
  void _init();
  int mouse_down;
protected:
  void draw() FL_OVERRIDE;
  void draw_overlay() FL_OVERRIDE;
  int handle(int) FL_OVERRIDE;
public: // so the inline functions work
  int number;
  int menu[3];
  void make_current();
  void (*display)();
  void (*overlaydisplay)();
  void (*reshape)(int w, int h);
  void (*keyboard)(uchar, int x, int y);
  void (*mouse)(int b, int state, int x, int y);
  void (*motion)(int x, int y);
  void (*passivemotion)(int x, int y);
  void (*entry)(int);
  void (*visibility)(int);
  void (*special)(int, int x, int y);
  Fl_Glut_Window(int w, int h, const char *t=0);
  Fl_Glut_Window(int x, int y, int w, int h, const char *t=0);
  ~Fl_Glut_Window();
};

extern FL_EXPORT Fl_Glut_Window *glut_window;   // the current window
extern FL_EXPORT int glut_menu;                 // the current menu

// function pointers that are not per-window:
extern FL_EXPORT void (*glut_idle_function)();
extern FL_EXPORT void (*glut_menustate_function)(int);
extern FL_EXPORT void (*glut_menustatus_function)(int,int,int);

////////////////////////////////////////////////////////////////

//#  define GLUT_API_VERSION This does not match any version of GLUT exactly...

FL_EXPORT void glutInit(int *argcp, char **argv); // creates first window

FL_EXPORT void glutInitDisplayMode(unsigned int mode);
// the FL_ symbols have the same value as the GLUT ones:
#  define GLUT_RGB            FL_RGB
#  define GLUT_RGBA           FL_RGB
#  define GLUT_INDEX          FL_INDEX
#  define GLUT_SINGLE         FL_SINGLE
#  define GLUT_DOUBLE         FL_DOUBLE
#  define GLUT_ACCUM          FL_ACCUM
#  define GLUT_ALPHA          FL_ALPHA
#  define GLUT_DEPTH          FL_DEPTH
#  define GLUT_STENCIL        FL_STENCIL
#  define GLUT_MULTISAMPLE    FL_MULTISAMPLE
#  define GLUT_STEREO         FL_STEREO
// #  define GLUT_LUMINANCE   512

FL_EXPORT void glutInitWindowPosition(int x, int y);

FL_EXPORT void glutInitWindowSize(int w, int h);

FL_EXPORT void glutMainLoop();

FL_EXPORT int glutCreateWindow(char *title);
FL_EXPORT int glutCreateWindow(const char *title);

FL_EXPORT int glutCreateSubWindow(int win, int x, int y, int width, int height);

FL_EXPORT void glutDestroyWindow(int win);

inline void glutPostRedisplay() {
  if (glut_window) glut_window->redraw();
}

FL_EXPORT void glutPostWindowRedisplay(int win);

FL_EXPORT void glutSwapBuffers();

inline int glutGetWindow() {
  return glut_window ? glut_window->number : 0;
}

FL_EXPORT void glutSetWindow(int win);

inline void glutSetWindowTitle(char *t) {
  if (glut_window) glut_window->label(t);
}

inline void glutSetIconTitle(char *t) {
  if (glut_window) glut_window->iconlabel(t);
}

inline void glutPositionWindow(int x, int y) {
  if (glut_window) glut_window->position(x,y);
}

inline void glutReshapeWindow(int w, int h) {
  if (glut_window) glut_window->size(w,h);
}

inline void glutPopWindow() {
  if (glut_window) glut_window->show();
}

inline void glutPushWindow() { /* do nothing */ }

inline void glutIconifyWindow() {
  if (glut_window) glut_window->iconize();
}

inline void glutShowWindow() {
  if (glut_window) glut_window->show();
}

inline void glutHideWindow() {
  if (glut_window) glut_window->hide();
}

inline void glutFullScreen() {
  if (glut_window) glut_window->fullscreen();
}

inline void glutSetCursor(Fl_Cursor cursor) {
  if (glut_window) glut_window->cursor(cursor);
}

// notice that the numeric values are different than glut:
#  define GLUT_CURSOR_RIGHT_ARROW               ((Fl_Cursor)2)
#  define GLUT_CURSOR_LEFT_ARROW                ((Fl_Cursor)67)
#  define GLUT_CURSOR_INFO                      FL_CURSOR_HAND
#  define GLUT_CURSOR_DESTROY                   ((Fl_Cursor)45)
#  define GLUT_CURSOR_HELP                      FL_CURSOR_HELP
#  define GLUT_CURSOR_CYCLE                     ((Fl_Cursor)26)
#  define GLUT_CURSOR_SPRAY                     ((Fl_Cursor)63)
#  define GLUT_CURSOR_WAIT                      FL_CURSOR_WAIT
#  define GLUT_CURSOR_TEXT                      FL_CURSOR_INSERT
#  define GLUT_CURSOR_CROSSHAIR                 FL_CURSOR_CROSS
#  define GLUT_CURSOR_UP_DOWN                   FL_CURSOR_NS
#  define GLUT_CURSOR_LEFT_RIGHT                FL_CURSOR_WE
#  define GLUT_CURSOR_TOP_SIDE                  FL_CURSOR_N
#  define GLUT_CURSOR_BOTTOM_SIDE               FL_CURSOR_S
#  define GLUT_CURSOR_LEFT_SIDE                 FL_CURSOR_W
#  define GLUT_CURSOR_RIGHT_SIDE                FL_CURSOR_E
#  define GLUT_CURSOR_TOP_LEFT_CORNER           FL_CURSOR_NW
#  define GLUT_CURSOR_TOP_RIGHT_CORNER          FL_CURSOR_NE
#  define GLUT_CURSOR_BOTTOM_RIGHT_CORNER       FL_CURSOR_SE
#  define GLUT_CURSOR_BOTTOM_LEFT_CORNER        FL_CURSOR_SW
#  define GLUT_CURSOR_INHERIT                   FL_CURSOR_DEFAULT
#  define GLUT_CURSOR_NONE                      FL_CURSOR_NONE
#  define GLUT_CURSOR_FULL_CROSSHAIR            FL_CURSOR_CROSS

inline void glutWarpPointer(int, int) { /* do nothing */ }

inline void glutEstablishOverlay() {
  if (glut_window) glut_window->make_overlay_current();
}

inline void glutRemoveOverlay() {
  if (glut_window) glut_window->hide_overlay();
}

inline void glutUseLayer(GLenum layer) {
  if (!glut_window)
    return;
  layer ? glut_window->make_overlay_current() : glut_window->make_current();
}

enum {GLUT_NORMAL, GLUT_OVERLAY};

inline void glutPostOverlayRedisplay() {
  if (glut_window) glut_window->redraw_overlay();
}

inline void glutShowOverlay() {
  if (glut_window) glut_window->redraw_overlay();
}

inline void glutHideOverlay() {
  if (glut_window) glut_window->hide_overlay();
}

FL_EXPORT int glutCreateMenu(void (*)(int));

FL_EXPORT void glutDestroyMenu(int menu);

inline int glutGetMenu() {return glut_menu;}

inline void glutSetMenu(int m) {glut_menu = m;}

FL_EXPORT void glutAddMenuEntry(const char *label, int value);

FL_EXPORT void glutAddSubMenu(char *label, int submenu);

FL_EXPORT void glutChangeToMenuEntry(int item, char *labela, int value);

FL_EXPORT void glutChangeToSubMenu(int item, char *label, int submenu);

FL_EXPORT void glutRemoveMenuItem(int item);

inline void glutAttachMenu(int b) {
  if (glut_window) glut_window->menu[b] = glut_menu;
}

inline void glutDetachMenu(int b) {
  if (glut_window) glut_window->menu[b] = 0;
}

inline void glutDisplayFunc(void (*f)()) {
  if (glut_window) glut_window->display = f;
}

inline void glutReshapeFunc(void (*f)(int w, int h)) {
  if (glut_window) glut_window->reshape = f;
}

inline void glutKeyboardFunc(void (*f)(uchar key, int x, int y)) {
  if (glut_window) glut_window->keyboard = f;
}

inline void glutMouseFunc(void (*f)(int b, int state, int x, int y)) {
  if (glut_window) glut_window->mouse = f;
}

#  define GLUT_LEFT_BUTTON              0
#  define GLUT_MIDDLE_BUTTON            1
#  define GLUT_RIGHT_BUTTON             2
#  define GLUT_DOWN                     0
#  define GLUT_UP                       1

inline void glutMotionFunc(void (*f)(int x, int y)) {
  if (glut_window) glut_window->motion = f;
}

inline void glutPassiveMotionFunc(void (*f)(int x, int y)) {
  if (glut_window) glut_window->passivemotion = f;
}

inline void glutEntryFunc(void (*f)(int s)) {
  if (glut_window) glut_window->entry = f;
}

enum {GLUT_LEFT, GLUT_ENTERED};

inline void glutVisibilityFunc(void (*f)(int s)) {
  if (glut_window) glut_window->visibility = f;
}
enum {GLUT_NOT_VISIBLE, GLUT_VISIBLE};

FL_EXPORT void glutIdleFunc(void (*f)());

inline void glutTimerFunc(unsigned int msec, void (*f)(int), int value) {
  Fl::add_timeout(msec*.001, (void (*)(void *))f, (void *)(fl_intptr_t)value);
}

inline void glutMenuStateFunc(void (*f)(int state)) {
  glut_menustate_function = f;}

inline void glutMenuStatusFunc(void (*f)(int status, int x, int y)) {
  glut_menustatus_function = f;}
enum {GLUT_MENU_NOT_IN_USE, GLUT_MENU_IN_USE};

inline void glutSpecialFunc(void (*f)(int key, int x, int y)) {
  if (glut_window) glut_window->special = f;
}

#  define GLUT_KEY_F1                   1
#  define GLUT_KEY_F2                   2
#  define GLUT_KEY_F3                   3
#  define GLUT_KEY_F4                   4
#  define GLUT_KEY_F5                   5
#  define GLUT_KEY_F6                   6
#  define GLUT_KEY_F7                   7
#  define GLUT_KEY_F8                   8
#  define GLUT_KEY_F9                   9
#  define GLUT_KEY_F10                  10
#  define GLUT_KEY_F11                  11
#  define GLUT_KEY_F12                  12
// WARNING: Different values than GLUT uses:
#  define GLUT_KEY_LEFT                 FL_Left
#  define GLUT_KEY_UP                   FL_Up
#  define GLUT_KEY_RIGHT                FL_Right
#  define GLUT_KEY_DOWN                 FL_Down
#  define GLUT_KEY_PAGE_UP              FL_Page_Up
#  define GLUT_KEY_PAGE_DOWN            FL_Page_Down
#  define GLUT_KEY_HOME                 FL_Home
#  define GLUT_KEY_END                  FL_End
#  define GLUT_KEY_INSERT               FL_Insert

// inline void glutSpaceballMotionFunc(void (*)(int x, int y, int z));

// inline void glutSpaceballRotateFunc(void (*)(int x, int y, int z));

// inline void glutSpaceballButtonFunc(void (*)(int button, int state));

// inline void glutButtonBoxFunc(void (*)(int button, int state));

// inline void glutDialsFunc(void (*)(int dial, int value));

// inline void glutTabletMotionFunc(void (*)(int x, int y));

// inline void glutTabletButtonFunc(void (*)(int button, int state, int x, int y));

inline void glutOverlayDisplayFunc(void (*f)()) {
  if (glut_window) glut_window->overlaydisplay = f;
}

// inline void glutWindowStatusFunc(void (*)(int state));
// enum {GLUT_HIDDEN, GLUT_FULLY_RETAINED, GLUT_PARTIALLY_RETAINED,
//       GLUT_FULLY_COVERED};

// inline void glutSetColor(int, GLfloat red, GLfloat green, GLfloat blue);

// inline GLfloat glutGetColor(int ndx, int component);
// #define GLUT_RED                     0
// #define GLUT_GREEN                   1
// #define GLUT_BLUE                    2

// inline void glutCopyColormap(int win);

// Warning: values are changed from GLUT!
// Also relies on the GL_ symbols having values greater than 100
FL_EXPORT int glutGet(GLenum type);
enum {
  GLUT_RETURN_ZERO = 0,
  GLUT_WINDOW_X,
  GLUT_WINDOW_Y,
  GLUT_WINDOW_WIDTH,
  GLUT_WINDOW_HEIGHT,
  GLUT_WINDOW_PARENT,
  GLUT_SCREEN_WIDTH,
  GLUT_SCREEN_HEIGHT,
  GLUT_MENU_NUM_ITEMS,
  GLUT_DISPLAY_MODE_POSSIBLE,
  GLUT_INIT_WINDOW_X,
  GLUT_INIT_WINDOW_Y,
  GLUT_INIT_WINDOW_WIDTH,
  GLUT_INIT_WINDOW_HEIGHT,
  GLUT_INIT_DISPLAY_MODE,
  GLUT_WINDOW_BUFFER_SIZE,
  GLUT_VERSION,
//GLUT_WINDOW_NUM_CHILDREN,
//GLUT_WINDOW_CURSOR,
//GLUT_SCREEN_WIDTH_MM,
//GLUT_SCREEN_HEIGHT_MM,
  GLUT_ELAPSED_TIME
};

#  define GLUT_WINDOW_STENCIL_SIZE      GL_STENCIL_BITS
#  define GLUT_WINDOW_DEPTH_SIZE        GL_DEPTH_BITS
#  define GLUT_WINDOW_RED_SIZE          GL_RED_BITS
#  define GLUT_WINDOW_GREEN_SIZE        GL_GREEN_BITS
#  define GLUT_WINDOW_BLUE_SIZE         GL_BLUE_BITS
#  define GLUT_WINDOW_ALPHA_SIZE        GL_ALPHA_BITS
#  define GLUT_WINDOW_ACCUM_RED_SIZE    GL_ACCUM_RED_BITS
#  define GLUT_WINDOW_ACCUM_GREEN_SIZE  GL_ACCUM_GREEN_BITS
#  define GLUT_WINDOW_ACCUM_BLUE_SIZE   GL_ACCUM_BLUE_BITS
#  define GLUT_WINDOW_ACCUM_ALPHA_SIZE  GL_ACCUM_ALPHA_BITS
#  define GLUT_WINDOW_DOUBLEBUFFER      GL_DOUBLEBUFFER
#  define GLUT_WINDOW_RGBA              GL_RGBA
#  define GLUT_WINDOW_COLORMAP_SIZE     GL_INDEX_BITS
#  ifdef GL_SAMPLES_SGIS
#    define GLUT_WINDOW_NUM_SAMPLES     GL_SAMPLES_SGIS
#  else
#    define GLUT_WINDOW_NUM_SAMPLES     GLUT_RETURN_ZERO
#  endif
#  define GLUT_WINDOW_STEREO            GL_STEREO

#  define GLUT_HAS_KEYBOARD             600
#  define GLUT_HAS_MOUSE                601
#  define GLUT_HAS_SPACEBALL            602
#  define GLUT_HAS_DIAL_AND_BUTTON_BOX  603
#  define GLUT_HAS_TABLET               604
#  define GLUT_NUM_MOUSE_BUTTONS        605
#  define GLUT_NUM_SPACEBALL_BUTTONS    606
#  define GLUT_NUM_BUTTON_BOX_BUTTONS   607
#  define GLUT_NUM_DIALS                608
#  define GLUT_NUM_TABLET_BUTTONS       609
FL_EXPORT int glutDeviceGet(GLenum type);

// WARNING: these values are different than GLUT uses:
#  define GLUT_ACTIVE_SHIFT               FL_SHIFT
#  define GLUT_ACTIVE_CTRL                FL_CTRL
#  define GLUT_ACTIVE_ALT                 FL_ALT

inline int glutGetModifiers() {
  return Fl::event_state() & (GLUT_ACTIVE_SHIFT | GLUT_ACTIVE_CTRL | GLUT_ACTIVE_ALT);
}

FL_EXPORT int glutLayerGet(GLenum);
#  define GLUT_OVERLAY_POSSIBLE         800
//#define GLUT_LAYER_IN_USE             801
//#define GLUT_HAS_OVERLAY              802
#  define GLUT_TRANSPARENT_INDEX        803
#  define GLUT_NORMAL_DAMAGED           804
#  define GLUT_OVERLAY_DAMAGED          805

extern "C" {
typedef void (*GLUTproc)();
}

FL_EXPORT GLUTproc glutGetProcAddress(const char *procName);

// inline int glutVideoResizeGet(GLenum param);
// #define GLUT_VIDEO_RESIZE_POSSIBLE     900
// #define GLUT_VIDEO_RESIZE_IN_USE       901
// #define GLUT_VIDEO_RESIZE_X_DELTA      902
// #define GLUT_VIDEO_RESIZE_Y_DELTA      903
// #define GLUT_VIDEO_RESIZE_WIDTH_DELTA  904
// #define GLUT_VIDEO_RESIZE_HEIGHT_DELTA 905
// #define GLUT_VIDEO_RESIZE_X            906
// #define GLUT_VIDEO_RESIZE_Y            907
// #define GLUT_VIDEO_RESIZE_WIDTH        908
// #define GLUT_VIDEO_RESIZE_HEIGHT       909

// inline void glutSetupVideoResizing();

// inline void glutStopVideoResizing();

// inline void glutVideoResize(int x, int y, int width, int height);

// inline void glutVideoPan(int x, int y, int width, int height);

// Font argument must be a void* for compatibility, so...
/** fltk glut font/size attributes used in the glutXXX functions */
struct Fl_Glut_Bitmap_Font {Fl_Font font; Fl_Fontsize size;};

extern FL_EXPORT struct Fl_Glut_Bitmap_Font
  glutBitmap9By15, glutBitmap8By13, glutBitmapTimesRoman10,
  glutBitmapTimesRoman24, glutBitmapHelvetica10, glutBitmapHelvetica12,
  glutBitmapHelvetica18;
#  define GLUT_BITMAP_9_BY_15             (&glutBitmap9By15)
#  define GLUT_BITMAP_8_BY_13             (&glutBitmap8By13)
#  define GLUT_BITMAP_TIMES_ROMAN_10      (&glutBitmapTimesRoman10)
#  define GLUT_BITMAP_TIMES_ROMAN_24      (&glutBitmapTimesRoman24)
#  define GLUT_BITMAP_HELVETICA_10        (&glutBitmapHelvetica10)
#  define GLUT_BITMAP_HELVETICA_12        (&glutBitmapHelvetica12)
#  define GLUT_BITMAP_HELVETICA_18        (&glutBitmapHelvetica18)

FL_EXPORT void glutBitmapCharacter(void *font, int character);
FL_EXPORT int glutBitmapHeight(void *font);
FL_EXPORT int glutBitmapLength(void *font, const unsigned char *string);
FL_EXPORT void glutBitmapString(void *font, const unsigned char *string);
FL_EXPORT int glutBitmapWidth(void *font, int character);

FL_EXPORT int glutExtensionSupported(char *name);

/* GLUT stroked font sub-API */
struct Fl_Glut_StrokeVertex {
  GLfloat X, Y;
};

struct Fl_Glut_StrokeStrip {
  int Number;
  const Fl_Glut_StrokeVertex* Vertices;
};

struct Fl_Glut_StrokeChar {
  GLfloat Right;
  int Number;
  const Fl_Glut_StrokeStrip* Strips;
};

struct Fl_Glut_StrokeFont {
  char* Name;                           // The source font name
  int Quantity;                         // Number of chars in font
  GLfloat Height;                       // Height of the characters
  const Fl_Glut_StrokeChar** Characters;// The characters mapping
};
extern FL_EXPORT Fl_Glut_StrokeFont glutStrokeRoman;
extern FL_EXPORT Fl_Glut_StrokeFont glutStrokeMonoRoman;
#  define GLUT_STROKE_ROMAN             (&glutStrokeRoman)
#  define GLUT_STROKE_MONO_ROMAN        (&glutStrokeMonoRoman)

FL_EXPORT void glutStrokeCharacter(void *font, int character);
FL_EXPORT GLfloat glutStrokeHeight(void *font);
FL_EXPORT int glutStrokeLength(void *font, const unsigned char *string);
FL_EXPORT void glutStrokeString(void *font, const unsigned char *string);
FL_EXPORT int glutStrokeWidth(void *font, int character);

/* GLUT pre-built models sub-API */
FL_EXPORT void glutWireSphere(GLdouble radius, GLint slices, GLint stacks);
FL_EXPORT void glutSolidSphere(GLdouble radius, GLint slices, GLint stacks);
FL_EXPORT void glutWireCone(GLdouble base, GLdouble height, GLint slices, GLint stacks);
FL_EXPORT void glutSolidCone(GLdouble base, GLdouble height, GLint slices, GLint stacks);
FL_EXPORT void glutWireCube(GLdouble size);
FL_EXPORT void glutSolidCube(GLdouble size);
FL_EXPORT void glutWireTorus(GLdouble innerRadius, GLdouble outerRadius, GLint sides, GLint rings);
FL_EXPORT void glutSolidTorus(GLdouble innerRadius, GLdouble outerRadius, GLint sides, GLint rings);
FL_EXPORT void glutWireDodecahedron();
FL_EXPORT void glutSolidDodecahedron();
FL_EXPORT void glutWireTeapot(GLdouble size);
FL_EXPORT void glutSolidTeapot(GLdouble size);
FL_EXPORT void glutWireOctahedron();
FL_EXPORT void glutSolidOctahedron();
FL_EXPORT void glutWireTetrahedron();
FL_EXPORT void glutSolidTetrahedron();
FL_EXPORT void glutWireIcosahedron();
FL_EXPORT void glutSolidIcosahedron();

#endif // !_FL_glut_H_