// Emacs style mode select   -*- C++ -*- 
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// $Log:$
//
// DESCRIPTION:
//	DOOM graphics stuff for X11, UNIX.
//
//-----------------------------------------------------------------------------

static const char
rcsid[] = "$Id: i_x.c,v 1.6 1997/02/03 22:45:10 b1 Exp $";

#include "config.h"
#include "v_video.h"
#include "m_argv.h"
#include "d_event.h"
#include "d_main.h"
#include "i_video.h"
#include "z_zone.h"

#include "tables.h"
#include "doomkeys.h"

#include <stdint.h>
#include <stdbool.h>

#include "platform_config.h"

#ifdef HAS_T4_VGA
extern void emu_DrawLine16(unsigned short * VBuf, int width, int height, int line);
#else
extern void * emu_LineBuffer(int line);
#endif
extern void * emu_Malloc(int size);


#define GFX_RGB565(r, g, b)			((((r & 0xF8) >> 3) << 11) | (((g & 0xFC) >> 2) << 5) | ((b & 0xF8) >> 3))
#define GFX_RGB565_R(color)			((0xF800 & color) >> 11)
#define GFX_RGB565_G(color)			((0x07E0 & color) >> 5)
#define GFX_RGB565_B(color)			(0x001F & color)
  
// The screen buffer; this is modified to draw things to the screen

byte *I_VideoBuffer = NULL;

// If true, game is running as a screensaver

boolean screensaver_mode = false;

// Flag indicating whether the screen is currently visible:
// when the screen isnt visible, don't render the screen

boolean screenvisible;

// Mouse acceleration
//
// This emulates some of the behavior of DOS mouse drivers by increasing
// the speed when the mouse is moved fast.
//
// The mouse input values are input directly to the game, but when
// the values exceed the value of mouse_threshold, they are multiplied
// by mouse_acceleration to increase the speed.

float mouse_acceleration = 2.0;
int mouse_threshold = 10;

// Gamma correction level to use

int usegamma = 0;

int usemouse = 0;

// If true, keyboard mapping is ignored, like in Vanilla Doom.
// The sensible thing to do is to disable this if you have a non-US
// keyboard.

int vanilla_keyboard_mapping = true;


typedef struct
{
	byte r;
	byte g;
	byte b;
} col_t;

// Palette converted to RGB565

static uint16_t rgb565_palette[256];

// run state

static bool run;


void I_InitGraphics (void)
{
//#ifdef HAS_T4_VGA
  I_VideoBuffer = emu_Malloc(SCREENWIDTH * SCREENHEIGHT);
//#else
//  I_VideoBuffer = (byte*)Z_Malloc (SCREENWIDTH * SCREENHEIGHT, PU_STATIC, NULL);
//#endif
	screenvisible = true;
}

void I_ShutdownGraphics (void)
{
	Z_Free (I_VideoBuffer);
}

void I_StartFrame (void)
{
}

static int oldjoystick=0;
extern int joystick;

void I_GetEvent (void)
{
  event_t event;
  event.data2 = -1;
  event.data3 = -1;
  if ( (!(oldjoystick & 0x04)) && (joystick & 0x04) ) {
    event.type = ev_keydown;
    event.data1 = KEY_LEFTARROW;
    D_PostEvent (&event);     
  }
  else if ( (!(joystick & 0x04)) && (oldjoystick & 0x04) ) {
    event.type = ev_keyup;
    event.data1 = KEY_LEFTARROW;
    D_PostEvent (&event);       
  } 
  if ( (!(oldjoystick & 0x08)) && (joystick & 0x08) ) {
    event.type = ev_keydown;
    event.data1 = KEY_RIGHTARROW;
    D_PostEvent (&event);     
  }
  else if ( (!(joystick & 0x08)) && (oldjoystick & 0x08) ) {
    event.type = ev_keyup;
    event.data1 = KEY_RIGHTARROW;
    D_PostEvent (&event);       
  } 
  if ( (!(oldjoystick & 0x01)) && (joystick & 0x01) ) {
    event.type = ev_keydown;
    event.data1 = KEY_UPARROW;
    D_PostEvent (&event);     
  }
  else if ( (!(joystick & 0x01)) && (oldjoystick & 0x01) ) {
    event.type = ev_keyup;
    event.data1 = KEY_UPARROW;
    D_PostEvent (&event);       
  } 
  if ( (!(oldjoystick & 0x02)) && (joystick & 0x02) ) {
    event.type = ev_keydown;
    event.data1 = KEY_DOWNARROW;
    D_PostEvent (&event);     
  }
  else if ( (!(joystick & 0x02)) && (oldjoystick & 0x02) ) {
    event.type = ev_keyup;
    event.data1 = KEY_DOWNARROW;
    D_PostEvent (&event);       
  }

  if ( (!(oldjoystick & 0x10)) && (joystick & 0x10) ) {
    event.type = ev_keydown;
    event.data1 = KEY_FIRE;
    D_PostEvent (&event);     
  }
  else if ( (!(joystick & 0x10)) && (oldjoystick & 0x10) ) {
    event.type = ev_keyup;
    event.data1 = KEY_FIRE;
    D_PostEvent (&event);       
  } 
  if ( (!(oldjoystick & 0x20)) && (joystick & 0x20) ) {
    event.type = ev_keydown;
    event.data1 = KEY_ENTER;
    D_PostEvent (&event);     
  }
  else if ( (!(joystick & 0x20)) && (oldjoystick & 0x20) ) {
    event.type = ev_keyup;
    event.data1 = KEY_ENTER;
    D_PostEvent (&event);       
  } 
  if ( (!(oldjoystick & 0x40)) && (joystick & 0x40) ) {
    event.type = ev_keydown;
    event.data1 = KEY_USE;
    D_PostEvent (&event);     
  }
  else if ( (!(joystick & 0x40)) && (oldjoystick & 0x40) ) {
    event.type = ev_keyup;
    event.data1 = KEY_USE;
    D_PostEvent (&event);       
  } 
  if ( (!(oldjoystick & 0x80)) && (joystick & 0x80) ) {
    event.type = ev_keydown;
    event.data1 = KEY_TAB;
    D_PostEvent (&event);     
  }
  else if ( (!(joystick & 0x80)) && (oldjoystick & 0x80) ) {
    event.type = ev_keyup;
    event.data1 = KEY_TAB;
    D_PostEvent (&event);       
  } 
  oldjoystick = joystick;
}

void I_StartTic (void)
{
	I_GetEvent();
}

void I_UpdateNoBlit (void)
{
}

#ifdef HAS_T4_VGA
static unsigned short line[SCREENWIDTH];
#endif
 
void I_FinishUpdate (void)
{
	int x, y;
	byte index;
	for (y = 0; y < SCREENHEIGHT; y++)
	{
#ifdef HAS_T4_VGA
    for (x = 0; x < SCREENWIDTH; x++)
    {
      index = I_VideoBuffer[y * SCREENWIDTH + x];
      line[x] = rgb565_palette[index];
    }
    emu_DrawLine16(&line[0], SCREENWIDTH, SCREENHEIGHT, y); 
#else
    unsigned short * dst = (unsigned short *)emu_LineBuffer(y);
    for (x = 0; x < SCREENWIDTH; x++)
    {
      index = I_VideoBuffer[y * SCREENWIDTH + x];
      *dst++ = rgb565_palette[index];
    }
#endif     
	}
}

//
// I_ReadScreen
//
void I_ReadScreen (byte* scr)
{
    memcpy (scr, I_VideoBuffer, SCREENWIDTH * SCREENHEIGHT);
}

//
// I_SetPalette
//
void I_SetPalette (byte* palette)
{
	int i;
	col_t* c;

	for (i = 0; i < 256; i++)
	{
		c = (col_t*)palette;

		rgb565_palette[i] = GFX_RGB565(gammatable[usegamma][c->r],
									   gammatable[usegamma][c->g],
									   gammatable[usegamma][c->b]);

		palette += 3;
	}
}

// Given an RGB value, find the closest matching palette index.

int I_GetPaletteIndex (int r, int g, int b)
{
    int best, best_diff, diff;
    int i;
    col_t color;

    best = 0;
    best_diff = INT_MAX;

    for (i = 0; i < 256; ++i)
    {
    	color.r = GFX_RGB565_R(rgb565_palette[i]);
    	color.g = GFX_RGB565_G(rgb565_palette[i]);
    	color.b = GFX_RGB565_B(rgb565_palette[i]);

        diff = (r - color.r) * (r - color.r)
             + (g - color.g) * (g - color.g)
             + (b - color.b) * (b - color.b);

        if (diff < best_diff)
        {
            best = i;
            best_diff = diff;
        }

        if (diff == 0)
        {
            break;
        }
    }

    return best;
}

void I_BeginRead (void)
{
}

void I_EndRead (void)
{
}

void I_SetWindowTitle (char *title)
{
}

void I_GraphicsCheckCommandLine (void)
{
}

void I_SetGrabMouseCallback (grabmouse_callback_t func)
{
}

void I_EnableLoadingDisk (void)
{
}

void I_BindVideoVariables (void)
{
}

void I_DisplayFPSDots (boolean dots_on)
{
}

void I_CheckIsScreensaver (void)
{
}