/*
    Copyright 2005-2010 Intel Corporation.  All Rights Reserved.

    This file is part of Threading Building Blocks.

    Threading Building Blocks is free software; you can redistribute it
    and/or modify it under the terms of the GNU General Public License
    version 2 as published by the Free Software Foundation.

    Threading Building Blocks 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.

    You should have received a copy of the GNU General Public License
    along with Threading Building Blocks; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    As a special exception, you may use this file as part of a free software
    library without restriction.  Specifically, if other files instantiate
    templates or use macros or inline functions from this file, or you compile
    this file and link it with other files to produce an executable, this
    file does not by itself cause the resulting executable to be covered by
    the GNU General Public License.  This exception does not however
    invalidate any other reasons why the executable file might be covered by
    the GNU General Public License.
*/

#ifndef __VIDEO_H__
#define __VIDEO_H__

#include <cassert>
#if _WIN32 || _WIN64
#include <windows.h>
#else
#include <unistd.h>
#endif

typedef unsigned int color_t;
typedef unsigned char colorcomp_t;

//! Simple proxy class for managing of different video systems
class video
{
    //! colorspace information
    char depth, red_shift, green_shift, blue_shift;
    color_t red_mask, green_mask, blue_mask;
    friend class drawing_area;

public:
    //! Constructor
    video();
    //! Destructor
    ~video();
    //! member to set window name
    const char *title;
    //! true is enable to show fps
    bool calc_fps;
    //! if true: on windows fork processing thread for on_process(), on non-windows note that next_frame() is called concurrently.
    bool threaded;
    //! true while running within main_loop()
    bool running;
    //! if true, do gui updating
    bool updating;
    //! initialize graphical video system
    bool init_window(int sizex, int sizey);
    //! initialize console. returns true if console is available
    bool init_console();
    //! terminate video system
    void terminate();
    //! Do standard event & processing loop. Use threaded = true to separate event/updating loop from frame processing
    void main_loop();
    //! Process next frame
    bool next_frame();
    //! Change window title
    void show_title();
    //! translate RGB components into packed type
    inline color_t get_color(colorcomp_t red, colorcomp_t green, colorcomp_t blue) const;

    //! Mouse events handler.
    virtual void on_mouse(int x, int y, int key) { }
    //! Mouse events handler.
    virtual void on_key(int key) { }
    //! Main processing loop. Redefine with your own
    virtual void on_process() { while(next_frame()); }

#ifdef _WINDOWS
    //! Windows specific members
    //! if VIDEO_WINMAIN isn't defined then set this just before init() by arguments of WinMain
    static HINSTANCE win_hInstance; static int win_iCmdShow;
    //! optionally call it just before init() to set own. Use ascii strings convention
    void win_set_class(WNDCLASSEX &);
    //! load and set accelerator table from resources
    void win_load_accelerators(int idc);
#endif
};

//! Drawing class
class drawing_area
{
    const size_t base_index, max_index, index_stride;
    const char pixel_depth;
    unsigned int * const ptr32;
    size_t index;
public:
    const int start_x, start_y, size_x, size_y;
    //! constructor
    drawing_area(int x, int y, int sizex, int sizey);
    //! destructor
    ~drawing_area();
    //! set current position. local_x could be bigger then size_x
    inline void set_pos(int local_x, int local_y);
    //! put pixel in current position with incremental address calculating to next right pixel
    inline void put_pixel(color_t color);
    //! draw pixel at position by packed color
    void set_pixel(int localx, int localy, color_t color)
        { set_pos(localx, localy); put_pixel(color); }
};

inline color_t video::get_color(colorcomp_t red, colorcomp_t green, colorcomp_t blue) const
{
    if(red_shift == 16) // only for depth == 24 && red_shift > blue_shift
        return (red<<16) | (green<<8) | blue;
    else if(depth >= 24)
        return (red<<red_shift) | (green<<green_shift) | (blue<<blue_shift);
    else if(depth > 0) {
        register char bs = blue_shift, rs = red_shift;
        if(blue_shift < 0) blue >>= -bs, bs = 0;
        else /*red_shift < 0*/ red >>= -rs, rs = 0;
        return (red<<rs)&red_mask | (green<<green_shift)&green_mask | (blue<<bs)&blue_mask;
    } else { // UYVY colorspace
        register unsigned y, u, v;
        y = red * 77 + green * 150 + blue * 29; // sum(77+150+29=256) * max(=255):  limit->2^16
        u = (2048 + (blue << 3) - (y >> 5)) >> 4; // (limit->2^12)>>4
        v = (2048 + (red << 3) - (y >> 5)) >> 4;
        y = y >> 8;
        return u | (y << 8) | (v << 16) | (y << 24);
    }
}

inline void drawing_area::set_pos(int local_x, int local_y)
{
    index = base_index + local_x + local_y*index_stride;
}

inline void drawing_area::put_pixel(color_t color)
{
    assert(index < max_index);
    if(pixel_depth > 16) ptr32[index++] = color;
    else if(pixel_depth > 0)
        ((unsigned short*)ptr32)[index++] = (unsigned short)color;
    else { // UYVY colorspace
        if(index&1) color >>= 16;
        ((unsigned short*)ptr32)[index++] = (unsigned short)color;
    }
}

#if defined(_WINDOWS) && (defined(VIDEO_WINMAIN) || defined(VIDEO_WINMAIN_ARGS) )
#include <cstdlib>
//! define WinMain for subsystem:windows.
#ifdef VIDEO_WINMAIN_ARGS
int main(int, char *[]);
#else
int main();
#endif
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, PSTR szCmdLine, int iCmdShow)
{
    video::win_hInstance = hInstance;  video::win_iCmdShow = iCmdShow;
#ifdef VIDEO_WINMAIN_ARGS
    return main(__argc, __argv);
#else
    return main();
#endif
}
#endif

#endif// __VIDEO_H__