//
//  SuperTuxKart - a fun racing game with go-kart
//  Copyright (C) 2004-2015 Steve Baker <sjbaker1@airmail.net>
//  Copyright (C) 2006-2015 Joerg Henrichs, SuperTuxKart-Team, Steve Baker
//
//  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 3
//  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.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

#include "states_screens/race_gui.hpp"

using namespace irr;

#include <algorithm>

#include "challenges/unlock_manager.hpp"
#include "config/user_config.hpp"
#include "graphics/camera.hpp"
#include "graphics/2dutils.hpp"
#ifndef SERVER_ONLY
#include "graphics/glwrap.hpp"
#endif
#include "graphics/irr_driver.hpp"
#include "graphics/material.hpp"
#include "graphics/material_manager.hpp"
#include "guiengine/engine.hpp"
#include "guiengine/modaldialog.hpp"
#include "guiengine/scalable_font.hpp"
#include "io/file_manager.hpp"
#include "items/attachment.hpp"
#include "items/attachment_manager.hpp"
#include "items/powerup_manager.hpp"
#include "karts/abstract_kart.hpp"
#include "karts/controller/controller.hpp"
#include "karts/controller/spare_tire_ai.hpp"
#include "karts/kart_properties.hpp"
#include "karts/kart_properties_manager.hpp"
#include "modes/follow_the_leader.hpp"
#include "modes/linear_world.hpp"
#include "modes/world.hpp"
#include "modes/soccer_world.hpp"
#include "race/race_manager.hpp"
#include "states_screens/race_gui_multitouch.hpp"
#include "tracks/track.hpp"
#include "tracks/track_object_manager.hpp"
#include "utils/constants.hpp"
#include "utils/string_utils.hpp"
#include "utils/translation.hpp"

/** The constructor is called before anything is attached to the scene node.
 *  So rendering to a texture can be done here. But world is not yet fully
 *  created, so only the race manager can be accessed safely.
 */
RaceGUI::RaceGUI()
{
    m_enabled = true;
    
    if (UserConfigParams::m_artist_debug_mode && UserConfigParams::m_hide_gui)
        m_enabled = false;

    // Determine maximum length of the rank/lap text, in order to
    // align those texts properly on the right side of the viewport.
    gui::ScalableFont* font = GUIEngine::getHighresDigitFont();
    core::dimension2du area = font->getDimension(L"99:99:99");
    m_timer_width = area.Width;
    m_font_height = area.Height;

    if (race_manager->getMinorMode()==RaceManager::MINOR_MODE_FOLLOW_LEADER ||
        race_manager->getMinorMode()==RaceManager::MINOR_MODE_3_STRIKES     ||
        race_manager->getNumLaps() > 9)
        m_lap_width = font->getDimension(L"99/99").Width;
    else
        m_lap_width = font->getDimension(L"9/9").Width;

    // Originally m_map_height was 100, and we take 480 as minimum res
    float scaling = irr_driver->getFrameSize().Height / 480.0f;
    const float map_size = 100.0f;
    const float top_margin = 3.5f * m_font_height;
    
    if (UserConfigParams::m_multitouch_enabled && 
        UserConfigParams::m_multitouch_mode != 0 &&
        race_manager->getNumLocalPlayers() == 1)
    {
        m_multitouch_gui = new RaceGUIMultitouch(this);
    }
    
    // Check if we have enough space for minimap when touch steering is enabled
    if (m_multitouch_gui != NULL)
    {
        const float map_bottom = (float)(m_multitouch_gui->getMinimapBottom());
        
        if ((map_size + 20.0f) * scaling > map_bottom - top_margin)
        {
            scaling = (map_bottom - top_margin) / (map_size + 20.0f);
        }
    }
    
    // Marker texture has to be power-of-two for (old) OpenGL compliance
    //m_marker_rendered_size  =  2 << ((int) ceil(1.0 + log(32.0 * scaling)));
    m_minimap_ai_size       = (int)( 14.0f * scaling);
    m_minimap_player_size   = (int)( 16.0f * scaling);
    m_map_width             = (int)(map_size * scaling);
    m_map_height            = (int)(map_size * scaling);
    m_map_left              = (int)( 10.0f * scaling);
    m_map_bottom            = (int)( 10.0f * scaling);

    // Minimap is also rendered bigger via OpenGL, so find power-of-two again
    const int map_texture   = 2 << ((int) ceil(1.0 + log(128.0 * scaling)));
    m_map_rendered_width    = map_texture;
    m_map_rendered_height   = map_texture;


    // special case : when 3 players play, use available 4th space for such things
    if (race_manager->getIfEmptyScreenSpaceExists())
    {
        m_map_left = irr_driver->getActualScreenSize().Width - m_map_width;
    }
    else if (m_multitouch_gui != NULL)
    {
        m_map_left = (int)((irr_driver->getActualScreenSize().Width - 
                                                        m_map_width) * 0.95f);
        m_map_bottom = (int)(irr_driver->getActualScreenSize().Height - 
                                                    top_margin - m_map_height);
    }

    m_is_tutorial = (race_manager->getTrackName() == "tutorial");

    // Load speedmeter texture before rendering the first frame
    m_speed_meter_icon = material_manager->getMaterial("speedback.png");
    m_speed_meter_icon->getTexture(false,false);
    m_speed_bar_icon   = material_manager->getMaterial("speedfore.png");
    m_speed_bar_icon->getTexture(false,false);
    //createMarkerTexture();
}   // RaceGUI

//-----------------------------------------------------------------------------
RaceGUI::~RaceGUI()
{
    delete m_multitouch_gui;
}   // ~Racegui


//-----------------------------------------------------------------------------
void RaceGUI::init()
{
    RaceGUIBase::init();
    // Technically we only need getNumLocalPlayers, but using the
    // global kart id to find the data for a specific kart.
    int n = race_manager->getNumberOfKarts();

    m_animation_states.resize(n);
    m_rank_animation_duration.resize(n);
    m_last_ranks.resize(n);
}   // init

//-----------------------------------------------------------------------------
/** Reset the gui before a race. It initialised all rank animation related
 *  values back to the default.
 */
void RaceGUI::reset()
{
    RaceGUIBase::reset();
    for(unsigned int i=0; i<race_manager->getNumberOfKarts(); i++)
    {
        m_animation_states[i] = AS_NONE;
        m_last_ranks[i]       = i+1;
    }
}  // reset

//-----------------------------------------------------------------------------
/** Render all global parts of the race gui, i.e. things that are only
 *  displayed once even in splitscreen.
 *  \param dt Timestep sized.
 */
void RaceGUI::renderGlobal(float dt)
{
#ifndef SERVER_ONLY
    RaceGUIBase::renderGlobal(dt);
    cleanupMessages(dt);

    // Special case : when 3 players play, use 4th window to display such
    // stuff (but we must clear it)
    if (race_manager->getIfEmptyScreenSpaceExists() &&
        !GUIEngine::ModalDialog::isADialogActive())
    {
        static video::SColor black = video::SColor(255,0,0,0);

        GL32_draw2DRectangle(black, irr_driver->getSplitscreenWindow(
            race_manager->getNumLocalPlayers()));
    }

    World *world = World::getWorld();
    assert(world != NULL);
    if(world->getPhase() >= WorldStatus::READY_PHASE &&
       world->getPhase() <= WorldStatus::GO_PHASE      )
    {
        drawGlobalReadySetGo();
    }
    if(world->getPhase() == World::GOAL_PHASE)
            drawGlobalGoal();

    // Timer etc. are not displayed unless the game is actually started.
    if(!world->isRacePhase()) return;
    if (!m_enabled) return;


    if (!m_is_tutorial)
    {
        //stop displaying timer as soon as race is over
        if (world->getPhase()<WorldStatus::DELAY_FINISH_PHASE)
           drawGlobalTimer();

        if(world->getPhase() == WorldStatus::GO_PHASE ||
           world->getPhase() == WorldStatus::MUSIC_PHASE)
        {
            drawGlobalMusicDescription();
        }
    }

    drawGlobalMiniMap();

    if (!m_is_tutorial)               drawGlobalPlayerIcons(m_map_height);
    if(Track::getCurrentTrack()->isSoccer()) drawScores();
#endif
}   // renderGlobal

//-----------------------------------------------------------------------------
/** Render the details for a single player, i.e. speed, energy,
 *  collectibles, ...
 *  \param kart Pointer to the kart for which to render the view.
 */
void RaceGUI::renderPlayerView(const Camera *camera, float dt)
{
    if (!m_enabled) return;

    RaceGUIBase::renderPlayerView(camera, dt);
    
    const core::recti &viewport = camera->getViewport();

    core::vector2df scaling = camera->getScaling();
    const AbstractKart *kart = camera->getKart();
    if(!kart) return;
    
    drawPlungerInFace(camera, dt);

    if (viewport.getWidth() != irr_driver->getActualScreenSize().Width)
    {
        scaling *= float(viewport.getWidth()) / float(irr_driver->getActualScreenSize().Width); // scale race GUI along screen size
    }
    else
    {
        scaling *= float(viewport.getWidth()) / 800.0f; // scale race GUI along screen size
    }
    
    drawAllMessages(kart, viewport, scaling);

    if(!World::getWorld()->isRacePhase()) return;

    if (m_multitouch_gui == NULL)
    {
        drawPowerupIcons(kart, viewport, scaling);
        drawSpeedEnergyRank(kart, viewport, scaling, dt);
    }

    if (!m_is_tutorial)
        drawLap(kart, viewport, scaling);
}   // renderPlayerView


//-----------------------------------------------------------------------------
/** Shows the current soccer result.
 */
void RaceGUI::drawScores()
{
#ifndef SERVER_ONLY
    SoccerWorld* sw = dynamic_cast<SoccerWorld*>(World::getWorld());
    int offset_y = 5;
    int offset_x = 5;
    gui::ScalableFont* font = GUIEngine::getTitleFont();
    static video::SColor color = video::SColor(255,255,255,255);

    //Draw two teams score
    irr::video::ITexture *red_team = irr_driver->getTexture(FileManager::GUI,
                                                            "soccer_ball_red.png");
    irr::video::ITexture *blue_team = irr_driver->getTexture(FileManager::GUI,
                                                            "soccer_ball_blue.png");
    irr::video::ITexture *team_icon = red_team;

    for(unsigned int i=0; i<2; i++)
    {
        core::recti position(offset_x, offset_y,
            offset_x + 2*m_minimap_player_size, offset_y + 2*m_minimap_player_size);

        core::stringw score = StringUtils::toWString(sw->getScore((SoccerTeam)i));
        int string_height =
            GUIEngine::getFont()->getDimension(score.c_str()).Height;
        core::recti pos(position.UpperLeftCorner.X + 5,
                        position.LowerRightCorner.Y + offset_y,
                        position.LowerRightCorner.X,
                        position.LowerRightCorner.Y + string_height);

        font->draw(score.c_str(),pos,color);

        if (i == 1)
        {
            team_icon = blue_team;
        }
        core::rect<s32> indicator_pos(offset_x, offset_y,
                                     offset_x + (int)(m_minimap_player_size*2),
                                     offset_y + (int)(m_minimap_player_size*2));
        core::rect<s32> source_rect(core::position2d<s32>(0,0),
                                                   team_icon->getSize());
        draw2DImage(team_icon,indicator_pos,source_rect,
            NULL,NULL,true);
        offset_x += position.LowerRightCorner.X + 30;
    }
#endif
}   // drawScores

//-----------------------------------------------------------------------------
/** Displays the racing time on the screen.s
 */
void RaceGUI::drawGlobalTimer()
{
    assert(World::getWorld() != NULL);

    if (!World::getWorld()->shouldDrawTimer())
    {
        return;
    }

    core::stringw sw;
    video::SColor time_color = video::SColor(255, 255, 255, 255);
    int dist_from_right = 10 + m_timer_width;

    bool use_digit_font = true;

    float elapsed_time = World::getWorld()->getTime();
    if (!race_manager->hasTimeTarget() || race_manager
        ->getMinorMode()==RaceManager::MINOR_MODE_SOCCER)
    {
        sw = core::stringw (
            StringUtils::timeToString(elapsed_time).c_str() );
    }
    else
    {
        float time_target = race_manager->getTimeTarget();
        if (elapsed_time < time_target)
        {
            sw = core::stringw (
              StringUtils::timeToString(time_target - elapsed_time).c_str());
        }
        else
        {
            sw = _("Challenge Failed");
            int string_width =
                GUIEngine::getFont()->getDimension(_("Challenge Failed")).Width;
            dist_from_right = 10 + string_width;
            time_color = video::SColor(255,255,0,0);
            use_digit_font = false;
        }
    }

    core::rect<s32> pos(irr_driver->getActualScreenSize().Width - dist_from_right, 30,
                        irr_driver->getActualScreenSize().Width                  , 50);

    // special case : when 3 players play, use available 4th space for such things
    if (race_manager->getIfEmptyScreenSpaceExists())
    {
        pos -= core::vector2d<s32>(0, pos.LowerRightCorner.Y / 2);
        pos += core::vector2d<s32>(0, irr_driver->getActualScreenSize().Height - irr_driver->getSplitscreenWindow(0).getHeight());
    }

    gui::ScalableFont* font = (use_digit_font ? GUIEngine::getHighresDigitFont() : GUIEngine::getFont());
    if (use_digit_font)
        font->setShadow(video::SColor(255, 128, 0, 0));
    font->setScale(1.0f);
    font->draw(sw.c_str(), pos, time_color, false, false, NULL,
               true /* ignore RTL */);

}   // drawGlobalTimer

//-----------------------------------------------------------------------------
/** Draws the mini map and the position of all karts on it.
 */
void RaceGUI::drawGlobalMiniMap()
{
#ifndef SERVER_ONLY
    // draw a map when arena has a navigation mesh.
    Track *track = Track::getCurrentTrack();
    if ( (track->isArena() || track->isSoccer()) && !(track->hasNavMesh()) )
        return;

    int upper_y = irr_driver->getActualScreenSize().Height - m_map_bottom - m_map_height;
    int lower_y = irr_driver->getActualScreenSize().Height - m_map_bottom;

    core::rect<s32> dest(m_map_left, upper_y,
                         m_map_left + m_map_width, lower_y);

    track->drawMiniMap(dest);

    World *world = World::getWorld();
    for(unsigned int i=0; i<world->getNumKarts(); i++)
    {
        const AbstractKart *kart = world->getKart(i);
        const SpareTireAI* sta =
            dynamic_cast<const SpareTireAI*>(kart->getController());
        // don't draw eliminated kart
        if(kart->isEliminated() && !(sta && sta->isMoving())) continue;
        const Vec3& xyz = kart->getXYZ();
        Vec3 draw_at;
        track->mapPoint2MiniMap(xyz, &draw_at);
        
        video::ITexture* icon = sta ?
            irr_driver->getTexture(FileManager::GUI, "heart.png") :
            kart->getKartProperties()->getMinimapIcon();
        if (icon == NULL)
        {
            continue;
        }
        // int marker_height = m_marker->getSize().Height;
        core::rect<s32> source(core::position2di(0, 0), icon->getSize());
        int marker_half_size = (kart->getController()->isLocalPlayerController()
                                ? m_minimap_player_size
                                : m_minimap_ai_size                        )>>1;
        core::rect<s32> position(m_map_left+(int)(draw_at.getX()-marker_half_size),
                                 lower_y   -(int)(draw_at.getY()+marker_half_size),
                                 m_map_left+(int)(draw_at.getX()+marker_half_size),
                                 lower_y   -(int)(draw_at.getY()-marker_half_size));
        draw2DImage(icon, position, source, NULL, NULL, true);
    }   // for i<getNumKarts

    SoccerWorld *sw = dynamic_cast<SoccerWorld*>(World::getWorld());
    if (sw)
    {
        Vec3 draw_at;
        track->mapPoint2MiniMap(sw->getBallPosition(), &draw_at);
        
        video::ITexture* icon =
            irr_driver->getTexture(FileManager::GUI, "soccer_ball_normal.png");

        core::rect<s32> source(core::position2di(0, 0), icon->getSize());
        core::rect<s32> position(m_map_left+(int)(draw_at.getX()-(m_minimap_player_size/2.5f)),
                                 lower_y   -(int)(draw_at.getY()+(m_minimap_player_size/2.5f)),
                                 m_map_left+(int)(draw_at.getX()+(m_minimap_player_size/2.5f)),
                                 lower_y   -(int)(draw_at.getY()-(m_minimap_player_size/2.5f)));
        draw2DImage(icon, position, source, NULL, NULL, true);
    }
#endif
}   // drawGlobalMiniMap

//-----------------------------------------------------------------------------
/** Energy meter that gets filled with nitro. This function is called from
 *  drawSpeedEnergyRank, which defines the correct position of the energy
 *  meter.
 *  \param x X position of the meter.
 *  \param y Y position of the meter.
 *  \param kart Kart to display the data for.
 *  \param scaling Scaling applied (in case of split screen)
 */
void RaceGUI::drawEnergyMeter(int x, int y, const AbstractKart *kart,
                              const core::recti &viewport,
                              const core::vector2df &scaling)
{
#ifndef SERVER_ONLY
    float min_ratio        = std::min(scaling.X, scaling.Y);
    const int GAUGEWIDTH   = 94;//same inner radius as the inner speedometer circle
    int gauge_width        = (int)(GAUGEWIDTH*min_ratio);
    int gauge_height       = (int)(GAUGEWIDTH*min_ratio);

    float state = (float)(kart->getEnergy())
                / kart->getKartProperties()->getNitroMax();
    if (state < 0.0f) state = 0.0f;
    else if (state > 1.0f) state = 1.0f;

    core::vector2df offset;
    offset.X = (float)(x-gauge_width) - 9.5f*scaling.X;
    offset.Y = (float)y-11.5f*scaling.Y;


    // Background
    draw2DImage(m_gauge_empty, core::rect<s32>((int)offset.X,
                                               (int)offset.Y-gauge_height,
                                               (int)offset.X + gauge_width,
                                               (int)offset.Y) /* dest rect */,
                core::rect<s32>(core::position2d<s32>(0,0),
                                m_gauge_empty->getSize()) /* source rect */,
                NULL /* clip rect */, NULL /* colors */,
                true /* alpha */);

    // The positions for A to G are defined here.
    // They are calculated from gauge_full.png
    // They are further than the nitrometer farther position because
    // the lines between them would otherwise cut through the outside circle.
    
    const int vertices_count = 9;

    core::vector2df position[vertices_count];
    position[0].X = 0.324f;//A
    position[0].Y = 0.35f;//A
    position[1].X = 0.01f;//B1 (margin for gauge goal)
    position[1].Y = 0.88f;//B1
    position[2].X = 0.029f;//B2
    position[2].Y = 0.918f;//B2
    position[3].X = 0.307f;//C
    position[3].Y = 0.99f;//C
    position[4].X = 0.589f;//D
    position[4].Y = 0.932f;//D
    position[5].X = 0.818f;//E
    position[5].Y = 0.755f;//E
    position[6].X = 0.945f;//F
    position[6].Y = 0.497f;//F
    position[7].X = 0.948f;//G1
    position[7].Y = 0.211f;//G1
    position[8].X = 0.94f;//G2 (margin for gauge goal)
    position[8].Y = 0.17f;//G2

    // The states at which different polygons must be used.

    float threshold[vertices_count-2];
    threshold[0] = 0.0001f; //for gauge drawing
    threshold[1] = 0.2f;
    threshold[2] = 0.4f;
    threshold[3] = 0.6f;
    threshold[4] = 0.8f;
    threshold[5] = 0.9999f;
    threshold[6] = 1.0f;

    // Filling (current state)

    if (state > 0.0f)
    {
        video::S3DVertex vertices[vertices_count];

        //3D effect : wait for the full border to appear before drawing
        for (int i=0;i<5;i++)
        {
            if ((state-0.2f*i < 0.006f && state-0.2f*i >= 0.0f) || (0.2f*i-state < 0.003f && 0.2f*i-state >= 0.0f) )
            {
                state = 0.2f*i-0.003f;
                break;
            }
        }

        unsigned int count = computeVerticesForMeter(position, threshold, vertices, vertices_count,
                                                     state, gauge_width, gauge_height, offset);

        if(kart->getControls().getNitro() || kart->isOnMinNitroTime())
            drawMeterTexture(m_gauge_full_bright, vertices, count);
        else
            drawMeterTexture(m_gauge_full, vertices, count);
    }

    // Target

    if (race_manager->getCoinTarget() > 0)
    {
        float coin_target = (float)race_manager->getCoinTarget()
                          / kart->getKartProperties()->getNitroMax();

        video::S3DVertex vertices[vertices_count];

        unsigned int count = computeVerticesForMeter(position, threshold, vertices, vertices_count, 
                                                     coin_target, gauge_width, gauge_height, offset);

        drawMeterTexture(m_gauge_goal, vertices, count);
    }
#endif
}   // drawEnergyMeter

//-----------------------------------------------------------------------------
/** Draws the rank of a player.
 *  \param kart The kart of the player.
 *  \param offset Offset of top left corner for this display (for splitscreen).
 *  \param min_ratio Scaling of the screen (for splitscreen).
 *  \param meter_width Width of the meter (inside which the rank is shown).
 *  \param meter_height Height of the meter (inside which the rank is shown).
 *  \param dt Time step size.
 */
void RaceGUI::drawRank(const AbstractKart *kart,
                      const core::vector2df &offset,
                      float min_ratio, int meter_width,
                      int meter_height, float dt)
{
    // Draw rank
    WorldWithRank *world = dynamic_cast<WorldWithRank*>(World::getWorld());
    if (!world || !world->displayRank())
        return;

    int id = kart->getWorldKartId();

    if (m_animation_states[id] == AS_NONE)
    {
        if (m_last_ranks[id] != kart->getPosition())
        {
            m_rank_animation_duration[id] = 0.0f;
            m_animation_states[id] = AS_SMALLER;
        }
    }
    else
    {
        m_rank_animation_duration[id] += dt;
    }

    float scale = 1.0f;
    int rank = kart->getPosition();
    const float DURATION = 0.4f;
    const float MIN_SHRINK = 0.3f;
    if (m_animation_states[id] == AS_SMALLER)
    {
        scale = 1.0f - m_rank_animation_duration[id]/ DURATION;
        rank = m_last_ranks[id];
        if (scale < MIN_SHRINK)
        {
            m_animation_states[id] = AS_BIGGER;
            m_rank_animation_duration[id] = 0.0f;
            // Store the new rank
            m_last_ranks[id] = kart->getPosition();
            scale = MIN_SHRINK;
        }
    }
    else if (m_animation_states[id] == AS_BIGGER)
    {
        scale = m_rank_animation_duration[id] / DURATION + MIN_SHRINK;
        rank = m_last_ranks[id];
        if (scale > 1.0f)
        {
            m_animation_states[id] = AS_NONE;
            scale = 1.0f;
        }

    }
    else
    {
        m_last_ranks[id] = kart->getPosition();
    }

    gui::ScalableFont* font = GUIEngine::getHighresDigitFont();
    font->setScale(min_ratio * scale);
    font->setShadow(video::SColor(255, 128, 0, 0));
    std::ostringstream oss;
    oss << rank; // the current font has no . :(   << ".";

    core::recti pos;
    pos.LowerRightCorner = core::vector2di(int(offset.X + 0.64f*meter_width),
                                           int(offset.Y - 0.49f*meter_height));
    pos.UpperLeftCorner = core::vector2di(int(offset.X + 0.64f*meter_width),
                                          int(offset.Y - 0.49f*meter_height));

    static video::SColor color = video::SColor(255, 255, 255, 255);
    font->draw(oss.str().c_str(), pos, color, true, true);
    font->setScale(1.0f);
}   // drawRank

//-----------------------------------------------------------------------------
/** Draws the speedometer, the display of available nitro, and
 *  the rank of the kart (inside the speedometer).
 *  \param kart The kart for which to show the data.
 *  \param viewport The viewport to use.
 *  \param scaling Which scaling to apply to the speedometer.
 *  \param dt Time step size.
 */
void RaceGUI::drawSpeedEnergyRank(const AbstractKart* kart,
                                 const core::recti &viewport,
                                 const core::vector2df &scaling,
                                 float dt)
{
#ifndef SERVER_ONLY
    float min_ratio         = std::min(scaling.X, scaling.Y);
    const int SPEEDWIDTH   = 128;
    int meter_width        = (int)(SPEEDWIDTH*min_ratio);
    int meter_height       = (int)(SPEEDWIDTH*min_ratio);

    drawEnergyMeter(viewport.LowerRightCorner.X ,
                    (int)(viewport.LowerRightCorner.Y),
                    kart, viewport, scaling);

    // First draw the meter (i.e. the background )
    // -------------------------------------------------------------------------
    core::vector2df offset;
    offset.X = (float)(viewport.LowerRightCorner.X-meter_width) - 24.0f*scaling.X;
    offset.Y = viewport.LowerRightCorner.Y-10.0f*scaling.Y;

    const core::rect<s32> meter_pos((int)offset.X,
                                    (int)(offset.Y-meter_height),
                                    (int)(offset.X+meter_width),
                                    (int)offset.Y);
    video::ITexture *meter_texture = m_speed_meter_icon->getTexture();
    const core::rect<s32> meter_texture_coords(core::position2d<s32>(0,0),
                                               meter_texture->getSize());
    draw2DImage(meter_texture, meter_pos, meter_texture_coords, NULL,
                       NULL, true);
    // TODO: temporary workaround, shouldn't have to use
    // draw2DVertexPrimitiveList to render a simple rectangle

    const float speed =  kart->getSpeed();

    drawRank(kart, offset, min_ratio, meter_width, meter_height, dt);


    if(speed <=0) return;  // Nothing to do if speed is negative.

    // Draw the actual speed bar (if the speed is >0)
    // ----------------------------------------------
    float speed_ratio = speed/40.0f; //max displayed speed of 40
    if(speed_ratio>1) speed_ratio = 1;

    // see computeVerticesForMeter for the detail of the drawing
    // If increasing this, update drawMeterTexture

    const int vertices_count = 12;

    video::S3DVertex vertices[vertices_count];

    // The positions for A to J2 are defined here.

    // They are calculated from speedometer.png
    // A is the center of the speedometer's circle
    // B2, C, D, E, F, G, H, I and J1 are points on the line
    // from A to their respective 1/8th threshold division
    // B2 is 36,9° clockwise from the vertical (on bottom-left)
    // J1 s 70,7° clockwise from the vertical (on upper-right)
    // B1 and J2 are used for correct display of the 3D effect
    // They are 1,13* further than the speedometer farther position because
    // the lines between them would otherwise cut through the outside circle.

    core::vector2df position[vertices_count];

    position[0].X = 0.546f;//A
    position[0].Y = 0.566f;//A
    position[1].X = 0.216f;//B1
    position[1].Y = 1.036f;//B1
    position[2].X = 0.201f;//B2
    position[2].Y = 1.023f;//B2
    position[3].X = 0.036f;//C
    position[3].Y = 0.831f;//C
    position[4].X = -0.029f;//D
    position[4].Y = 0.589f;//D
    position[5].X = 0.018f;//E
    position[5].Y = 0.337f;//E
    position[6].X = 0.169f;//F
    position[6].Y = 0.134f;//F
    position[7].X = 0.391f;//G
    position[7].Y = 0.014f;//G
    position[8].X = 0.642f;//H
    position[8].Y = 0.0f;//H
    position[9].X = 0.878f;//I
    position[9].Y = 0.098f;//I
    position[10].X = 1.046f;//J1
    position[10].Y = 0.285f;//J1
    position[11].X = 1.052f;//J2
    position[11].Y = 0.297f;//J2

    // The speed ratios at which different triangles must be used.

    float threshold[vertices_count-2];
    threshold[0] = 0.00001f;//for the 3D margin
    threshold[1] = 0.125f;
    threshold[2] = 0.25f;
    threshold[3] = 0.375f;
    threshold[4] = 0.50f;
    threshold[5] = 0.625f;
    threshold[6] = 0.750f;
    threshold[7] = 0.875f;
    threshold[8] = 0.99999f;//for the 3D margin
    threshold[9] = 1.0f;

    //3D effect : wait for the full border to appear before drawing
    for (int i=0;i<8;i++)
    {
        if ((speed_ratio-0.125f*i < 0.00625f && speed_ratio-0.125f*i >= 0.0f) || (0.125f*i-speed_ratio < 0.0045f && 0.125f*i-speed_ratio >= 0.0f) )
        {
            speed_ratio = 0.125f*i-0.0045f;
            break;
        }
    }

    unsigned int count = computeVerticesForMeter(position, threshold, vertices, vertices_count, 
                                                     speed_ratio, meter_width, meter_height, offset);


    drawMeterTexture(m_speed_bar_icon->getTexture(), vertices, count);
#endif
}   // drawSpeedEnergyRank

void RaceGUI::drawMeterTexture(video::ITexture *meter_texture, video::S3DVertex vertices[], unsigned int count)
{
#ifndef SERVER_ONLY
    //Should be greater or equal than the greatest vertices_count used by the meter functions
    short int index[12];
    for(unsigned int i=0; i<count; i++)
    {
        index[i]=i;
        vertices[i].Color = video::SColor(255, 255, 255, 255);
    }

    video::SMaterial m;
    m.setTexture(0, meter_texture);
    m.MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;
    irr_driver->getVideoDriver()->setMaterial(m);
    glEnable(GL_BLEND);
    glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
    draw2DVertexPrimitiveList(m.getTexture(0), vertices, count,
        index, count-2, video::EVT_STANDARD, scene::EPT_TRIANGLE_FAN);
    glDisable(GL_BLEND);
#endif
}   // drawMeterTexture



//-----------------------------------------------------------------------------
/** This function computes a polygon used for drawing the measure for a meter (speedometer, etc.)
 *  The variable measured by the meter is compared to the thresholds, and is then used to
 *  compute a point between the two points associated with the lower and upper threshold
 *  Then, a polygon is calculated linking all the previous points and the variable point
 *  which link back to the first point. This polygon is used for drawing.
 *
 *  Consider the following example :
 *
 *      A                E
 *                      -|
 *                      x
 *                      |
 *                   -D-|
 *                -w-|
 *           |-C--|
 *     -B--v-|
 *
 *  If the measure is inferior to the first threshold, the function will create a triangle ABv
 *  with the position of v varying proportionally on a line between B and C ;
 *  at B with 0 and at C when it reaches the first threshold.
 *  If the measure is between the first and second thresholds, the function will create a quad ABCw,
 *  with w varying in the same way than v.
 *  If the measure exceds the higher threshold, the function will return the poly ABCDE.
 *  
 *  \param position The relative positions of the vertices.
 *  \param threshold The thresholds at which the variable point switch from a segment to the next.
 *                   The size of this array should be smaller by two than the position array.
 *                   The last threshold determines the measure over which the meter is full
 *  \param vertices Where the results of the computation are put, for use by the calling function.
 *  \param vertices_count The maximum number of vertices to use. Should be superior or equal to the
 *                       size of the arrays.
 *  \param measure The value of the variable measured by the meter.
 *  \param gauge_width The width of the meter
 *  \param gauge_height The height of the meter
 *  \param offset The offset to position the meter
 */
unsigned int RaceGUI::computeVerticesForMeter(core::vector2df position[], float threshold[], video::S3DVertex vertices[], unsigned int vertices_count,
                                     float measure, int gauge_width, int gauge_height, core::vector2df offset)
{
    //Nothing to draw ; we need at least three points to draw a triangle
    if (vertices_count <= 2 || measure < 0)
    {
        return 0;
    }

    unsigned int count=2;
    float f = 1.0f;

    for (unsigned int i=2 ; i < vertices_count ; i++)
    {
        count++;

        //Stop when we have found between which thresholds the measure is
        if (measure < threshold[i-2])
        {
            if (i-2 == 0)
            {
                f = measure/threshold[i-2];
            }
            else
            {
                f = (measure - threshold[i-3])/(threshold[i-2]-threshold[i-3]);
            }

            break;
        }
    }

    for (unsigned int i=0 ; i < count ; i++)
    {
        //if the measure don't fall in this segment, use the next predefined point
        if (i<count-1 || (count == vertices_count && f == 1.0f))
        {
            vertices[i].TCoords = core::vector2df(position[i].X, position[i].Y);
            vertices[i].Pos     = core::vector3df(offset.X+position[i].X*gauge_width,
                                  offset.Y-(1-position[i].Y)*gauge_height, 0);
        }
        //if the measure fall in this segment, compute the variable position
        else
        {
            //f : the proportion of the next point. 1-f : the proportion of the previous point
            vertices[i].TCoords = core::vector2df(position[i].X*(f)+position[i-1].X*(1.0f-f),
                                                  position[i].Y*(f)+position[i-1].Y*(1.0f-f));
            vertices[i].Pos = core::vector3df(offset.X+ ((position[i].X*(f)+position[i-1].X*(1.0f-f))*gauge_width),
                                              offset.Y-(((1-position[i].Y)*(f)+(1-position[i-1].Y)*(1.0f-f))*gauge_height),0);
        }
    }

    //the count is used in the drawing functions
    return count;
} //computeVerticesForMeter

//-----------------------------------------------------------------------------
/** Displays the rank and the lap of the kart.
 *  \param info Info object c
*/
void RaceGUI::drawLap(const AbstractKart* kart,
                      const core::recti &viewport,
                      const core::vector2df &scaling)
{
    // Don't display laps or ranks if the kart has already finished the race.
    if (kart->hasFinishedRace()) return;

    World *world = World::getWorld();
    if (!world->raceHasLaps()) return;
    const int lap = world->getKartLaps(kart->getWorldKartId());

    // don't display 'lap 0/..' at the start of a race
    if (lap < 0 ) return;

    core::recti pos;
    
    pos.UpperLeftCorner.Y = viewport.UpperLeftCorner.Y + m_font_height;

    // If the time display in the top right is in this viewport,
    // move the lap/rank display down a little bit so that it is
    // displayed under the time.
    if (viewport.UpperLeftCorner.Y == 0 &&
        viewport.LowerRightCorner.X == (int)(irr_driver->getActualScreenSize().Width) &&
        !race_manager->getIfEmptyScreenSpaceExists()) 
    {
        pos.UpperLeftCorner.Y += m_font_height;
    }
    pos.LowerRightCorner.Y  = viewport.LowerRightCorner.Y+20;
    pos.UpperLeftCorner.X   = viewport.LowerRightCorner.X
                            - m_lap_width - 10;
    pos.LowerRightCorner.X  = viewport.LowerRightCorner.X;

    static video::SColor color = video::SColor(255, 255, 255, 255);
    std::ostringstream out;
    out << lap + 1 << "/" << race_manager->getNumLaps();

    gui::ScalableFont* font = GUIEngine::getHighresDigitFont();
    font->setScale(scaling.Y < 1.0f ? 0.5f: 1.0f);
    font->draw(out.str().c_str(), pos, color);
    font->setScale(1.0f);

} // drawLap