TouchInput.cpp

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/* Copyright (C) 2013 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. 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.
 *
 * 0 A.D. 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 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "precompiled.h"

#include "TouchInput.h"

#include "graphics/Camera.h"
#include "graphics/GameView.h"
#include "lib/timer.h"
#include "lib/external_libraries/libsdl.h"
#include "ps/Game.h"

// When emulation is enabled:
// Left-click to put finger 0 down.
// Then left-click-and-drag to move finger 0.
// Then left-click to put finger 0 up.
// Same with right-click for finger 1.
#define EMULATE_FINGERS_WITH_MOUSE 0

extern int g_xres, g_yres;

// NOTE: All this code is currently just a basic prototype for testing;
// it might need significant redesigning for proper usage.

CTouchInput::CTouchInput() :
    m_State(STATE_INACTIVE)
{
    for (size_t i = 0; i < MAX_FINGERS; ++i)
        m_Down[i] = false;

    for (size_t i = 0; i < MAX_MOUSE; ++i)
        m_MouseEmulateState[i] = MOUSE_INACTIVE;
}

CTouchInput::~CTouchInput()
{
}

bool CTouchInput::IsEnabled()
{
#if OS_ANDROID || EMULATE_FINGERS_WITH_MOUSE
    return true;
#else
    return false;
#endif
}

void CTouchInput::OnFingerDown(int id, int x, int y)
{
    debug_printf(L"finger down %d %d %d; state %d\n", id, x, y, m_State);
    m_Down[id] = true;
    m_Prev[id] = m_Pos[id] = CVector2D(x, y);

    if (m_State == STATE_INACTIVE && id == 0)
    {
        m_State = STATE_FIRST_TOUCH;
        m_FirstTouchTime = timer_Time();
        m_FirstTouchPos = CVector2D(x, y);
    }
    else if ((m_State == STATE_FIRST_TOUCH || m_State == STATE_PANNING) && id == 1)
    {
        m_State = STATE_ZOOMING;
    }
}

void CTouchInput::OnFingerUp(int id, int x, int y)
{
    debug_printf(L"finger up %d %d %d; state %d\n", id, x, y, m_State);
    m_Down[id] = false;
    m_Pos[id] = CVector2D(x, y);

    if (m_State == STATE_FIRST_TOUCH && id == 0 && timer_Time() < m_FirstTouchTime + 0.5)
    {
        m_State = STATE_INACTIVE;

        SDL_Event_ ev;
        ev.ev.button.button = SDL_BUTTON_LEFT;
        ev.ev.button.x = m_Pos[0].X;
        ev.ev.button.y = m_Pos[0].Y;

        ev.ev.type = SDL_MOUSEBUTTONDOWN;
        ev.ev.button.state = SDL_PRESSED;
        SDL_PushEvent(&ev.ev);

        ev.ev.type = SDL_MOUSEBUTTONUP;
        ev.ev.button.state = SDL_RELEASED;
        SDL_PushEvent(&ev.ev);
    }
    else if (m_State == STATE_ZOOMING && id == 1)
    {
        m_State = STATE_PANNING;
    }
    else
    {
        m_State = STATE_INACTIVE;
    }
}

void CTouchInput::OnFingerMotion(int id, int x, int y)
{
    debug_printf(L"finger motion %d %d %d; state %d\n", id, x, y, m_State);

    CVector2D pos(x, y);

    m_Prev[id] = m_Pos[id];
    m_Pos[id] = pos;

    if (m_State == STATE_FIRST_TOUCH && id == 0)
    {
        if ((pos - m_FirstTouchPos).Length() > 16)
        {
            m_State = STATE_PANNING;

            CCamera& camera = *(g_Game->GetView()->GetCamera());
            m_PanFocus = camera.GetWorldCoordinates(m_FirstTouchPos.X, m_FirstTouchPos.Y, true);
            m_PanDist = (m_PanFocus - camera.GetOrientation().GetTranslation()).Y;
        }
    }

    if (m_State == STATE_PANNING && id == 0)
    {
        CCamera& camera = *(g_Game->GetView()->GetCamera());
        CVector3D origin, dir;
        camera.BuildCameraRay(x, y, origin, dir);
        dir *= m_PanDist / dir.Y;
        camera.GetOrientation().Translate(m_PanFocus - dir - origin);
        camera.UpdateFrustum();
    }

    if (m_State == STATE_ZOOMING && id == 1)
    {
        float oldDist = (m_Prev[id] - m_Pos[1 - id]).Length();
        float newDist = (m_Pos[id] - m_Pos[1 - id]).Length();
        float zoomDist = (newDist - oldDist) * -0.005f * m_PanDist;

        CCamera& camera = *(g_Game->GetView()->GetCamera());
        CVector3D origin, dir;
        camera.BuildCameraRay(m_Pos[0].X, m_Pos[0].Y, origin, dir);
        dir *= zoomDist;
        camera.GetOrientation().Translate(dir);
        camera.UpdateFrustum();

        m_PanFocus = camera.GetWorldCoordinates(m_Pos[0].X, m_Pos[0].Y, true);
        m_PanDist = (m_PanFocus - camera.GetOrientation().GetTranslation()).Y;
    }
}

void CTouchInput::Frame()
{
    double t = timer_Time();
    if (m_State == STATE_FIRST_TOUCH && t > m_FirstTouchTime + 1.0)
    {
        m_State = STATE_INACTIVE;

        SDL_Event_ ev;
        ev.ev.button.button = SDL_BUTTON_RIGHT;
        ev.ev.button.x = m_Pos[0].X;
        ev.ev.button.y = m_Pos[0].Y;

        ev.ev.type = SDL_MOUSEBUTTONDOWN;
        ev.ev.button.state = SDL_PRESSED;
        SDL_PushEvent(&ev.ev);

        ev.ev.type = SDL_MOUSEBUTTONUP;
        ev.ev.button.state = SDL_RELEASED;
        SDL_PushEvent(&ev.ev);
    }
}

InReaction CTouchInput::HandleEvent(const SDL_Event_* ev)
{
    UNUSED2(ev); // may be unused depending on #ifs

    if (!IsEnabled())
        return IN_PASS;

#if EMULATE_FINGERS_WITH_MOUSE
    switch(ev->ev.type)
    {
    case SDL_MOUSEBUTTONDOWN:
    {
        int button;
        if (ev->ev.button.button == SDL_BUTTON_LEFT)
            button = 0;
        else if (ev->ev.button.button == SDL_BUTTON_RIGHT)
            button = 1;
        else
            return IN_PASS;

        m_MouseEmulateDownPos[button] = CVector2D(ev->ev.button.x, ev->ev.button.y);
        if (m_MouseEmulateState[button] == MOUSE_INACTIVE)
        {
            m_MouseEmulateState[button] = MOUSE_ACTIVATING;
            OnFingerDown(button, ev->ev.button.x, ev->ev.button.y);
        }
        else if (m_MouseEmulateState[button] == MOUSE_ACTIVE_UP)
        {
            m_MouseEmulateState[button] = MOUSE_ACTIVE_DOWN;
        }
        return IN_HANDLED;
    }

    case SDL_MOUSEBUTTONUP:
    {
        int button;
        if (ev->ev.button.button == SDL_BUTTON_LEFT)
            button = 0;
        else if (ev->ev.button.button == SDL_BUTTON_RIGHT)
            button = 1;
        else
            return IN_PASS;

        if (m_MouseEmulateState[button] == MOUSE_ACTIVATING)
        {
            m_MouseEmulateState[button] = MOUSE_ACTIVE_UP;
        }
        else if (m_MouseEmulateState[button] == MOUSE_ACTIVE_DOWN)
        {
            float dist = (m_MouseEmulateDownPos[button] - CVector2D(ev->ev.button.x, ev->ev.button.y)).Length();
            if (dist <= 2)
            {
                m_MouseEmulateState[button] = MOUSE_INACTIVE;
                OnFingerUp(button, ev->ev.button.x, ev->ev.button.y);
            }
            else
            {
                m_MouseEmulateState[button] = MOUSE_ACTIVE_UP;
            }
        }
        return IN_HANDLED;
    }

    case SDL_MOUSEMOTION:
    {
        for (size_t i = 0; i < MAX_MOUSE; ++i)
        {
            if (m_MouseEmulateState[i] == MOUSE_ACTIVE_DOWN)
            {
                OnFingerMotion(i, ev->ev.motion.x, ev->ev.motion.y);
            }
        }
        return IN_HANDLED;
    }
    }
#endif

#if SDL_VERSION_ATLEAST(2, 0, 0)
    switch(ev->ev.type)
    {
    case SDL_FINGERDOWN:
    case SDL_FINGERUP:
    case SDL_FINGERMOTION:
    {
        // Map finger events onto the mouse, for basic testing
        debug_printf(L"finger %s tid=%lld fid=%lld x=%d y=%d dx=%d dy=%d p=%d\n",
            ev->ev.type == SDL_FINGERDOWN ? "down" :
            ev->ev.type == SDL_FINGERUP ? "up" :
            ev->ev.type == SDL_FINGERMOTION ? "motion" : "?",
            ev->ev.tfinger.touchId, ev->ev.tfinger.fingerId,
            ev->ev.tfinger.x, ev->ev.tfinger.y, ev->ev.tfinger.dx, ev->ev.tfinger.dy, ev->ev.tfinger.pressure);

        if (ev->ev.type == SDL_FINGERDOWN)
            OnFingerDown(ev->ev.tfinger.fingerId, g_xres * (ev->ev.tfinger.x/32767.0f), g_yres * (ev->ev.tfinger.y/32767.0f));
        else if (ev->ev.type == SDL_FINGERUP)
            OnFingerUp(ev->ev.tfinger.fingerId, g_xres * (ev->ev.tfinger.x/32767.0f), g_yres * (ev->ev.tfinger.y/32767.0f));
        else if (ev->ev.type == SDL_FINGERMOTION)
            OnFingerMotion(ev->ev.tfinger.fingerId, g_xres * (ev->ev.tfinger.x/32767.0f), g_yres * (ev->ev.tfinger.y/32767.0f));
        return IN_HANDLED;
    }
    }
#endif

    return IN_PASS;
}

CTouchInput g_TouchInput;

InReaction touch_input_handler(const SDL_Event_* ev)
{
    return g_TouchInput.HandleEvent(ev);
}