shithub: choc

ref: 9c3d852db282e59996933316e65141504a756edd
dir: /src/i_input.c/

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//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// 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.
//
// DESCRIPTION:
//     SDL implementation of system-specific input interface.
//


#include "SDL.h"

#include "doomkeys.h"
#include "doomtype.h"
#include "d_event.h"
#include "i_input.h"
#include "m_argv.h"
#include "m_config.h"

static const int scancode_translate_table[] = SCANCODE_TO_KEYS_ARRAY;

// Lookup table for mapping ASCII characters to their equivalent when
// shift is pressed on an American layout keyboard:

static const char shiftxform[] =
{
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
    11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
    21, 22, 23, 24, 25, 26, 27, 28, 29, 30,
    31, ' ', '!', '"', '#', '$', '%', '&',
    '"', // shift-'
    '(', ')', '*', '+',
    '<', // shift-,
    '_', // shift--
    '>', // shift-.
    '?', // shift-/
    ')', // shift-0
    '!', // shift-1
    '@', // shift-2
    '#', // shift-3
    '$', // shift-4
    '%', // shift-5
    '^', // shift-6
    '&', // shift-7
    '*', // shift-8
    '(', // shift-9
    ':',
    ':', // shift-;
    '<',
    '+', // shift-=
    '>', '?', '@',
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
    'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
    '[', // shift-[
    '!', // shift-backslash - OH MY GOD DOES WATCOM SUCK
    ']', // shift-]
    '"', '_',
    '\'', // shift-`
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
    'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
    '{', '|', '}', '~', 127
};

// Bit mask of mouse button state.
static unsigned int mouse_button_state = 0;

// Disallow mouse and joystick movement to cause forward/backward
// motion.  Specified with the '-novert' command line parameter.
// This is an int to allow saving to config file
int novert = 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;

// 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;

//
// Translates the SDL key
//
static int TranslateKey(SDL_Keysym *sym)
{
    int scancode = sym->scancode;

    switch (scancode)
    {
        case SDL_SCANCODE_LCTRL:
        case SDL_SCANCODE_RCTRL:
            return KEY_RCTRL;

        case SDL_SCANCODE_LSHIFT:
        case SDL_SCANCODE_RSHIFT:
            return KEY_RSHIFT;

        case SDL_SCANCODE_LALT:
            return KEY_LALT;

        case SDL_SCANCODE_RALT:
            return KEY_RALT;

        default:
            if (scancode >= 0 && scancode < arrlen(scancode_translate_table))
            {
                return scancode_translate_table[scancode];
            }
            else
            {
                return 0;
            }
    }
}

// Get the equivalent ASCII (Unicode?) character for a keypress.
static int GetTypedChar(SDL_Event *event)
{
    // If we're strictly emulating Vanilla, we should always act like
    // we're using a US layout keyboard (in ev_keydown, data1=data2).
    // Otherwise we should use the native key mapping.
    if (vanilla_keyboard_mapping)
    {
        int result = TranslateKey(&event->key.keysym);

        // If shift is held down, apply the original uppercase
        // translation table used under DOS.
        if ((SDL_GetModState() & KMOD_SHIFT) != 0
         && result >= 0 && result < arrlen(shiftxform))
        {
            result = shiftxform[result];
        }

        return result;
    }
    else
    {
        int unicode = event->key.keysym.sym;

        if (unicode < 128)
        {
            return unicode;
        }
        else
        {
            return 0;
        }
    }
}

void I_HandleKeyboardEvent(SDL_Event *sdlevent)
{
    event_t event;

    switch (sdlevent->type)
    {
        case SDL_KEYDOWN:
            // data1 has the key pressed, data2 has the character
            // (shift-translated, etc)
            event.type = ev_keydown;
            event.data1 = TranslateKey(&sdlevent->key.keysym);
            event.data2 = GetTypedChar(sdlevent);

            if (event.data1 != 0)
            {
                D_PostEvent(&event);
            }
            break;

        case SDL_KEYUP:
            event.type = ev_keyup;
            event.data1 = TranslateKey(&sdlevent->key.keysym);

            // data2 is just initialized to zero for ev_keyup.
            // For ev_keydown it's the shifted Unicode character
            // that was typed, but if something wants to detect
            // key releases it should do so based on data1
            // (key ID), not the printable char.

            event.data2 = 0;

            if (event.data1 != 0)
            {
                D_PostEvent(&event);
            }
            break;

        default:
            break;
    }
}

static void UpdateMouseButtonState(unsigned int button, boolean on)
{
    event_t event;

    if (button < SDL_BUTTON_LEFT || button > MAX_MOUSE_BUTTONS)
    {
        return;
    }

    // Note: button "0" is left, button "1" is right,
    // button "2" is middle for Doom.  This is different
    // to how SDL sees things.

    switch (button)
    {
        case SDL_BUTTON_LEFT:
            button = 0;
            break;

        case SDL_BUTTON_RIGHT:
            button = 1;
            break;

        case SDL_BUTTON_MIDDLE:
            button = 2;
            break;

        default:
            // SDL buttons are indexed from 1.
            --button;
            break;
    }

    // Turn bit representing this button on or off.

    if (on)
    {
        mouse_button_state |= (1 << button);
    }
    else
    {
        mouse_button_state &= ~(1 << button);
    }

    // Post an event with the new button state.

    event.type = ev_mouse;
    event.data1 = mouse_button_state;
    event.data2 = event.data3 = 0;
    D_PostEvent(&event);
}

void I_HandleMouseEvent(SDL_Event *sdlevent)
{
    switch (sdlevent->type)
    {
        case SDL_MOUSEBUTTONDOWN:
            UpdateMouseButtonState(sdlevent->button.button, true);
            break;

        case SDL_MOUSEBUTTONUP:
            UpdateMouseButtonState(sdlevent->button.button, false);
            break;

        default:
            break;
    }
}

static int AccelerateMouse(int val)
{
    if (val < 0)
        return -AccelerateMouse(-val);

    if (val > mouse_threshold)
    {
        return (int)((val - mouse_threshold) * mouse_acceleration + mouse_threshold);
    }
    else
    {
        return val;
    }
}

//
// Read the change in mouse state to generate mouse motion events
//
// This is to combine all mouse movement for a tic into one mouse
// motion event.
void I_ReadMouse(void)
{
    int x, y;
    event_t ev;

    SDL_GetRelativeMouseState(&x, &y);

    if (x != 0 || y != 0) 
    {
        ev.type = ev_mouse;
        ev.data1 = mouse_button_state;
        ev.data2 = AccelerateMouse(x);

        if (!novert)
        {
            ev.data3 = -AccelerateMouse(y);
        }
        else
        {
            ev.data3 = 0;
        }

        D_PostEvent(&ev);
    }
}

void I_InputCheckCommandLine(void)
{
    //!
    // @category video
    //
    // Disable vertical mouse movement.
    //

    if (M_CheckParm("-novert"))
    {
        novert = true;
    }

    //!
    // @category video
    //
    // Enable vertical mouse movement.
    //

    if (M_CheckParm("-nonovert"))
    {
        novert = false;
    }
}

// Bind all variables controlling input options.
void I_BindInputVariables(void)
{
    M_BindFloatVariable("mouse_acceleration",      &mouse_acceleration);
    M_BindIntVariable("mouse_threshold",           &mouse_threshold);
    M_BindIntVariable("vanilla_keyboard_mapping",  &vanilla_keyboard_mapping);
    M_BindIntVariable("novert",                    &novert);
}