borgware-2d/games/tetris/input.c

390 lines
10 KiB
C

/**
* \addtogroup tetris
* @{
*/
/**
* @file input.c
* @brief Implementation of the input routines of Tetris.
* @author Christian Kroll
*/
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include "../../compat/pgmspace.h"
#include "../../joystick/joystick.h"
#include "../../util.h"
#include "bearing.h"
#include "input.h"
/***********
* defines *
***********/
#define WAIT(ms) wait(ms)
#define PM(value) pgm_read_byte(&value)
/** Number of milliseconds that each loop cycle waits. */
#define TETRIS_INPUT_TICKS 5
/**
* Number of milliseconds the input is ignored after the pause key combination
* has been pressed, since it is difficult to release all buttons
* simultaneously.
*/
#define TETRIS_INPUT_PAUSE_TICKS 100
/**
* Number of allowed loop cycles while in pause mode so that the game
* automatically continues after five minutes.
*/
#define TETRIS_INPUT_PAUSE_CYCLES 60000
/** initial delay (in loop cycles) for key repeat */
#define TETRIS_INPUT_REPEAT_INITIALDELAY 35
/** delay (in loop cycles) for key repeat */
#define TETRIS_INPUT_REPEAT_DELAY 5
/** Number of loop cyles the left button is ignored */
#define TETRIS_INPUT_CHATTER_TICKS_LEFT 12
/** Number of loop cyles the right button is ignored */
#define TETRIS_INPUT_CHATTER_TICKS_RIGHT 12
/** Number of loop cyles the down button is ignored */
#define TETRIS_INPUT_CHATTER_TICKS_DOWN 12
/** Number of loop cyles the clockwise rotation button is ignored */
#define TETRIS_INPUT_CHATTER_TICKS_ROT_CW 24
/** Number of loop cyles the counter clockwise rotation button is ignored */
#define TETRIS_INPUT_CHATTER_TICKS_ROT_CCW 24
/** Number of loop cyles the drop button is ignored */
#define TETRIS_INPUT_CHATTER_TICKS_DROP 36
/** wait cycles per level (array of uint8_t) */
#define TETRIS_INPUT_LVL_CYCLES 200, 133, 100, 80, 66, 57, 50, 44, 40, 36, 33, \
30, 28, 26, 25, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9
/***************************
* non-interface functions *
***************************/
/**
* sets an ignore counter to a command specific value if it is 0
* @param pIn pointer to an input object
* @param cmd the command whose counter should be set
*/
static void tetris_input_chatterProtect(tetris_input_t *pIn,
tetris_input_command_t cmd)
{
// never exceed the index
assert(cmd < TETRIS_INCMD_NONE);
// number of loop cycles a command is ignored after its button has been
// released (every command has its own counter)
static uint8_t const nInitialIgnoreValue[TETRIS_INCMD_NONE] PROGMEM =
{
TETRIS_INPUT_CHATTER_TICKS_LEFT,
TETRIS_INPUT_CHATTER_TICKS_RIGHT,
TETRIS_INPUT_CHATTER_TICKS_DOWN,
TETRIS_INPUT_CHATTER_TICKS_ROT_CW,
TETRIS_INPUT_CHATTER_TICKS_ROT_CCW,
TETRIS_INPUT_CHATTER_TICKS_DROP,
0, // TETRIS_INCMD_GRAVITY (irrelevant because it doesn't have a button)
0 // TETRIS_INCMD_PAUSE (is a combination of ROT_CW and DOWN)
};
// setting ignore counter according to the predefined array
if (pIn->nIgnoreCmdCounter[cmd] == 0)
{
// if the command isn't TETRIS_INCMD_PAUSE, setting the ignore counter
// is straight forward
if (cmd != TETRIS_INCMD_PAUSE)
{
pIn->nIgnoreCmdCounter[cmd] = PM(nInitialIgnoreValue[cmd]);
}
// TETRIS_INCMD_PAUSE is issued via a combination of the buttons for
// TETRIS_INCMD_ROT_CW and TETRIS_INCMD_DOWN, so we must set their
// ignore counters
else
{
pIn->nIgnoreCmdCounter[TETRIS_INCMD_ROT_CW] =
TETRIS_INPUT_CHATTER_TICKS_ROT_CW;
pIn->nIgnoreCmdCounter[TETRIS_INCMD_DOWN] =
TETRIS_INPUT_CHATTER_TICKS_DOWN;
}
}
// The ignore counter of TETRIS_INCMD_PAUSE is either set to the counter
// value of TETRIS_INCMD_ROT_CW or TETRIS_INCMD_DOWN (whichever is higher).
if ((cmd == TETRIS_INCMD_ROT_CW) || (cmd == TETRIS_INCMD_DOWN))
{
// helper variables (which the compiler hopefully optimizes away)
uint8_t const nRotCw = pIn->nIgnoreCmdCounter[TETRIS_INCMD_ROT_CW];
uint8_t const nDown = pIn->nIgnoreCmdCounter[TETRIS_INCMD_DOWN];
pIn->nIgnoreCmdCounter[TETRIS_INCMD_PAUSE] =
nRotCw > nDown ? nRotCw : nDown;
}
}
/**
* remaps tetris commands according to current bearing of the bucket
* @param nBearing bearing of the bucket
* @param nCmd command which has to be mapped
* @return mapped tetris command
* @see tetris_input_command_t
*/
static
tetris_input_command_t tetris_input_mapCommand(tetris_bearing_t nBearing,
tetris_input_command_t nCmd)
{
return (nCmd < TETRIS_INCMD_ROT_CCW) ? (nCmd - nBearing + 4u) % 4u : nCmd;
}
/**
* translates joystick movements into tetris commands
* @return interpreted joystick command
* @see tetris_input_command_t
*/
static tetris_input_command_t tetris_input_queryJoystick(tetris_input_t *pIn)
{
// map port input to a tetris command
tetris_input_command_t cmdJoystick;
if (JOYISFIRE)
{
cmdJoystick = TETRIS_INCMD_DROP;
}
else if (JOYISLEFT)
{
cmdJoystick = TETRIS_INCMD_LEFT;
}
else if (JOYISRIGHT)
{
cmdJoystick = TETRIS_INCMD_RIGHT;
}
else if (JOYISUP && JOYISDOWN)
{
cmdJoystick = TETRIS_INCMD_PAUSE;
WAIT(TETRIS_INPUT_PAUSE_TICKS);
}
else if (JOYISDOWN)
{
cmdJoystick = TETRIS_INCMD_DOWN;
}
else if (JOYISUP)
{
cmdJoystick = TETRIS_INCMD_ROT_CW;
}
else
{
cmdJoystick = TETRIS_INCMD_NONE;
}
// decrement all ignore counters
for (uint8_t nIgnIndex = 0; nIgnIndex < TETRIS_INCMD_NONE; ++nIgnIndex)
{
if (pIn->nIgnoreCmdCounter[nIgnIndex] != 0)
{
--pIn->nIgnoreCmdCounter[nIgnIndex];
}
}
// chatter protection
if (cmdJoystick < TETRIS_INCMD_NONE)
{
if (pIn->nIgnoreCmdCounter[cmdJoystick] == 0)
{
tetris_input_chatterProtect(pIn, cmdJoystick);
}
else if (cmdJoystick != pIn->cmdRawLast)
{
cmdJoystick = TETRIS_INCMD_NONE;
}
}
// memorize current command (for detecting prolonged key presses)
pIn->cmdRawLast = cmdJoystick;
// remap command according to current bearing
tetris_input_command_t cmdReturn =
tetris_input_mapCommand(pIn->nBearing, cmdJoystick);
return cmdReturn;
}
/****************************
* construction/destruction *
****************************/
tetris_input_t *tetris_input_construct(void)
{
tetris_input_t *pIn = (tetris_input_t *)malloc(sizeof(tetris_input_t));
assert(pIn != NULL);
pIn->cmdRawLast = pIn->cmdLast = TETRIS_INCMD_NONE;
pIn->nBearing = TETRIS_BEARING_0;
tetris_input_setLevel(pIn, 0);
pIn->nLoopCycles = 0;
pIn->nRepeatCount = -TETRIS_INPUT_REPEAT_INITIALDELAY;
pIn->nPauseCount = 0;
memset(pIn->nIgnoreCmdCounter, 0, TETRIS_INCMD_NONE);
return pIn;
}
/***************************
* input related functions *
***************************/
tetris_input_command_t tetris_input_getCommand(tetris_input_t *pIn,
tetris_input_pace_t nPace)
{
assert (pIn != NULL);
// this variable both serves as the return value and as a flag for not
// leaving the function as long as its value is TETRIS_INCMD_NONE
tetris_input_command_t cmdReturn = TETRIS_INCMD_NONE;
// if the piece is gliding we grant the player a reasonable amount of time
// to make the game more controllable at higher falling speeds
uint8_t nMaxCycles = pIn->nMaxCycles > nPace ? pIn->nMaxCycles : nPace;
while (pIn->nLoopCycles < nMaxCycles)
{
// holds the (mapped) command value of the joystick
tetris_input_command_t cmdJoystick = tetris_input_queryJoystick(pIn);
switch (cmdJoystick)
{
case TETRIS_INCMD_LEFT:
case TETRIS_INCMD_RIGHT:
case TETRIS_INCMD_DOWN:
// only react if either the current command differs from the last
// one or enough loop cycles have been run on the same command (for
// key repeat)
if (pIn->cmdLast != cmdJoystick ||
pIn->nRepeatCount++ >= TETRIS_INPUT_REPEAT_DELAY)
{
// reset repeat counter
if (pIn->cmdLast != cmdJoystick)
{
// different command: we set an extra initial delay
pIn->nRepeatCount = -TETRIS_INPUT_REPEAT_INITIALDELAY;
}
else
{
// same command: there's no extra initial delay
pIn->nRepeatCount = 0;
}
// update cmdLast and return value
pIn->cmdLast = cmdReturn = cmdJoystick;
}
break;
case TETRIS_INCMD_DROP:
case TETRIS_INCMD_ROT_CW:
case TETRIS_INCMD_ROT_CCW:
// no key repeat here
if (pIn->cmdLast != cmdJoystick)
{
pIn->cmdLast = cmdReturn = cmdJoystick;
}
break;
case TETRIS_INCMD_PAUSE:
// if this is an initial pause command, make sure that the logic
// module is informed about it
if (pIn->cmdLast != TETRIS_INCMD_PAUSE)
{
pIn->cmdLast = cmdReturn = cmdJoystick;
pIn->nPauseCount = 0;
}
break;
case TETRIS_INCMD_NONE:
// If the game is paused (last command was TETRIS_INCMD_PAUSE) we
// ensure that the variable which holds that last command isn't
// touched. We use this as a flag so that the loop cycle counter
// doesn't get incremented. We count the number of pause cycles,
// though. If enough cycles have been run, we enforce the
// continuation of the game.
if ((pIn->cmdLast != TETRIS_INCMD_PAUSE) ||
(++pIn->nPauseCount > TETRIS_INPUT_PAUSE_CYCLES))
{
pIn->cmdLast = TETRIS_INCMD_NONE;
}
// reset repeat counter
pIn->nRepeatCount = -TETRIS_INPUT_REPEAT_INITIALDELAY;
break;
default:
break;
}
// reset automatic falling if the player has dropped a piece
if (cmdReturn == TETRIS_INCMD_DOWN || cmdReturn == TETRIS_INCMD_DROP)
{
pIn->nLoopCycles = 0;
}
// otherwise ensure automatic falling (unless the game is running)
else if (pIn->cmdLast != TETRIS_INCMD_PAUSE)
{
++pIn->nLoopCycles;
}
WAIT(TETRIS_INPUT_TICKS);
if (cmdReturn != TETRIS_INCMD_NONE)
{
return cmdReturn;
}
}
// since we have left the loop we reset the cycle counter
pIn->nLoopCycles = 0;
return TETRIS_INCMD_GRAVITY;
}
void tetris_input_setLevel(tetris_input_t *pIn,
uint8_t nLvl)
{
assert(pIn != NULL);
assert(nLvl <= TETRIS_INPUT_LEVELS - 1);
static uint8_t const nCycles[] PROGMEM = {TETRIS_INPUT_LVL_CYCLES};
pIn->nMaxCycles = PM(nCycles[nLvl]);
}
void tetris_input_resetDownKeyRepeat(tetris_input_t *pIn)
{
assert(pIn != NULL);
if (pIn->cmdLast == TETRIS_INCMD_DOWN)
{
pIn->nRepeatCount = -TETRIS_INPUT_REPEAT_INITIALDELAY;
}
}
void tetris_input_setBearing(tetris_input_t *pIn,
tetris_bearing_t nBearing)
{
pIn->nBearing = nBearing;
// avoid weird key repeating effects because the currently pressed button
// changes its meaning as soon as the bearing changes
pIn->cmdLast = tetris_input_mapCommand(pIn->nBearing, pIn->cmdRawLast);
}
/*@}*/