no-more-secrets-rust/src/nmseffect.c
Brian Barto 0b44f64468 Update documentation for nmseffect library
modified:   src/nmseffect.c
2017-01-19 15:15:24 -05:00

389 lines
10 KiB
C

/*
* Copyright (c) 2017 Brian Barto
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the MIT License. See LICENSE for more details.
*/
#define _XOPEN_SOURCE 700
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <ctype.h>
#include <time.h>
#include <locale.h>
#include <wchar.h>
#include "nmseffect.h"
#include "nmstermio.h"
#include "nmscharset.h"
// Program settings
#define TYPE_EFFECT_SPEED 4 // miliseconds per char
#define JUMBLE_SECONDS 2 // number of seconds for jumble effect
#define JUMBLE_LOOP_SPEED 35 // miliseconds between each jumble
#define REVEAL_LOOP_SPEED 50 // miliseconds between each reveal loop
// Character attribute structure, linked list. Keeps track of every
// character's attributes required for rendering and decryption effect.
struct charAttr {
char *source;
char *mask;
int width;
int is_space;
int time;
struct charAttr *next;
};
// Static function prototypes
static void nmseffect_sleep(int);
// NMS settings
static char *returnOpts = NULL; // Return option setting
static int autoDecrypt = 0; // Auto-decrypt flag
static int colorOn = 1; // Terminal color flag
static int inputPositionX = -1; // X coordinate for input position
static int inputPositionY = -1; // Y coordinate for input position
/*
* This function applies the data decryption effect to the character
* string that is provided as an argument. It returns the last character
* pressed by the user.
*/
char nmseffect_exec(char *string) {
struct charAttr *list_pointer = NULL;
struct charAttr *list_head = NULL;
struct charAttr *list_temp = NULL;
int i, revealed = 0;
int maxRows, maxCols, curRow, curCol, origRow = 0, origCol = 0;
char ret = 0;
// Error if we have an empty string.
if (string == NULL || string[0] == '\0') {
fprintf(stderr, "Error. Empty string.\n");
return 0;
}
// Reassociate STDIN to the terminal is needed
if (!isatty(STDIN_FILENO) && !freopen ("/dev/tty", "r", stdin)) {
fprintf(stderr, "Error. Can't associate STDIN with terminal.\n");
return 0;
}
// Needed for UTF-8 support
setlocale(LC_ALL, "");
// Seed my random number generator with the current time
srand(time(NULL));
// Initialize terminal
nmstermio_init_terminal();
if (!nmstermio_get_clearscr()) {
// Get current row position
origRow = nmstermio_get_cursor_row();
// nms_get_cursor_row() may display output in some terminals. So
// we need to reposition the cursor to the start of the row.
nmstermio_move_cursor(origRow, 0);
}
// Get terminal window rows/cols
maxRows = nmstermio_get_rows();
maxCols = nmstermio_get_cols();
// Assign current row/col positions
curRow = origRow;
curCol = origCol;
// Processing input
for (i = 0; string[i] != '\0'; ++i) {
// Don't go beyond maxRows
if (curRow - origRow >= maxRows - 1) {
break;
}
// Allocate memory for next list link
if (list_pointer == NULL) {
list_pointer = malloc(sizeof(struct charAttr));
list_head = list_pointer;
} else {
list_pointer->next = malloc(sizeof(struct charAttr));
list_pointer = list_pointer->next;
}
// Get character's byte-length and store character.
if (mblen(&string[i], 4) > 0) {
list_pointer->source = malloc(mblen(&string[i], 4) + 1);
strncpy(list_pointer->source, &string[i], mblen(&string[i], 4));
list_pointer->source[mblen(&string[i], 4)] = '\0';
i += (mblen(&string[i], 4) - 1);
} else {
fprintf(stderr, "Unknown character encountered. Quitting.\n");
nmstermio_restore_terminal();
return 0;
}
// Set flag if we have a whitespace character
if (strlen(list_pointer->source) == 1 && isspace(list_pointer->source[0]))
list_pointer->is_space = 1;
else
list_pointer->is_space = 0;
// Set initial mask chharacter
list_pointer->mask = nmscharset_get_random();
// Set reveal time
list_pointer->time = rand() % 5000;
// Set character column width
wchar_t widec[sizeof(list_pointer->source)] = {};
mbstowcs(widec, list_pointer->source, sizeof(list_pointer->source));
list_pointer->width = wcwidth(*widec);
// Set next node to null
list_pointer->next = NULL;
// Track row count
if (string[i] == '\n' || (curCol += list_pointer->width) > maxCols) {
curCol = 0;
curRow++;
if (curRow == maxRows + 1 && origRow > 0) {
origRow--;
curRow--;
}
}
}
// Print mask characters with 'type effect'
for (list_pointer = list_head; list_pointer != NULL; list_pointer = list_pointer->next) {
// Print mask character (or space)
if (list_pointer->is_space) {
nmstermio_print_string(list_pointer->source);
continue;
}
// print mask character
nmstermio_print_string(list_pointer->mask);
if (list_pointer->width == 2) {
nmstermio_print_string(nmscharset_get_random());
}
// flush output and sleep
nmstermio_refresh();
nmseffect_sleep(TYPE_EFFECT_SPEED);
}
// Flush any input up to this point
nmstermio_clear_input();
// If autoDecrypt flag is set, we sleep. Otherwise require user to
// press a key to continue.
if (autoDecrypt)
sleep(1);
else
nmstermio_get_char();
// Jumble loop
for (i = 0; i < (JUMBLE_SECONDS * 1000) / JUMBLE_LOOP_SPEED; ++i) {
// Move cursor to start position
nmstermio_move_cursor(origRow, origCol);
// Print new mask for all characters
for (list_pointer = list_head; list_pointer != NULL; list_pointer = list_pointer->next) {
// Print mask character (or space)
if (list_pointer->is_space) {
nmstermio_print_string(list_pointer->source);
continue;
}
// print new mask character
nmstermio_print_string(nmscharset_get_random());
if (list_pointer->width == 2) {
nmstermio_print_string(nmscharset_get_random());
}
}
// flush output and sleep
nmstermio_refresh();
nmseffect_sleep(JUMBLE_LOOP_SPEED);
}
// Reveal loop
while (!revealed) {
// Move cursor to start position
nmstermio_move_cursor(origRow, origCol);
// Set revealed flag
revealed = 1;
for (list_pointer = list_head; list_pointer != NULL; list_pointer = list_pointer->next) {
// Print mask character (or space)
if (list_pointer->is_space) {
nmstermio_print_string(list_pointer->source);
continue;
}
// If we still have time before the char is revealed, display the mask
if (list_pointer->time > 0) {
// Change the mask randomly
if (list_pointer->time < 500) {
if (rand() % 3 == 0) {
list_pointer->mask = nmscharset_get_random();
}
} else {
if (rand() % 10 == 0) {
list_pointer->mask = nmscharset_get_random();
}
}
// Print mask
nmstermio_print_string(list_pointer->mask);
// Decrement reveal time
list_pointer->time -= REVEAL_LOOP_SPEED;
// Unset revealed flag
revealed = 0;
} else {
// print source character
nmstermio_print_reveal_string(list_pointer->source, colorOn);
}
}
// flush output and sleep
nmstermio_refresh();
nmseffect_sleep(REVEAL_LOOP_SPEED);
}
// Flush any input up to this point
nmstermio_clear_input();
// Check if user must select from a set of options
if (returnOpts != NULL && strlen(returnOpts) > 0) {
// Position cursor if necessary
if (inputPositionY >= 0 && inputPositionX >= 0) {
nmstermio_move_cursor(inputPositionY, inputPositionX);
}
nmstermio_show_cursor();
// Get and validate user selection
while (strchr(returnOpts, ret = nmstermio_get_char()) == NULL) {
nmstermio_beep();
}
}
// User must press a key to continue when clearSrc is set
// without returnOpts
else if (nmstermio_get_clearscr()) {
nmstermio_get_char();
}
// Restore terminal
nmstermio_restore_terminal();
// Freeing the list.
list_pointer = list_head;
while (list_pointer != NULL) {
list_temp = list_pointer;
list_pointer = list_pointer->next;
free(list_temp->source);
free(list_temp);
}
return ret;
}
/*
* Pass the 'color' argument to the nmstermio module where it will set the
* foreground color of the unencrypted characters as they are
* revealed. Valid arguments are "white", "yellow", "magenta", "blue",
* "green", "red", and "cyan".
*/
void nmseffect_set_foregroundcolor(char *color) {
nmstermio_set_foregroundcolor(color);
}
/*
* Copy the string argument to the 'returnOpts' variable. This string is
* used to determine what character the user must choose from before
* nmseffect_exec() returns execution to the calling function. Normally
* this is left NULL. Use only when you want to present a menu with
* selection choices to the user.
*/
void nmseffect_set_returnopts(char *opts) {
returnOpts = realloc(returnOpts, strlen(opts) + 1);
strcpy(returnOpts, opts);
}
/*
* Set the autoDecrypt flag according to the true/false value of the
* 'setting' argument. When set to true, nmseffect_exec() will not
* require a key press to start the decryption effect.
*/
void nmseffect_set_autodecrypt(int setting) {
if (setting)
autoDecrypt = 1;
else
autoDecrypt = 0;
}
/*
* Pass the 'setting' argument to the nmstermio module where it will set
* the clearScr flag according to the true/false value. When set to true,
* nmseffect_exec() will clear the screen before displaying any characters.
*/
void nmseffect_set_clearscr(int setting) {
nmstermio_set_clearscr(setting);
}
/*
* Set the 'colorOn' flag according to the true/false value of the 'setting'
* argument. This flag tells nmseffect_exec() to use colors in it's output.
* This is true by default, and meant to be used only for terminals that
* do not support color. Though, compiling with ncurses support is perhaps
* a better option, as it will detect color capabilities automatically.
*/
void nmseffect_set_color(int setting) {
if (setting)
colorOn = 1;
else
colorOn = 0;
}
/*
* Set the desired coordinates of the cursor in the terminal window when
* nmseffect_exec() gets the character selection from the user that is set
* with nmseffect_set_returnopts().
*/
void nmseffect_set_input_position(int x, int y) {
if (x >= 0 && y >= 0) {
inputPositionX = x;
inputPositionY = y;
}
}
/*
* Sleep for the number of milliseconds indicated by argument 't'.
*/
static void nmseffect_sleep(int t) {
struct timespec ts;
ts.tv_sec = t / 1000;
ts.tv_nsec = (t % 1000) * 1000000;
nanosleep(&ts, NULL);
}