ref: 2b8fef5c41783bd7a01fab40727d4d353426cb75
dir: /textscreen/txt_io.c/
// // 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. // // // Text mode I/O functions, similar to C stdio // #include <stdlib.h> #include <string.h> #include "txt_io.h" #include "txt_main.h" static int cur_x = 0, cur_y = 0; static txt_color_t fgcolor = TXT_COLOR_GREY; static txt_color_t bgcolor = TXT_COLOR_BLACK; static void NewLine(unsigned char *screendata) { int i; unsigned char *p; cur_x = 0; ++cur_y; if (cur_y >= TXT_SCREEN_H) { // Scroll the screen up cur_y = TXT_SCREEN_H - 1; memmove(screendata, screendata + TXT_SCREEN_W * 2, TXT_SCREEN_W * 2 * (TXT_SCREEN_H -1)); // Clear the bottom line p = screendata + (TXT_SCREEN_H - 1) * 2 * TXT_SCREEN_W; for (i=0; i<TXT_SCREEN_W; ++i) { *p++ = ' '; *p++ = fgcolor | (bgcolor << 4); } } } static void PutSymbol(unsigned char *screendata, int c) { unsigned char *p; p = screendata + cur_y * TXT_SCREEN_W * 2 + cur_x * 2; // Add a new character to the buffer p[0] = c; p[1] = fgcolor | (bgcolor << 4); ++cur_x; if (cur_x >= TXT_SCREEN_W) { NewLine(screendata); } } // "Blind" version of TXT_PutChar() below which doesn't do any interpretation // of control signals. Just write a particular symbol to the screen buffer. void TXT_PutSymbol(int c) { PutSymbol(TXT_GetScreenData(), c); } static void PutChar(unsigned char *screendata, int c) { switch (c) { case '\n': NewLine(screendata); break; case '\b': // backspace --cur_x; if (cur_x < 0) cur_x = 0; break; default: PutSymbol(screendata, c); break; } } void TXT_PutChar(int c) { PutChar(TXT_GetScreenData(), c); } void TXT_Puts(const char *s) { unsigned char *screen; const char *p; screen = TXT_GetScreenData(); for (p=s; *p != '\0'; ++p) { PutChar(screen, *p); } PutChar(screen, '\n'); } void TXT_GotoXY(int x, int y) { cur_x = x; cur_y = y; } void TXT_GetXY(int *x, int *y) { *x = cur_x; *y = cur_y; } void TXT_FGColor(txt_color_t color) { fgcolor = color; } void TXT_BGColor(int color, int blinking) { bgcolor = color; if (blinking) bgcolor |= TXT_COLOR_BLINKING; } void TXT_SaveColors(txt_saved_colors_t *save) { save->bgcolor = bgcolor; save->fgcolor = fgcolor; } void TXT_RestoreColors(txt_saved_colors_t *save) { bgcolor = save->bgcolor; fgcolor = save->fgcolor; } void TXT_ClearScreen(void) { unsigned char *screen; int i; screen = TXT_GetScreenData(); for (i=0; i<TXT_SCREEN_W * TXT_SCREEN_H; ++i) { screen[i * 2] = ' '; screen[i * 2 + 1] = (bgcolor << 4) | fgcolor; } cur_x = 0; cur_y = 0; }