vt100/src/vt100.h

vt_key vt100

/* A DEC VT100, emulated from DEC's own documentation: *   VT100 User Guide (EK-VT100-UG) - codes the keyboard sends, control sequences *   VT100 Technical Manual (EK-VT100-TM), chapter 4 - raster, dot stretcher, attributes, *   blink rates, bell, keyclick, auto repeat * Basic VT100 without the Advanced Video Option is what matters here, but the AVO attributes * (bold, blink, underline, reverse on any character) are implemented too. 80 columns only. */#pragma once#include <stdbool.h>#include <stddef.h>#include <stdint.h>#define VT_COLS 80#define VT_ROWS 24#define VT_CELL_DOTS 10  /* "each character ... is made up of a matrix of dots, ten wide and ten high" */#define VT_CELL_SCANS 10#define VT_DOTS (VT_COLS * VT_CELL_DOTS)    /* "There are 800 dots in a scan" */#define VT_SCANS (VT_ROWS * VT_CELL_SCANS)  /* "and the raster is made of 240 scans" *//* Keys, by position on the VT100 keyboard. The typewriter keys are named by the character they * send unshifted ('a', '1', '[', ' ' ...); everything else has a code here. */enum vt_key {  VK_RETURN = 0x100,  VK_LINEFEED,  VK_BACKSPACE,  VK_DELETE,  VK_TAB,  VK_ESC,  VK_BREAK,  VK_NOSCROLL,  VK_SETUP,  VK_UP,  VK_DOWN,  VK_LEFT,  VK_RIGHT,  VK_PF1,  VK_PF2,  VK_PF3,  VK_PF4,  VK_KP0, /* VK_KP0 + n for digit n */  VK_KP9 = VK_KP0 + 9,  VK_KP_MINUS,  VK_KP_COMMA,  VK_KP_PERIOD,  VK_KP_ENTER,  VK_SHIFT,  VK_CTRL,  VK_CAPSLOCK};/* character attributes */#define VT_ATTR_BOLD 1#define VT_ATTR_UNDERLINE 2#define VT_ATTR_BLINK 4#define VT_ATTR_REVERSE 8/* line attributes */enum { VT_LINE_NORMAL, VT_LINE_DOUBLE_WIDTH, VT_LINE_DOUBLE_TOP, VT_LINE_DOUBLE_BOTTOM };/* LEDs, bit numbers in vt100.leds */enum { VT_LED_ONLINE, VT_LED_LOCAL, VT_LED_KBDLOCKED, VT_LED_L1, VT_LED_L2, VT_LED_L3, VT_LED_L4 };typedef struct {  uint8_t glyph; /* index into the character ROM (graphics characters are 0x01-0x1F there) */  uint8_t attr;} vt_cell;typedef struct {  int row, col;  uint8_t attr;  bool origin_mode;  uint8_t g[2];  int gl;} vt_saved_cursor;typedef struct vt100 {  vt_cell cells[VT_ROWS][VT_COLS];  uint8_t line_attr[VT_ROWS];  int row, col;  bool wrap_pending; /* the VT100 stays on the last column until the next printable character */  uint8_t attr;  int top, bottom; /* scrolling region, inclusive, 0-based */  bool tabs[VT_COLS];  uint8_t g[2]; /* designated character sets: 'B' ASCII, 'A' UK, '0' special graphics */  int gl;       /* 0 = G0 (SI), 1 = G1 (SO) */  vt_saved_cursor saved;  /* modes */  bool lnm, decckm, decawm, decom, decscnm, deckpam, decarm;  bool block_cursor; /* SET-UP: blinking block (true) or blinking underline */  bool keyclick;  /* parser */  int state;  int params[16];  int nparams;  bool private_marker; /* '?' */  uint8_t intermediate;  /* keyboard */  bool shift, ctrl, caps;  int held_key;          /* the key being auto-repeated, 0 if none */  int keys_down;  double repeat_at;      /* when the held key is sent again */  bool xoff_sent;        /* NO SCROLL */  /* to the host (serial line), filled by the keyboard and by answers to DA/DSR */  uint8_t tx[256];  int tx_len;  /* sounds for the host page to play, counted since the last vt_take_sounds */  int clicks, bells;  uint8_t leds;  /* 800 x 240 dots, each 0 (black), 1 (dim), 2 (normal), 3 (bright) - the four levels the   * DC012 video processor can put out */  uint8_t raster[VT_SCANS][VT_DOTS];  bool dirty;         /* cells changed since the last render */  int last_phase;     /* blink/cursor phase of the last render */  bool raster_changed; /* set by vt_render when the raster was redrawn */} vt100;void vt_init(vt100 *t);/* bytes from the host */void vt_receive(vt100 *t, uint8_t byte);void vt_receive_buf(vt100 *t, const uint8_t *buf, size_t n);/* keyboard; now_ms drives auto repeat */void vt_key(vt100 *t, int key, bool down, double now_ms);void vt_tick(vt100 *t, double now_ms);/* bytes to send to the host; returns how many were copied (and removes them) */int vt_take_tx(vt100 *t, uint8_t *out, int max);/* redraws the raster if anything visible changed; returns true if it did */bool vt_render(vt100 *t, double now_ms);/* the 24 lines as text (for tests and the screen-reader mirror); out must hold 24*81 bytes */void vt_text(const vt100 *t, char *out);