Add partial support for keyboard input

src/main.c

@@ -1,3 +1,4 @@
+#include <errno.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -5,6 +6,8 @@
 #include <time.h>
 #include <unistd.h>
 
+#include <linux/input.h>
+
 #include "shorthand.h"
 #include "ppu.c"
 #include "uxn-fast.c"
@@ -30,6 +33,142 @@ time_elapsed(Time since){
     return (now.tv_sec - since.tv_sec) * 1e9 + (now.tv_nsec - since.tv_nsec);
 }
 
+typedef struct Keyboard {
+    int fd;
+    char map[KEY_MAX / 8 + 1];
+} Keyboard;
+
+static Keyboard keyboard;
+
+void
+init_input(void) {
+    const char *dev = "/dev/input/by-id/usb-Apple_Inc._Magic_Keyboard_with_Numeric_Keypad_F0T0167000DHTHKAD-if01-event-kbd";
+    keyboard.fd = open(dev, O_RDONLY);
+    if (keyboard.fd == -1) {
+        // TODO: should this be a warning and still work for applications that
+        //       don't require a keyboard?
+        fprintf(stderr, "error: no couldn't open keyboard %s: %s.\n", dev, strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+
+    memset(keyboard.map, 0, sizeof(keyboard.map));
+}
+
+void
+poll_keyboard(void) {
+    char map[KEY_MAX / 8 + 1];
+    memset(map, 0, sizeof(map));
+    ioctl(keyboard.fd, EVIOCGKEY(sizeof(map)), map);
+    for (size_t i = 0; i < sizeof(map); i++) {
+        keyboard.map[i] |= map[i];
+    }
+}
+
+void
+handle_keyboard(void) {
+    // Find mod keys.
+    bool shift_mod = false;
+    // bool ctrl_mod = false;
+    // bool alt_mod = false;
+    // bool meta_mod = false;
+    for (size_t i = 0; i < sizeof(keyboard.map); i++) {
+        for (size_t j = 0; j < 8; j++) {
+            char key = keyboard.map[i] & (1 << j);
+            if (key) {
+                char key_code = i * 8 + j;
+                switch (key_code) {
+                    case KEY_LEFTSHIFT:
+                    case KEY_RIGHTSHIFT: { shift_mod = true; } break;
+                    // case KEY_LEFTCTRL:
+                    // case KEY_RIGHTCTRL: { ctrl_mod = true; } break;
+                    // case KEY_LEFTALT:
+                    // case KEY_RIGHTALT: { alt_mod = true; } break;
+                    // case KEY_LEFTMETA:
+                    // case KEY_RIGHTMETA: { meta_mod = true; } break;
+                    default: break;
+                }
+            }
+        }
+    }
+
+    // Handle normal keys.
+    for (size_t i = 0; i < sizeof(keyboard.map); i++) {
+        for (size_t j = 0; j < 8; j++) {
+            char key = keyboard.map[i] & (1 << j);
+            if (key) {
+                char key_code = i * 8 + j;
+                // Special keys.
+                // TODO: ...
+
+                // Normal keys.
+                char rune = '\0';
+                switch (key_code) {
+                    case KEY_1: { rune = shift_mod ? '!' : '1'; } break;
+                    case KEY_2: { rune = shift_mod ? '@' : '2'; } break;
+                    case KEY_3: { rune = shift_mod ? '#' : '3'; } break;
+                    case KEY_4: { rune = shift_mod ? '$' : '4'; } break;
+                    case KEY_5: { rune = shift_mod ? '%' : '5'; } break;
+                    case KEY_6: { rune = shift_mod ? '^' : '6'; } break;
+                    case KEY_7: { rune = shift_mod ? '&' : '7'; } break;
+                    case KEY_8: { rune = shift_mod ? '*' : '8'; } break;
+                    case KEY_9: { rune = shift_mod ? '(' : '9'; } break;
+                    case KEY_0: { rune = shift_mod ? ')' : '0'; } break;
+                    case KEY_MINUS: { rune = shift_mod ? '_' : '-'; } break;
+                    case KEY_EQUAL: { rune = shift_mod ? '+' : '+'; } break;
+                    case KEY_Q: { rune = shift_mod ? 'Q' : 'q'; } break;
+                    case KEY_W: { rune = shift_mod ? 'W' : 'w'; } break;
+                    case KEY_E: { rune = shift_mod ? 'E' : 'e'; } break;
+                    case KEY_R: { rune = shift_mod ? 'T' : 't'; } break;
+                    case KEY_T: { rune = shift_mod ? 'T' : 't'; } break;
+                    case KEY_Y: { rune = shift_mod ? 'Y' : 'y'; } break;
+                    case KEY_U: { rune = shift_mod ? 'U' : 'u'; } break;
+                    case KEY_I: { rune = shift_mod ? 'I' : 'i'; } break;
+                    case KEY_O: { rune = shift_mod ? 'O' : 'o'; } break;
+                    case KEY_P: { rune = shift_mod ? 'P' : 'p'; } break;
+                    case KEY_LEFTBRACE: { rune = shift_mod ? '{' : '['; } break;
+                    case KEY_RIGHTBRACE: { rune = shift_mod ? '}' : ']'; } break;
+                    case KEY_A: { rune = shift_mod ? 'A' : 'a'; } break;
+                    case KEY_S: { rune = shift_mod ? 'S' : 's'; } break;
+                    case KEY_D: { rune = shift_mod ? 'D' : 'd'; } break;
+                    case KEY_F: { rune = shift_mod ? 'F' : 'f'; } break;
+                    case KEY_G: { rune = shift_mod ? 'G' : 'g'; } break;
+                    case KEY_H: { rune = shift_mod ? 'H' : 'h'; } break;
+                    case KEY_J: { rune = shift_mod ? 'J' : 'j'; } break;
+                    case KEY_K: { rune = shift_mod ? 'K' : 'k'; } break;
+                    case KEY_L: { rune = shift_mod ? 'L' : 'l'; } break;
+                    case KEY_SEMICOLON: { rune = shift_mod ? ':' : ';'; } break;
+                    case KEY_APOSTROPHE: { rune = shift_mod ? '"' : '\''; } break;
+                    case KEY_GRAVE: { rune = shift_mod ? '~' : '`'; } break;
+                    case KEY_BACKSLASH: { rune = shift_mod ? '|' : '\\'; } break;
+                    case KEY_Z: { rune = shift_mod ? 'Z' : 'z'; } break;
+                    case KEY_X: { rune = shift_mod ? 'X' : 'x'; } break;
+                    case KEY_C: { rune = shift_mod ? 'C' : 'c'; } break;
+                    case KEY_V: { rune = shift_mod ? 'V' : 'v'; } break;
+                    case KEY_B: { rune = shift_mod ? 'B' : 'b'; } break;
+                    case KEY_N: { rune = shift_mod ? 'N' : 'n'; } break;
+                    case KEY_M: { rune = shift_mod ? 'M' : 'm'; } break;
+                    case KEY_COMMA: { rune = shift_mod ? '<' : ','; } break;
+                    case KEY_DOT: { rune = shift_mod ? '>' : '.'; } break;
+                    case KEY_SLASH: { rune = shift_mod ? '?' : '/'; } break;
+                    case KEY_SPACE: { rune = ' '; } break;
+                    case KEY_TAB: { rune = '\t'; } break;
+                    case KEY_BACKSPACE: { rune = 0x08; } break;
+                    case KEY_ENTER:
+                    case KEY_KPENTER: { rune = 0x0d; } break;
+                    default: break;
+                }
+                if (rune) {
+                    devctrl->dat[3] = rune;
+                    uxn_eval(&u, mempeek16(devctrl->dat, 0));
+                    devctrl->dat[3] = 0;
+                    continue;
+                }
+            }
+        }
+    }
+    memset(keyboard.map, 0, sizeof(keyboard.map));
+}
+
 void
 nil_talk(Device *d, u8 b0, u8 w) {
     (void)d;
@@ -208,6 +347,9 @@ init_uxn(char *file_name) {
     // Initialize framebuffer.
     ppu_init();
 
+    // Initialize keybord.
+    init_input();
+
     // Prepare devices.
     uxn_port(&u, 0x0, "system", system_talk);
     uxn_port(&u, 0x1, "console", console_talk);
@@ -242,8 +384,11 @@ main(int argc, char *argv[]) {
     uxn_eval(&u, 0x0100);
     Time frame_time = time_now();
     while (true) {
+        poll_keyboard();
         size_t elapsed = time_elapsed(frame_time);
         if (elapsed >= 16666666) {
+            handle_keyboard();
+
             // Echo input to standard output.
             uxn_eval(&u, mempeek16(devscreen->dat, 0));