From 5a54774474f43ae29716751d6415563a59b92c7d Mon Sep 17 00:00:00 2001
From: pk33 <pk33@pk33.space>
Date: Mon, 11 Nov 2024 18:06:18 +0100
Subject: tidying up and basic input

---
 src/input33.c | 232 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 232 insertions(+)
 create mode 100644 src/input33.c

(limited to 'src/input33.c')

diff --git a/src/input33.c b/src/input33.c
new file mode 100644
index 0000000..1ba1ff2
--- /dev/null
+++ b/src/input33.c
@@ -0,0 +1,232 @@
+#include "fcntl.h"
+#include "dirent.h"
+#include "stdio.h"
+#include "stdlib.h"
+#include "unistd.h"
+#include "string.h"
+#include "sys/stat.h"
+#include "sys/kd.h"
+#include <linux/input-event-codes.h>
+#include <linux/input.h>
+
+#include "input33.h"
+#include "logger33.h"
+#include "strings33.h"
+
+
+#define _INPUT_DEVICES_MAX 8
+#define _POLL_EVENTS_MAX 16
+
+
+Input33 __input = {0};
+
+
+static int _is_char_device( const struct dirent *f );
+static Boolean _is_keyboard( Size fd );
+static Boolean _is_mouse( Size fd );
+static Size _has_key( Size fd, unsigned int event );
+static Size _has_rel( Size fd, unsigned int event );
+static u64 _has_evbits( Size fd, unsigned int type );
+
+
+Error input33_init( void )
+{
+  Size i, deviceCount;
+  Boolean hasKeyboard = E33_FALSE;
+  Boolean hasMouse = E33_FALSE;
+  struct dirent **evfs;
+
+  deviceCount = scandir( "/dev/input", &evfs, _is_char_device, 0 );
+
+  if( deviceCount <= 0 ) {
+    LOGE( "No valid character devices found." );
+    return E33_EXIT_FAILURE;
+  }
+
+  for( i = 0; i < deviceCount; ++i )
+  {
+    Size j;
+    Size devFd;
+    char path[ _STRING_MAX ];
+
+    snprintf( path, _STRING_MAX , "%s%s", "/dev/input/", evfs[i]->d_name );
+    free( evfs[i] );
+
+    devFd = open( path, O_RDONLY | O_NONBLOCK );
+    if( devFd == -1 ) {
+      continue;
+    }
+
+    if( _is_keyboard( devFd ) )
+    {
+      hasKeyboard = E33_TRUE;
+      __input.devices[ __input.deviceCount++ ] = devFd;
+    }
+    else if( _is_mouse(devFd) )
+    {
+      hasMouse = E33_TRUE;
+      __input.devices[ __input.deviceCount++ ] = devFd;
+      ioctl( devFd, EVIOCGRAB, 1 );
+    }
+    else {
+      close( devFd );
+    }
+
+    if( __input.deviceCount == _INPUT_DEVICES_MAX ){
+      break;
+    }
+  }
+
+  free( evfs );
+
+  if( (hasKeyboard == E33_TRUE) && (hasMouse == E33_TRUE) ) {
+    return E33_EXIT_SUCCESS;
+  }
+
+  return E33_EXIT_FAILURE;
+}
+
+void input33_poll( void )
+{
+  u16 i;
+
+  for( i = 0; i < __input.deviceCount; ++i )
+  {
+    Size j;
+    Size readBytes;
+    Size eventCount;
+    struct input_event events[ _POLL_EVENTS_MAX ];
+
+    __input.relStates[REL_X] = 0;
+    __input.relStates[REL_Y] = 0;
+    __input.relStates[REL_WHEEL] = 0;
+
+    readBytes = read( __input.devices[i], events,
+      sizeof(struct input_event) * _POLL_EVENTS_MAX );
+
+    if( readBytes == -1 ) {
+      continue;
+    }
+
+    eventCount = readBytes / sizeof( struct input_event );
+
+    for( j = 0; j < eventCount; ++j )
+    {
+      switch( events[j].type )
+      {
+        case EV_KEY:
+          __input.keyStates[ events[j].code ] = events[j].value;
+
+          if( (events[j].value == _PRESS) || (events[j].value == _REPEAT) )
+          {
+            __input.buffer[__input.tail++] = events[j].code;
+            __input.tail &= (_KBBUFF_LEN - 1);
+
+            if( __input.tail == __input.head )
+            {
+              ++__input.head;
+              __input.head &= (_KBBUFF_LEN - 1);
+            }
+          }
+        break;
+
+        case EV_REL:
+          __input.relStates[ events[j].code ] = events[j].value;
+        break;
+      }
+    }
+  }
+
+  __input.modFlags = 6;
+  ioctl( 0, TIOCLINUX, &__input.modFlags );
+  ioctl( 0, KDGKBLED, &__input.cnsFlags );
+}
+
+void input33_term( void )
+{
+  Size i;
+
+  for( i = 0; i < __input.deviceCount; ++i ) {
+    close( __input.devices[i] );
+  }
+}
+
+
+static u64 _has_evbits( Size fd, unsigned int type )
+{
+  u64 kbb;
+
+  if( ioctl( fd, EVIOCGBIT( 0, (int)sizeof(kbb) ), &kbb ) == -1 ) {
+    return 0;
+  }
+
+  return (kbb & (1 << type));
+}
+
+static Size _has_key( Size fd, unsigned int event )
+{
+  unsigned char bits[ (KEY_MAX >> 3) + 1 ];
+
+  if( ioctl( fd, EVIOCGBIT(EV_KEY, (int)sizeof(bits)), &bits ) == -1 ) {
+    return 0;
+  }
+
+  return ( (bits[event >> 3] & (1 << (event % 8))) > 0 );
+}
+
+static Size _has_rel( Size fd, unsigned int event )
+{
+  unsigned char bits[ (REL_MAX >> 3) + 1 ];
+
+  if( ioctl( fd, EVIOCGBIT(EV_REL, (int)sizeof(bits)), &bits ) == -1 ) {
+    return 0;
+  }
+
+  return ( (bits[event >> 3] & (1 << (event % 8))) > 0 );
+}
+
+static Boolean _is_mouse( Size fd )
+{
+  if( _has_evbits( fd, EV_KEY ) &&
+      _has_evbits( fd, EV_REL ) )
+  {
+    return( _has_rel( fd, REL_X ) &
+            _has_rel( fd, REL_Y ) &
+            _has_key( fd, BTN_LEFT ) &
+            _has_key( fd, BTN_RIGHT ) & 1 );
+  }
+
+  return E33_FALSE;
+}
+
+static Boolean _is_keyboard( Size fd )
+{
+  if( _has_evbits( fd, EV_KEY ) )
+  {
+    return( _has_key( fd, KEY_W ) &
+            _has_key( fd, KEY_SPACE ) &
+            _has_key( fd, KEY_LEFTSHIFT ) &
+            _has_key( fd, KEY_I ) & 1 );
+  }
+
+  return E33_FALSE;
+}
+
+static int _is_char_device( const struct dirent *f )
+{
+  struct stat fstat;
+  char path[512];
+
+  if( strncmp( f->d_name, "event", 5 ) ) {
+    return 0;
+  }
+
+  snprintf( path, 512, "%s%s", "/dev/input/", f->d_name );
+
+  if( stat( path, &fstat ) ) {
+    return 0;
+  }
+
+  return S_ISCHR( fstat.st_mode );
+}
+
-- 
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