console, textbox changes, some other shit

1 files changed, 876 insertions, 135 deletions

diff --git a/src/gui/textbox.cpp b/src/gui/textbox.cpp
index c367193..0a9745f 100644
--- a/src/gui/textbox.cpp
+++ b/src/gui/textbox.cpp
@@ -1,51 +1,363 @@
 #include "base.h"
+#include "../render/gl_2d_font.h"
 #include "../util/input.h"
 
 #include <SDL_keycode.h>
 
 const U32 TEXTBOX_TITLE_OFFSET = 15;
 
-U8 is_printable_char( U8 key ) {
-  return key >= 32 && key < 127;
+struct GUI_TEXTBOX_KEY_RESULT {
+  U8 value_changed{};
+  U8 cursor_moved{};
+};
+
+static I32 gui_textbox_line_height() {
+  GL_FONT* font = _gui.fonts.jpn12.glfnt;
+  return font
+    ? max<I32>( 1, (I32)font->char_height )
+    : 1;
 }
 
-void gui_textbox_draw_newline_str( GUI_TEXTBOX* tb, I32 x, I32 y, CLR clr, I32* endposx, I32* endposy ) {
-  char linebuf[GUI_TEXTBOX_MAX];
-  char* start = tb->value;
-  I32 tw, th;
+static U32 gui_textbox_line_start( const char* text, U32 cursor ) {
+  while( cursor > 0 && text[cursor - 1] != '\n' )
+    --cursor;
+  return cursor;
+}
 
-  for( char* c = start; !!*c; ++c ) {
-    if( *c == '\n' ) {
-      U32 len = (U32)( c - start );
-      memcpy( linebuf, start, len );
-      linebuf[len] = 0;
+static U32 gui_textbox_line_end( const char* text, U32 length, U32 cursor ) {
+  while( cursor < length && text[cursor] != '\n' )
+    ++cursor;
+  return cursor;
+}
+
+static U8 gui_textbox_has_selection( const GUI_TEXTBOX* tb ) {
+  return tb->cursorin != tb->cursorout;
+}
 
-      gui_draw_str( x, y, ALIGN_L, FNT_JPN12, clr, linebuf );
-      gui_draw_get_str_bounds( &tw, &th, FNT_JPN12, linebuf );
-      y += th + 1;
+static U32 gui_textbox_selection_start( const GUI_TEXTBOX* tb ) {
+  return min<U32>( tb->cursorin, tb->cursorout );
+}
 
-      *endposx = x + tw;
-      *endposy = y + th;
+static U32 gui_textbox_selection_end( const GUI_TEXTBOX* tb ) {
+  return max<U32>( tb->cursorin, tb->cursorout );
+}
 
-      if( *(c+1) == 0 )
-        break;
+static U8 gui_textbox_shift_down( const GUI_TEXTBOX* tb ) {
+  return tb->keys[SDLK_LSHIFT & 0xff]
+      || tb->keys[SDLK_RSHIFT & 0xff];
+}
 
-      start = ++c;
-    }
-    else if( (*c+1) == 0 ) {
-      U32 len = (U32)( c - start );
-      memcpy( linebuf, start, len );
-      linebuf[len] = 0;
+static I32 gui_textbox_range_width( const char* text, U32 start, U32 end ) {
+  GL_FONT* font = _gui.fonts.jpn12.glfnt;
+  if( !font )
+    return 0;
 
-      gui_draw_str( x, y, ALIGN_L, FNT_JPN12, clr, linebuf );
-      gui_draw_get_str_bounds( &tw, &th, FNT_JPN12, linebuf );
-      y += th + 1;
-      *endposx = x + tw;
-      *endposy = y + th;
+  F32 width = 0.f;
 
+  for( U32 idx = start; idx < end; ++idx ) {
+    U8 c = (U8)text[idx];
+    if( !c || c == '\n' )
       break;
-    }
+    width += font->glyphs[c].advance_x;
+  }
+
+  return (I32)( width + 0.5f );
+}
+
+static I32 gui_textbox_cursor_row( const char* text, U32 cursor ) {
+  I32 row = 0;
+  for( U32 idx = 0; idx < cursor; ++idx ) {
+    if( text[idx] == '\n' )
+      ++row;
+  }
+  return row;
+}
+
+static I32 gui_textbox_line_count( const char* text, U32 length ) {
+  I32 count = 1;
+  for( U32 idx = 0; idx < length; ++idx ) {
+    if( text[idx] == '\n' )
+      ++count;
+  }
+  return count;
+}
+
+static U32 gui_textbox_line_start_from_row(
+  const char* text,
+  U32 length,
+  I32 wanted_row
+) {
+  U32 start = 0;
+  for( I32 row = 0; row < wanted_row; ++row ) {
+    U32 end = gui_textbox_line_end( text, length, start );
+    if( end >= length )
+      return length;
+    start = end + 1;
+  }
+  return start;
+}
+
+static U32 gui_textbox_nearest_cursor_x(
+  const char* text,
+  U32 line_start, U32 line_end,
+  I32 wanted_x
+) {
+  GL_FONT* font = _gui.fonts.jpn12.glfnt;
+  if( !font || wanted_x <= 0 )
+    return line_start;
+
+  F32 x = 0.f;
+
+  for( U32 idx = line_start; idx < line_end; ++idx ) {
+    F32 advance = font->glyphs[(U8)text[idx]].advance_x;
+    if( (F32)wanted_x < x + advance * 0.5f )
+      return idx;
+    x += advance;
+  }
+  return line_end;
+}
+
+static void gui_textbox_update_cursor_metrics( GUI_TEXTBOX* tb ) {
+  U32 length = (U32)strlen( tb->value );
+
+  tb->cursorin = min<U32>( tb->cursorin, length );
+  tb->cursorout = min<U32>( tb->cursorout, length );
+
+  U32 line_start_in = gui_textbox_line_start( tb->value, tb->cursorin );
+  U32 line_start_out = gui_textbox_line_start( tb->value, tb->cursorout );
+
+  tb->cursorpxin = gui_textbox_range_width(
+    tb->value,
+    line_start_in,
+    tb->cursorin
+  );
+  tb->cursorpxout = gui_textbox_range_width(
+    tb->value,
+    line_start_out,
+    tb->cursorout
+  );
+
+  tb->cursorpy = gui_textbox_cursor_row(
+    tb->value,
+    tb->cursorout
+  ) * gui_textbox_line_height();
+}
+
+static void gui_textbox_set_cursor(
+  GUI_TEXTBOX* tb,
+  U32 cursor,
+  U8 extend_selection = 0,
+  U8 preserve_vertical_goal = 0
+) {
+  U32 length = (U32)strlen( tb->value );
+  tb->cursorout = min<U32>( cursor, length );
+
+  if( !extend_selection )
+    tb->cursorin = tb->cursorout;
+
+  gui_textbox_update_cursor_metrics( tb );
+
+  if( !preserve_vertical_goal )
+    tb->cursor_goal_valid = 0;
+}
+
+static U32 gui_textbox_cursor_from_point(
+  GUI_TEXTBOX* tb,
+  I32 local_x, I32 local_y
+) {
+  U32 length = (U32)strlen( tb->value );
+  I32 line_height = gui_textbox_line_height();
+  I32 line_count = gui_textbox_line_count( tb->value, length );
+  I32 row = local_y / line_height;
+  row = m_clamp<I32>( row, 0, line_count - 1 );
+  U32 line_start = gui_textbox_line_start_from_row(
+    tb->value, length, row
+  );
+  U32 line_end = gui_textbox_line_end(
+    tb->value, length, line_start
+  );
+  return gui_textbox_nearest_cursor_x(
+    tb->value,
+    line_start,
+    line_end,
+    max<I32>( 0, local_x )
+  );
+}
+
+static U8 gui_textbox_move_vertical(
+  GUI_TEXTBOX* tb,
+  I32 direction,
+  U8 extend_selection = 0
+) {
+  if( !direction )
+    return 0;
+
+  U32 length = (U32)strlen( tb->value );
+  gui_textbox_update_cursor_metrics( tb );
+
+  if( !tb->cursor_goal_valid ) {
+    tb->cursor_goal_px = tb->cursorpxout;
+    tb->cursor_goal_valid = 1;
+  }
+
+  U32 current_start = gui_textbox_line_start( tb->value, tb->cursorout );
+  U32 target_start = 0;
+  U32 target_end = 0;
+
+  if( direction < 0 ) {
+    if( current_start == 0 )
+      return 0;
+
+    target_end = current_start - 1;
+    target_start = gui_textbox_line_start( tb->value, target_end );
+  }
+  else {
+    U32 current_end = gui_textbox_line_end(
+      tb->value,
+      length,
+      tb->cursorout
+    );
+    if( current_end >= length )
+      return 0;
+
+    target_start = current_end + 1;
+    target_end = gui_textbox_line_end( tb->value, length, target_start );
+  }
+
+  U32 target = gui_textbox_nearest_cursor_x(
+    tb->value,
+    target_start,
+    target_end,
+    tb->cursor_goal_px
+  );
+  gui_textbox_set_cursor( tb, target, extend_selection, 1 );
+  return 1;
+}
+
+static U8 gui_textbox_delete_selection( GUI_TEXTBOX* tb ) {
+  if( !gui_textbox_has_selection( tb ) )
+    return 0;
+
+  U32 length = (U32)strlen( tb->value );
+  U32 start = min<U32>(
+    gui_textbox_selection_start( tb ),
+    length
+  );
+  U32 end = min<U32>(
+    gui_textbox_selection_end( tb ),
+    length
+  );
+
+  if( start >= end ) {
+    gui_textbox_set_cursor( tb, start );
+    return 0;
   }
+
+  if( tb->pre_cb )
+    tb->pre_cb( tb );
+
+  memmove(
+    tb->value + start,
+    tb->value + end,
+    length - end + 1
+  );
+
+  gui_textbox_set_cursor( tb, start );
+  return 1;
+}
+
+static U32 gui_textbox_insert_bytes(
+  GUI_TEXTBOX* tb,
+  const char* source,
+  U32 count
+) {
+  if( !tb || !source || !count || !tb->maxlen )
+    return 0;
+
+  U32 length = (U32)strlen( tb->value );
+  U32 limit = min<U32>( tb->maxlen, GUI_TEXTBOX_MAX );
+
+  U32 start = min<U32>(
+    gui_textbox_selection_start( tb ),
+    length
+  );
+  U32 end = min<U32>(
+    gui_textbox_selection_end( tb ),
+    length
+  );
+
+  U32 selected = end - start;
+  U32 remaining = length - selected;
+
+  if( limit <= 1 || remaining >= limit - 1 )
+    return 0;
+
+  U32 available = limit - 1 - remaining;
+  count = min<U32>( count, available );
+
+  if( !count )
+    return 0;
+
+  if( tb->pre_cb )
+    tb->pre_cb( tb );
+
+  memmove(
+    tb->value + start + count,
+    tb->value + end,
+    length - end + 1
+  );
+
+  memcpy(
+    tb->value + start,
+    source, count
+  );
+
+  gui_textbox_set_cursor( tb, start + count );
+  return count;
+}
+
+static U8 gui_textbox_backspace( GUI_TEXTBOX* tb ) {
+  if( gui_textbox_delete_selection( tb ) )
+    return 1;
+
+  U32 length = (U32)strlen( tb->value );
+  U32 cursor = min<U32>( tb->cursorout, length );
+  if( !cursor )
+    return 0;
+
+  if( tb->pre_cb )
+    tb->pre_cb( tb );
+
+  memmove(
+    tb->value + cursor - 1,
+    tb->value + cursor,
+    length - cursor + 1
+  );
+
+  gui_textbox_set_cursor( tb, cursor - 1 );
+  return 1;
+}
+
+static U8 gui_textbox_delete_forward( GUI_TEXTBOX* tb ) {
+  if( gui_textbox_delete_selection( tb ) )
+    return 1;
+
+  U32 length = (U32)strlen( tb->value );
+  U32 cursor = min<U32>( tb->cursorout, length );
+  if( cursor >= length )
+    return 0;
+
+  if( tb->pre_cb )
+    tb->pre_cb( tb );
+
+  memmove(
+    tb->value + cursor,
+    tb->value + cursor + 1,
+    length - cursor
+  );
+
+  gui_textbox_set_cursor( tb, cursor );
+  return 1;
 }
 
 void gui_textbox_draw_blinker( GUI_TEXTBOX* tb, I32 x, I32 y, CLR clr ) {
@@ -56,154 +368,574 @@ void gui_textbox_draw_blinker( GUI_TEXTBOX* tb, I32 x, I32 y, CLR clr ) {
     tb->blinktime = gui_time();
   }
 
-  if( tb->blink )
-    gui_draw_str( x, y, ALIGN_L, FNT_JPN12, clr, "|" );
+  if( tb->blink ) {
+    I32 caret_h = max<I32>( 1,
+      gui_textbox_line_height() - 2
+    );
+    gui_draw_frect(
+      x, y + 1,
+      1, caret_h,
+      clr
+    );
+  }
 }
 
-void gui_textbox_draw_fn( void* ptr ) {
-  GUI_TEXTBOX* tb = (GUI_TEXTBOX*)ptr;
+static I32 gui_textbox_newline_width() {
+  GL_FONT* font = _gui.fonts.jpn12.glfnt;
 
-  I32 x = gui_relx( tb );
-  I32 y = gui_rely( tb );
+  if( !font )
+    return 1;
 
-  gui_draw_str( x, y, ALIGN_L, FNT_JPN12, ui_clr.txt, tb->name );
-  y += TEXTBOX_TITLE_OFFSET;
+  return max<I32>( 1,
+    (I32)( font->glyphs[(U8)' '].advance_x + 0.5f )
+  );
+}
 
-  CLR col = gui_is_fg_window( tb )? ui_clr.border : ui_clr.border_inactive;
+static void gui_textbox_draw_selection(
+  GUI_TEXTBOX* tb,
+  I32 draw_x, I32 draw_y,
+  I32 line_height,
+  CLR color
+) {
+  if( !gui_textbox_has_selection( tb ) )
+    return;
 
-  gui_draw_frect( x, y, tb->w, tb->h, col );
-  gui_draw_frect( x+1, y+1, tb->w-2, tb->h-2, ui_clr.bg_sec );
+  U32 length = (U32)strlen( tb->value );
+  U32 selection_start = min<U32>(
+    gui_textbox_selection_start( tb ), length
+  );
+  U32 selection_end = min<U32>(
+    gui_textbox_selection_end( tb ), length
+  );
+
+  U32 line_start = gui_textbox_line_start(
+    tb->value, selection_start
+  );
+
+  I32 row = gui_textbox_cursor_row( tb->value, line_start );
+
+  I32 newline_width = gui_textbox_newline_width();
+
+  for( ;; ) {
+    U32 line_end = gui_textbox_line_end(
+      tb->value, length, line_start
+    );
+
+    U32 range_start = max<U32>(
+      selection_start, line_start
+    );
+    U32 range_end = min<U32>(
+      selection_end, line_end
+    );
+
+    I32 x0 = gui_textbox_range_width(
+      tb->value, line_start, range_start
+    );
+    I32 x1 = gui_textbox_range_width(
+      tb->value, line_start, range_end
+    );
+    I32 width = x1 - x0;
+
+    if( line_end < length && selection_end > line_end )
+      width += newline_width;
+
+    if( width > 0 ) {
+      gui_draw_frect(
+        draw_x + x0,
+        draw_y + row * line_height,
+        width, line_height, color
+      );
+    }
 
-  CLR clr = tb->active? ui_clr.txt : ui_clr.txt_inactive;
-  I32 ypos = y + 3;
-  I32 xpos = x + 2;
+    if( line_end >= length || line_end >= selection_end )
+      break;
 
-  I32 endposx, endposy;
+    line_start = line_end + 1;
+    ++row;
+  }
+}
 
-  if( tb->allow_newl ) {
-    gui_textbox_draw_newline_str( tb, xpos, ypos, clr, &endposx, &endposy );
-  } else {
-    gui_draw_str( xpos, ypos, ALIGN_L, FNT_JPN12, clr, tb->value );
+static void gui_textbox_draw_frame(
+  GUI_TEXTBOX* tb,
+  I32 x, I32 y
+) {
+  CLR border = gui_is_fg_window( tb )
+    ? ui_clr.border
+    : ui_clr.border_inactive;
+
+  gui_draw_frect( x, y, tb->w, tb->h, border );
+  gui_draw_frect(
+    x + 1, y + 1,
+    max<I32>( 0, tb->w - 2 ),
+    max<I32>( 0, tb->h - 2 ),
+    ui_clr.bg_sec
+  );
+}
 
-    I32 tw, th;
-    gui_draw_get_str_bounds( &tw, &th, FNT_JPN12, tb->value );
-    endposx = xpos + tw;
-    endposy = ypos;
+static void gui_textbox_update_scroll(
+  GUI_TEXTBOX* tb,
+  I32 content_w,
+  I32 content_h,
+  I32 line_height
+) {
+  I32 text_h = line_height;
+  I32 text_w = 0;
+
+  gui_draw_get_str_bounds(
+    &text_w, &text_h, FNT_JPN12,
+    "%s", tb->value
+  );
+
+  text_h = max<I32>( text_h,
+    tb->cursorpy + line_height
+  );
+
+  if( tb->cursorpxout < tb->scrollpx )
+    tb->scrollpx = tb->cursorpxout;
+  else if( tb->cursorpxout + 1 > tb->scrollpx + content_w )
+    tb->scrollpx = tb->cursorpxout + 1 - content_w;
+
+  I32 max_scroll_x = max<I32>( 0,
+    max<I32>( text_w, tb->cursorpxout + 1 ) - content_w
+  );
+
+  tb->scrollpx = m_clamp<I32>(
+    tb->scrollpx, 0, max_scroll_x
+  );
+
+  if( !tb->allow_newl ) {
+    tb->cursorpy = 0;
+    tb->scrollpy = 0;
+    return;
   }
 
-  gui_textbox_draw_blinker( tb, endposx, endposy, clr );
+  if( tb->cursorpy < tb->scrollpy )
+    tb->scrollpy = tb->cursorpy;
+  else if( tb->cursorpy + line_height > tb->scrollpy + content_h )
+    tb->scrollpy = tb->cursorpy + line_height - content_h;
+
+  tb->scrollpy = m_clamp<I32>(
+    tb->scrollpy,
+    0,
+    max<I32>( 0, text_h - content_h )
+  );
+}
+
+static void gui_textbox_draw_content(
+  GUI_TEXTBOX* tb,
+  I32 x, I32 y,
+  I32 line_height,
+  CLR text_color
+) {
+  I32 draw_x = x + 2 - tb->scrollpx;
+  I32 draw_y = y + 3 - tb->scrollpy;
+
+  gui_draw_push_clip(
+    x + 1, y + 1,
+    max<I32>( 0, tb->w - 2 ),
+    max<I32>( 0, tb->h - 2 )
+  );
+
+  gui_textbox_draw_selection( tb,
+    draw_x, draw_y,
+    line_height,
+    ui_clr.selection
+  );
+
+  gui_draw_str(
+    draw_x, draw_y, ALIGN_L, FNT_JPN12,
+    text_color, "%s", tb->value
+  );
+
+  gui_textbox_draw_blinker( tb,
+    draw_x + tb->cursorpxout,
+    draw_y + tb->cursorpy,
+    text_color
+  );
+
+  gui_draw_pop_clip();
+}
+
+void gui_textbox_draw_fn( void* ptr ) {
+  GUI_TEXTBOX* tb = (GUI_TEXTBOX*)ptr;
+  I32 x = gui_relx( tb );
+  I32 title_y = gui_rely( tb );
+
+  gui_draw_str(
+    x, title_y, ALIGN_L,
+    FNT_JPN12, ui_clr.txt,
+    "%s", tb->name
+  );
+
+  I32 y = title_y + TEXTBOX_TITLE_OFFSET;
+  I32 line_height = gui_textbox_line_height();
+
+  gui_textbox_draw_frame( tb, x, y );
+  gui_textbox_update_cursor_metrics( tb );
+  gui_textbox_update_scroll( tb,
+    max<I32>( 1, tb->w - 4 ),
+    max<I32>( 1, tb->h - 4 ),
+    line_height
+  );
+
+  CLR text_color = tb->active
+    ? ui_clr.txt
+    : ui_clr.txt_inactive;
+
+  gui_textbox_draw_content( tb, x, y, line_height, text_color );
 }
 
 void gui_textbox_handle_mouse( GUI_TEXTBOX* tb ) {
   I32 x = gui_relx( tb );
   I32 y = gui_rely( tb ) + TEXTBOX_TITLE_OFFSET;
-  I32 w = tb->w;
-  I32 h = tb->h;
 
-  U8 m1 = gui_mbutton_down( 0 );
-  I32 mx, my;
+  U8 m1 = gui_mbutton_down( GUI_MBTNLEFT );
+  I32 mx = 0;
+  I32 my = 0;
   gui_cursor_pos( &mx, &my );
 
-  U8 inbounds = mx >= x && mx <= x + w && my >= y && my <= y + h;
+  U8 inbounds = mx >= x
+             && mx < x + tb->w
+             && my >= y
+             && my < y + tb->h;
 
-  if( m1 ) {
-    if( inbounds )
-      tb->m1held = 1;
-    else
-     tb->active = 0;
-  } else {
-    if( inbounds && tb->m1held ) {
-      tb->active = 1;
-      tb->blink = 1;
-      tb->blinktime = gui_time();
-    }
+  if( !m1 ) {
     tb->m1held = 0;
+    return;
+  }
+
+  if( !tb->m1held ) {
+    if( !inbounds ) {
+      tb->m1held = 2;
+      tb->active = 0;
+      return;
+    }
+
+    I32 local_x = mx - ( x + 2 ) + tb->scrollpx;
+    I32 local_y = my - ( y + 3 ) + tb->scrollpy;
+
+    U32 cursor = gui_textbox_cursor_from_point(
+      tb, local_x, local_y
+    );
+
+    gui_textbox_set_cursor( tb, cursor );
+    tb->m1held = 1;
+    tb->active = 1;
+  }
+  else if( tb->m1held == 1 ) {
+    I32 local_x = mx - ( x + 2 ) + tb->scrollpx;
+    I32 local_y = my - ( y + 3 ) + tb->scrollpy;
+
+    U32 cursor = gui_textbox_cursor_from_point(
+      tb, local_x, local_y
+    );
+
+    gui_textbox_set_cursor( tb, cursor, 1 );
+  }
+
+  if( tb->m1held == 1 ) {
+    tb->blink = 1;
+    tb->blinktime = gui_time();
+  }
+}
+
+static U8 gui_textbox_move_horizontal_key(
+  GUI_TEXTBOX* tb,
+  I32 direction,
+  U8 extend_selection
+) {
+  if( !extend_selection && gui_textbox_has_selection( tb ) ) {
+    U32 target = direction < 0
+      ? gui_textbox_selection_start( tb )
+      : gui_textbox_selection_end( tb );
+    gui_textbox_set_cursor( tb, target );
+    return 1;
+  }
+
+  U32 length = (U32)strlen( tb->value );
+
+  if( direction < 0 && tb->cursorout > 0 ) {
+    gui_textbox_set_cursor( tb,
+      tb->cursorout - 1,
+      extend_selection
+    );
+    return 1;
+  }
+
+  if( direction > 0 && tb->cursorout < length ) {
+    gui_textbox_set_cursor( tb,
+      tb->cursorout + 1,
+      extend_selection
+    );
+    return 1;
+  }
+  return 0;
+}
+
+static U8 gui_textbox_move_vertical_key(
+  GUI_TEXTBOX* tb,
+  I32 direction,
+  U8 extend_selection
+) {
+  U8 had_selection = gui_textbox_has_selection( tb );
+  U8 moved = gui_textbox_move_vertical( tb,
+    direction,
+    extend_selection
+  );
+
+  if( !extend_selection && had_selection && !moved ) {
+    gui_textbox_set_cursor( tb, tb->cursorout );
+    return 1;
+  }
+  return moved;
+}
+
+static U8 gui_textbox_move_line_edge(
+  GUI_TEXTBOX* tb,
+  U8 move_to_end,
+  U8 extend_selection
+) {
+  U32 length = (U32)strlen( tb->value );
+  U32 target = move_to_end
+    ? gui_textbox_line_end( tb->value, length, tb->cursorout )
+    : gui_textbox_line_start( tb->value, tb->cursorout );
+  U8 moved = target != tb->cursorout
+          || ( !extend_selection
+            && gui_textbox_has_selection( tb )
+          );
+  gui_textbox_set_cursor( tb,
+    target, extend_selection
+  );
+  return moved;
+}
+
+static U8 gui_textbox_apply_edit_key(
+  GUI_TEXTBOX* tb,
+  U32 key,
+  GUI_TEXTBOX_KEY_RESULT* result
+) {
+  constexpr U32 kp_enter = SDLK_KP_ENTER & 0xff;
+  constexpr U32 del = SDLK_DELETE & 0xff;
+
+  if( key == '\b' ) {
+    result->value_changed = gui_textbox_backspace( tb );
+    result->cursor_moved = result->value_changed;
+    return 1;
   }
+
+  if( key == del ) {
+    result->value_changed = gui_textbox_delete_forward( tb );
+    return 1;
+  }
+
+  if( key == '\r' || key == kp_enter ) {
+    if( tb->allow_newl ) {
+      result->value_changed = gui_textbox_insert_bytes( tb, "\n", 1 ) == 1;
+      result->cursor_moved = result->value_changed;
+    }
+    else
+      tb->active = 0;
+    return 1;
+  }
+
+  if( key == '\x1b' ) {
+    tb->active = 0;
+    return 1;
+  }
+  return 0;
+}
+
+static U8 gui_textbox_apply_move_key(
+  GUI_TEXTBOX* tb,
+  U32 key,
+  U8 extend_selection,
+  GUI_TEXTBOX_KEY_RESULT* result
+) {
+  constexpr U32 right = SDLK_RIGHT & 0xff;
+  constexpr U32 down = SDLK_DOWN & 0xff;
+  constexpr U32 home = SDLK_HOME & 0xff;
+  constexpr U32 left = SDLK_LEFT & 0xff;
+  constexpr U32 end = SDLK_END & 0xff;
+  constexpr U32 up = SDLK_UP & 0xff;
+
+  if( key == left || key == right ) {
+    result->cursor_moved = gui_textbox_move_horizontal_key(
+      tb,
+      key == left ? -1 : 1,
+      extend_selection
+    );
+    return 1;
+  }
+
+  if( key == up || key == down ) {
+    if( !tb->allow_newl )
+      return 0;
+    result->cursor_moved = gui_textbox_move_vertical_key(
+      tb,
+      key == up ? -1 : 1,
+      extend_selection
+    );
+    return 1;
+  }
+
+  if( key == home || key == end ) {
+    result->cursor_moved = gui_textbox_move_line_edge(
+      tb,
+      key == end,
+      extend_selection
+    );
+    return 1;
+  }
+  return 0;
+}
+
+static void gui_textbox_apply_key_result(
+  GUI_TEXTBOX* tb,
+  const GUI_TEXTBOX_KEY_RESULT& result,
+  F32 now
+) {
+  if( result.value_changed && tb->cb )
+    tb->cb( tb );
+
+  if( result.value_changed || result.cursor_moved ) {
+    tb->blink = 1;
+    tb->blinktime = now;
+  }
+}
+
+static U8 gui_textbox_key_repeatable(
+  const GUI_TEXTBOX* tb,
+  U32 key
+) {
+  constexpr U32 right = SDLK_RIGHT & 0xff;
+  constexpr U32 down = SDLK_DOWN & 0xff;
+  constexpr U32 left = SDLK_LEFT & 0xff;
+  constexpr U32 del = SDLK_DELETE & 0xff;
+  constexpr U32 up = SDLK_UP & 0xff;
+
+  return key == '\b'
+      || key == del
+      || key == left
+      || key == right
+      || ( tb->allow_newl && ( key == up || key == down ) );
 }
 
 void gui_textbox_loop_keys( GUI_TEXTBOX* tb ) {
-  U32 len = strlen( tb->value );
-
-  for( U32 i = 0; i < 0xff; ++i ) {
-    U8 key  = tb->keys[i];
-    U8 prev = tb->prevkeys[i];
-
-    if( !key && prev && i == tb->heldkey )
-      tb->heldkey = 0;
-    else if( key && !prev ) {
-      if( is_printable_char( i ) && len < tb->maxlen - 1 ) {
-        if( tb->keys[SDLK_LSHIFT & 0xff] || tb->keys[SDLK_RSHIFT & 0xff] )
-          tb->value[len] = (char)i + ('a' - 'A');
-        else
-          tb->value[len] = (char)i;
-        tb->value[++len] = 0;
-      }
-      else if( i == '\b' ) {
-        if( len > 0 ) {
-          tb->value[--len] = 0;
-        }
-      }
-      else if( i == '\r' ) {
-        if( tb->allow_newl ) {
-          tb->value[len] = '\n';
-          tb->value[++len] = 0;
-        }
-        else {
-          tb->active = 0;
-        }
-      } else {
-        if( i == '\x1b' )
-          tb->active = 0;
-        if( tb->cb )
-          tb->cb( tb );
-        continue;
-      }
-
-      tb->heldkey = i;
-      tb->heldtime = gui_time();
-      if( tb->cb )
-        tb->cb( tb );
+  U32 length = strlen( tb->value );
+  tb->cursorin = min<U32>( tb->cursorin, length );
+  tb->cursorout = min<U32>( tb->cursorout, length );
+  U8 extend_selection = gui_textbox_shift_down( tb );
+
+  for( U32 idx = 0; idx < 0x100; ++idx ) {
+    U8 prev = tb->prevkeys[idx];
+    U8 key = tb->keys[idx];
+
+    if( !key ) {
+      if( prev && idx == tb->heldkey )
+        tb->heldkey = 0;
+      continue;
+    }
+
+    if( prev )
+      continue;
+
+    GUI_TEXTBOX_KEY_RESULT result{};
+    U8 handled = gui_textbox_apply_edit_key(
+      tb,
+      idx,
+      &result
+    );
+    if( !handled ) {
+      handled = gui_textbox_apply_move_key(
+        tb, idx,
+        extend_selection,
+        &result
+      );
     }
+    if( !handled )
+      continue;
+
+    F32 now = gui_time();
+    gui_textbox_apply_key_result( tb, result, now );
+
+    tb->heldtime = now;
+    tb->repeattime = now;
+    tb->heldkey = (U8)idx;
   }
 }
 
 void gui_textbox_handle_repeat( GUI_TEXTBOX* tb ) {
-  if( !tb->heldkey )
+  if( !gui_textbox_key_repeatable( tb, tb->heldkey ) )
     return;
 
-  F32 delta = gui_time() - tb->heldtime;
-  if( delta <= 0.75f )
+  F32 now = gui_time();
+  if( now - tb->heldtime <= 0.75f
+   || now - tb->repeattime <= 0.05f )
     return;
 
-  if( gui_time() - tb->repeattime > 0.05f ) {
-    U32 len = strlen( tb->value );
-    if( is_printable_char( tb->heldkey ) && len < (tb->maxlen - 1) ) {
-      if( tb->pre_cb ) tb->pre_cb( tb );
+  GUI_TEXTBOX_KEY_RESULT result{};
+  U8 extend_selection = gui_textbox_shift_down( tb );
+  U8 handled = gui_textbox_apply_edit_key(
+    tb,
+    tb->heldkey,
+    &result
+  );
+  if( !handled ) {
+    handled = gui_textbox_apply_move_key(
+      tb, tb->heldkey,
+      extend_selection,
+      &result
+    );
+  }
 
-      if( tb->keys[SDLK_LSHIFT & 0xff] || tb->keys[SDLK_RSHIFT & 0xff] )
-        tb->value[len] = tb->heldkey + ('a' - 'A');
-      else
-        tb->value[len] = tb->heldkey;
-      tb->value[++len] = 0;
+  if( handled )
+    gui_textbox_apply_key_result( tb, result, now );
 
-      if( tb->cb ) tb->cb( tb );
-    }
-    else if( tb->heldkey == '\b' && len > 0 ) {
-      if( tb->pre_cb ) tb->pre_cb( tb );
-      tb->value[--len] = 0;
-      if( tb->cb ) tb->cb( tb );
+  tb->repeattime = now;
+}
+
+void gui_textbox_append_input_text( GUI_TEXTBOX* tb ) {
+  if( !tb->active || !input.textlen || !tb->maxlen )
+    return;
+
+  if( !tb->allow_newl ) {
+    U32 filtered = 0;
+    for( U32 idx = 0; idx < input.textlen; ++idx ) {
+      char c =  input.text[idx];
+
+      if( c != '\n' && c != '\r' )
+        input.text[filtered++] = c;
     }
+    input.textlen = filtered;
+    input.text[filtered] = 0;
+  }
 
-    tb->repeattime = gui_time();
+  U32 inserted = gui_textbox_insert_bytes(
+    tb,
+    input.text,
+    input.textlen
+  );
+
+  if( inserted ) {
+    tb->blink = 1;
+    tb->blinktime = gui_time();
+
+    if( tb->cb )
+      tb->cb( tb );
   }
+
+  input.textlen = 0;
+  input.text[0] = 0;
 }
 
 void gui_textbox_handle_keyboard( GUI_TEXTBOX* tb ) {
   if( !tb->active )
     return;
 
-  memcpy( tb->prevkeys, tb->keys, 0xff );
-  memcpy( tb->keys, input.keys, 0xff );
+  gui_textbox_append_input_text( tb );
+
+  memcpy( tb->prevkeys, tb->keys, 0x100 );
+  memcpy( tb->keys, input.keys, 0x100 );
 
   gui_textbox_loop_keys( tb );
   gui_textbox_handle_repeat( tb );
@@ -217,7 +949,7 @@ void gui_textbox_input_fn( void* ptr ) {
 }
 
 GUI_TEXTBOX* gui_textbox( I32 x, I32 y, I32 w, I32 h, const char* title, U32 maxlen, U8 allow_newl ) {
-  GUI_TEXTBOX* tb = new GUI_TEXTBOX;
+  GUI_TEXTBOX* tb = new GUI_TEXTBOX{};
 
   tb->x = x;
   tb->y = y;
@@ -234,13 +966,22 @@ GUI_TEXTBOX* gui_textbox( I32 x, I32 y, I32 w, I32 h, const char* title, U32 max
   tb->active = 0;
   tb->m1held = 0;
   tb->heldkey = 0;
+  tb->cursorpy = 0;
   tb->heldtime = 0;
   tb->repeattime = 0;
   tb->maxlen = maxlen;
+  tb->cursor_goal_px = 0;
+  tb->cursor_goal_valid = 0;
   tb->allow_newl = allow_newl;
+  tb->scrollpx = tb->scrollpy = 0;
+  tb->cursorin = tb->cursorout = 0;
+  tb->cursorpxin = tb->cursorpxout = 0;
   memset( tb->value, 0, GUI_TEXTBOX_MAX );
-  memset( tb->keys, 0, 0xff );
-  memset( tb->prevkeys, 0, 0xff );
+  memset( tb->keys, 0, 0x100 );
+  memset( tb->prevkeys, 0, 0x100 );
+
+  tb->blink = 1;
+  tb->blinktime = gui_time();
 
   gui_get_view()->children.push( tb );