diff --git a/Makefile b/Makefile
index 015b086..46e6b6d 100644
--- a/Makefile
+++ b/Makefile
@@ -11,7 +11,13 @@ geometry/%.hpp: geometry/%.obj
 	PYTHONPATH=regs/gen python tools/obj_to_cpp.py $< > $@.tmp
 	mv $@.tmp $@
 
+build-fonts:
+	./tools/ttf_outline 20 7f 20 0 little /usr/share/fonts/dejavu/DejaVuSans.ttf dejavusansmono.data
+	./tools/ttf_outline 20 7f 20 1 little /usr/share/fonts/dejavu/DejaVuSans.ttf dejavusansmono_mono.data
+	./tools/ttf_outline 20 7f 20 1 little /usr/share/fonts/terminus/ter-u20n.otb ter_u20n.data
+
 include example/example.mk
+include text_editor/text_editor.mk
 include pokemon/pokemon.mk
 
 .PHONY: phony
diff --git a/dejavusansmono.data b/dejavusansmono.data
index d25d936..d644ae6 100644
Binary files a/dejavusansmono.data and b/dejavusansmono.data differ
diff --git a/dejavusansmono_mono.data b/dejavusansmono_mono.data
index 9dea48d..987a7f9 100644
Binary files a/dejavusansmono_mono.data and b/dejavusansmono_mono.data differ
diff --git a/example/example.mk b/example/example.mk
index 61b9cff..9877d0b 100644
--- a/example/example.mk
+++ b/example/example.mk
@@ -481,3 +481,15 @@ LFSR_OBJ = \
 
 example/lfsr.elf: LDSCRIPT = $(LIB)/main.lds
 example/lfsr.elf: $(START_OBJ) $(LFSR_OBJ)
+
+TA_TRANSFER_PROFILE_OBJ = \
+	example/ta_transfer_profile.o \
+	holly/core.o \
+	holly/region_array.o \
+	holly/background.o \
+	holly/ta_fifo_polygon_converter.o \
+	holly/video_output.o \
+	sh7091/serial.o
+
+example/ta_transfer_profile.elf: LDSCRIPT = $(LIB)/main.lds
+example/ta_transfer_profile.elf: $(START_OBJ) $(TA_TRANSFER_PROFILE_OBJ)
diff --git a/font/font.hpp b/font/font.hpp
index 3f13133..4b18a14 100644
--- a/font/font.hpp
+++ b/font/font.hpp
@@ -30,14 +30,14 @@ static_assert((sizeof (glyph)) == ((sizeof (glyph_bitmap)) + (sizeof (glyph_metr
 
 struct font {
   uint32_t first_char_code;
+  uint32_t last_char_code;
+  int32_t glyph_height; // 26.6 fixed point
   uint16_t glyph_count;
-  uint16_t glyph_height;
   uint16_t texture_stride;
   uint16_t texture_width;
   uint16_t texture_height;
-  uint16_t _pad;
   uint32_t texture_size;
   uint32_t max_z_curve_ix;
 } __attribute__ ((packed));
 
-static_assert((sizeof (font)) == ((sizeof (uint32_t)) * 6));
+static_assert((sizeof (font)) == ((sizeof (uint32_t)) * 7));
diff --git a/ter_u20n.data b/ter_u20n.data
new file mode 100644
index 0000000..0e69572
Binary files /dev/null and b/ter_u20n.data differ
diff --git a/ter_u20n.hpp b/ter_u20n.hpp
new file mode 100644
index 0000000..151c6b9
--- /dev/null
+++ b/ter_u20n.hpp
@@ -0,0 +1,5 @@
+#include <cstdint>
+
+extern uint32_t _binary_ter_u20n_data_start __asm("_binary_ter_u20n_data_start");
+extern uint32_t _binary_ter_u20n_data_end __asm("_binary_ter_u20n_data_end");
+extern uint32_t _binary_ter_u20n_data_size __asm("_binary_ter_u20n_data_size");
diff --git a/text_editor/gap_buffer.cpp b/text_editor/gap_buffer.cpp
new file mode 100644
index 0000000..1994c5f
--- /dev/null
+++ b/text_editor/gap_buffer.cpp
@@ -0,0 +1,116 @@
+#include "gap_buffer.hpp"
+
+#include "sh7091/serial.hpp"
+/*
+           2   3     4   5   6   7
+       s   e
+  [a] [ ] [b] [q] | [ ] [ ] [ ] [ ]
+               i                 ^
+ */
+
+void line_init_from_buf(struct gap_buffer& gb,
+			int32_t * offsets,
+			int32_t size)
+{
+  gb.line.offsets = offsets;
+  gb.line.size = size;
+  gb.line.length = 0;
+
+  for (int32_t i = 0; i < gb.gap_start; i++) {
+    serial::integer<uint32_t>(i);
+    if (gb.buf[i] == '\n') {
+      gb.line.offsets[gb.line.length++] = i;
+    }
+  }
+
+  gb.line.gap = gb.line.length;
+
+  serial::string("gbgapend\n");
+  for (int32_t i = gb.gap_end; i < gb.size; i++) {
+    serial::integer<uint32_t>(i);
+    if (gb.buf[i] == '\n') {
+      gb.line.offsets[gb.line.length++] = i;
+    }
+  }
+}
+
+void gap_init_from_buf(struct gap_buffer& gb,
+		       char_type * buf,
+		       int32_t size,
+		       int32_t length)
+{
+  gb.buf = buf;
+  gb.size = size;
+
+  gb.gap_start = length;
+  gb.gap_end = size;
+}
+
+/*
+void gap_resize(struct gap_buffer& gb)
+{
+  for (int32_t i = (gb.size - 1); i >= gb.gap_end; i--) {
+    gb.buf[i + gb.size] = gb.buf[i];
+  }
+  gb.gap_end += gb.size;
+  gb.size += gb.size;
+}
+*/
+
+void gap_append(struct gap_buffer& gb, char_type c)
+{
+  if (gb.gap_start == gb.gap_end) {
+    return;
+    //gap_resize(gb);
+  }
+
+  if (c == '\n') {
+    for (int32_t i = gb.line.length - 1; i >= gb.line.gap; i--) {
+      gb.line.offsets[i + 1] = gb.line.offsets[i];
+    }
+    gb.line.offsets[gb.line.gap++] = gb.gap_start;
+    gb.line.length += 1;
+  }
+  gb.buf[gb.gap_start++] = c;
+}
+
+void gap_pop(struct gap_buffer& gb)
+{
+  gb.gap_start--;
+}
+
+/*
+   0   1   2   3   4   5   6   7
+  [a] [b] [ ] [ ] [ ] [ ] [q] [r]
+           ^              e
+ */
+
+/*
+ */
+
+void gap_cursor_pos(struct gap_buffer& gb, int32_t delta)
+{
+  if (delta > 0) {
+    if (gb.gap_end + delta >= gb.size) {
+      delta = gb.size - gb.gap_end;
+    }
+    for (int32_t i = 0; i < delta; i++) {
+      char_type c = gb.buf[gb.gap_end++];
+      if (c == '\n') {
+	gb.line.offsets[gb.line.gap++] = gb.gap_start;
+      }
+      gb.buf[gb.gap_start++] = c;
+    }
+  } else {
+    if (gb.gap_start + delta < 0) {
+      delta = -gb.gap_start;
+    }
+    for (int32_t i = delta; i < 0; i++) {
+      char_type c = gb.buf[--gb.gap_start];
+      gb.buf[--gb.gap_end] = c;
+      if (c == '\n') {
+	gb.line.offsets[--gb.line.gap] = gb.gap_end;
+      }
+    }
+  }
+}
diff --git a/text_editor/gap_buffer.hpp b/text_editor/gap_buffer.hpp
new file mode 100644
index 0000000..5211ee8
--- /dev/null
+++ b/text_editor/gap_buffer.hpp
@@ -0,0 +1,34 @@
+#pragma once
+
+#include <stdint.h>
+
+typedef uint8_t char_type;
+
+struct line_metadata {
+  int32_t * offsets;
+  int32_t size;
+  int32_t length;
+  int32_t gap;
+};
+
+struct gap_buffer {
+  char_type * buf;
+  int32_t size;
+  int32_t gap_start;
+  int32_t gap_end;
+  struct line_metadata line;
+};
+
+void line_init_from_buf(struct gap_buffer& gb,
+			int32_t * offsets,
+			int32_t size);
+
+void gap_init_from_buf(struct gap_buffer& gb,
+		       char_type * buf,
+		       int32_t size,
+		       int32_t length);
+
+void gap_resize(struct gap_buffer& gb);
+void gap_append(struct gap_buffer& gb, char_type c);
+void gap_pop(struct gap_buffer& gb);
+void gap_cursor_pos(struct gap_buffer& gb, int32_t delta);
diff --git a/text_editor/text_editor.cpp b/text_editor/text_editor.cpp
new file mode 100644
index 0000000..4adeee1
--- /dev/null
+++ b/text_editor/text_editor.cpp
@@ -0,0 +1,430 @@
+#include <cstdint>
+#include <bit>
+
+#include "align.hpp"
+#include "holly/video_output.hpp"
+
+#include "holly/texture_memory_alloc.hpp"
+#include "holly/holly.hpp"
+#include "holly/core.hpp"
+#include "holly/core_bits.hpp"
+#include "holly/ta_fifo_polygon_converter.hpp"
+#include "holly/ta_parameter.hpp"
+#include "holly/ta_global_parameter.hpp"
+#include "holly/ta_vertex_parameter.hpp"
+#include "holly/ta_bits.hpp"
+#include "holly/isp_tsp.hpp"
+#include "memorymap.hpp"
+#include "holly/background.hpp"
+#include "holly/region_array.hpp"
+#include "twiddle.hpp"
+#include "palette.hpp"
+
+#include "sh7091/serial.hpp"
+
+#include "maple/maple.hpp"
+#include "maple/maple_impl.hpp"
+#include "maple/maple_bus_bits.hpp"
+#include "maple/maple_bus_commands.hpp"
+#include "maple/maple_bus_ft0.hpp"
+
+#include "font/font.hpp"
+#include "ter_u20n.hpp"
+
+#include "gap_buffer.hpp"
+
+struct vertex {
+  float x;
+  float y;
+  float u;
+  float v;
+};
+
+const struct vertex strip_vertices[4] = {
+  // [ position ]  [ uv coordinates ]
+  {  0.f,  0.f,    0.f, 0.f, },
+  {  1.f,  0.f,    1.f, 0.f, },
+  {  1.f,  1.f,    1.f, 1.f, },
+  {  0.f,  1.f,    0.f, 1.f, },
+};
+constexpr uint32_t strip_length = (sizeof (strip_vertices)) / (sizeof (struct vertex));
+
+constexpr inline float float_26_6(int32_t n)
+{
+  float v = n >> 6;
+//float d = n & 63;
+//return v + (d / 64.f);
+  return v;
+}
+
+void transform(ta_parameter_writer& parameter,
+	       const uint32_t texture_width, uint32_t texture_height,
+	       const glyph& glyph,
+	       const float origin_x,
+	       const float origin_y)
+{
+  const uint32_t parameter_control_word = para_control::para_type::sprite
+					| para_control::list_type::opaque
+					| obj_control::col_type::packed_color
+					| obj_control::texture
+					| obj_control::_16bit_uv;
+
+  const uint32_t isp_tsp_instruction_word = isp_tsp_instruction_word::depth_compare_mode::greater
+					  | isp_tsp_instruction_word::culling_mode::no_culling;
+
+  const uint32_t tsp_instruction_word = tsp_instruction_word::src_alpha_instr::src_alpha
+				      | tsp_instruction_word::dst_alpha_instr::one
+				      | tsp_instruction_word::fog_control::no_fog
+				      | tsp_instruction_word::use_alpha
+				      | tsp_instruction_word::texture_u_size::from_int(texture_width)
+				      | tsp_instruction_word::texture_v_size::from_int(texture_height);
+
+  const uint32_t texture_address = texture_memory_alloc::texture.start;
+  const uint32_t texture_control_word = texture_control_word::pixel_format::_4bpp_palette
+				      | texture_control_word::scan_order::twiddled
+				      | texture_control_word::texture_address(texture_address / 8);
+
+  parameter.append<ta_global_parameter::polygon_type_0>() =
+    ta_global_parameter::polygon_type_0(parameter_control_word,
+					isp_tsp_instruction_word,
+					tsp_instruction_word,
+					texture_control_word,
+					0, // data_size_for_sort_dma
+					0  // next_address_for_sort_dma
+					);
+
+  struct vertex out[strip_length];
+  for (uint32_t i = 0; i < strip_length; i++) {
+    float x = strip_vertices[i].x;
+    float y = strip_vertices[i].y;
+
+    x *= glyph.bitmap.width;
+    y *= glyph.bitmap.height;
+    x += origin_x + float_26_6(glyph.metrics.horiBearingX);
+    y += origin_y - float_26_6(glyph.metrics.horiBearingY);
+
+    float u = strip_vertices[i].u;
+    float v = strip_vertices[i].v;
+    u *= glyph.bitmap.width;
+    v *= glyph.bitmap.height;
+    u += glyph.bitmap.x;
+    v += glyph.bitmap.y;
+    u = u / static_cast<float>(texture_width);
+    v = v / static_cast<float>(texture_height);
+
+    out[i].x = x;
+    out[i].y = y;
+    out[i].u = u;
+    out[i].v = v;
+  }
+
+  const float z = 0.1f;
+  parameter.append<ta_vertex_parameter::sprite_type_1>() =
+    ta_vertex_parameter::sprite_type_1(para_control::para_type::vertex_parameter,
+				       out[0].x,
+				       out[0].y,
+				       z,
+				       out[1].x,
+				       out[1].y,
+				       z,
+				       out[2].x,
+				       out[2].y,
+				       z,
+				       out[3].x,
+				       out[3].y,
+				       uv_16bit(out[0].u, out[0].v),
+				       uv_16bit(out[1].u, out[1].v),
+				       uv_16bit(out[2].u, out[2].v)
+				       );
+}
+
+void init_texture_memory(const struct opb_size& opb_size)
+{
+  region_array2(640 / 32, // width
+                480 / 32, // height
+                opb_size
+                );
+  background_parameter(0xff0000ff);
+}
+
+void inflate_font(const uint32_t * src,
+                  const uint32_t stride,
+                  const uint32_t curve_end_ix)
+{
+  auto texture = reinterpret_cast<volatile uint16_t *>(&texture_memory64[texture_memory_alloc::texture.start / 4]);
+
+  twiddle::texture3<4, 1>(texture, reinterpret_cast<const uint8_t *>(src),
+                          stride,
+                          curve_end_ix);
+}
+
+uint32_t _command_buf[(1024 + 32) / 4];
+uint32_t _receive_buf[(1024 + 32) / 4];
+
+struct button_state {
+  bool ra;
+  bool la;
+  bool da;
+  bool ua;
+  bool a;
+  bool b;
+  bool x;
+  bool y;
+  bool start;
+
+  void reset()
+  {
+    ra = la = da = ua = 0;
+    a = b = x = y = 0;
+    start = 0;
+  }
+};
+
+void do_get_condition(uint32_t * command_buf,
+		      uint32_t * receive_buf,
+		      button_state& buttons)
+{
+  using command_type = get_condition;
+  using response_type = data_transfer<ft0::data_transfer::data_format>;
+
+  get_condition::data_fields data_fields = {
+    .function_type = std::byteswap(function_type::controller)
+  };
+
+  const uint32_t command_size = maple::init_host_command_all_ports<command_type, response_type>(command_buf, receive_buf,
+                                                                                        data_fields);
+  using host_response_type = struct maple::command_response<response_type::data_fields>;
+  auto host_response = reinterpret_cast<host_response_type *>(receive_buf);
+
+  maple::dma_start(command_buf, command_size,
+                   receive_buf, maple::sizeof_command(host_response));
+
+  buttons.reset();
+
+  for (uint8_t port = 0; port < 4; port++) {
+    auto& bus_data = host_response[port].bus_data;
+    if (bus_data.command_code != response_type::command_code) {
+      return;
+    }
+    auto& data_fields = bus_data.data_fields;
+    if ((data_fields.function_type & std::byteswap(function_type::controller)) == 0) {
+      return;
+    }
+
+    buttons.ra |= ft0::data_transfer::digital_button::ra(data_fields.data.digital_button) == 0;
+    buttons.la |= ft0::data_transfer::digital_button::la(data_fields.data.digital_button) == 0;
+    buttons.da |= ft0::data_transfer::digital_button::da(data_fields.data.digital_button) == 0;
+    buttons.ua |= ft0::data_transfer::digital_button::ua(data_fields.data.digital_button) == 0;
+
+    buttons.a |= ft0::data_transfer::digital_button::a(data_fields.data.digital_button) == 0;
+    buttons.b |= ft0::data_transfer::digital_button::b(data_fields.data.digital_button) == 0;
+    buttons.x |= ft0::data_transfer::digital_button::x(data_fields.data.digital_button) == 0;
+    buttons.y |= ft0::data_transfer::digital_button::y(data_fields.data.digital_button) == 0;
+
+    buttons.start |= ft0::data_transfer::digital_button::start(data_fields.data.digital_button) == 0;
+  }
+}
+
+uint32_t _ta_parameter_buf[((32 * 10 * 17) + 32) / 4];
+
+struct editor_state {
+  struct gap_buffer gb;
+};
+
+void render_gap_buffer(ta_parameter_writer& parameter,
+		       const struct font * font,
+		       const struct glyph * glyphs,
+		       struct gap_buffer& gb)
+{
+  int32_t advance = 0;
+  int32_t cursor = 0;
+  for (int32_t i = 0; i < gb.size; i++) {
+    char_type c;
+
+    if (i < gb.gap_start || i >= gb.gap_end) {
+      c = gb.buf[i];
+    } else {
+      c = '_';
+    }
+    if (i == gb.gap_start)
+      cursor = advance;
+
+    uint32_t ix;
+    if (c >= font->first_char_code && c <= font->last_char_code) {
+      ix = c - font->first_char_code;
+    } else {
+      ix = '#' - font->first_char_code;
+    }
+    auto& glyph = glyphs[ix];
+
+    transform(parameter,
+	      font->texture_width,
+	      font->texture_height,
+	      glyph,
+	      50.f + float_26_6(advance), // x
+	      100.f  // y
+	      );
+
+    advance += glyph.metrics.horiAdvance;
+  }
+
+  for (int32_t i = 0; i < gb.line.length; i++) {
+    int32_t j = gb.line.offsets[i];
+
+    auto& glyph = glyphs['X' - font->first_char_code];
+    transform(parameter,
+	      font->texture_width,
+	      font->texture_height,
+	      glyph,
+	      50.f + 10.f * j, // x
+	      100.f - float_26_6(font->glyph_height) // y
+	      );
+  }
+
+  auto& glyph = glyphs['^' - font->first_char_code];
+  transform(parameter,
+	    font->texture_width, font->texture_height,
+	    glyph,
+	    50.f + float_26_6(cursor), // x
+	    100.f + float_26_6(font->glyph_height) // y
+	    );
+
+  {
+    auto& glyph = glyphs['`' - font->first_char_code];
+    int32_t j;
+    if (gb.line.gap < gb.line.length) {
+      j = gb.line.offsets[gb.line.gap];
+    } else {
+      j = gb.size;
+    }
+    transform(parameter,
+	      font->texture_width, font->texture_height,
+	      glyph,
+	      50.f + 10.f * j, // x
+	      100.f + float_26_6(font->glyph_height) * 2 // y
+	      );
+  }
+
+  int32_t h_advance = 0;
+  int32_t v_advance = 0;
+  for (int32_t i = 0; i < gb.size; i++) {
+    char_type c;
+
+    if (i < gb.gap_start || i >= gb.gap_end) {
+      c = gb.buf[i];
+    } else {
+      continue;
+    }
+
+    uint32_t ix;
+    if (c >= font->first_char_code && c <= font->last_char_code) {
+      ix = c - font->first_char_code;
+    } else {
+      ix = '#' - font->first_char_code;
+    }
+    auto& glyph = glyphs[ix];
+
+    transform(parameter,
+	      font->texture_width,
+	      font->texture_height,
+	      glyph,
+	      350.f + float_26_6(h_advance), // x
+	      100.f + float_26_6(v_advance) // y
+	      );
+
+    if (c == '\n') {
+      h_advance = 0;
+      v_advance += font->glyph_height;
+    } else {
+      h_advance += glyph.metrics.horiAdvance;
+    }
+  }
+}
+
+void update_state(button_state& prev, button_state& next, editor_state& state)
+{
+  if ((next.la == true) && (next.la != prev.la)) {
+    gap_cursor_pos(state.gb, -1);
+  }
+  if ((next.ra == true) && (next.ra != prev.ra)) {
+    gap_cursor_pos(state.gb, +1);
+  }
+}
+
+void main()
+{
+  video_output::set_mode_vga();
+
+  auto font = reinterpret_cast<const struct font *>(&_binary_ter_u20n_data_start);
+  auto glyphs = reinterpret_cast<const struct glyph *>(&font[1]);
+  auto texture = reinterpret_cast<const uint32_t *>(&glyphs[font->glyph_count]);
+
+  inflate_font(texture,
+               font->texture_stride,
+               font->max_z_curve_ix);
+  palette_data<2>();
+
+  // The address of `ta_parameter_buf` must be a multiple of 32 bytes.
+  // This is mandatory for ch2-dma to the ta fifo polygon converter.
+  uint32_t * ta_parameter_buf = align_32byte(_ta_parameter_buf);
+
+  constexpr uint32_t ta_alloc = ta_alloc_ctrl::pt_opb::no_list
+                              | ta_alloc_ctrl::tm_opb::no_list
+                              | ta_alloc_ctrl::t_opb::no_list
+                              | ta_alloc_ctrl::om_opb::no_list
+                              | ta_alloc_ctrl::o_opb::_16x4byte;
+
+  constexpr struct opb_size opb_size = { .opaque = 16 * 4
+                                       , .opaque_modifier = 0
+                                       , .translucent = 0
+                                       , .translucent_modifier = 0
+                                       , .punch_through = 0
+                                       };
+
+  holly.SOFTRESET = softreset::pipeline_soft_reset
+                  | softreset::ta_soft_reset;
+  holly.SOFTRESET = 0;
+
+  core_init();
+  init_texture_memory(opb_size);
+
+  uint32_t frame_ix = 0;
+
+  uint32_t * command_buf = align_32byte(_command_buf);
+  uint32_t * receive_buf = align_32byte(_receive_buf);
+  struct button_state buttons[2] = { 0 };
+  struct editor_state state = { 0 };
+  //                  01234567
+  char_type buf[64] = "abqb\neggs1\nbarley";
+  int32_t offsets[64];
+  gap_init_from_buf(state.gb, buf, 24, 17);
+  line_init_from_buf(state.gb, offsets, 64);
+  gap_cursor_pos(state.gb, (-state.gb.gap_start) + 6);
+  gap_append(state.gb, '\n');
+
+  while (true) {
+    do_get_condition(command_buf, receive_buf, buttons[frame_ix & 1]);
+    update_state(buttons[(frame_ix + 1) & 1], buttons[frame_ix & 1], state);
+
+    ta_polygon_converter_init(opb_size.total(),
+                              ta_alloc,
+                              640 / 32,
+                              480 / 32);
+
+    auto parameter = ta_parameter_writer(ta_parameter_buf);
+    render_gap_buffer(parameter, font, glyphs, state.gb);
+    parameter.append<ta_global_parameter::end_of_list>() = ta_global_parameter::end_of_list(para_control::para_type::end_of_list);
+
+    ta_polygon_converter_transfer(ta_parameter_buf, parameter.offset);
+    ta_wait_opaque_list();
+
+    core_start_render(frame_ix);
+    core_wait_end_of_render_video();
+
+    while (!spg_status::vsync(holly.SPG_STATUS));
+    core_flip(frame_ix);
+    while (spg_status::vsync(holly.SPG_STATUS));
+
+    frame_ix = (frame_ix + 1) & 1;
+  }
+}
diff --git a/text_editor/text_editor.mk b/text_editor/text_editor.mk
new file mode 100644
index 0000000..079daf5
--- /dev/null
+++ b/text_editor/text_editor.mk
@@ -0,0 +1,14 @@
+TEXT_EDITOR_OBJ = \
+	text_editor/text_editor.o \
+	text_editor/gap_buffer.o \
+	holly/video_output.o \
+	holly/core.o \
+	holly/region_array.o \
+	holly/background.o \
+	holly/ta_fifo_polygon_converter.o \
+	maple/maple.o \
+	sh7091/serial.o \
+	ter_u20n.data.o
+
+text_editor/text_editor.elf: LDSCRIPT = $(LIB)/main.lds
+text_editor/text_editor.elf: $(START_OBJ) $(TEXT_EDITOR_OBJ)
diff --git a/tools/ttf_outline.cpp b/tools/ttf_outline.cpp
index ba5c042..70f569a 100644
--- a/tools/ttf_outline.cpp
+++ b/tools/ttf_outline.cpp
@@ -18,10 +18,11 @@ std::endian _target_endian;
 constexpr uint32_t max_texture_dim = 1024;
 constexpr uint32_t max_texture_size = max_texture_dim * max_texture_dim;
 
-uint32_t byteswap(const uint32_t n)
+template< class T >
+constexpr T byteswap(const T n)
 {
   if (std::endian::native != _target_endian) {
-    return std::byteswap(n);
+    return std::byteswap<T>(n);
   } else {
     return n;
   }
@@ -128,15 +129,15 @@ load_outline_char(const FT_Face face,
   }
 
   glyph_bitmap& bitmap = glyph->bitmap;
-  bitmap.x = byteswap(rect.x);
-  bitmap.y = byteswap(rect.y);
-  bitmap.width = byteswap(rect.width);
-  bitmap.height = byteswap(rect.height);
+  bitmap.x = byteswap<uint16_t>(rect.x);
+  bitmap.y = byteswap<uint16_t>(rect.y);
+  bitmap.width = byteswap<uint16_t>(rect.width);
+  bitmap.height = byteswap<uint16_t>(rect.height);
 
   glyph_metrics& metrics = glyph->metrics;
-  metrics.horiBearingX = byteswap(face->glyph->metrics.horiBearingX);
-  metrics.horiBearingY = byteswap(face->glyph->metrics.horiBearingY);
-  metrics.horiAdvance = byteswap(face->glyph->metrics.horiAdvance);
+  metrics.horiBearingX = byteswap<int32_t>(face->glyph->metrics.horiBearingX);
+  metrics.horiBearingY = byteswap<int32_t>(face->glyph->metrics.horiBearingY);
+  metrics.horiAdvance = byteswap<int32_t>(face->glyph->metrics.horiAdvance);
 
   return 0;
 }
@@ -286,14 +287,15 @@ int main(int argc, char *argv[])
   }
 
   font font;
-  font.first_char_code = byteswap(start);
-  font.glyph_count = byteswap(num_glyphs);
-  font.glyph_height = byteswap(face->size->metrics.height);
-  font.texture_stride = byteswap(texture_stride);
-  font.texture_width = byteswap(window_curve_ix.window.width);
-  font.texture_height = byteswap(window_curve_ix.window.height);
-  font.texture_size = byteswap(texture_size);
-  font.max_z_curve_ix = byteswap(window_curve_ix.max_z_curve_ix);
+  font.first_char_code = byteswap<uint32_t>(start);
+  font.last_char_code = byteswap<uint32_t>(end);
+  font.glyph_height = byteswap<int32_t>(face->size->metrics.height);
+  font.glyph_count = byteswap<uint16_t>(num_glyphs);
+  font.texture_stride = byteswap<uint16_t>(texture_stride);
+  font.texture_width = byteswap<uint16_t>(window_curve_ix.window.width);
+  font.texture_height = byteswap<uint16_t>(window_curve_ix.window.height);
+  font.texture_size = byteswap<uint32_t>(texture_size);
+  font.max_z_curve_ix = byteswap<uint32_t>(window_curve_ix.max_z_curve_ix);
 
   std::cerr << "start: 0x" << std::hex << start << '\n';
   std::cerr << "end: 0x"   << std::hex << end   << '\n';