allegro_v.cpp

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/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <https://www.gnu.org/licenses/old-licenses/gpl-2.0>.
 */

 
#ifdef WITH_ALLEGRO
 
#include "../stdafx.h"
#include "../openttd.h"
#include "../error_func.h"
#include "../gfx_func.h"
#include "../blitter/factory.hpp"
#include "../core/random_func.hpp"
#include "../core/math_func.hpp"
#include "../framerate_type.h"
#include "../progress.h"
#include "../thread.h"
#include "../window_func.h"
#include "allegro_v.h"
#include <allegro.h>
 
#ifdef _DEBUG
/* Allegro replaces SEGV/ABRT signals meaning that the debugger will never
 * be triggered, so rereplace the signals and make the debugger useful. */
#include <signal.h>
#endif
 
#include "../safeguards.h"
 
static FVideoDriver_Allegro iFVideoDriver_Allegro;
 
static BITMAP *_allegro_screen;
 
static PointDimension _dirty_rects[100];
static size_t _num_dirty_rects;
static Palette _local_palette; 
 
void VideoDriver_Allegro::MakeDirty(int left, int top, int width, int height)
{
  if (_num_dirty_rects < std::size(_dirty_rects)) {
    _dirty_rects[_num_dirty_rects].x = left;
    _dirty_rects[_num_dirty_rects].y = top;
    _dirty_rects[_num_dirty_rects].width = width;
    _dirty_rects[_num_dirty_rects].height = height;
  }
  _num_dirty_rects++;
}
 
void VideoDriver_Allegro::Paint()
{
  PerformanceMeasurer framerate(PFE_VIDEO);
 
  size_t n = _num_dirty_rects;
  if (n == 0) return;
 
  _num_dirty_rects = 0;
  if (n > std::size(_dirty_rects)) {
    blit(_allegro_screen, screen, 0, 0, 0, 0, _allegro_screen->w, _allegro_screen->h);
    return;
  }
 
  for (size_t i = 0; i < n; i++) {
    blit(_allegro_screen, screen, _dirty_rects[i].x, _dirty_rects[i].y, _dirty_rects[i].x, _dirty_rects[i].y, _dirty_rects[i].width, _dirty_rects[i].height);
  }
}
 
 
static void UpdatePalette(uint start, uint count)
{
  static PALETTE pal;
 
  uint end = start + count;
  for (uint i = start; i != end; i++) {
    pal[i].r = _local_palette.palette[i].r / 4;
    pal[i].g = _local_palette.palette[i].g / 4;
    pal[i].b = _local_palette.palette[i].b / 4;
    pal[i].filler = 0;
  }
 
  set_palette_range(pal, start, end - 1, 1);
}
 
static void InitPalette()
{
  UpdatePalette(0, 256);
}
 
void VideoDriver_Allegro::CheckPaletteAnim()
{
  if (!CopyPalette(_local_palette)) return;
 
  Blitter *blitter = BlitterFactory::GetCurrentBlitter();
 
  switch (blitter->UsePaletteAnimation()) {
    case Blitter::PaletteAnimation::VideoBackend:
      UpdatePalette(_local_palette.first_dirty, _local_palette.count_dirty);
      break;
 
    case Blitter::PaletteAnimation::Blitter:
      blitter->PaletteAnimate(_local_palette);
      break;
 
    case Blitter::PaletteAnimation::None:
      break;
 
    default:
      NOT_REACHED();
  }
}
 
static const Dimension default_resolutions[] = {
  { 640,  480},
  { 800,  600},
  {1024,  768},
  {1152,  864},
  {1280,  800},
  {1280,  960},
  {1280, 1024},
  {1400, 1050},
  {1600, 1200},
  {1680, 1050},
  {1920, 1200}
};
 
static void GetVideoModes()
{
  /* Need to set a gfx_mode as there is NO other way to autodetect for
   * cards ourselves... and we need a card to get the modes. */
  set_gfx_mode(_fullscreen ? GFX_AUTODETECT_FULLSCREEN : GFX_AUTODETECT_WINDOWED, 640, 480, 0, 0);
 
  _resolutions.clear();
 
  GFX_MODE_LIST *mode_list = get_gfx_mode_list(gfx_driver->id);
  if (mode_list == nullptr) {
    _resolutions.assign(std::begin(default_resolutions), std::end(default_resolutions));
    return;
  }
 
  GFX_MODE *modes = mode_list->mode;
 
  for (int i = 0; modes[i].bpp != 0; i++) {
    uint w = modes[i].width;
    uint h = modes[i].height;
    if (w < 640 || h < 480) continue;
    if (std::ranges::find(_resolutions, Dimension(w, h)) != _resolutions.end()) continue;
    _resolutions.emplace_back(w, h);
  }
 
  SortResolutions();
 
  destroy_gfx_mode_list(mode_list);
}
 
static void GetAvailableVideoMode(uint *w, uint *h)
{
  /* No video modes, so just try it and see where it ends */
  if (_resolutions.empty()) return;
 
  /* is the wanted mode among the available modes? */
  if (std::ranges::find(_resolutions, Dimension(*w, *h)) != _resolutions.end()) return;
 
  /* use the closest possible resolution */
  uint best = 0;
  uint delta = Delta(_resolutions[0].width, *w) * Delta(_resolutions[0].height, *h);
  for (uint i = 1; i != _resolutions.size(); ++i) {
    uint newdelta = Delta(_resolutions[i].width, *w) * Delta(_resolutions[i].height, *h);
    if (newdelta < delta) {
      best = i;
      delta = newdelta;
    }
  }
  *w = _resolutions[best].width;
  *h = _resolutions[best].height;
}
 
static bool CreateMainSurface(uint w, uint h)
{
  int bpp = BlitterFactory::GetCurrentBlitter()->GetScreenDepth();
  if (bpp == 0) UserError("Can't use a blitter that blits 0 bpp for normal visuals");
  set_color_depth(bpp);
 
  GetAvailableVideoMode(&w, &h);
  if (set_gfx_mode(_fullscreen ? GFX_AUTODETECT_FULLSCREEN : GFX_AUTODETECT_WINDOWED, w, h, 0, 0) != 0) {
    Debug(driver, 0, "Allegro: Couldn't allocate a window to draw on '{}'", allegro_error);
    return false;
  }
 
  /* The size of the screen might be bigger than the part we can actually draw on!
   * So calculate the size based on the top, bottom, left and right */
  _allegro_screen = create_bitmap_ex(bpp, screen->cr - screen->cl, screen->cb - screen->ct);
  _screen.width = _allegro_screen->w;
  _screen.height = _allegro_screen->h;
  _screen.pitch = ((uint8_t*)screen->line[1] - (uint8_t*)screen->line[0]) / (bpp / 8);
  _screen.dst_ptr = _allegro_screen->line[0];
 
  /* Initialise the screen so we don't blit garbage to the screen */
  std::fill_n(static_cast<std::byte *>(_screen.dst_ptr), static_cast<size_t>(_screen.height) * _screen.pitch, static_cast<std::byte>(0));
 
  /* Set the mouse at the place where we expect it */
  poll_mouse();
  _cursor.pos.x = mouse_x;
  _cursor.pos.y = mouse_y;
 
  BlitterFactory::GetCurrentBlitter()->PostResize();
 
  InitPalette();
 
  std::string caption = VideoDriver::GetCaption();
  set_window_title(caption.c_str());
 
  enable_hardware_cursor();
  select_mouse_cursor(MOUSE_CURSOR_ARROW);
  show_mouse(_allegro_screen);
 
  GameSizeChanged();
 
  return true;
}
 
void VideoDriver_Allegro::ClaimMousePointer()
{
  select_mouse_cursor(MOUSE_CURSOR_NONE);
  show_mouse(nullptr);
  disable_hardware_cursor();
}
 
std::vector<int> VideoDriver_Allegro::GetListOfMonitorRefreshRates()
{
  std::vector<int> rates = {};
 
  int refresh_rate = get_refresh_rate();
  if (refresh_rate != 0) rates.push_back(refresh_rate);
 
  return rates;
}
 
struct AllegroVkMapping {
  uint16_t vk_from;
  uint8_t vk_count;
  uint8_t map_to;
};
 
#define AS(x, z) {x, 1, z}
#define AM(x, y, z, w) {x, y - x + 1, z}
 
static const AllegroVkMapping _vk_mapping[] = {
  /* Pageup stuff + up/down */
  AM(KEY_PGUP, KEY_PGDN, WKC_PAGEUP, WKC_PAGEDOWN),
  AS(KEY_UP,     WKC_UP),
  AS(KEY_DOWN,   WKC_DOWN),
  AS(KEY_LEFT,   WKC_LEFT),
  AS(KEY_RIGHT,  WKC_RIGHT),
 
  AS(KEY_HOME,   WKC_HOME),
  AS(KEY_END,    WKC_END),
 
  AS(KEY_INSERT, WKC_INSERT),
  AS(KEY_DEL,    WKC_DELETE),
 
  /* Map letters & digits */
  AM(KEY_A, KEY_Z, 'A', 'Z'),
  AM(KEY_0, KEY_9, '0', '9'),
 
  AS(KEY_ESC,       WKC_ESC),
  AS(KEY_PAUSE,     WKC_PAUSE),
  AS(KEY_BACKSPACE, WKC_BACKSPACE),
 
  AS(KEY_SPACE,     WKC_SPACE),
  AS(KEY_ENTER,     WKC_RETURN),
  AS(KEY_TAB,       WKC_TAB),
 
  /* Function keys */
  AM(KEY_F1, KEY_F12, WKC_F1, WKC_F12),
 
  /* Numeric part. */
  AM(KEY_0_PAD, KEY_9_PAD, '0', '9'),
  AS(KEY_SLASH_PAD,   WKC_NUM_DIV),
  AS(KEY_ASTERISK,    WKC_NUM_MUL),
  AS(KEY_MINUS_PAD,   WKC_NUM_MINUS),
  AS(KEY_PLUS_PAD,    WKC_NUM_PLUS),
  AS(KEY_ENTER_PAD,   WKC_NUM_ENTER),
  AS(KEY_DEL_PAD,     WKC_DELETE),
 
  /* Other non-letter keys */
  AS(KEY_SLASH,        WKC_SLASH),
  AS(KEY_SEMICOLON,    WKC_SEMICOLON),
  AS(KEY_EQUALS,       WKC_EQUALS),
  AS(KEY_OPENBRACE,    WKC_L_BRACKET),
  AS(KEY_BACKSLASH,    WKC_BACKSLASH),
  AS(KEY_CLOSEBRACE,   WKC_R_BRACKET),
 
  AS(KEY_QUOTE,   WKC_SINGLEQUOTE),
  AS(KEY_COMMA,   WKC_COMMA),
  AS(KEY_MINUS,   WKC_MINUS),
  AS(KEY_STOP,    WKC_PERIOD),
  AS(KEY_TILDE,   WKC_BACKQUOTE),
};
 
static uint32_t ConvertAllegroKeyIntoMy(char32_t *character)
{
  int scancode;
  int unicode = ureadkey(&scancode);
 
  uint key = 0;
 
  for (const auto &map : _vk_mapping) {
    if (IsInsideBS(scancode, map.vk_from, map.vk_count)) {
      key = scancode - map.vk_from + map.map_to;
      break;
    }
  }
 
  if (key_shifts & KB_SHIFT_FLAG) key |= WKC_SHIFT;
  if (key_shifts & KB_CTRL_FLAG)  key |= WKC_CTRL;
  if (key_shifts & KB_ALT_FLAG)   key |= WKC_ALT;
#if 0
  Debug(driver, 0, "Scancode character pressed {}", scancode);
  Debug(driver, 0, "Unicode character pressed {}", unicode);
#endif
 
  *character = unicode;
  return key;
}
 
static const uint LEFT_BUTTON  = 0;
static const uint RIGHT_BUTTON = 1;
 
bool VideoDriver_Allegro::PollEvent()
{
  poll_mouse();
 
  bool mouse_action = false;
 
  /* Mouse buttons */
  static int prev_button_state;
  if (prev_button_state != mouse_b) {
    uint diff = prev_button_state ^ mouse_b;
    while (diff != 0) {
      uint button = FindFirstBit(diff);
      ClrBit(diff, button);
      if (HasBit(mouse_b, button)) {
        /* Pressed mouse button */
        if (_rightclick_emulate && (key_shifts & KB_CTRL_FLAG)) {
          button = RIGHT_BUTTON;
          ClrBit(diff, RIGHT_BUTTON);
        }
        switch (button) {
          case LEFT_BUTTON:
            _left_button_down = true;
            break;
 
          case RIGHT_BUTTON:
            _right_button_down = true;
            _right_button_clicked = true;
            break;
 
          default:
            /* ignore rest */
            break;
        }
      } else {
        /* Released mouse button */
        if (_rightclick_emulate) {
          _right_button_down = false;
          _left_button_down = false;
          _left_button_clicked = false;
        } else if (button == LEFT_BUTTON) {
          _left_button_down = false;
          _left_button_clicked = false;
        } else if (button == RIGHT_BUTTON) {
          _right_button_down = false;
        }
      }
    }
    prev_button_state = mouse_b;
    mouse_action = true;
  }
 
  /* Mouse movement */
  if (_cursor.UpdateCursorPosition(mouse_x, mouse_y)) {
    position_mouse(_cursor.pos.x, _cursor.pos.y);
  }
  if (_cursor.delta.x != 0 || _cursor.delta.y) mouse_action = true;
 
  static int prev_mouse_z = 0;
  if (prev_mouse_z != mouse_z) {
    _cursor.wheel = (prev_mouse_z - mouse_z) < 0 ? -1 : 1;
    prev_mouse_z = mouse_z;
    mouse_action = true;
  }
 
  if (mouse_action) HandleMouseEvents();
 
  poll_keyboard();
  if ((key_shifts & KB_ALT_FLAG) && (key[KEY_ENTER] || key[KEY_F])) {
    ToggleFullScreen(!_fullscreen);
  } else if (keypressed()) {
    char32_t character;
    uint keycode = ConvertAllegroKeyIntoMy(&character);
    HandleKeypress(keycode, character);
  }
 
  return false;
}

int _allegro_instance_count = 0;
 
std::optional<std::string_view> VideoDriver_Allegro::Start(const StringList &param)
{
  if (_allegro_instance_count == 0 && install_allegro(SYSTEM_AUTODETECT, &errno, nullptr)) {
    Debug(driver, 0, "allegro: install_allegro failed '{}'", allegro_error);
    return "Failed to set up Allegro";
  }
  _allegro_instance_count++;
 
  this->UpdateAutoResolution();
 
  install_timer();
  install_mouse();
  install_keyboard();
 
#if defined _DEBUG
/* Allegro replaces SEGV/ABRT signals meaning that the debugger will never
 * be triggered, so rereplace the signals and make the debugger useful. */
  signal(SIGABRT, nullptr);
  signal(SIGSEGV, nullptr);
#endif
 
  GetVideoModes();
  if (!CreateMainSurface(_cur_resolution.width, _cur_resolution.height)) {
    return "Failed to set up Allegro video";
  }
  MarkWholeScreenDirty();
  set_close_button_callback(HandleExitGameRequest);
 
  this->is_game_threaded = !GetDriverParamBool(param, "no_threads") && !GetDriverParamBool(param, "no_thread");
 
  return std::nullopt;
}
 
void VideoDriver_Allegro::Stop()
{
  if (--_allegro_instance_count == 0) allegro_exit();
}
 
void VideoDriver_Allegro::InputLoop()
{
  bool old_ctrl_pressed = _ctrl_pressed;
 
  _ctrl_pressed  = !!(key_shifts & KB_CTRL_FLAG);
  _shift_pressed = !!(key_shifts & KB_SHIFT_FLAG);
 
  /* Speedup when pressing tab, except when using ALT+TAB
   * to switch to another application. */
  this->fast_forward_key_pressed = key[KEY_TAB] && (key_shifts & KB_ALT_FLAG) == 0;
 
  /* Determine which directional keys are down. */
  _dirkeys =
    (key[KEY_LEFT]  ? 1 : 0) |
    (key[KEY_UP]    ? 2 : 0) |
    (key[KEY_RIGHT] ? 4 : 0) |
    (key[KEY_DOWN]  ? 8 : 0);
 
  if (old_ctrl_pressed != _ctrl_pressed) HandleCtrlChanged();
}
 
void VideoDriver_Allegro::MainLoop()
{
  this->StartGameThread();
 
  for (;;) {
    if (_exit_game) break;
 
    this->Tick();
    this->SleepTillNextTick();
  }
 
  this->StopGameThread();
}
 
bool VideoDriver_Allegro::ChangeResolution(int w, int h)
{
  return CreateMainSurface(w, h);
}
 
bool VideoDriver_Allegro::ToggleFullscreen(bool fullscreen)
{
  _fullscreen = fullscreen;
  GetVideoModes(); // get the list of available video modes
  if (_resolutions.empty() || !this->ChangeResolution(_cur_resolution.width, _cur_resolution.height)) {
    /* switching resolution failed, put back full_screen to original status */
    _fullscreen ^= true;
    return false;
  }
  return true;
}
 
bool VideoDriver_Allegro::AfterBlitterChange()
{
  return CreateMainSurface(_screen.width, _screen.height);
}
 
#endif /* WITH_ALLEGRO */