在 OSX 上运行 Allegro 时出错

Question

我在 OSX 上运行了 brew install allegro

按照本教程进行操作：https://wiki.allegro.cc/index.php?title=Example_ExHello

我的代码

include <allegro.h>

int main(void) { 
  if (allegro_init() != 0)
     return 1;

  /* set up the keyboard handler */
  install_keyboard(); 

  /* set a graphics mode sized 320x200 */
  if (set_gfx_mode(GFX_AUTODETECT, 320, 200, 0, 0) != 0) {
     if (set_gfx_mode(GFX_SAFE, 320, 200, 0, 0) != 0) {
   set_gfx_mode(GFX_TEXT, 0, 0, 0, 0);
   allegro_message("Unable to set any graphic mode\n%s\n", allegro_error);
   return 1;
     }
  }

  /* set the color palette */
  set_palette(desktop_palette);

  /* clear the screen to white */
  clear_to_color(screen, makecol(255, 255, 255));

  /* you don't need to do this, but on some platforms (eg. Windows) things
   * will be drawn more quickly if you always acquire the screen before
   * trying to draw onto it.
   */
  acquire_screen();

  /* write some text to the screen with black letters and transparent background */
  textout_centre_ex(screen, font, "Hello, world!", SCREEN_W/2, SCREEN_H/2, makecol(0,0,0), -1);

  /* you must always release bitmaps before calling any input functions */
  release_screen();

  /* wait for a keypress */
  readkey();

  return 0;
}



1.c:1:1: error: unknown type name 'include'
include <allegro.h>
^
1.c:1:9: error: expected identifier or '('
include <allegro.h>
        ^
2 errors generated.
make: *** [1] Error 1

Answer 1

假设include <allegro.h> 的拼写错误应该是#include <allegro.h>，您已经安装了allegro5 - allegro4（本示例来自）和allegro5 之间的API 非常不同。显示初始化sample program for allegro5 显示了一些差异：

#include <stdio.h>
#include <allegro5/allegro.h>

int main(int argc, char **argv){

   ALLEGRO_DISPLAY *display = NULL;

   if(!al_init()) { // allegro_init in allegro4
      fprintf(stderr, "failed to initialize allegro!\n");
      return -1;
   }

   display = al_create_display(640, 480); // very different to allegro4
   if(!display) {
      fprintf(stderr, "failed to create display!\n");
      return -1;
   }

   al_clear_to_color(al_map_rgb(0,0,0)); // makecol -> al_map_rgb, clear_to_color -> al_clear_to_color

   al_flip_display();

   al_rest(10.0);

   al_destroy_display(display);

   return 0;
}

我使用：

 c++ -I/usr/local/include allegro_display.cc -o allegro_display -L/usr/local/lib -lallegro -lallegro_main

代码在文件allegro_display.cc 中的位置。请注意，我使用 C++ 编译器进行编译，因为 allegro 实际上是一个 C++ api（并且示例在编译为 C 代码时不起作用，因为 C 中的结构没有正确的调用约定，而 C++ 有）