Allegro 5 include file rejected

RazorSharpFang

Interestingly, an include file of mine has been rejected by my compiler.

The file is "allegro_image.h".

My compiler says that al_init_image_addon and al_shutdown_image_addon have not been declared. I am using the static version of Allegro 5.0.7.
Allegro works absolutely fine without this one, though I kinda need it to draw bitmaps... :|

After those complaints, it goes on to say "expected constructors, destructors of '{
' before ';', but I think that's just because it didn't recognise the functions.
I would diagnose these, but I don't understand the #ifndef and other stuff in the file...

I have been using Code::blocks and the mingw g++ compiler, and nothing has gone wrong so far. (since I started using an IDE)

Please help, I can't draw any bitmaps until I get this working...

LennyLen

Please post your code.

RazorSharpFang

allegro_image.h -> This file has been unedited from it's download and install

#SelectExpand
  1#ifndef __al_included_allegro5_allegro_image_h
  2#define __al_included_allegro5_allegro_image_h
  3
  4#if (defined ALLEGRO_MINGW32) || (defined ALLEGRO_MSVC) || (defined ALLEGRO_BCC32)
  5   #ifndef ALLEGRO_STATICLINK
  6      #ifdef ALLEGRO_IIO_SRC
  7         #define _ALLEGRO_IIO_DLL __declspec(dllexport)
  8      #else
  9         #define _ALLEGRO_IIO_DLL __declspec(dllimport)
 10      #endif
 11   #else
 12      #define _ALLEGRO_IIO_DLL
 13   #endif
 14#endif
 15
 16#if defined ALLEGRO_MSVC
 17   #define ALLEGRO_IIO_FUNC(type, name, args)      _ALLEGRO_IIO_DLL type __cdecl name args
 18#elif defined ALLEGRO_MINGW32
 19   #define ALLEGRO_IIO_FUNC(type, name, args)      extern type name args
 20#elif defined ALLEGRO_BCC32
 21   #define ALLEGRO_IIO_FUNC(type, name, args)      extern _ALLEGRO_IIO_DLL type name args
 22#else
 23   #define ALLEGRO_IIO_FUNC      AL_FUNC
 24#endif
 25
 26
 27#ifdef __cplusplus
 28extern "C" {
 29#endif
 30
 31
 32ALLEGRO_IIO_FUNC(bool, al_init_image_addon, (void));
 33ALLEGRO_IIO_FUNC(void, al_shutdown_image_addon, (void));
 34ALLEGRO_IIO_FUNC(uint32_t, al_get_allegro_image_version, (void));
 35
 36
 37#ifdef __cplusplus
 38}
 39#endif
 40
 41#endif

Hope that helps

Matthew Leverton

That's not your code. Your code looks exactly like:

#include <allegro5/allegro_image.h>

RazorSharpFang

Exactly, and that is the code that is throwing the error!
If I remove the link to the allegro_image.h file, it works fine!
But here's mine, single file, main.cpp.

#SelectExpand
   1#define ALLEGRO_STATICLINK
   2// ^ needed, below are includes
   3#include "allegro5/allegro_image.h" //image library throwing errors
   4#include "allegro5/allegro.h" //main allegro library. No errors here.
   5#include <iostream>
   6#include <stdio.h>
   7#include <stdlib.h>
   8using namespace std;
   9// ^ I think I need that... dunno why...
  10void AbortGame(const char* message);
  11//avoids redundancy, abort game after message display
  12ALLEGRO_DISPLAY* SetUpDisplay();
  13//set the display to fullscreen, no res change, handles keyboard, mouse, and  others...
  14//returns ONLY the display
  15ALLEGRO_TIMER* SetUpTimer();
  16//sets up the timer, ticks 60 times each frame...
  17FILE* SetUpLog();
  18//prepares the log file for logging...
  19void Message(const char *input);
  20//standard message, output to terminal, and out to the log file as well. Useful for debugging...
  21ALLEGRO_BITMAP* SetUpScreenBuffer();
  22// Returns the screen buffer which will be used for resolution independace. Write to this, then write this
  23// to the screen after finished drawing. Scale as needed.
  24//START GLOBAL VARIABLES
  25FILE *log; //log file. Write messages to this for debugging
  26ALLEGRO_DISPLAY *display; //the main display.
  27ALLEGRO_BITMAP *screenBuffer; //screen buffer
  28ALLEGRO_TIMER *timer; //umm... timer?
  29int  screenWidth, screenHeight, scaleX, scaleY, scaleW, scaleH;//global scaling variables.
  30int main(int argc, char **argv)
  31{
  32  log = SetUpLog();
  33  display = SetUpDisplay();
  34  screenWidth = al_get_display_width(display);
  35  screenHeight = al_get_display_height(display);
  36  screenBuffer = SetUpScreenBuffer();
  37  timer = SetUpTimer();
  38  al_flip_display();
  39  //al_init_image_addon(void);
  40  while(true) //main game-loop. should never return until game close
  41  {
  42    Sleep(3000);
  43    AbortGame("Success!\n");
  44  }
  45}
  46
  47ALLEGRO_TIMER* SetUpTimer()
  48{
  49  ALLEGRO_TIMER* time = al_create_timer(1.0 / 60);
  50  if (!time) {
  51    AbortGame("Failed to create timer\n");
  52  }
  53  Message("Timer created successfully\n");
  54  return time;
  55}
  56
  57ALLEGRO_DISPLAY* SetUpDisplay()
  58{
  59  ALLEGRO_DISPLAY *disp = NULL;
  60  ALLEGRO_DISPLAY_MODE disp_data;
  61  if(!al_init()) {
  62    AbortGame("Allegro Error, fatal.\n");
  63  }
  64  Message("Allegro Initialized Successfully\n");
  65  if (!al_install_keyboard()) {
  66        AbortGame("Failed to install keyboard\n");
  67  }
  68  Message("Keyboard initialized successfully\n");
  69  if (!al_install_mouse()) {
  70    AbortGame("Failure to install mouse\n");
  71  }
  72  Message("Mouse initialized successfully\n");
  73  al_get_display_mode(al_get_num_display_modes() - 1, &disp_data);
  74  Message("Display resolution enunciated successfully: width:");
  75  char buffer[8];
  76  sprintf(buffer,"%d",disp_data.width);
  77  Message(buffer);
  78  Message(" height: ");
  79  sprintf(buffer,"%d",disp_data.height);
  80  Message(buffer);
  81  Message("\n");
  82  al_set_new_display_flags(ALLEGRO_FULLSCREEN_WINDOW);
  83  disp = al_create_display(disp_data.width, disp_data.height);
  84  if (!disp) {
  85        AbortGame("Failed to create display");
  86  }
  87  Message("Display created successfully, width:");
  88  sprintf(buffer,"%d",al_get_display_width(disp));
  89  Message(buffer);
  90  Message(" height: ");
  91  sprintf(buffer,"%d",al_get_display_height(disp));
  92  Message(buffer);
  93  Message("\n");
  94  al_clear_to_color(al_map_rgb(0,0,0));
  95  return disp;
  96}
  97
  98void AbortGame(const char* message)
  99{
 100    printf("%s \n", message);
 101  fprintf(log, "%s \n", message);
 102  fclose(log);
 103    exit(1);
 104}
 105
 106FILE* SetUpLog()
 107{
 108  FILE *fp = NULL;
 109  fp = fopen("log.log","w");
 110  fprintf(fp, "Game started\n");
 111  printf("Game started\n");
 112  return fp;
 113}
 114
 115void Message(const char* message)
 116{
 117  printf(message);
 118  fprintf(log,message);
 119  return;
 120}
 121
 122ALLEGRO_BITMAP* SetUpScreenBuffer()
 123{
 124  ALLEGRO_BITMAP *buffer = al_create_bitmap(1080,1920);
 125  int sx = screenWidth/1920;
 126  int sy = screenHeight/1080;
 127  int scale = std::min(sx,sy);
 128  scaleW = 1920 * scale;
 129  scaleH = 1080 * scale;
 130  scaleX = (screenWidth - scaleW) / 2;
 131  scaleY = (screenWidth - scaleH) / 2;
 132}

Dennis

Exchange lines 3 and 4, so that allegro.h is included first.

weapon_S

Matthew Leverton said:

exactly like:
#include <allegro5/allegro_image.h>

RazorSharpFang said:

#include "allegro5/allegro_image.h"

RazorSharpFang

Yep, that was it.
I had no idea that the order of includes could affect building...
Then again, I've never had more than 3 include files before...

Many thanks for your quick help, you guys are awesome, just sayin'.

Keep it awesome!
RazorSharpFang

LennyLen

RazorSharpFang said:

I had no idea that the order of includes could affect building...

When the preprocessor includes files, it copies the contents of them into the file that was including them, putting them where the directive was written. This is why the order is important.

Dennis

You should give credit to everyone who helped.

Also please try to make an effort to investigate and understand what's going on and WHY you needed to make that change.

RazorSharpFang

Oh. That's what credit means! (I understand now!)

Incidentally, I did manage to get it to compile, but after editing the allegro_image.h file a lot, which would probably impede it's cross-platform nature.

I suspect now that the allegro.h or the include of allegro.h have #defines which would change the preprocessor's output, which would cause differences if the files were included in a different order.
Wow, I'm learning a lot from this. I should come here more often.

weapon_S

RazorSharpFang said:

after editing the allegro_image.h file a lot

You normally shouldn't do that. Especially if you want to use it again You can set the directory where GCC searches for include files with -I.

Quote:

I suspect now

It's much simpler than that.

Luiji99

Actually, he's exactly right as to why they need to be included in that order. allegro_image.h requires ALLEGRO_MSVC to be defined if it is running on Microsoft's compiler while utilizing DLLs. If allegro.h is included, then platform/almsvc.h will be automatically included through Allegro's internal/ header-set. If allegro_image.h is included before allegro.h, it does not recognize that it must use a declspec to declare the functions and, thus, MSVC assumes that it must be declared inside of the executable and this results in a not-defined error.

Thread #610640. Printed from Allegro.cc