Allegro Access Violation while Drawing

RickOwensFit

Hey guys, I'm trying to use Allegro to draw some shapes for a school project. I got the error: Process returned -1073741819 (0xC0000005). This was the same error I got when I tried to draw bitmaps previously. I borrowed code that my teacher uses for a demo to see if it was just my code that was the problem. I am still getting the same error. From my research, 0xC0000005 seems to be an access violation error. I believe that it is a problem with my computer, what can I do to fix? Thank you.

Attached below is the code from my teacher that I am using. Other Allegro functions that do not require drawing shapes, such as creating a pop-up or drawing a single pixel work.

#SelectExpand
  1// Here is your first line. You must include the allegro header file or else nothing will work!
  2#include <allegro5/allegro.h>// You must include the Allegro Header file
  3#include <allegro5/allegro_primitives.h>
  4#include <allegro5/allegro_native_dialog.h>
  5
  6// lots of colours to choose from
  7#define RED     al_map_rgb(230, 25, 75)
  8#define GREEN   al_map_rgb(60, 180, 75)
  9#define YELLOW   al_map_rgb(255, 225, 25)
 10#define BLUE   al_map_rgb(0, 130, 200)
 11#define ORANGE   al_map_rgb(245, 130, 48)
 12#define PURPLE   al_map_rgb(145, 30, 180)
 13#define CYAN   al_map_rgb(70, 240, 240)
 14#define MAGENTA   al_map_rgb(240, 50, 230)
 15#define LIME   al_map_rgb(210, 245, 60)
 16#define PINK   al_map_rgb(250, 190, 190)
 17#define TEAL   al_map_rgb(0, 128, 128)
 18#define LAVENDER al_map_rgb(230, 190, 255)
 19#define BROWN   al_map_rgb(170, 110, 40)
 20#define BEIGE   al_map_rgb(255, 250, 200)
 21#define MAROON   al_map_rgb(128, 0, 0)
 22#define MINT   al_map_rgb(170, 255, 195)
 23#define OLIVE   al_map_rgb(128, 128, 0)
 24#define CORAL   al_map_rgb(255, 215, 180)
 25#define NAVY   al_map_rgb(0, 0, 128)
 26#define GREY   al_map_rgb(128, 128, 128)
 27#define WHITE   al_map_rgb(255, 255, 255)
 28#define BLACK   al_map_rgb(0, 0, 0)
 29
 30const int SCREEN_W = 640;       // screen width
 31const int SCREEN_H = 480;       // screen height
 32
 33int main(int argc, char *argv[]) {
 34  ALLEGRO_DISPLAY *display = nullptr;
 35
 36  // Initialize Allegro
 37  al_init();
 38
 39  // Initialize display
 40  display = al_create_display(SCREEN_W, SCREEN_H);
 41  if (!display) {
 42      al_show_native_message_box(display, "Error", "Error", "Failed to initialize display!",
 43                                 nullptr, ALLEGRO_MESSAGEBOX_ERROR);
 44         return -1;
 45  }
 46    al_set_window_title(display, "Allegro Example 8 - Shapes");
 47
 48  // Initialize primative add on
 49   if (!al_init_primitives_addon()) {
 50      al_show_native_message_box(display, "Error", "Error", "Failed to initialize primatives addon!",
 51                                 nullptr, ALLEGRO_MESSAGEBOX_ERROR);
 52      return -1;
 53  }
 54
 55  // paint rectangle  (x1, y1, x2, y2, colour) - Upper left and lower right points of the rectangle
 56  al_draw_filled_rectangle(100, 100, 200, 150, MAROON);
 57  al_draw_filled_circle(100, 100, 50, LAVENDER);
 58  al_draw_circle(400, 400, 80, TEAL, 10);    // last parameter is thickness of line
 59  al_draw_line(10, 240, 310, 250, NAVY, 25);
 60
 61  // display what has been drawn
 62    al_flip_display();
 63
 64    // Wait for a 5 seconds before destroy the dispaly and exit the program.
 65  al_rest(5);
 66  al_destroy_display(display);
 67  return 0;
 68}

DanielH

You are saying it works if you comment out the draw functions? Or it doesn't work at all?

Do you have a step-by-step debugger to go through each line to find out where it breaks?

also, when you post code put it inside the code tags please. Makes it easier to read and allegro functions link to the manual (Even though they need updated)

<code>
//source code goes here
</code>

Peter Hull

One thing I noticed is that you're not calling `al_init_native_dialog_addon`

DanielH

But that would only matter if something went wrong creating display or initializing primitives. Correct? Otherwise those calls would never be called to cause issues with native dialog not being initialized.

RickOwensFit

DanielH, it is breaking at the draw functions. If I comment out lines 56 through 59 it works perfectly. It creates a window titled "Allegro Example 8 - Shapes", waits, then closes. From my previous work with Allegro, I can create pop-ups and draw individual pixels as well.

I believe that the problem lies with my computer, as this code works on my teacher's.

Edgar Reynaldo

You're not checking the return value of al_init. If it fails, it means your runtime version of allegro is not the same as your compile time allegro. Delete old copies of allegro and relink.

DanielH

Yes, get a clean copy of Allegro. Your code is fine.

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