I've been trying to get masked_blit to work and having problem as shown in the screenshots.

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{"name":"591205","src":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/0\/5\/05980b83476c03fb74aebbd6bf06fe99.jpg","w":646,"h":512,"tn":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/0\/5\/05980b83476c03fb74aebbd6bf06fe99"}

The 1st image is all blit(...);
The 2nd image is using masked_blit(...); and blit(...) for the background image which shows up clear. Does anyone have an suggestions on how to get this to work?

My transparent color is (255, 0, 255).

set_color_depth(32);

And I am setting it before I call

int ret = set_gfx_mode(MODE, WIDTH, HEIGHT, 0, 0);

And I load the graphics after this setup. In fact the icons that are loading are the same for those using blut() and those using masked_blit()

I've attached the 24bit tank.bmp icon created in MS Paint.

As for my blit / masked_blit code..(buffer is my backbuffer which writes to the screen, same buffer that is used for blit(), which works fine.)

void drawPlayer()
{
  if(Player.alive)
  {
    int x = Player.x;
    int y = Player.y;
    if(MASKED)
      masked_blit(player_bmp, buffer, 0, 0, x, y, PLAYER_SIZE, PLAYER_SIZE);
    else
            blit(player_bmp, buffer, 0, 0, x, y, PLAYER_SIZE, PLAYER_SIZE);
  }
}

EDIT: I'm using Allegro 4.2

The loaded images have a different color depth than the buffer. Make sure you load/create them all after setting the gfx mode (which you do after setting the color depth).

The only image that didn't have a 255, 0, 255 background was the one I picked to post here. Glad I found that error. I changed the background for the tank image to 255, 0, 255 and still no go. I also have a background that loads when Masking is turned on. It appears something is forcing my color depth to go 256-pal mode from the look of the background. Also to note, each image is loaded from a 24-bit BMP that is not animated. Is it still required to use create the images after loading? If so, how would I create a static image from one that is been loaded and to ensure the 24 - 36 bit colors are retained?

I call it Week 5, because I'm making a game a week in class. This project has already been completed and turned in. But, I need to clear up my masking problem for future projects, which will heavily depend upon masked sprites.

Here is my game setup function.

This is how I'm loading the player bitmap

  player_bmp = load_bitmap("gfx/tank.bmp", NULL);

And this is the code that draws the player to the screen

void drawPlayer()
{
  if(Player.alive)
  {
    int x = Player.x;
    int y = Player.y;
    if(MASKED)
      masked_blit(player_bmp, buffer, 0, 0, x, y, PLAYER_SIZE, PLAYER_SIZE);
    else
            blit(player_bmp, buffer, 0, 0, x, y, PLAYER_SIZE, PLAYER_SIZE);
  }
}

Keep in mind that the MASKED is a #define that makes it easier to turn masking on/off.

When you boot up your graphics mode, add a textout or textprintf line to show you the results of a get_color_depth() call. It sounds to me that your computer doesn't like 24-Bit or 32-Bit graphics modes. (Which can sometimes be caused by incorrect video or monitor drivers.)

In 8-bit mode, the background colour needs to be palette entry 0, which would be one way to explain why the magic pink isn't disappearing.

Also, if it isn't liking 24-Bit or 32-Bit colour, try running the program in a window and you may have better luck.

EDIT: Oh wait... you are, aren't you? Maybe you should try full-screen then...

EDIT: Waitaminute... I think I recognize this problem. I believe masked_blit() requires that the bitmaps and the screen be the same colour depth... the images look as though you're trying to blit 32-Bit data onto an 8 or 16-bit surface. Is your desktop colour depth set to 8 or 16-Bit?

--- Kris Asick (Gemini)
--- http://www.pixelships.com

Does draw_sprite() do the same thing as masked_blit() when you use it instead? (The two functions are almost identical in functionality.)

--- Kris Asick (Gemini)
--- http://www.pixelships.com

As an update, I was testing out various things and decided to set it to 8-bit 256-pal mode. I also took the non-animated sprite and converted it to an 8bit image with 0 for the masking. Surprisingly, the masking worked fine, however, the image itself was still distorted.

Someone suggested I try to set color to 32bit and use TGA instead of BMP. I'm going to give this a try later tonight.

Just wanted to mention the 8bit test in case this clues anyone in to what my problem may be. It really seems like something is force me into 8bit PAL mode, but I have set everything to 24bit / 32bit and pass NULL for the PAL info.

Ok Mr. Evert,

I've gotten around to making a Test program and got it working, but the masking is not.
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As you can see, the problem is still there. It should be the tank icon over a green field. Everything is grey.

{"name":"591229","src":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/6\/7\/676c9e9f40766c305cc403d79f7c0f5e.png","w":640,"h":480,"tn":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/6\/7\/676c9e9f40766c305cc403d79f7c0f5e"} 591230

There, see? Didn't take long, did it?

Watch it.

Is Mr an insult these days?

Functions placed in macros aren't called until the macro is used.

Think of the preprocessor as a big search and replace engine. The compiler only sees what happens after the search and replace takes place.

So "BLACK" gets translated into makecol(0,0,0) where ever its used, before it hits the compiler, thus, the compiler only sees a bunch of makecol calls.

edit, but to answer your question, generally no, things wont work if allegro hasn't been initialized.