Creating a sprite from surface may give sprite of wrong depth if it's size is invalid about ags HOT 4 CLOSED

Not long ago I added following safety check for DynamicSprite.Create:

    if (width <= 0 || height <= 0)
    {
        debug_script_warn("WARNING: DynamicSprite.Create: invalid size %d x %d, will adjust", width, height);
        width = std::max(1, width);
        height = std::max(1, height);
    }

IIRC this was done for backwards compatibility.

I believe then same should be added to CreateFromDrawingSurface for consistency.

from ags.

Alright, so what happens here actually is that the bitmap is created with correct color depth, but when trying to put it into a SpriteCache, SpriteCache rejects it as being "size = 0", and the slot remains empty. Next time this sprite is requested, SpriteCache returns a placeholder, which is a 1x1 8-bit image. It looks like it's 8-bit by coincidence.

What needs to be done here is to check the result of setting a sprite into a SpriteCache, and also check whether bitmap is valid earlier when adding a dynamic sprite, and make sure that DynamicSprite.Create... functions return null if something like this happens.

There are actually asserts for width or height being zero in allegro code when a bitmap is created but neither of them are triggered when running in debug for me.

Allegro code allows width to be zero, but requires height to be non-zero:

ASSERT(width >= 0);
ASSERT(height > 0);

EDIT: the "background" in a warning should be replaced with "destination" or "surface", as this code runs for any drawing surface, not just room background.

from ags.

Okay, I pushed 3 small commits in regards to this:
9c54262
83e78fb
9d12250

• if dynamic sprite could not be added for any reason, the script functions will return null pointer instead of a invalid DynamicSprite object.
• in DynamicSprite.CreateFrom* functions <= 0 width and height will be automatically fixed to 1, with a warning.

from ags.

Thank you! This fixes. Tried in my actual game and also in my test game. Got the [Game][Warn]: (room:1)[R 14] WARNING: DynamicSprite.CreateFromDrawingSurface: invalid size 0 x 100, will adjust message in the test game.

from ags.