IL.ClearColour broken

[tobim-zz]

In 1.7.8 the underlying function ilClearColour expects color values as floating point factors (0.0 - 1.0), but the ruby wrapper is handing it bytes.

Setting the background color to some basic colors like black/white or a solid red or green actually works, as every color value above zero will be clamped to 1.0. Values in the 0x01-0xfe range will be treated as if 0xff was provided, hence setting wrong colors when used.

In example #120034 produces #FF00FF, orange #e6762b will set the clear color to white #FFFFFF.

I was unable to download older DevIL versions, so don't know if this also applies to earlier versions. Edit: Same applies to DevIL 1.1.1

---

DevIL 1.7.8 - src-IL/src/il_devil.c - Lines 251-268:

void ILAPIENTRY ilClearColour(ILclampf Red, ILclampf Green, ILclampf Blue, ILclampf Alpha)
{
    // Clamp to 0.0f - 1.0f.
    ClearRed    = Red < 0.0f ? 0.0f : (Red > 1.0f ? 1.0f : Red);
    ClearGreen  = Green < 0.0f ? 0.0f : (Green > 1.0f ? 1.0f : Green);
    ClearBlue   = Blue < 0.0f ? 0.0f : (Blue > 1.0f ? 1.0f : Blue);
    ClearAlpha  = Alpha < 0.0f ? 0.0f : (Alpha > 1.0f ? 1.0f : Alpha);

    if ((Red == Green) && (Red == Blue) && (Green == Blue)) {
        ClearLum = Red < 0.0f ? 0.0f : (Red > 1.0f ? 1.0f : Red);
    }
    else {
        ClearLum = 0.212671f * ClearRed + 0.715160f * ClearGreen + 0.072169f * ClearBlue;
        ClearLum = ClearLum < 0.0f ? 0.0f : (ClearLum > 1.0f ? 1.0f : ClearLum);
    }

    return;
}

rdevil - /ext/devil/ruby_il.c - Lines 362-372:

static VALUE il_ClearColour(VALUE obj, VALUE rb_red, VALUE rb_green, VALUE rb_blue, VALUE rb_alpha)
{
    ILubyte red = NUM2INT(rb_red);
    ILubyte green = NUM2INT(rb_green);
    ILubyte blue = NUM2INT(rb_blue);
    ILubyte alpha = NUM2INT(rb_alpha);

    ilClearColour(red, green, blue, alpha);

    return Qnil;
}

[tobim-zz]

Simple Patch:

 static VALUE il_ClearColour(VALUE obj, VALUE rb_red, VALUE rb_green, VALUE rb_blue, VALUE rb_alpha)
 {
     ILclampf red = (ILubyte)NUM2INT(rb_red);
     ILclampf green = (ILubyte)NUM2INT(rb_green);
     ILclampf blue = (ILubyte)NUM2INT(rb_blue);
     ILclampf alpha = (ILubyte)NUM2INT(rb_alpha);

     ilClearColour(red / 255.0, green / 255.0, blue / 255.0, alpha / 255.0);

     return Qnil;
 }     

[banister]

hi thanks. I think this is an issue with DevIL and its incredibly unstable API. It was, in a previous version, designed to accept bytes but it's moved to floats now?

There is also an issue that the official windows binary seems to be a different version to the linux binary. It's all very confusing and hard to maintain.

I guess i could add some conditional compilation (#ifdef) to the extension so it builds the correct wrapper for the appropriate version, but then the rdocs would be out of whack.

Im currently finishing off some other projects before i come back and take a good look at the state of Devil (which i haven't done in a long time) and sort out some of its issues.

What platform are you running Devil on ?

[tobim-zz]

Im using the libdevil1c2 apt package, aka DevIL 1.7.8-6 under current ubuntu and debian releases.