Class: Magick::Pixel

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
ext/RMagick/rmmain.c

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Object

Ruby usage:

- @verbatim Pixel#initialize @endverbatim
- @verbatim Pixel#initialize(red) @endverbatim
- @verbatim Pixel#initialize(red,green) @endverbatim
- @verbatim Pixel#initialize(red,green,blue) @endverbatim
- @verbatim Pixel#initialize(red,green,blue,opacity) @endverbatim

Notes:

- Default red is 0.0
- Default green is 0.0
- Default blue is 0.0
- Default opacity is 0.0
- For backward compatibility, arguments may be nil.

Parameters:

  • argc

    number of input arguments

  • argv

    array of input arguments

  • self

    this object


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# File 'ext/RMagick/rmpixel.c', line 766

VALUE
Pixel_initialize(int argc, VALUE *argv, VALUE self)
{
    Pixel *pixel;

    Data_Get_Struct(self, Pixel, pixel);

    switch(argc)
    {
        case 4:
            if (argv[3] != Qnil)
            {
                pixel->opacity = APP2QUANTUM(argv[3]);
            }
        case 3:
            if (argv[2] != Qnil)
            {
                pixel->blue = APP2QUANTUM(argv[2]);
            }
        case 2:
            if (argv[1] != Qnil)
            {
                pixel->green = APP2QUANTUM(argv[1]);
            }
        case 1:
            if (argv[0] != Qnil)
            {
                pixel->red = APP2QUANTUM(argv[0]);
            }
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 4)", argc);
    }

    return self;
}

Class Method Details

.from_color(name) ⇒ Object

Construct an Magick::Pixel corresponding to the given color name.

Ruby usage:

- @verbatim Magick::Pixel.from_color(string) @endverbatim

Notes:

- The "inverse" is Image_to_color, b/c the conversion of a pixel to a
  color name requires both a color depth and if the opacity value has
  meaning (i.e. whether image->matte == True or not).

Parameters:

  • class

    the Ruby class to use

  • name

    the color name

Returns:

  • a new Magic::Pixel object

See Also:

  • Image_to_color
  • Pixel_to_color

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# File 'ext/RMagick/rmpixel.c', line 510

VALUE
Pixel_from_color(VALUE class ATTRIBUTE_UNUSED, VALUE name)
{
    PixelColor pp;
    ExceptionInfo *exception;
    MagickBooleanType okay;

    exception = AcquireExceptionInfo();
    okay = QueryColorCompliance(StringValuePtr(name), AllCompliance, &pp, exception);
    CHECK_EXCEPTION()
    (void) DestroyExceptionInfo(exception);

    if (!okay)
    {
        rb_raise(rb_eArgError, "invalid color name: %s", StringValuePtr(name));
    }

    return Pixel_from_PixelColor(&pp);
}

.from_hsla(*args) ⇒ Object

Construct an RGB pixel.

Ruby usage:

- @verbatim Pixel#from_hsla(hue, saturation, lightness) @endverbatim
- @verbatim Pixel#from_hsla(hue, saturation, lightness, alpha) @endverbatim

Notes:

- Default alpha is 1.0
- 0 <= hue < 360 OR "0%" <= hue < "100%"
- 0 <= saturation <= 255 OR "0%" <= saturation <= "100%"
- 0 <= lightness <= 255 OR "0%" <= lightness <= "100%"
- 0 <= alpha <= 1 (0 is transparent, 1 is opaque) OR "0%" <= alpha <= "100%"

Parameters:

  • argc

    number of input arguments

  • argv

    array of input arguments

  • class

    the Ruby class to use

Returns:

  • a new Magick::Pixel object


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# File 'ext/RMagick/rmpixel.c', line 550

VALUE
Pixel_from_hsla(int argc, VALUE *argv, VALUE class ATTRIBUTE_UNUSED)
{
    double h, s, l, a = 1.0;
    MagickPixel pp;
    ExceptionInfo *exception;
    char name[50];
    MagickBooleanType alpha = MagickFalse;

    switch (argc)
    {
        case 4:
            a = rm_percentage(argv[3],1.0);
            alpha = MagickTrue;
        case 3:
            // saturation and lightness are out of 255 in new ImageMagicks and
            // out of 100 in old ImageMagicks. Compromise: always use %.
            l = rm_percentage(argv[2],255.0);
            s = rm_percentage(argv[1],255.0);
            h = rm_percentage(argv[0],360.0);
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 3 or 4)", argc);
            break;
    }

    if (alpha && (a < 0.0 || a > 1.0))
    {
        rb_raise(rb_eRangeError, "alpha %g out of range [0.0, 1.0]", a);
    }
    if (l < 0.0 || l > 255.0)
    {
        rb_raise(rb_eRangeError, "lightness %g out of range [0.0, 255.0]", l);
    }
    if (s < 0.0 || s > 255.0)
    {
        rb_raise(rb_eRangeError, "saturation %g out of range [0.0, 255.0]", s);
    }
    if (h < 0.0 || h >= 360.0)
    {
        rb_raise(rb_eRangeError, "hue %g out of range [0.0, 360.0)", h);
    }

    memset(name, 0, sizeof(name));
    if (alpha)
    {
        sprintf(name, "hsla(%-2.1f,%-2.1f,%-2.1f,%-2.1f)", h, s, l, a);
    }
    else
    {
        sprintf(name, "hsl(%-2.1f,%-2.1f,%-2.1f)", h, s, l);
    }

    exception = AcquireExceptionInfo();

    (void) QueryMagickColor(name, &pp, exception);
    CHECK_EXCEPTION()

    (void) DestroyExceptionInfo(exception);

    return Pixel_from_MagickPixel(&pp);
}

Instance Method Details

#<=>(other) ⇒ Object

Support Comparable mixin.

Ruby usage:

- @verbatim Pixel#<=> @endverbatim

Parameters:

  • self

    this object

  • other

    the other Pixel

Returns:

  • -1, 0, 1


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# File 'ext/RMagick/rmpixel.c', line 892

VALUE
Pixel_spaceship(VALUE self, VALUE other)
{
    Pixel *this, *that;

    Data_Get_Struct(self, Pixel, this);
    Data_Get_Struct(other, Pixel, that);

    if (this->red != that->red)
    {
        return INT2NUM((this->red - that->red)/abs(this->red - that->red));
    }
    else if(this->green != that->green)
    {
        return INT2NUM((this->green - that->green)/abs(this->green - that->green));
    }
    else if(this->blue != that->blue)
    {
        return INT2NUM((this->blue - that->blue)/abs(this->blue - that->blue));
    }
    else if(this->opacity != that->opacity)
    {
        return INT2NUM(((QuantumRange - this->opacity) - (QuantumRange - that->opacity))/abs((QuantumRange - this->opacity) - (QuantumRange - that->opacity)));
    }

    // Values are equal, check class.

    return rb_funcall(CLASS_OF(self), rb_intern("<=>"), 1, CLASS_OF(other));

}

#===(other) ⇒ Object

“Case equal” operator for Pixel.

Ruby usage:

- @verbatim Pixel#=== @endverbatim

Parameters:

  • self

    this object

  • other

    the other object

Returns:

  • true or false


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# File 'ext/RMagick/rmpixel.c', line 327

VALUE
Pixel_case_eq(VALUE self, VALUE other)
{
    Pixel *this, *that;

    if (CLASS_OF(self) == CLASS_OF(other))
    {
        Data_Get_Struct(self, Pixel, this);
        Data_Get_Struct(other, Pixel, that);
        return (this->red == that->red
            && this->blue == that->blue
            && this->green == that->green
            && this->opacity == that->opacity) ? Qtrue : Qfalse;
    }

    return Qfalse;
}

#cloneObject

Clone a Pixel.

Ruby usage:

- @verbatim Pixel#clone @endverbatim

Parameters:

  • self

    this object

Returns:

  • a clone

See Also:

  • Pixel_dup
  • Pixel_init_copy

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# File 'ext/RMagick/rmpixel.c', line 357

VALUE
Pixel_clone(VALUE self)
{
    VALUE clone;

    clone = Pixel_dup(self);
    if (OBJ_FROZEN(self))
    {
        OBJ_FREEZE(clone);
    }

    RB_GC_GUARD(clone);

    return clone;
}

#dupObject

Duplicate a Pixel.

Ruby usage:

- @verbatim Pixel#dup @endverbatim

Parameters:

  • self

    this object

Returns:

  • a clone

See Also:

  • Pixel_clone
  • Pixel_init_copy

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# File 'ext/RMagick/rmpixel.c', line 385

VALUE
Pixel_dup(VALUE self)
{
    Pixel *pixel;
    VALUE dup;

    pixel = ALLOC(Pixel);
    memset(pixel, '\0', sizeof(Pixel));
    dup = Data_Wrap_Struct(CLASS_OF(self), NULL, destroy_Pixel, pixel);
    if (rb_obj_tainted(self))
    {
        (void) rb_obj_taint(dup);
    }

    RB_GC_GUARD(dup);

    return rb_funcall(dup, rm_ID_initialize_copy, 1, self);
}

#eql?(other) ⇒ Boolean

For use with Hash.

Ruby usage:

- @verbatim Pixel#eql? @endverbatim

Parameters:

  • self

    this object

  • other

    the other object

Returns:

  • (Boolean)

    true if hash to the same value, otherwise false


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# File 'ext/RMagick/rmpixel.c', line 415

VALUE
Pixel_eql_q(VALUE self, VALUE other)
{
    return NUM2INT(Pixel_spaceship(self, other)) == 0 ? Qtrue : Qfalse;
}

#fcmp(*args) ⇒ Object

Compare pixel values for equality.

Ruby usage:

- @verbatim Pixel#fcmp(other, fuzz, colorspace) @endverbatim

Notes:

- Default fuzz is 0.0
- Default colorspace is RGBColorspace

Parameters:

  • argc

    number of input arguments

  • argv

    array of input arguments

  • self

    this object

Returns:

  • true if equal, otherwise false


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# File 'ext/RMagick/rmpixel.c', line 437

VALUE
Pixel_fcmp(int argc, VALUE *argv, VALUE self)
{
    double fuzz = 0.0;
    unsigned int equal;
    ColorspaceType colorspace = RGBColorspace;
    Image *image;
    Info *info;
    Pixel *this, *that;

    switch (argc)
    {
        case 3:
            VALUE_TO_ENUM(argv[2], colorspace, ColorspaceType);
        case 2:
            fuzz = NUM2DBL(argv[1]);
        case 1:
            // Allow 1 argument
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 1 to 3)", argc);
            break;
    }

    Data_Get_Struct(self, Pixel, this);
    Data_Get_Struct(argv[0], Pixel, that);

    // The IsColorSimilar function expects to get the
    // colorspace and fuzz parameters from an Image structure.

    info = CloneImageInfo(NULL);
    if (!info)
    {
        rb_raise(rb_eNoMemError, "not enough memory to continue");
    }

    image = rm_acquire_image(info);

    // Delete Info now in case we have to raise an exception
    (void) DestroyImageInfo(info);

    if (!image)
    {
        rb_raise(rb_eNoMemError, "not enough memory to continue");
    }

    image->colorspace = colorspace;
    image->fuzz = fuzz;

    equal = IsColorSimilar(image, this, that);
    (void) DestroyImage(image);

    return equal ? Qtrue : Qfalse;
}

#hashObject

Ruby usage:

- @verbatim Pixel#hash @endverbatim

Notes:

- INT2FIX left-shifts 1 bit. Sacrifice 1 bit from the opacity attribute to
  the FIXNUM_FLAG.

Parameters:

  • self

    this object

Returns:

  • the hash of self


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# File 'ext/RMagick/rmpixel.c', line 703

VALUE
Pixel_hash(VALUE self)
{
    Pixel *pixel;
    unsigned int hash;

    Data_Get_Struct(self, Pixel, pixel);

    hash  = ScaleQuantumToChar(pixel->red)   << 24;
    hash += ScaleQuantumToChar(pixel->green) << 16;
    hash += ScaleQuantumToChar(pixel->blue)  << 8;
    hash += ScaleQuantumToChar(QuantumRange - pixel->opacity);

    return UINT2NUM(hash >> 1);
}

#initialize_copy(orig) ⇒ Object

Initialize clone, dup methods.

Ruby usage:

- @verbatim Pixel#initialize_copy @endverbatim

Parameters:

  • self

    this object

  • orig

    the original Pixel

Returns:

  • self

See Also:

  • Pixel_clone
  • Pixel_dup

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# File 'ext/RMagick/rmpixel.c', line 732

VALUE
Pixel_init_copy(VALUE self, VALUE orig)
{
    Pixel *copy, *original;

    Data_Get_Struct(orig, Pixel, original);
    Data_Get_Struct(self, Pixel, copy);

    *copy = *original;

    return self;
}

#intensityObject

Return the “intensity” of a pixel.

Ruby usage:

- @verbatim Pixel#intensity @endverbatim

Parameters:

  • self

    this object

Returns:

  • the intensity


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# File 'ext/RMagick/rmpixel.c', line 814

VALUE
Pixel_intensity(VALUE self)
{
    Pixel *pixel;
    Quantum intensity;

    Data_Get_Struct(self, Pixel, pixel);

    intensity = ROUND_TO_QUANTUM((0.299*pixel->red)
                                + (0.587*pixel->green)
                                + (0.114*pixel->blue));

    return QUANTUM2NUM((unsigned long) intensity);
}

#marshal_dumpObject

Support Marshal.dump.

Ruby usage:

- @verbatim Pixel#marshal_dump @endverbatim

Parameters:

  • self

    this object

Returns:

  • a string representing the dumped pixel


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# File 'ext/RMagick/rmpixel.c', line 839

VALUE
Pixel_marshal_dump(VALUE self)
{
    Pixel *pixel;
    VALUE dpixel;

    Data_Get_Struct(self, Pixel, pixel);
    dpixel = rb_hash_new();
    rb_hash_aset(dpixel, CSTR2SYM("red"), QUANTUM2NUM(pixel->red));
    rb_hash_aset(dpixel, CSTR2SYM("green"), QUANTUM2NUM(pixel->green));
    rb_hash_aset(dpixel, CSTR2SYM("blue"), QUANTUM2NUM(pixel->blue));
    rb_hash_aset(dpixel, CSTR2SYM("opacity"), QUANTUM2NUM(pixel->opacity));

    RB_GC_GUARD(dpixel);

    return dpixel;
}

#marshal_load(dpixel) ⇒ Object

Support Marshal.load.

Ruby usage:

- @verbatim Pixel#marshal_load @endverbatim

Parameters:

  • self

    this object

  • dpixel

    the dumped pixel

Returns:

  • self


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# File 'ext/RMagick/rmpixel.c', line 868

VALUE
Pixel_marshal_load(VALUE self, VALUE dpixel)
{
    Pixel *pixel;

    Data_Get_Struct(self, Pixel, pixel);
    pixel->red = NUM2QUANTUM(rb_hash_aref(dpixel, CSTR2SYM("red")));
    pixel->green = NUM2QUANTUM(rb_hash_aref(dpixel, CSTR2SYM("green")));
    pixel->blue = NUM2QUANTUM(rb_hash_aref(dpixel, CSTR2SYM("blue")));
    pixel->opacity = NUM2QUANTUM(rb_hash_aref(dpixel, CSTR2SYM("opacity")));
    return self;
}

#to_color(*args) ⇒ Object

Return the color name corresponding to the pixel values.

Ruby usage:

- @verbatim Magick::Pixel#to_color @endverbatim
- @verbatim Magick::Pixel#to_color(compliance) @endverbatim
- @verbatim Magick::Pixel#to_color(compliance, matte) @endverbatim
- @verbatim Magick::Pixel#to_color(compliance, matte, depth) @endverbatim
- @verbatim Magick::Pixel#to_color(compliance, matte, depth, hex) @endverbatim

Notes:

- Default compliance is AllCompliance
- Default matte is false
- Default depth is MAGICKCORE_QUANTUM_DEPTH
- Default hex is false
- The conversion respects the value of the 'opacity' field in the Pixel

Parameters:

  • argc

    number of input arguments

  • argv

    array of input arguments

  • self

    this object

Returns:

  • the color name as a String


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# File 'ext/RMagick/rmpixel.c', line 1015

VALUE
Pixel_to_color(int argc, VALUE *argv, VALUE self)
{
    Info *info;
    Image *image;
    Pixel *pixel;
    MagickPixel mpp;
    MagickBooleanType hex = MagickFalse;
    char name[MaxTextExtent];
    ExceptionInfo *exception;
    ComplianceType compliance = AllCompliance;
    unsigned int matte = MagickFalse;
    unsigned int depth = MAGICKCORE_QUANTUM_DEPTH;

    switch (argc)
    {
        case 4:
            hex = RTEST(argv[3]);
        case 3:
            depth = NUM2UINT(argv[2]);

            // Ensure depth is appropriate for the way xMagick was compiled.
            switch (depth)
            {
                case 8:
#if MAGICKCORE_QUANTUM_DEPTH == 16 || MAGICKCORE_QUANTUM_DEPTH == 32
                case 16:
#endif
#if MAGICKCORE_QUANTUM_DEPTH == 32
                case 32:
#endif
                    break;
                default:
                    rb_raise(rb_eArgError, "invalid depth (%d)", depth);
                    break;
            }
       case 2:
            matte = RTEST(argv[1]);
        case 1:
            VALUE_TO_ENUM(argv[0], compliance, ComplianceType);
        case 0:
            break;
        default:
            rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 to 2)", argc);
    }

    Data_Get_Struct(self, Pixel, pixel);

    info = CloneImageInfo(NULL);
    image = rm_acquire_image(info);
    (void) DestroyImageInfo(info);

    if (!image)
    {
        rb_raise(rb_eNoMemError, "not enough memory to continue.");
    }

    image->depth = depth;
    image->matte = matte;

    rm_init_magickpixel(image, &mpp);
    rm_set_magick_pixel_packet(pixel, &mpp);

    exception = AcquireExceptionInfo();

    // Support for hex-format color names moved out of QueryMagickColorname
    // in 6.4.1-9. The 'hex' argument was removed as well.
    if (hex)
    {
        if (compliance == XPMCompliance)
        {
            mpp.matte = MagickFalse;
            mpp.depth = (unsigned long) min(1.0 * image->depth, 16.0);
        }
        (void) GetColorTuple(&mpp, MagickTrue, name);
    }
    else
    {
        (void) QueryMagickColorname(image, &mpp, compliance, name, exception);
    }

    (void) DestroyImage(image);
    CHECK_EXCEPTION()
    (void) DestroyExceptionInfo(exception);

    // Always return a string, even if it's ""
    return rb_str_new2(name);
}

#to_hslaObject

Return [hue, saturation, lightness, alpha] in the same ranges as Pixel_from_hsla.

Ruby usage:

- @verbatim Pixel#to_hsla @endverbatim

Parameters:

  • self

    this object

Returns:

  • an array with hsla data

See Also:

  • Pixel_from_hsla

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# File 'ext/RMagick/rmpixel.c', line 936

VALUE
Pixel_to_hsla(VALUE self)
{
    double hue, sat, lum, alpha;
    Pixel *pixel;
    VALUE hsla;

    Data_Get_Struct(self, Pixel, pixel);

    ConvertRGBToHSL(pixel->red, pixel->green, pixel->blue, &hue, &sat, &lum);
    hue *= 360.0;
    sat *= 255.0;
    lum *= 255.0;

    if (pixel->opacity == OpaqueOpacity)
    {
        alpha = 1.0;
    }
    else if (pixel->opacity == TransparentOpacity)
    {
        alpha = 0.0;
    }
    else
    {
        alpha = (double)(QuantumRange - pixel->opacity) / (double)QuantumRange;
    }

    hsla = rb_ary_new3(4, rb_float_new(hue), rb_float_new(sat), rb_float_new(lum), rb_float_new(alpha));

    RB_GC_GUARD(hsla);

    return hsla;
}

#to_sObject

Create a string representation of a Magick::Pixel.

Ruby usage:

- @verbatim Magick::Pixel#to_s @endverbatim

Parameters:

  • self

    this object

Returns:

  • the string


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# File 'ext/RMagick/rmpixel.c', line 1114

VALUE
Pixel_to_s(VALUE self)
{
    Pixel *pixel;
    char buff[100];

    Data_Get_Struct(self, Pixel, pixel);
    sprintf(buff, "red=" QuantumFormat ", green=" QuantumFormat ", blue=" QuantumFormat ", alpha=" QuantumFormat,
            pixel->red, pixel->green, pixel->blue,
            (QuantumRange - pixel->opacity));
    return rb_str_new2(buff);
}