Method: Magick::Draw#annotate

Defined in:
ext/RMagick/rmdraw.c

#annotate(image_arg, width_arg, height_arg, x_arg, y_arg, text) ⇒ Magick::Draw

Annotates an image with text.

  • Additional Draw attribute methods may be called in the optional block, which is executed in the context of an Draw object.



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# File 'ext/RMagick/rmdraw.c', line 816

VALUE Draw_annotate(
                   VALUE self,
                   VALUE image_arg,
                   VALUE width_arg,
                   VALUE height_arg,
                   VALUE x_arg,
                   VALUE y_arg,
                   VALUE text)
{
    Draw *draw;
    Image *image;
    unsigned long width, height;
    long x, y;
    AffineMatrix keep;
    char geometry_str[100];
    char *embed_text;
#if defined(IMAGEMAGICK_7)
    ExceptionInfo *exception;
#endif

    // Save the affine matrix in case it is modified by
    // Draw#rotation=
    TypedData_Get_Struct(self, Draw, &rm_draw_data_type, draw);
    keep = draw->info->affine;

    image_arg = rm_cur_image(image_arg);
    image = rm_check_frozen(image_arg);

    // If we have an optional parm block, run it in self's context,
    // allowing the app a chance to modify the object's attributes
    if (rb_block_given_p())
    {
        rb_yield(self);
    }

    // Translate & store in Draw structure
    embed_text = StringValueCStr(text);
#if defined(IMAGEMAGICK_7)
    exception = AcquireExceptionInfo();
    draw->info->text = InterpretImageProperties(NULL, image, embed_text, exception);
    if (rm_should_raise_exception(exception, RetainExceptionRetention))
    {
        if (draw->info->text)
        {
            magick_free(draw->info->text);
        }
        rm_raise_exception(exception);
    }
#else
    draw->info->text = InterpretImageProperties(NULL, image, embed_text);
#endif
    if (!draw->info->text)
    {
#if defined(IMAGEMAGICK_7)
        DestroyExceptionInfo(exception);
#endif
        rb_raise(rb_eArgError, "no text");
    }

    // Create geometry string, copy to Draw structure, overriding
    // any previously existing value.
    width  = NUM2ULONG(width_arg);
    height = NUM2ULONG(height_arg);
    x      = NUM2LONG(x_arg);
    y      = NUM2LONG(y_arg);

    if (width == 0 && height == 0)
    {
        snprintf(geometry_str, sizeof(geometry_str), "%+ld%+ld", x, y);
    }

    // WxH is non-zero
    else
    {
        snprintf(geometry_str, sizeof(geometry_str), "%lux%lu%+ld%+ld", width, height, x, y);
    }

    magick_clone_string(&draw->info->geometry, geometry_str);

#if defined(IMAGEMAGICK_7)
    GVL_STRUCT_TYPE(AnnotateImage) args = { image, draw->info, exception };
#else
    GVL_STRUCT_TYPE(AnnotateImage) args = { image, draw->info };
#endif
    CALL_FUNC_WITHOUT_GVL(GVL_FUNC(AnnotateImage), &args);

    magick_free(draw->info->text);
    draw->info->text = NULL;
    draw->info->affine = keep;

#if defined(IMAGEMAGICK_7)
    CHECK_EXCEPTION();
    DestroyExceptionInfo(exception);
#else
    rm_check_image_exception(image, RetainOnError);
#endif

    return self;
}