Question about transparent image RMAGIK

ruby-talk
1

Hello there all,
i have a simple function to draw an image, but i cannot for the life
of me figgure out from the docs how to make it about 20% transparent.

def circle_image(zoom)
    site = self.site
     zoomhash = {13 => 0.5, 14 => 1, 15 => 2, 16 => 4}
    r = (self.radius.to_f * zoomhash[zoom.to_i].to_f)
    canvas = Magick::Image.new((2 * r), (2*r),
Magick::HatchFill.new('transparent', 'transparent'))
    gc = Magick::Draw.new
    # for the outside perimeter of the circle
    gc.stroke('black')
    gc.stroke_width(1)
    # fill in the inside
    color = KeyWord.stat_description(site.status_sensor.last_value)[1]
    gc.fill(color)
    gc.circle(r, r, 0, r)
    image = gc.draw(canvas)
    canvas.write("public/images/tmp/#{site.id}.png")
  end

please help, thanks

shawn

2

Shawn Bright wrote:

Hello there all,
i have a simple function to draw an image, but i cannot for the life
of me figgure out from the docs how to make it about 20% transparent.

def circle_image(zoom)
    site = self.site
     zoomhash = {13 => 0.5, 14 => 1, 15 => 2, 16 => 4}
    r = (self.radius.to_f * zoomhash[zoom.to_i].to_f)
    canvas = Magick::Image.new((2 * r), (2*r),
Magick::HatchFill.new('transparent', 'transparent'))
    gc = Magick::Draw.new
    # for the outside perimeter of the circle
    gc.stroke('black')
    gc.stroke_width(1)
    # fill in the inside
    color = KeyWord.stat_description(site.status_sensor.last_value)[1]
    gc.fill(color)
    gc.circle(r, r, 0, r)
    image = gc.draw(canvas)
    canvas.write("public/images/tmp/#{site.id}.png")
  end

please help, thanks

shawn

Do you want to make the entire image 20% transparent? Use the
Image#opacity= attribute
[http://studio.imagemagick.org/RMagick/doc/imageattrs.html#opacity\].

Do you want to make the drawing 20% transparent so that the drawn-upon
image shows through? See the Draw#stroke_opacity
[http://studio.imagemagick.org/RMagick/doc/draw.html#stroke_opacity\] and
Draw#fill_opacity
[http://studio.imagemagick.org/RMagick/doc/draw.html#fill_opacity\]
methods.

Also check out the example drawing here
[http://studio.imagemagick.org/RMagick/doc/usage.html#drawing_on\].

···

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3

fill_opacity was what i was looking for,
thanks very much.

shawn

···

On Feb 6, 2008 9:27 AM, Tim Hunter <rmagick@gmail.com> wrote:

Shawn Bright wrote:
> Hello there all,
> i have a simple function to draw an image, but i cannot for the life
> of me figgure out from the docs how to make it about 20% transparent.
>
> def circle_image(zoom)
> site = self.site
> zoomhash = {13 => 0.5, 14 => 1, 15 => 2, 16 => 4}
> r = (self.radius.to_f * zoomhash[zoom.to_i].to_f)
> canvas = Magick::Image.new((2 * r), (2*r),
> Magick::HatchFill.new('transparent', 'transparent'))
> gc = Magick::Draw.new
> # for the outside perimeter of the circle
> gc.stroke('black')
> gc.stroke_width(1)
> # fill in the inside
> color = KeyWord.stat_description(site.status_sensor.last_value)[1]
> gc.fill(color)
> gc.circle(r, r, 0, r)
> image = gc.draw(canvas)
> canvas.write("public/images/tmp/#{site.id}.png")
> end
>
> please help, thanks
>
> shawn

Do you want to make the entire image 20% transparent? Use the
Image#opacity= attribute
[http://studio.imagemagick.org/RMagick/doc/imageattrs.html#opacity\].

Do you want to make the drawing 20% transparent so that the drawn-upon
image shows through? See the Draw#stroke_opacity
[http://studio.imagemagick.org/RMagick/doc/draw.html#stroke_opacity\] and
Draw#fill_opacity
[http://studio.imagemagick.org/RMagick/doc/draw.html#fill_opacity\]
methods.

Also check out the example drawing here
[http://studio.imagemagick.org/RMagick/doc/usage.html#drawing_on\].
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