Question

GDI+ - drawing a glossy half ellipse, help with inverting glossy ellipse

Asked by: stormist

I have a clock face which i apply a gloss to. The below code adds the gloss. It adds the gloss to the top 1/3 of the clock. To help visualize the gloss currently getting added and the desired see attached pictures. The gloss is added in the shape of a crescent moon, but I need it to be inverted.

Any ideas?

Thank you

/// <summary>
        /// Applies gloss to clock
        /// </summary>
        /// <param name="e"></param>
        private void DrawGloss(PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            float x = (float)_CenterX / _PI;
            float y = (float)_CenterY / _PI;
            float width = ((this.ClientSize.Width / 2)) + _hourLength;
            float height = ((this.ClientSize.Height / 2)) + _hourLength;
 
            RectangleF glossRect = new RectangleF(
           x + (float)(width * 0.10),
           y + (float)(height * 0.07),
           (float)(width * .8),
           (float)(height * 0.4));
 
            Color gloss1 = Color.FromArgb(233, 233, 233);
            Color gloss2 = Color.FromArgb(239, 239, 239);
 
            LinearGradientBrush gradientBrush =
                new LinearGradientBrush(glossRect,
                Color.FromArgb((int)glossiness, Color.Transparent),
                glossColor,
                LinearGradientMode.Vertical);
            g.FillEllipse(gradientBrush, glossRect);
           
        }

                                  
1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:

Select allOpen in new window

  • Desired.jpg
    • 51 KB

    Desired gloss applied to top half of circle

    Desired gloss applied to top half of circle
  • Current.jpg
    • 49 KB

    Current gloss applied to top half of circle

    Current gloss applied to top half of circle

This Question has been solved and asker verified All Experts Exchange premium technology solutions are available to subscription members.

Subscribe now for full access to Experts Exchange and get

Instant Access to this Solution

  • Plus...
  • 30 Day FREE access, no risk, no obligation
  • Collaborate with the world's top tech experts
  • Unlimited access to our exclusive solution database
  • Never be left without tech help again

Subscribe Now

Asked On
2009-09-14 at 13:58:07ID24730997
Topics

C# Programming Language

,

.NET

,

Microsoft Visual C#.Net

Participating Experts
4
Points
500
Comments
15

Trusted by hundreds of thousands everyday for fast, accurate and reliable tech support.

  • "The time we save is the biggest benefit of Experts Exchange to Warner Bros. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange." Mike Kapnisakis, Warner Bros.
  • "Our team likes having a resource that is more secure than just using Google and most experts using this service really know their stuff. It's nice to look here first versus using Google." Dayna Sellner, Lockheed Martin
  • "Anytime that I've been stumped with a problem, 9 out of 10 times Experts Exchange has either the accepted solution or an open discussion of the potential solution to the problem." Kenny Red, eBay Inc.

See what Experts Exchange can do for you.

Got a question?

We've got the answer.

Experts Exchange has been collecting answers to technology questions since 1996…3 million and counting! If you have a question, chances are we already have your answer.

Screenshot of Experts Exchange Knowledgebase

Need individual assistance?

Our experts are ready to help.

If you can't find the exact answer you're looking for, ask our exclusive community of 50,000 experts. You’ll get a personalized answer from a trusted professional.

Screenshot of Experts Exchange Knowledgebase

Want to learn from the best?

Read articles from industry experts.

Thousands of free tech tips, tricks, how-to’s and tutorials are available in our peer reviewed articles section. See for yourself how smart our experts are, no login required.

Screenshot of an Article

Working on a long term project?

Store your work and research.

Save solutions to your questions, answers you’ve discovered through searching plus helpful articles in your personal knowledgebase for easy future access.

Screenshot of Experts Exchange Knowledgebase

Access the answers to your technology questions today.

Subscribe Now

30-day free trial. Register in 60 seconds.

What Makes Experts Exchange Unique?

Members of the expert community talk about why the experience at Experts Exchange is different than what you will find anywhere else.

Trusted by the world's most respected brands.

image of each brand's logo

Faithfully serving IT professionals since 1996.

Experts Exchange Logo

Try it out and discover for yourself.

Subscribe Now

30-day free trial. Register in 60 seconds.

Related Solutions

  1. Inverters
    How many watts do I need from an inverter to run my laptop computer? Most of the ones I see are rated at 50 watts. I have a Compaq Presario 1030, CD Rom, etc. I want to use an inverter in my car to power the laptop for use with GPS. Compaq Tech Support says I need 240 watts,...
  2. Invert colors....
    I'm looking if there is a way to invert colors... like i'm making buttons for my site.. the theme is black and white... First of the background is black and the text is white on mouse over the backround is white and text is black instead of making to different pictures is th...

Free Tech Articles

  1. WARNING: 5 Reasons why you should NEVER fix a computer for free.
    It is in our nature to love the puzzle. We are obsessed. The lot of us. We love puzzles. We love the challenge. We thrive on finding the answer. We hate disarray. It bothers us deep in our soul. W...
  2. SCCM OSD Basic troubleshooting
    SCCM 2007 OSD is a fantastic way to deploy operating systems, however, like most things SCCM issues can sometimes be difficult to resolve due to the sheer volume of logs to sift through and the dispe...
  3. Migrate Small Business Server 2003 to Exchange 2010 and Windows 2008 R2
    This guide is intended to provide step by step instructions on how to migrate from Small Business Server 2003 to Windows 2008 R2 with Exchange 2010. For this migration to work you will need the fo...
  4. Create a Win7 Gadget
    This article shows you how to create a simple "Gadget" -- a sort of mini-application supported by Windows 7 and Vista. Gadgets can be dropped anywhere on the desktop to provide instant information, ...
  5. Outlook continually prompting for username and password
    There have been a lot of questions recently regarding Outlook prompting for a username and password whilst using Exchange 2007. There are a few reasons why this would happen and I will try to cover t...
  6. Backup Exchange 2010 Information Store using Windows Backup
    There seems to be quite a lot of confusion around the ability to backup Exchange 2010 using the built in Windows Backup feature. This stems from the omission of this feature prior to Exchange 2007 s...

Cloud Class Webinars

  1. Avoiding Bugs in Microsoft Access
    Alison Balter takes and in-depth look at avoiding bugs in Access. In this webinar you will learn about using the immediate window to debug your applications, invoking the debugger, using breakpoints to troubleshoot, stepping through code, setting the next statement to execute, ...
  2. Top 10 Best New Features in Visio 2010
    Scott Helmers gives live demonstrations of the top 10 new features in Visio 2010. This webinar will teach you how to create compelling diagrams by adding shapes to the page with a single click, linking the shapes in a diagram to data in Excel (or SQL Server, or SharePoint), ...
  3. IT Consultant Business Secrets Revealed
    Michael Munger, Experts Exchange tech pro and IT consultant, pulls back the curtain on his very successful businesses and answers question on every IT consultant and business owner should know about. He shares secrets on what he did to solve the 5 most common problems in IT, ...
  4. Disaster Recovery and Business Continuity
    Quest CTO, Mike Billon, gives an overview of the steps involved in building a dunamic disaster recovery plan. Through case studies and an examination of software/hardware tooles for monitoring and testing, you'll gain a better understandin of where you are, where you want ...
  5. Organize Your Visio Diagrams with Containers and Lists
    Scott Helmers uses cross functional flowcharts, wireframe diagrams, data graphic legends and seating charts to teach you: how to ustilize all three new structured diagram components in Visio 2010, the best practices for organizeing shapes in previous version of Visio, how to organize ...
  6. How to Us Objects, Properties, Events and Methods in Microsoft Access
    Alison Dalter gives an in-depbth look at objects, properties, events and methods in Microsoft Access. In this webinar you will learn about using the object browser, referring to objects, working with properties and methods, working with object variables, understanding the ...

Join the Community

Give a Little. Get a Lot.

Join the community of experts here and help other tech pros by answering question in your area of expertise. You can earn FREE access to all Experts Exchange's premium features and resources.

Join the Community

Answers

 

by: daryalPosted on 2009-09-14 at 14:50:40ID: 25329679

Hello,
If you change your rectangle it will do it, but you maybe you need to modify your center points, please give a try.

Please do not forget Y axis value increases as you go down, and decreases as you go up. So you should give a minus height value to your rectangle.

  RectangleF glossRect = new RectangleF(
           x + (float)(width * 0.10),
           y + (float)(height * 0.07) + (float)(height * 0.4),
           (float)(width * .8),
           (float)(-height * 0.4));

                                              
1:
2:
3:
4:
5:

Select allOpen in new window

 

by: stormistPosted on 2009-09-14 at 14:56:48ID: 25329720

HI Daryal, thanks for your response!

The code above shows the full ellipse instead of half of it. The bottom of the ellipse still looks like the current.jpg, but the top half is visible as well. I'm trying to apply a half ellipse of gloss inverted like in desired.jpg.

 

by: daryalPosted on 2009-09-14 at 15:29:47ID: 25329912

Hi,
can you post the values which are not declared in this function like glossiness and glossColor...?

 

by: stormistPosted on 2009-09-14 at 15:56:21ID: 25330052

Sure thing
Glossiness is set to 25
gloss color is white

 

by: mac-willPosted on 2009-09-14 at 18:19:55ID: 25330680

What about flipping the axis before drawing the ellipse?

TranslateTransform(0, -height);

 

by: stormistPosted on 2009-09-14 at 18:22:50ID: 25330690

I'm afraid that messes up all my other clock features, as its done on the same graphics object

 

by: stormistPosted on 2009-09-14 at 18:37:44ID: 25330734

daryal, if you would be so kind as to take a look I can e-mail you the whole project if that is not enough code to deduce the modification?

 

by: mac-willPosted on 2009-09-15 at 05:31:15ID: 25334096


only flip when you need to:

regular drawing...

TranslateTransform(0, -height);

flipped drawing...

TranslateTransform(0, height);

regular drawing...

 

by: stormistPosted on 2009-09-15 at 11:37:14ID: 25337846

Hi mac-will thanks for the help,

It appears that no longer distorts my whole rendering. However, now I can't see the gloss at all. I'm not quite sure where it went but its off the screen. (using both my old code and the modification suggested above)


        /// <summary>
        /// Applies gloss to clock
        /// </summary>
        /// <param name="e"></param>
        private void DrawGloss(PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            float x = (float)_CenterX / _PI;
            float y = (float)_CenterY / _PI;
            float width = ((this.ClientSize.Width / 2)) + _hourLength;
            float height = ((this.ClientSize.Height / 2)) + _hourLength;
 
            RectangleF glossRect = new RectangleF(
           x + (float)(width * 0.10),
           y + (float)(height * 0.07),
           (float)(width * .8),
           (float)(height * 0.4));
          //  RectangleF glossRect = new RectangleF(
          //x + (float)(width * 0.10),
          //y + (float)(height * 0.07) + (float)(height * 0.4),
          //(float)(width * .8),
          //(float)(-height * 0.4));
 
            LinearGradientBrush gradientBrush =
                new LinearGradientBrush(glossRect,
                Color.FromArgb((int)glossiness, Color.Transparent),
                glossColor,
                LinearGradientMode.Vertical);
            g.TranslateTransform(0, -height);
            g.FillEllipse(gradientBrush, glossRect);
            g.TranslateTransform(0, height);
           
        }

                                              
1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:

Select allOpen in new window

 

by: stormistPosted on 2009-09-15 at 12:20:52ID: 25338271

Perhaps if I rephrase this. I think what I need to do is remove just above the bottom half of the ellipse by an opacity mask or similar function. Then I can just center it on top and get the desired effect. Can anyone show how this might be done?

 

by: stormistPosted on 2009-09-16 at 20:38:40ID: 25352647

Still at this one with no luck.. Any other suggestions would be appreciated!

 

by: mac-willPosted on 2009-09-17 at 05:31:33ID: 25355246

Can you attach a small sample solution?

 

by: TheLearnedOnePosted on 2009-09-17 at 09:10:29ID: 25357779

It sounds like you need to change the angle of the LinearGradientBrush:

LinearGradientBrush Constructor (Rectangle, Color, Color, Single)
http://msdn.microsoft.com/en-us/library/ms142563.aspx

public LinearGradientBrush(Rectangle rect, Color color1, Color color2, float angle)

 

by: p_davisPosted on 2009-09-17 at 09:11:34ID: 25357790

maybe i'm not understanding, but what about                
g.RotateTransform(180f);

 

by: TheLearnedOnePosted on 2009-09-17 at 09:15:51ID: 25357843

RotateTransform is an option, but if you haven't worked with it, can add more complication.  You have to think about how it is applied, origins for the rotation, and that everything would be rotated if you aren't careful.

20120131-EE-VQP-002

3 Ways to Join

30-Day Free Trial

The Experts

98% positive feedback on 31,087 answers since March 2000. angeliii is a Microsoft Most Valuable Professional for his work with MS SQL Server & Develoment.

He has also proven his knowledge of Visual Basic Programming, PHP Scripting and Oracle Databases.

The Experts

97% positive feedback on 10,752 answers since July 2000. lrmoore has more than 18 years experience in the networking industry.

The six-time Mircosoft MVPs specialties include firewalls, virtual private networking, and network management.

Testimonials

"...and excellent source for support... Kind of like having your very own IT dept." Electriciansnet

Testimonials

"I was apprehensive at signing up at first. However... it has already made my life as an IT administrator much easier." JaCrews

Testimonials

"WOW! You guys have great, active, and knowledgeable people on here." moore50

Business Clients

Business Clients

In the Press

"If you’ve got a question... Experts Exchange can supply an answer.”

In the Press

"...an invaluable aid for both IT professionals and those who require tech support."

In the Press

"where IT professionals provide quick answers on just about any topic"

Business Account Plans

Loading Advertisement...