About

My name is Diney Bomfim.
I was born in Campos dos Goytacases, Rio de Janeiro – Brazil.
Graduated as Publicitary by Casper Libero College, Sao Paulo – Brazil.


Start working with advertising and loving the art of communication. I worked for years as Art Director in agencies. The communication knowledge drove me to Neurolinguistic (NLP) and this one made me realize the magic of creation. Then I decided gave all my life and soul to the art of development. My golden rule is: “Keep it simple!”. If some idea can’t be comunicated in less 30 sec, it’s not good enough. Thanks to the advertising for this thought. Besides, I believe in a world with no money, just people doing what they love to do.


Today, my specialities are:

  • Objective-C (iOS and MacOS)
  • C/C++ (Linux)
  • OpenGL, OpenGL ES, WebGL
  • 3D Maths and 3D World
  • Web Platform (AS3, JavaScript, PHP, HTML 5, MySQL, SQL Server)
  • #1 written by Salim A Jaliwala 
    about 11 months ago
    Reply Quote

    Hi Diney,

    Read yoru write-up on Open GL. Excellent work. Thanks for sharing. I downloaded the cube example. Runs on my Xcode and iPad.

    Question for you, if you don’t mind. I created a similar image like your cube_example, except instead of Top, Bottom etc, I had the faces if a dice. I substituted this image in the resource folder and called it by the same name, but it didn’t work. All I see is a cube with all black surfaces. What am I doiing wrong? Appreciate if you help me. Thanks.

    My name is Salim Jaliwala. I live in Peoria, Illinois, USA> I’m an Engineering Manager at Caterpillar Inc. My background is Electronic Controls. I really appreciate all your tutorials. They are fun to read and understand. You are making a tremendous contribution in this field.

    I wrote a book on Sudoku a couple of years back. When you get a chance, check out my website. If you lie, I can mail you a complementary hard copy of the book :-) . it will be my pleasure to do so.

    Also, if you get a chance, check out my mind-reader puzzle on http://www.s239436151.onlinehome.us

    Hope to hear from you.

    Cheers,
    Salim

    • #2 written by Diney Bomfim
      about 11 months ago
      Reply Quote

      Hello Salim!

      Thanks man,

      I love all kind of puzzels and intelectual games. Unfortunately I don’t live in USA, not yet… but I really want that.

      I looked at your site and sudoku book. Wow, almost 180 pages of sudoku! I took a gibi of sudoku some time, almost 30 pages… well.. I spent many months with all that. Your book looks be a fun for a year! I would really appreciate one. :)

      Now about ur question… well, you know, Xcode sometimes makes the things harder rather than easier. It’s making strong references to the files, so if you replace them in Finder, will be like a delete to Xcode.

      As your files have the same name as the originals ones, just delete the image files on the Xcode and then “drag & drop” your new files in place.

      Oh yeah, and make sure your image files have 8 bits per channel, the routine on that sample project just works for 8 bpc. You can check that on image softwares like Photoshop under the menu Image > Mode > 8 bits per channel.

      Thanks again!

  • #3 written by Salim A Jaliwala 
    about 11 months ago
    Reply Quote

    Hello Diney,

    Thanks for your prompt response. If you email me your postal address, I’ll put a hard copy of my book in the mail to you. This is the elast I can do for all the knowledge you are sharing with us. I’ll also sign the book, so you get an author-signed copy :-) .

    Did you get a chance to check out the mind-reader puzzle (website above?). Whatcha think?

    I think I did delete and replace in Finder. maybe its the resolution. I’ll look into it. Thanks.

    On a different note, would you be interested in writing the source code to display and move the slices for a Rubik’s cube? I don’t need a solver, just a graphical display of the cube and the 12 methods to rotate the slices: Top, Bottom, Left, Front, Back – Clockwise & Counterclockwise. It should be in Objective C and Open GLES. I don’t mean to offend you, but I would be willing to pay you $100 as a token of my appreciation for this effort. Let me know if this is feasible.

    Cheers,
    Salim

  • #4 written by Salim A Jaliwala 
    about 11 months ago
    Reply Quote

    Typo – NOT “elast”, but “best”.

    Also, left out Right in Top, Bottom, Left, Right, Front, Back.

  • #5 written by Salim A Jaliwala 
    about 11 months ago
    Reply Quote

    Looked into the bits per channel. Don’t have Photoshop, but created image in Microsoft Visio.

    Your cube_example is 3.5556 in x 3.5556 In.

    8 bits per channel = 24 bits / pixel, which represents True Color.

    If i save the image, it gives me the option to select pixels / in, so i select 96 pixels / in.

    This translates to the image being 341 pixels x 341 pixels.

    (3.5556 in * 96 pixels / in = 341 pixels)

    How do I correlate all these numbers when I create my image?

    Hope i’m not asking questions that are too simple:-). Will appreciate your help.

    Thanks,
    Salim

    • #6 written by Diney Bomfim
      about 11 months ago
      Reply Quote

      Hi again Salim,

      Thanks for your comments.

      Let’s talk more about that via email.

      Now about your problem with images. Now I get it!
      Are u using images with 341 x 341?

      To the OpenGL, and to that sample project as well, the image’s size should be POT (Power of Two). This is an OpenGL’s limitation/optimization. So you can’t use 341 x 341. This is why your images looks black. There is nothing related to Xcode, importing or with the bits per channel. Right from the beginning, what happened was about the image size.

      OK, so try one of these sizes:
      256 x 256
      512 x 512
      1024 x 1024

      You can find related info here: http://db-in.com/blog/2011/02/all-about-opengl-es-2-x-part-23/#textures

      Sorry for my first answer, I thought in the most improbable possibilities and forgot the most obvious one.

      ;)

  • #7 written by Salim A Jaliwala 
    about 11 months ago
    Reply Quote

    I created an image identical to yours in Visio. I sized it 3.5556 in. x 3.5556 in. Then I saved it as a JPEG image with a resolution of 71.9991 pixels / in. So that should give me an image of 256 pixels x 256 pixels. I’ll try it this evening to see if this works. Am I on the right track?

    Why do you have a black strip in the image?

    Going back to rubik’s cube, how should we communicate by email? You have my email address: salimj1@comcast.net

    If you send me an email, we can start the dialogue. I I can elaborate on the requirements.

    Cheers,
    Salim

    P.S. I can send you a check for $100 along with a copy of my book. Need your postal address.

  • #8 written by Salim A Jaliwala 
    about 11 months ago
    Reply Quote

    I tired 6 in x 6 in images of various total pixels ranging from 256 to 512 to 1024 to 2048 to 4096 to 8192, but it didn’t work. Does the image size have to be 3.5556 in x 3.5556 in, because one such image at 256×256 resolution worked.

    Also, if I delete your image and then drag and drop the same image (from another saved location into the resources folder, sometime it works and sometimes it doesn’t.

  • #9 written by Salim A Jaliwala 
    about 11 months ago
    Reply Quote

    Oh I just noticed in Finder that the image sizes are not POT. There is rounding error. The 256 image from Visio shows 257, the 512 shows 513, etc.

    Could that be the problem?

    I have sent you the images. let me know if you are able to download.

    Is it possible to structure your code so the image does not have to an exact POT? Just curious.

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