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About ebikhan

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  1. ebikhan

    Windows Screen Buffer

    Quote: Original post by EnselicJust out of curiousity, what kind of application are you writing? Quote: Well its about recording activities of the Screen. Original post by Skeleton_V@T As I said, the processing speed depends mostly on I/O operations. Let's just do some calculations: I captured a 640x480x16 region and wrote them to a file with a loop of 400 times, the result is 27 fps. The amount of transfered data is:640 (px) * 480 (px) * 2 (bytes) * 400 (times) ~ 234 MBThere were roughly 234MB had been transfered and wrote to a file in (400 / 27) = 15 secs. So, the transfer rate is: 15.6 MB/sec. ---> You may try copying a large file to somewhere in the same hard drive, this speed is not easy to archive, the normal transfer rate in a 7200 rpm, 2MB cache HDD is 10 - 12 MB in my experiences. Without writing to a file, I created a large enough buffer (around 384 MB), then perform the same operation (400 times with 640x480x16 region). I got 914 fps, 33 times faster than the former test. The transfer rate is: ~535 MB/sec These tests are not precise I know, however, you can allocate a buffer first then manipulate on that buffer, it's probably better than torturing your HDD[grin]. By the way, did you try AnimGet I mentioned ? Well if I can access the Screen Buffer why would I need the temporary Buffers ... I know I/O Operations are slow but wat abt block copy .. I think they are pretty fast ... Just give me a help about accessing the Screen Buffer under WinxP OS, I shall be very thankful to u :P
  2. ebikhan

    Windows Screen Buffer

    Well The 27 Frames/sec of 640 * 480 desktop screen with such specifications. I have got 256 Ram and use 1024 * 768 resolution. then he must be running one app at a time ... well i guess the result will be then very poor... So u Win32 ASM will help me ... Will I be able to access the Screen Buffer .. Well u see why cant simple access i.e. read-only access is not avaible ... if access was readonly then watever apprenhensions u have wud not exist since Screen Buffer wud not manipulated ... Anyways somebody any help on Video Miniports ???
  3. ebikhan

    Windows Screen Buffer

    Well guys thanx for ur help but u see I dont want to use the GDI functions .. These are very bad when performance is the key issue ... Not every1 uses the specification which my friend mentioned here ... Will Windows OS allow me to do its screen buffer(watever is called)... I did exactly the same thing in Assembly ... accessing Dos's Screen Buffer ... So can I do it in C++ .. I was told by some one to go and use Video Miniport ... thats related to Device Driver PRogramming ... Where can I ger help on it ... Any help on Video Miniport or Device Driver Programming for a start ... Anyhow thanx guys for the help :D
  4. I want to record all the screen activities ... You can say after every mini sec ... so then any help on accessing ...
  5. Well just like in Console we can access the Screen Buffer ... does the windows allow to read what it is displaying at a given moment ... I know I can use GDI functions to capture screen shot ... like use BitBlt or something etc ... but I dont want to use them since I dont find it very fast when performance is issue .. Has some body any idea abt it .. Any help on it ? ...
  6. ebikhan

    comparing two pixels

    Well my task is to capture screen shot of complete screen while my app will be running ... I dont want any performance issues ... so any method of dirtecly accessing the Screen Buffer ... I dont want to read not writing it ... So OS shud have no prob with it.
  7. ebikhan

    comparing two pixels

    I dont want to use the GDI functions while capturing the screen shot. Any other method to use it like reading Screen Buffer. How can i do it in C/C++ ?
  8. I want to save to capture screen shot of windows at any time. The normal screen shot is very slow. Can I access Windows Screen/Frame(waetver it is called) Buffer and copy its content to another Buffer. I guess if its possible copying block data from the address where the screen buffer first index will be... Is it possible ... somehow I want to achieve a fast Screen Capture ... Any help ???
  9. ebikhan

    Masters in Computer Graphics

    Well the thing is dat I recently graduated and was offered only a Computer Graphics course. But not much covered in it. I have developed special liking recently and Its some 2/3 months I am having some work to improve my skills & knowledge in this field. But its very difficult with job. So I have thought of specializing in it. I have search for some unis but their req is good GPA which unfortunately I dont have. I had myself 3.2 GPA in CS courses but performed very badly in those non-CS courses :@ ... well no repents :P .. So I am looking for uni which have a decent repute who will take a student like me :P ... Seeking more help :(
  10. Can some one please tell me some good unis for Masters in Computer Graphics ? Be it in Australia, Canada, UK, USA !! ... Plus my CGPA wasnt that good It was around 2.8(72%) ... So kindly dont mention the MITs, or Stanfords :P ... I shall be very thankful to him.
  11. Well I have downloaded a map from planetquake.com and unzipped it. First I loaded the bsp file and render the vertices with textures, it worked fine. Now with the help of a person here on gamedev, I tried for loading and rendering the animated characters but the models, lights, armors, healthj, music file etc. mentioned in Entity Lump are missing. I have tried for 2/3 maps from planetquake.com and I am getting similar errors related to missing textures and models. In simple words I am not able to load & render them ? Any map some1 can mention which has all the textures and models in it. and from where I can download it ?
  12. ebikhan

    Triangles vs Lines

    Well since u can create a triangle from three lines then why not create a complex model from lines ?
  13. Okay I understand that Triangles are simpler to use than Quads but why Graphics Card use Triangles. Why dont they use Lines if simplicity is the reason for not choosing Quads over Triangles ? Do all the cards use Triangle as lowest primitive. I heard some modern cards use high order surfaces. Is it true ? If yes, whats the reason behind it ?
  14. ebikhan

    Octree/Polygon splitting

    Compare two vertices in a triangle/polygon. Check if the two vertices lie in different cube. If yes,use line equation to split them. The newly created vertex wud lie on the border(or say axis) of the two cubes for which u are checking. You wud end with either three vertices on 1 side(no split required), or 1 verices against 2 (which will force one triangle to be split into two or three triangles). Line Equation will help in determing new vertices for a split and a simple logic will help in creating triangles from it. Well, I hope this helps
  15. What are these two mappings. and how different are they from each other and height maps ?. And For what purpose can they be use like height maps are for rendering terrains .. I guess thats abt it ... height map cant be use for other things thats what i think as the name suggests :P ... correct me if I m wrong ... so what abt these two mappings. .. Any good theortical tutorial abt them?.
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