Search Results

Search found 4759 results on 191 pages for 'depth buffer'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 3/191 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

  • Depth Map resolution shifting

    - by user3669538
    the problem is with shadow mapping as you can see, actually it works fine but in a certain condition that the Depth Map size must be equal to the size of rendering buffer, I use an infinite directional light so if the window is 800x600 the depth map must be 800x600, and when i change the size of the shadow map to be 900x600 it starts to be shifted and when it's size be 1024x1024 it also shifts till it disappears the GLSL shadow function float calcShadow(sampler2D Dmap, vec4 coor){ vec4 sh = vec4((coor.xyz/coor.w),1); sh.z *= 0.9; return step(sh.z,texture2D(Dmap,sh.xy).r); } here's the result when it's the same size as the window Colored result & Depth Map and here's the shifted result, as you can notice the depth map is exactly as the previous one with the addition of white space to the right. Colored result http://goo.gl/5lYIFV Depth Map http://goo.gl/7320Dd

    Read the article

  • who free's setvbuf buffer?

    - by Evan Teran
    So I've been digging into how the stdio portion of libc is implemented and I've come across another question. Looking at man setvbuf I see the following: When the first I/O operation occurs on a file, malloc(3) is called, and a buffer is obtained. This makes sense, your program should have a malloc in it for I/O unless you actually use it. My gut reaction to this is that libc will clean up its own mess here. Which I can only assume it does because valgrind reports no memory leaks (they could of course do something dirty and not allocate it via malloc directly... but we'll assume that it literally uses malloc for now). But, you can specify your own buffer too... int main() { char *p = malloc(100); setvbuf(stdio, p, _IOFBF, 100); puts("hello world"); } Oh no, memory leak! valgrind confirms it. So it seems that whenever stdio allocates a buffer on its own, it will get deleted automatically (at the latest on program exit, but perhaps on stream close). But if you specify the buffer explicitly, then you must clean it up yourself. There is a catch though. The man page also says this: You must make sure that the space that buf points to still exists by the time stream is closed, which also happens at program termination. For example, the following is invalid: Now this is getting interesting for the standard streams. How would one properly clean up a manually allocated buffer for them, since they are closed in program termination? I could imagine a "clean this up when I close flag" inside the file struct, but it get hairy because if I read this right doing something like this: setvbuf(stdio, 0, _IOFBF, 100); printf("hello "); setvbuf(stdio, 0, _IOLBF, 100); printf("world\n"); would cause 2 allocations by the standard library because of this sentence: If the argument buf is NULL, only the mode is affected; a new buffer will be allocated on the next read or write operation.

    Read the article

  • [ebp + 6] instead of +8 in a JIT compiler

    - by David Titarenco
    I'm implementing a simplistic JIT compiler in a VM I'm writing for fun (mostly to learn more about language design) and I'm getting some weird behavior, maybe someone can tell me why. First I define a JIT "prototype" both for C and C++: #ifdef __cplusplus typedef void* (*_JIT_METHOD) (...); #else typedef (*_JIT_METHOD) (); #endif I have a compile() function that will compile stuff into ASM and stick it somewhere in memory: void* compile (void* something) { // grab some memory unsigned char* buffer = (unsigned char*) malloc (1024); // xor eax, eax // inc eax // inc eax // inc eax // ret -> eax should be 3 /* WORKS! buffer[0] = 0x67; buffer[1] = 0x31; buffer[2] = 0xC0; buffer[3] = 0x67; buffer[4] = 0x40; buffer[5] = 0x67; buffer[6] = 0x40; buffer[7] = 0x67; buffer[8] = 0x40; buffer[9] = 0xC3; */ // xor eax, eax // mov eax, 9 // ret 4 -> eax should be 9 /* WORKS! buffer[0] = 0x67; buffer[1] = 0x31; buffer[2] = 0xC0; buffer[3] = 0x67; buffer[4] = 0xB8; buffer[5] = 0x09; buffer[6] = 0x00; buffer[7] = 0x00; buffer[8] = 0x00; buffer[9] = 0xC3; */ // push ebp // mov ebp, esp // mov eax, [ebp + 6] ; wtf? shouldn't this be [ebp + 8]!? // mov esp, ebp // pop ebp // ret -> eax should be the first value sent to the function /* WORKS! */ buffer[0] = 0x66; buffer[1] = 0x55; buffer[2] = 0x66; buffer[3] = 0x89; buffer[4] = 0xE5; buffer[5] = 0x66; buffer[6] = 0x66; buffer[7] = 0x8B; buffer[8] = 0x45; buffer[9] = 0x06; buffer[10] = 0x66; buffer[11] = 0x89; buffer[12] = 0xEC; buffer[13] = 0x66; buffer[14] = 0x5D; buffer[15] = 0xC3; // mov eax, 5 // add eax, ecx // ret -> eax should be 50 /* WORKS! buffer[0] = 0x67; buffer[1] = 0xB8; buffer[2] = 0x05; buffer[3] = 0x00; buffer[4] = 0x00; buffer[5] = 0x00; buffer[6] = 0x66; buffer[7] = 0x01; buffer[8] = 0xC8; buffer[9] = 0xC3; */ return buffer; } And finally I have the main chunk of the program: void main (int argc, char **args) { DWORD oldProtect = (DWORD) NULL; int i = 667, j = 1, k = 5, l = 0; // generate some arbitrary function _JIT_METHOD someFunc = (_JIT_METHOD) compile(NULL); // windows only #if defined _WIN64 || defined _WIN32 // set memory permissions and flush CPU code cache VirtualProtect(someFunc,1024,PAGE_EXECUTE_READWRITE, &oldProtect); FlushInstructionCache(GetCurrentProcess(), someFunc, 1024); #endif // this asm just for some debugging/testing purposes __asm mov ecx, i // run compiled function (from wherever *someFunc is pointing to) l = (int)someFunc(i, k); // did it work? printf("result: %d", l); free (someFunc); _getch(); } As you can see, the compile() function has a couple of tests I ran to make sure I get expected results, and pretty much everything works but I have a question... On most tutorials or documentation resources, to get the first value of a function passed (in the case of ints) you do [ebp+8], the second [ebp+12] and so forth. For some reason, I have to do [ebp+6] then [ebp+10] and so forth. Could anyone tell me why?

    Read the article

  • Usage of current-buffer in emacs?

    - by Zubair
    I'm using emacs and I have written a script which uses "current-buffer". However the emacs system doesn't recognise "current-buffer". When I try "M - x current-buffer" i get the response: no match : Any idea what I'm doing wrong?

    Read the article

  • How to get depth of array in PHP?

    - by user198729
    'test2' => array 'name' => string 'ntuser.dat.LOG' (length=14) 'type' => string 'application/octet-stream' (length=24) 'tmp_name' => string 'D:\wamp\tmp\php224.tmp' (length=22) 'error' => int 0 'size' => int 0 The above should be depth of 2.

    Read the article

  • J2ME Reduce Image color-depth/ Compress Image size

    - by updateraj
    Hi, I need to transmit the image from the mobile phone to the server. I am able to reduce the image screen size but not the memory size. I understand i have to deal with the color depth. J2ME does not seem to offer any scaling method which is available in J2SE: image rescaled = image.getScaledInstance(thumbWidth, thumbHeight, Image.SCALE_AREA_AVERAGING); BufferedImage biRescaled = toBufferedImage(rescaled, thumbWidth, thumbHeight, BufferedImage.TYPE_INT_RGB); How i would i tackle this ? I would like to reduce the image memory size before i transmit to the server. Thank you

    Read the article

  • function's return address is different from its supposed value, buffer overflow,

    - by ultrajohn
    Good day everyone! I’m trying to understand how buffer overflow works. I’m doing this for my project in a computer security course I’m taking. Right now, I’m in the process of determining the address of the function’s return address which I’m supposed to change to perform a buffer overflow attack. I’ve written a simple program based from an example I’ve read in the internet. What this program does is it creates an integer pointer that will be made to point to the address of the function return address in the stack. To do this, (granted I understand how a function/program variables get organized in the stack), I add 8 to the buffer variable’ address and set it as the value of ret. I’m not doing anything here that would change the address contained in the location of func’s return address. here's the program: Output of the program when gets excecuted: As you can see, I’m printing the address of the variables buffer and ret. I’ve added an additional statement printing the value of the ret variable (supposed location of func return address, so this should print the address of the next instruction which will get executed after func returns from execution). Here is the dump which shows the supposed address of the instruction to be executed after func returns. (Underlined in green) As you can see, that value is way different from the value printed contained in the variable ret. My question is, why are they different? (of course in the assumption that what I’ve done are all right). Else, what have I done wrong? Is my understanding of the program’s runtime stack wrong? Please, help me understand this. My project is due nextweek and I’ve barely touched it yet. I’m sorry if I’m being demanding, I badly need your help.

    Read the article

  • C# Application crashes with Buffer Overrun in deployed (.exe) version, but not in Visual Studio

    - by Ben
    Hi, I have a c# Windows Forms application that runs perfectly from within Visual Studio, but crashes when its deployed and run from the .exe. It crashes with a Buffer Overrun error...and its pretty clear that this error is not being thrown from within my code. Instead, windows must be detecting some sort of buffer overrun and shutting down the application from the outside. I don't think there's one specific line of code that is causing it..it simply happens intermittently. Does anybody have any thoughts on what the possible causes of a Buffer Overrun error might be, and why it would only occur in the deployed application and not when run from with Visual Studio? Thanks in advance, Ben

    Read the article

  • Buffer management for socket application best practice

    - by Poni
    Having a Windows IOCP app............ I understand that for async i/o operation (on network) the buffer must remain valid for the duration of the send/read operation. So for each connection I have one buffer for the reading. For sending I use buffers to which I copy the data to be sent. When the sending operation completes I release the buffer so it can be reused. So far it's nice and not of a big issue. What remains unclear is how do you guys do this? Another thing is that even when having things this way, I mean multi-buffers, the receiver side might be flooded (talking from experience) with data. Even setting SO_RCVBUF to 25MB didn't help in my testings. So what should I do? Have a to-be-sent queue?

    Read the article

  • MD3200i Slow Performance and Queue Depth

    - by Caleb_S
    Read performance on our SAN is slow under certain workloads. When we compare this to some local storage, we find the local storage performing 2x as fast. The SAN performs well with a high Queue Depth, and poorly with a low queue depth. However, the local storage performs well with a low Queue Depth. I'd like to know the reason for this occurring and find out what the specific limiting factor is in this situation. MD3200i iSCSI SAN ($15,000) 6 x 600GB 15k SAS RAID5 6 x 2TB 7.2k NLS RAID5 XCOPY /j Benchmark: (Slow) 15k Array - 71MB/s (Queue Depth 1) 7.2k Array- 71MB/s (Queue Depth 1) Robycopy /MT:32 Benchmark: (Fast) 15k Array - 171MB/s (Queue Depth ~12) 7.2k Array- 128MB/s (Queue Depth ~12) , , Read Performance on a Local controller is fast under the workload the SAN is slow at. , HighPoint 2230 RAID Controller ($600) 4 x 1TB 7.2k SATA RAID5 XCOPY /j Benchmark: 7.2k Array - 145MB/s (Queue Depth 1) (appears to max out the SATA bus)

    Read the article

  • OpenGL depth texture wrong

    - by CoffeeandCode
    I have been writing a game engine for a while now and have decided to reconstruct my positions from depth... but how I read the depth seems to be wrong :/ What is wrong in my rendering? How I init my depth texture in the FBO gl::BindTexture(gl::TEXTURE_2D, this->textures[0]); // Depth gl::TexImage2D( gl::TEXTURE_2D, 0, gl::DEPTH32F_STENCIL8, width, height, 0, gl::DEPTH_STENCIL, gl::FLOAT_32_UNSIGNED_INT_24_8_REV, nullptr ); gl::TexParameterf(gl::TEXTURE_2D, gl::TEXTURE_MAG_FILTER, gl::NEAREST); gl::TexParameterf(gl::TEXTURE_2D, gl::TEXTURE_MIN_FILTER, gl::NEAREST); gl::TexParameterf(gl::TEXTURE_2D, gl::TEXTURE_WRAP_S, gl::CLAMP_TO_EDGE); gl::TexParameterf(gl::TEXTURE_2D, gl::TEXTURE_WRAP_T, gl::CLAMP_TO_EDGE); gl::FramebufferTexture2D( gl::FRAMEBUFFER, gl::DEPTH_STENCIL_ATTACHMENT, gl::TEXTURE_2D, this->textures[0], 0 ); Linear depth readings in my shader Vertex #version 150 layout(location = 0) in vec3 position; layout(location = 1) in vec2 uv; out vec2 uv_f; void main(){ uv_f = uv; gl_Position = vec4(position, 1.0); } Fragment (where the issue probably is) #version 150\n uniform sampler2D depth_texture; in vec2 uv_f; out vec4 Screen; void main(){ float n = 0.00001; float f = 100.0; float z = texture(depth_texture, uv_f).x; float linear_depth = (n * z)/(f - z * (f - n)); Screen = vec4(linear_depth); // It ISN'T because I don't separate alpha } When Rendered so gamedev.stackexchange, what's wrong with my rendering/glsl?

    Read the article

  • How much buffer does NetworkStream and TcpClient have?

    - by Earlz
    Hello, We are writing a TCPServer and Client program. How much space is there in the TcpClient buffer? Like, at what point will it begin to throw away data? We are trying to determine if the TcpClient can be blocking or if it should go into it's own background thread(so that the buffer can not get full)..

    Read the article

  • What is the format of DXGI_FORMAT_D24_UNORM_S8_UINT?

    - by bobobobo
    I'm trying to read the values in a depth texture of type DXGI_FORMAT_D24_UNORM_S8_UINT. I know this means "24 bits for depth, 8 bits for stencil" "A 32-bit z-buffer format that supports 24 bits for depth and 8 bits for stencil.", but how do you interpret those 24 bits? It's clearly not going to be a 32-bit int, and it's not going to be a 32-bit float. If it is an integer value, how "far away" is a value of "1" in the depth texture?

    Read the article

  • Buffer size: N*sizeof(type) or sizeof(var)? C++

    - by flyout
    I am just starting with cpp and I've been following different examples to learn from them, and I see that buffer size is set in different ways, for example: char buffer[255]; StringCchPrintf(buffer, sizeof(buffer), TEXT("%s"), X); VS char buffer[255]; StringCchPrintf(buffer, 255*sizeof(char), TEXT("%s"), X); Which one is the correct way to use it? I've seen this in other functions like InternetReadFile, ZeroMemory and MultiByteToWideChar.

    Read the article

  • C# File IO with Streams - Best Memory Buffer Size

    - by AJ
    Hi, I am writing a small IO library to assist with a larger (hobby) project. A part of this library performs various functions on a file, which is read / written via the FileStream object. On each StreamReader.Read(...) pass, I fire off an event which will be used in the main app to display progress information. The processing that goes on in the loop is vaired, but is not too time consuming (it could just be a simple file copy, for example, or may involve encryption...). My main question is: What is the best memory buffer size to use? Thinking about physical disk layouts, I could pick 2k, which would cover a CD sector size and is a nice multiple of a 512 byte hard disk sector. Higher up the abstraction tree, you could go for a larger buffer which could read an entire FAT cluster at a time. I realise with today's PC's, I could go for a more memory hungry option (a couple of MiB, for example), but then I increase the time between UI updates and the user perceives a less responsive app. As an aside, I'm eventually hoping to provide a similar interface to files hosted on FTP / HTTP servers (over a local network / fastish DSL). What would be the best memory buffer size for those (again, a "best-case" tradeoff between perceived responsiveness vs. performance). Thanks in advance for any ideas, Adam

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >