   memory mapping !!?
  Hi all,I'm trying to write software to display a big floating point textures (RGB image 32 float). I am using :glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_FLOAT_RGB32_NV, w1, h1, 0,GL_RGB, GL_FLOAT, tableau);I now that it is possible to use Memory Mapping (CPU) but i'm not sure if it is possible in the case of shader+OpenGl(GPU)?Thanks a lot.   
  Hi,I'm not sure what you mean by 'memory mapping'.Care to explain?Dave   ;  I don't think memory mapping is the term you're looking for.   ;Memory mapping is the technique of making a part of the address space appear to contain an "object", such as a file or device, so that ordinary memory accesses act on that object.The object is said to be mapped to that range of addresses. Memory mapping uses the same mechanism as virtual memory to "trap" accesses to parts of the address space, so that data from the file or device can be paged in (and other parts paged out) before the access is completed.THANKS;  i think it is useful to use memory mapping when the texture is so big , it permit to manage the memory (swapping..)   ;  The largest texture you're likely to use is 4096x4096, and that'll only take up 64MB of memory. I really don't think it's worthwhile using memory mapping to do this.But if you are, there's no reason you can't pass the pointer to the data (from MapViewOfFile() [assuming Win32]) to OpenGL.   ;  Thank youthe problem, that i must display astrophysics image (1Go to 8Go : 16000*16000 for example)In float 32 Byte , so with this limit of 2096^2 is not possible !   ;Quote:Original post by Anonymous PosterThank youthe problem, that i must display astrophysics image (1Go to 8Go : 16000*16000 for example)In float 32 Byte , so with this limit of 2096^2 is not possible !In that case you might not to be able to. You'd need to map a 976MB area of memory, which is bound to cause some problems.The pointer you pass to OpenGL has to contain a view of the entire file.   ;  Look at this thread: megatexures,   you might be able to use a similar technique   ;  What exactly is that you want to do? Based on the program, there might be solutions other than dumping a big-ass texture to RAM or VRAM. For example, are you sure the texture can't be generated on the fly in the shaders? If the calculations are too complex to be performed entirely in real time, are you sure that you can't precompute some of the data and put them in a low-res texture, using that as a base to do more lightweight on-the-fly calculations with less performance hit?   