还没想好
还没想好
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http://www.gamedev.net/community/forums/topic.asp?topic_id=412504

No... In true, PVWp is wrong because P,V and W (as Direct3D defines) were created to satisfy the [row vector]*[matrix] multiplying order. In other words, the content of a transformation matrix could be different depending on the multiplying rule.

For example, consider a translation matrix:

For a [row vector]*[matrix] multiplying order, it is described as:
1 0 0 0
0 1 0 0
0 0 1 0
x y z 1

For a [matrix]*[column vector] multiplying order, it is described as:
1 0 0 x
0 1 0 y
0 0 1 z
0 0 0 1

 


I don't know the math details you're attempting to work out... I'm really bad at formal math theory. I do however know the D3D details of what's going on. Perhaps if I explain what D3D is doing, it'll help you.

Matrix in memory normally.
11 12 13 14
21 22 23 24
31 32 33 34
41 42 43 44

Normally a vector * matrix such a D3DXMatrixTransform will do:
outx = vec dot (11,21,31,41)
outy = vec dot (12,22,32,42)
outz = vec dot (13,23,33,43)
outw = vec dot (14,24,34,44)

When you give a matrix to a shader, it is transposed, which offers a small optimization for most matrices, which I'll explain in a bit. After it's transposed, it's stored in 4 constant registers (or 3... I'll get to that).

c0 = 11,21,31,41
c1 = 12,22,32,42
c2 = 13,23,33,43
c3 = 14,24,34,44

Next, in the shader performing a "mul(vec,mat)" will do this:
v0 = input register containing position
r0 = temp register
dp4 r0.x, v0, c0 // (r0.x = v0 dot c0)
dp4 r0.y, v0, c1
dp4 r0.z, v0, c2
dp4 r0.w, v0, c3

As you can see, this is the same as D3DXMatrixTransform. Why does D3D perform a hidden transpose? To save precious constant space. You can declare your matrix as float4x3 and the transformation becomes:
dp4 r0.x, v0, c0
dp4 r0.y, v0, c1
dp4 r0.z, v0, c2
mov r0.w, (some constant holding 1)

Any time the matrix isn't a projection, ie: for world, worldview, view, and bones especially, you can drop a constant without affecting the results, as it's always a (0,0,0,1) vector. Back in shader 1.1 with only 96 constants, it was a big deal. If you had 20 bone matrices, that would be either 80 or 60 constants. Personally, I'd take the 60, leaving more room for lights, fog, texture transforms, etc. It also takes time to upload all those useless (0,0,0,1) vectors to the video card, which is another small savings.

posted @ 2010-07-20 11:25 MDnullWHO 阅读(318) | 评论 (0)编辑 收藏
1): #define YY_NO_UNISTD_H
2): http://stackoverflow.com/questions/2793413/unistd-h-related-problem-when-compiling-bison-flex-program-under-vc

isatty is used by the lexer to determine if the input stream is a terminal or a pipe/file. The lexer uses this information to change its caching behavior (the lexer reads large chunks of the input when it is not a terminal). If you know that your program will never be used in an interactive kind, you can add %option never-interactive to you lexer. When the program is run with user input, use %option interactive. When both uses are desired, you can either generate an interactive lexer, which gives a performance loss when used in batch mode, or provide your own isatty function.

flex.exe --never-interactive
posted @ 2010-07-05 10:23 MDnullWHO 阅读(151) | 评论 (0)编辑 收藏
记录从VC6 到 VC8遇到的问题和解决办法
1) msvcr80d.dll 找不到
 1)) manifest WIN32 set Yes, 2)) ignore msvcrt.lib
 /*
 

Hi there,

I read every post in this thread without any help in my case.

The problem turned out: The DEBUG version was trying to link with BOTH msvcr80.dll and msvcr80d.dll.

Check if this is the case for you using the "dependency walker" on your executable. If these two are both loaded, then you got the same problem as I did.

The solution is to set "Properties->Linker->Input->Ignore Specific library" to "msvcrt.lib".

 

More details below:

I was compiling and running a program that uses opencv library. One of the libraries in opencv (highgui to be exact) was linking with non-debug versions of some graphics libraries even in its debug version. Apparently this was OK before. 

This resulted in my debug version program linking with both msvcr80.dll and msvcr80d.dll. It appears this is a problem since the manifest only mentions one of these libraries and the other one (msvcr80.dll) appears not to be found causing the error mentioned in this thread. Why no-one in this thread mentioned that this could be the case is beyond me. I found out about this using "dependency walker" on the .exe that I compile and/or the highgui100d.dll that I load from the library.

That is the reason the complaint is about msvcr80.dll and not msvcr80d.dll in VS8!!!

The fix is to re-compile highgui100d.dll (debug version) with Properties->Linker->Input->Ignore Specific library set to singly "msvcrt.dll".

Just wanted to add this so other people do not waste time as I did...

Hakan

*/

2) MFC 
 MFC 从VC6到V8变动很大,
// VC8
LRESULT CDialogBar::HandleInitDialog(WPARAM, LPARAM)
{
 Default();  // allow default to initialize first (common dialogs/etc)

 // create OLE controls
 COccManager* pOccManager = afxOccManager;
 if ((pOccManager != NULL) && (m_pOccDialogInfo != NULL))
 {
  if (!pOccManager->CreateDlgControls(this, m_lpszTemplateName,
   m_pOccDialogInfo))
  {
   TRACE(traceAppMsg, 0, "Warning: CreateDlgControls failed during dialog bar init.\n");
   return FALSE;
  }
 }

 return FALSE;
}

//VC6
LRESULT CDialogBar::HandleInitDialog(WPARAM, LPARAM)
{
 Default();  // allow default to initialize first (common dialogs/etc)

 // create OLE controls
 COccManager* pOccManager = afxOccManager;
 if ((pOccManager != NULL) && (m_pOccDialogInfo != NULL))
 {
  if (!pOccManager->CreateDlgControls(this, m_lpszTemplateName,
   m_pOccDialogInfo))
  {
   TRACE0("Warning: CreateDlgControls failed during dialog bar init.\n");
   return FALSE;
  }
 }

 return TRUE;
}

竟然有这么大的区别,同时看不懂VC8为什么要那么作

posted @ 2008-03-15 02:57 MDnullWHO 阅读(811) | 评论 (0)编辑 收藏
最近在用VS 2005写代码,非常痛苦,VS2005是SB作的,边写边骂,总是感觉VC8的界面是弱智设计的,浪费了太多了不必要的经历
VC6 我只有一点不爽,没有SOLUTIONG 的概念,几个工程合在一起的时候太笨拙了
想不出来,界面咋变得那么SB了,保持VC6的风格不好么,不过MS攻关能力真是够强大,那么多OPEN SOURCE放弃了VC6,开始只发布VC8的工程文件了
posted @ 2008-03-12 21:07 MDnullWHO 阅读(214) | 评论 (6)编辑 收藏
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