好吧,我已經成功地使用我自己的glwrapper掛鉤了所有的OpenGL函數。我遇到的問題是當談到英特爾/ Nvidia與ATI。我鉤住模型併爲每個模型生成ID,這樣我就可以知道渲染是什麼。掛鉤OpenGL幫助(4 - 5問題)
下面是我目前掌握的信息+的區別:
glPushMatrix()
glMultMatrixf({0.70710671, 0, 0.70710683, 0}
{0, 1, 0, 0}
{-0.70710683, 0, 0.70710671, 0}
{26368, -1125, 28416, 1})
glBindBufferARB(GL_ARRAY_BUFFER, 56)
glBufferSubDataARB(GL_ARRAY_BUFFER, 0, 11544, 0x0B2DF6EC)
glGenBuffersARB(1, 0x0AE6231C)
glBindBufferARB(GL_ARRAY_BUFFER, 65)
glBufferDataARB(GL_ARRAY_BUFFER, 11544, 0x0B2DF6EC, GL_STATIC_DRAW)
glGenBuffersARB(1, 0x0AE6231C)
glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER, 66)
glBufferDataARB(GL_ELEMENT_ARRAY_BUFFER, 7020, 0x0B2DF6EC, GL_STATIC_DRAW)
//上述一切都是由兩個顯卡來完成。下面是哪裏出了問題的用武之地。
glBindBufferARB(GL_ARRAY_BUFFER, 56) //Intel/Nvidia makes this NULL.
glVertexPointer(3, GL_FLOAT, 12, 0x00000000) //Intel/NVidia makes this Not 0x00000.
glEnableClientState(GL_VERTEX_ARRAY)
glDisableClientState(GL_NORMAL_ARRAY)
glBindBufferARB(GL_ARRAY_BUFFER, 65)
glColorPointer(4, GL_UNSIGNED_BYTE, 12, 0x00000000)
glEnableClientState(GL_COLOR_ARRAY)
glTexCoordPointer(2, GL_FLOAT, 12, 0x00000004)
glEnableClientState(GL_TEXTURE_COORD_ARRAY)
glDrawElements(GL_TRIANGLES, 3510, GL_UNSIGNED_SHORT, 0x00000000)
我想知道爲什麼還要NULL-ING的bindbuffer呼叫並沒有歸零頂點指針Nvidia的& & Intel網卡,而在ATI,一切都像以上。
有什麼區別?另外我的第二個問題是,如果我存儲了指向頂點和指示的指針(保證它們不會被刪除),我怎樣才能得到每個頂點?
例子:
VBO CurrentBuffer;
std::vector<VBO> Buffers;
Hook_glBufferDataARB(GLenum target, GLsizeiptrARB size, const GLvoid *data, GLenum usage)
{
CurrentBuffer.target = target;
CurrentBuffer.size = size;
CurrentBuffer.usage = usage; //To figure out if it's indices array or vertex array.
CurrentBuffer.data = data; //Let us assume that this pointer is never deleted.
(*original_BufferDataArb)(target, size, data, usage);
}
Hook_glVertexPointer(GLint size, GLenum type, GLsizei stride, const GLvoid *pointer)
{
CurrentBuffer.VNull = (pointer == NULL) ? true : false;
CurrentBuffer.VPointer = pointer; //This can be both null or not null.
CurrentBuffer.VSize = size;
CurrentBuffer.Vtype = type;
CurrentBuffer.Stride = stride;
Buffers.push_back(CurrentBuffer);
(*original_VPointer)(size, type, stride, pointer);
}
void Hook_glDrawElements(GLenum mode, GLsizei count, GLenum type, const GLvoid *indices)
{
if (mode == GL_TRIANGLES)
{
const GLfloat* Pointer = static_cast<const GLfloat*>(Buffers.back().VPointer); //Assuming it isn't NULL.
for (int I = 0; I < count/3; ++I) //For each triangle.
{
int X = *(reinterpret_cast<const GLfloat*>(reinterpret_cast<const char*>(Pointer)));
int Y = *(reinterpret_cast<const GLfloat*>(reinterpret_cast<const char*>(Pointer) + (Buffers.back().Stride)) + 1);
int Z = *(reinterpret_cast<const GLfloat*>(reinterpret_cast<const char*>(Pointer) + (2 * Buffers.back().Stride)) + 2);
}
}
(*original_DrawElements)(mode, count, type, indices);
}
我是否正確迭代指針?另外如果vertexpointer爲null,有沒有辦法使用bufferdata的用法來獲取每個頂點?我看,我可以這樣做:
if (CurrentBuffer.VNull)
{
GLfloat* IndexPointer = Buffers[Buffers.size()].data; //Index pointer is GL_Element_Array_Buffer
GLfloat* VertexPointer = Buffers[Buffers.size() - 1].data; //Vertex pointer is GL_Array_Buffer
for (int I = 0; I < TriangleCount; ++I)
{
int X = *VertexPointer[IndexPointer[I]];
int Y = *VertexPointer[IndexPointer[I]] + 1;
int Z = *VertexPointer[IndexPointer[I]] + 2;
}
}
+1我沒有想到這件事,是的它是設置它。嗯,但爲什麼它會在intel/nvidia上做到這一點,但把它放在ati上?這是我不確定的。無論哪種方式,它是同樣的事情,但對嗎? 我不明白的是爲什麼要這麼做或爲什麼將它設置爲0.是否有區別? – Brandon
@CantChooseUsernames:可能將其設置爲零隻是正常操作的一部分,您只是在程序執行時的不同時間看到它,因爲在NVidia或Intel HW上觸發了不同的代碼路徑。尋找調用'glGetString'的程序 - 如果是這樣,它可能會根據硬件(怪癖,解決方法等)對其渲染路徑進行一些更改。另外請注意,如果在版本> = OpenGL-2上,程序也可以請求'glBindBuffer'(不帶ARB) – datenwolf