Original Post
I am working with VBO's for a new project, I want to use flexible maaped VBO's which are similar to the Direct3D Lock() Unlock() mechanism. I have written some code below, which Maps and Unmaps the vertex data on the fly in the same way as the D3D lock, but it overwrites over the previous VBO vertex data... Here is the rough brief example of what i'm implementing... Now I am going to use the class to bind buffers Now if I render and bind VBOs, the only vertex buffer that renders is the second binded vertex mesh during both instances... Could anyone give me advice on how to map it the same way as D3D. [Edited by - WillPash on December 21, 2008 6:56:22 AM]
//Vertex structure
struct Vertex3D
{
float x;
float y;
float z;
float u;
float v;
};
class VertexBuffer
{
public:
VertexBuffer(){}
~VertexBuffer(){}
void InitialiseBuffer(Vuint buffer_size)
{
//NOW INTIAILISING VERTEX DATA FOR VBO
glGenBuffers(1, &ID);
glBindBuffer(GL_ARRAY_BUFFER,ID);
glBufferData(GL_ARRAY_BUFFER,buffer_size, NULL, V_VERT_BUF_STATIC);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glVertexPointer(3, GL_FLOAT, sizeof(Vertex3D), BUFFER_OFFSET(0));
glTexCoordPointer(2, GL_FLOAT, sizeof(Vertex3D), BUFFER_OFFSET(12));
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glDisableClientState(GL_VERTEX_ARRAY);
}
//MAPPING FUNCTION MEANT TO WORK LIKE LOCK FUNCTION IN DIRECT3D, BUT SHORTENED TO MAKE IT ONLY WRITE TO VERTEX BUFFER
void* MapBuffer()
{
glBindBufferARB(GL_ARRAY_BUFFER_ARB,ID);
return glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY_ARB);
}
void UnmapBuffer()
{
glBindBuffer(GL_ARRAY_BUFFER,ID);
glUnmapBuffer(GL_ARRAY_BUFFER);
glBindBufferARB(GL_ARRAY_BUFFER,0);
}
void BindBuffer()
{
glBindBuffer(GL_ARRAY_BUFFER, ID);
}
void Destroy()
{
glDeleteBuffers(1, &ID);
}
GLuint ID;
};
//PLACE VERTICES INTO VECTOR CONTAINER
vector<Vertex3D> points_one;
vector<Vertex3D> points_two;
VertexBuffer *buffer_one;
VertexBuffer *buffer_two;
buffer_one = new VertexBuffer();
buffer_two = new VertexBuffer();
Vuint buffer_size_one = points_one.size()*sizeof(Vertex3D);
Vuint buffer_size_two = points_two.size()*sizeof(Vertex3D);
buffer_one->InitialiseBuffer(buffer_size_one);
VertexBuffer* membuffer_one = (VertexBuffer*)buffer_one->MapBuffer();
for(vector<Vertex3D>::iterator it = points_one.begin(); it!=points_one.end(); it++)
{
membuffer_one->x = it->x;
membuffer_one->y = it->y;
membuffer_one->z = it->z;
membuffer_one->u = it->u;
membuffer_one->v = it->v;
membuffer_one++;
}
buffer_one->UnmapBuffer();
buffer_two->InitialiseBuffer(buffer_size_two);
VertexBuffer* membuffer_two = (VertexBuffer*)buffer_two->MapBuffer();
for(vector<Vertex3D>::iterator it = points_two.begin(); it!=points_two.end(); it++)
{
membuffer_two->x = it->x;
membuffer_two->y = it->y;
membuffer_two->z = it->z;
membuffer_two->u = it->u;
membuffer_two->v = it->v;
membuffer_two++;
}
buffer_two->UnmapBuffer();
buffer_one->BindBuffer();
//RENDER VERTEX BUFFER THROUGH GL DRAWARRAYS
buffer_two->BindBuffer();
//AGAIN RENDER VERTEX BUFFER THROUGH GL DRAWARRAYS
