VBO crashes

BlitzMax Forums/OpenGL Module/VBO crashes

JoshK

(Posted 2006) [#1]

I am getting unexplainable crashes when using VBO commands.

Declare the functions:

Global glGenBuffersARB(a,b:Byte Ptr) "Win32"
Global glBindBufferARB(a,b) "Win32"
Global glBufferDataARB(a,b,c:Byte Ptr,d) "Win32"

Get the function pointers:

	SUPPORT_VERTEXBUFFEROBJECT=True
	
	'glGenBuffersARB
	pointer=wglGetProcAddress("glGenBuffersARB")
	If pointer
		glGenBuffersARB=Byte Ptr(pointer)
		Else
		SUPPORT_VERTEXBUFFEROBJECT=False
	EndIf

	'glBindBufferARB
	pointer=wglGetProcAddress("glBindBufferARB")
	If pointer
		glBindBufferARB=Byte Ptr(pointer)
		Else
		SUPPORT_VERTEXBUFFEROBJECT=False
	EndIf
			
	'glBufferDataARB
	pointer=wglGetProcAddress("glBufferDataARB")
	If pointer
		glBufferDataARB=Byte Ptr(pointer)
		Else
		SUPPORT_VERTEXBUFFEROBJECT=False
	EndIf

Create the buffer:

							If Not limb.rendersurface.staticvertexarray
								glenableclientstate GL_VERTEX_ARRAY
								glGenBuffersARB 1,Varptr(limb.rendersurface.staticvertexarray)
								glBindBufferARB GL_ARRAY_BUFFER_ARB,limb.rendersurface.staticvertexarray
								glBufferDataARB GL_ARRAY_BUFFER_ARB,limb.rendersurface.vertexarray.size(),limb.rendersurface.vertexarray.buf(),GL_STATIC_DRAW_ARB
							EndIf

Draw using a VBO vertex array:

			glenableclientstate GL_VERTEX_ARRAY
			If staticvertexarray
				glBindBuffer GL_ARRAY_BUFFER_ARB,staticvertexarray
				glVertexPointer 3,GL_FLOAT,0,Int Ptr(0)
				Else
				glVertexPointer 3,GL_FLOAT,0,BankBuf(vertexarray)
			EndIf

When I call glBindBuffer() in the last block of code, the program crashes.

JoshK

(Posted 2006) [#2]

I finally tracked it down. If I call glBindBuffer() outside the method, it works fine. If I can glBindBuffer() with the same exact parameters inside the method, I get a crash!

JoshK

(Posted 2006) [#3]

Strange. It works fine now.