pyglet.graphics.vertexbuffer

Byte abstractions of OpenGL Buffer Objects.

Use create_buffer to create a Buffer Object.

Buffers can optionally be created “mappable” (incorporating the AbstractMappable mix-in). In this case the buffer provides a get_region method which provides the most efficient path for updating partial data within the buffer.

class AbstractBuffer

Abstract buffer of byte data.

Ivariables

sizeint

Size of buffer, in bytes

ptrint

Memory offset of the buffer, as used by the glVertexPointer family of functions

usageint

OpenGL buffer usage, for example GL_DYNAMIC_DRAW

bind(target=34962)

Bind this buffer to an OpenGL target.

delete()

Delete this buffer, reducing system resource usage.

map()

Map the entire buffer into system memory.

The mapped region must be subsequently unmapped with unmap before performing any other operations on the buffer.

Parameters

invalidatebool

If True, the initial contents of the mapped block need not reflect the actual contents of the buffer.

Return type

POINTER(ctypes.c_ubyte)

Returns

Pointer to the mapped block in memory

resize(size)

Resize the buffer to a new size.

Parameters

sizeint

New size of the buffer, in bytes

set_data(data)

Set the entire contents of the buffer.

Parameters

datasequence of int or ctypes pointer

The byte array to set.

set_data_region(data, start, length)

Set part of the buffer contents.

Parameters

datasequence of int or ctypes pointer

The byte array of data to set

startint

Offset to start replacing data

lengthint

Length of region to replace

unbind()

Reset the buffer’s OpenGL target.

unmap()

Unmap a previously mapped memory block.

ptr = 0

size = 0

class AbstractMappable

get_region(start, size, ptr_type)

Map a region of the buffer into a ctypes array of the desired type. This region does not need to be unmapped, but will become invalid if the buffer is resized.

Note that although a pointer type is required, an array is mapped. For example:

get_region(0, ctypes.sizeof(c_int) * 20, ctypes.POINTER(c_int * 20))

will map bytes 0 to 80 of the buffer to an array of 20 ints.

Changes to the array may not be recognised until the region’s AbstractBufferRegion.invalidate() method is called.

Parameters

startint

Offset into the buffer to map from, in bytes

sizeint

Size of the buffer region to map, in bytes

ptr_typectypes pointer type

Pointer type describing the array format to create

Return type

AbstractBufferRegion

class BufferObject(size, usage=35048)

Lightweight representation of an OpenGL Buffer Object.

The data in the buffer is not replicated in any system memory (unless it is done so by the video driver). While this can improve memory usage and possibly performance, updates to the buffer are relatively slow. The target of the buffer is GL_ARRAY_BUFFER internally to avoid accidentally overriding other states when altering the buffer contents. The intended target can be set when binding the buffer.

This class does not implement AbstractMappable, and so has no get_region() method. See MappableVertexBufferObject for a Buffer class that does implement get_region().

bind(target=34962)

Bind this buffer to an OpenGL target.

bind_to_index_buffer()

Binds this buffer as an index buffer on the active vertex array.

delete()

Delete this buffer, reducing system resource usage.

invalidate()

map()

Map the entire buffer into system memory.

The mapped region must be subsequently unmapped with unmap before performing any other operations on the buffer.

Parameters

invalidatebool

If True, the initial contents of the mapped block need not reflect the actual contents of the buffer.

Return type

POINTER(ctypes.c_ubyte)

Returns

Pointer to the mapped block in memory

map_range(start, size, ptr_type)

resize(size)

Resize the buffer to a new size.

Parameters

sizeint

New size of the buffer, in bytes

set_data(data)

Set the entire contents of the buffer.

Parameters

datasequence of int or ctypes pointer

The byte array to set.

set_data_region(data, start, length)

Set part of the buffer contents.

Parameters

datasequence of int or ctypes pointer

The byte array of data to set

startint

Offset to start replacing data

lengthint

Length of region to replace

unbind()

Reset the buffer’s OpenGL target.

unmap()

Unmap a previously mapped memory block.

class BufferObjectRegion(buffer, start, end, array)

A mapped region of a MappableBufferObject.

invalidate()

Mark this region as changed.

The buffer may not be updated with the latest contents of the array until this method is called. (However, it may not be updated until the next time the buffer is used, for efficiency).

array

buffer

end

start

class MappableBufferObject(size, usage=35048)

A buffer with system-memory backed store.

Updates to the data via set_data, set_data_region and map will be held in local memory until bind is called. The advantage is that fewer OpenGL calls are needed, increasing performance.

There may also be less performance penalty for resizing this buffer.

Updates to data via map() are committed immediately.

bind()

Bind this buffer to an OpenGL target.

get_region(start, size, ptr_type)

Map a region of the buffer into a ctypes array of the desired type. This region does not need to be unmapped, but will become invalid if the buffer is resized.

Note that although a pointer type is required, an array is mapped. For example:

get_region(0, ctypes.sizeof(c_int) * 20, ctypes.POINTER(c_int * 20))

will map bytes 0 to 80 of the buffer to an array of 20 ints.

Changes to the array may not be recognised until the region’s AbstractBufferRegion.invalidate() method is called.

Parameters

startint

Offset into the buffer to map from, in bytes

sizeint

Size of the buffer region to map, in bytes

ptr_typectypes pointer type

Pointer type describing the array format to create

Return type

AbstractBufferRegion

map(invalidate=False)

Map the entire buffer into system memory.

The mapped region must be subsequently unmapped with unmap before performing any other operations on the buffer.

Parameters

invalidatebool

If True, the initial contents of the mapped block need not reflect the actual contents of the buffer.

Return type

POINTER(ctypes.c_ubyte)

Returns

Pointer to the mapped block in memory

resize(size)

Resize the buffer to a new size.

Parameters

sizeint

New size of the buffer, in bytes

set_data(data)

Set the entire contents of the buffer.

Parameters

datasequence of int or ctypes pointer

The byte array to set.

set_data_region(data, start, length)

Set part of the buffer contents.

Parameters

datasequence of int or ctypes pointer

The byte array of data to set

startint

Offset to start replacing data

lengthint

Length of region to replace

unmap()

Unmap a previously mapped memory block.