# ---------------------------------------------------------------------------- # pyglet # Copyright (c) 2006-2008 Alex Holkner # Copyright (c) 2008-2021 pyglet contributors # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions # are met: # # * Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # * Redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in # the documentation and/or other materials provided with the # distribution. # * Neither the name of pyglet nor the names of its # contributors may be used to endorse or promote products # derived from this software without specific prior written # permission. # # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE # COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE # POSSIBILITY OF SUCH DAMAGE. # ---------------------------------------------------------------------------- """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. """ import sys import ctypes import pyglet from pyglet.gl import * def create_buffer(size, target=GL_ARRAY_BUFFER, usage=GL_DYNAMIC_DRAW, mappable=True): """Create a buffer object for vertex or other data. :Parameters: `size` : int Size of the buffer, in bytes `target` : int OpenGL target buffer (defaults to GL_ARRAY_BUFFER) `usage` : int OpenGL usage constant (defaults to GL_DYNAMIC_DRAW) `mappable` : bool True to create a mappable buffer (defaults to True) :rtype: `AbstractBuffer` or `AbstractBuffer` with `AbstractMappable` """ if mappable: return MappableBufferObject(size, target, usage) else: return BufferObject(size, target, usage) class AbstractBuffer: """Abstract buffer of byte data. :Ivariables: `size` : int Size of buffer, in bytes `ptr` : int Memory offset of the buffer, as used by the ``glVertexPointer`` family of functions `target` : int OpenGL buffer target, for example ``GL_ARRAY_BUFFER`` `usage` : int OpenGL buffer usage, for example ``GL_DYNAMIC_DRAW`` """ ptr = 0 size = 0 def bind(self): """Bind this buffer to its OpenGL target.""" raise NotImplementedError('abstract') def unbind(self): """Reset the buffer's OpenGL target.""" raise NotImplementedError('abstract') def set_data(self, data): """Set the entire contents of the buffer. :Parameters: `data` : sequence of int or ctypes pointer The byte array to set. """ raise NotImplementedError('abstract') def set_data_region(self, data, start, length): """Set part of the buffer contents. :Parameters: `data` : sequence of int or ctypes pointer The byte array of data to set `start` : int Offset to start replacing data `length` : int Length of region to replace """ raise NotImplementedError('abstract') def map(self, 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: `invalidate` : bool If True, the initial contents of the mapped block need not reflect the actual contents of the buffer. :rtype: ``POINTER(ctypes.c_ubyte)`` :return: Pointer to the mapped block in memory """ raise NotImplementedError('abstract') def unmap(self): """Unmap a previously mapped memory block.""" raise NotImplementedError('abstract') def resize(self, size): """Resize the buffer to a new size. :Parameters: `size` : int New size of the buffer, in bytes """ def delete(self): """Delete this buffer, reducing system resource usage.""" raise NotImplementedError('abstract') class AbstractMappable: def get_region(self, 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 :py:meth:`AbstractBufferRegion.invalidate` method is called. :Parameters: `start` : int Offset into the buffer to map from, in bytes `size` : int Size of the buffer region to map, in bytes `ptr_type` : ctypes pointer type Pointer type describing the array format to create :rtype: :py:class:`AbstractBufferRegion` """ raise NotImplementedError('abstract') class BufferObject(AbstractBuffer): """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. This class does not implement :py:class:`AbstractMappable`, and so has no :py:meth:`~AbstractMappable.get_region` method. See :py:class:`MappableVertexBufferObject` for a Buffer class that does implement :py:meth:`~AbstractMappable.get_region`. """ def __init__(self, size, target, usage): self.size = size self.target = target self.usage = usage self._context = pyglet.gl.current_context buffer_id = GLuint() glGenBuffers(1, buffer_id) self.id = buffer_id.value glBindBuffer(target, self.id) glBufferData(target, self.size, None, self.usage) def bind(self): glBindBuffer(self.target, self.id) def unbind(self): glBindBuffer(self.target, 0) def set_data(self, data): glBindBuffer(self.target, self.id) glBufferData(self.target, self.size, data, self.usage) def set_data_region(self, data, start, length): glBindBuffer(self.target, self.id) glBufferSubData(self.target, start, length, data) def map(self, invalidate=False): glBindBuffer(self.target, self.id) if invalidate: glBufferData(self.target, self.size, None, self.usage) ptr = ctypes.cast(glMapBuffer(self.target, GL_WRITE_ONLY), ctypes.POINTER(ctypes.c_byte * self.size)).contents return ptr def unmap(self): glUnmapBuffer(self.target) def __del__(self): try: if self.id is not None: self._context.delete_buffer(self.id) except: pass def delete(self): buffer_id = GLuint(self.id) try: glDeleteBuffers(1, buffer_id) except Exception: pass self.id = None def resize(self, size): # Map, create a copy, then reinitialize. temp = (ctypes.c_byte * size)() glBindBuffer(self.target, self.id) data = glMapBuffer(self.target, GL_READ_ONLY) ctypes.memmove(temp, data, min(size, self.size)) glUnmapBuffer(self.target) self.size = size glBufferData(self.target, self.size, temp, self.usage) class MappableBufferObject(BufferObject, AbstractMappable): """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 :py:meth:`map` are committed immediately. """ def __init__(self, size, target, usage): super(MappableBufferObject, self).__init__(size, target, usage) self.data = (ctypes.c_byte * size)() self.data_ptr = ctypes.cast(self.data, ctypes.c_void_p).value self._dirty_min = sys.maxsize self._dirty_max = 0 def bind(self): # Commit pending data super(MappableBufferObject, self).bind() size = self._dirty_max - self._dirty_min if size > 0: if size == self.size: glBufferData(self.target, self.size, self.data, self.usage) else: glBufferSubData(self.target, self._dirty_min, size, self.data_ptr + self._dirty_min) self._dirty_min = sys.maxsize self._dirty_max = 0 def set_data(self, data): super(MappableBufferObject, self).set_data(data) ctypes.memmove(self.data, data, self.size) self._dirty_min = 0 self._dirty_max = self.size def set_data_region(self, data, start, length): ctypes.memmove(self.data_ptr + start, data, length) self._dirty_min = min(start, self._dirty_min) self._dirty_max = max(start + length, self._dirty_max) def map(self, invalidate=False): self._dirty_min = 0 self._dirty_max = self.size return self.data def unmap(self): pass def get_region(self, start, size, ptr_type): array = ctypes.cast(self.data_ptr + start, ptr_type).contents return BufferObjectRegion(self, start, start + size, array) def resize(self, size): data = (ctypes.c_byte * size)() ctypes.memmove(data, self.data, min(size, self.size)) self.data = data self.data_ptr = ctypes.cast(self.data, ctypes.c_void_p).value self.size = size glBindBuffer(self.target, self.id) glBufferData(self.target, self.size, self.data, self.usage) self._dirty_min = sys.maxsize self._dirty_max = 0 class AbstractBufferRegion: """A mapped region of a buffer. Buffer regions are obtained using :py:meth:`~AbstractMappable.get_region`. :Ivariables: `array` : ctypes array Array of data, of the type and count requested by :py:meth:`~AbstractMappable.get_region`. """ def invalidate(self): """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). """ pass class BufferObjectRegion(AbstractBufferRegion): """A mapped region of a BufferObject.""" __slots__ = 'buffer', 'start', 'end', 'array' def __init__(self, buffer, start, end, array): self.buffer = buffer self.start = start self.end = end self.array = array def invalidate(self): buffer = self.buffer buffer._dirty_min = min(buffer._dirty_min, self.start) buffer._dirty_max = max(buffer._dirty_max, self.end) class IndirectArrayRegion(AbstractBufferRegion): """A mapped region in which data elements are not necessarily contiguous. This region class is used to wrap buffer regions in which the data must be accessed with some stride. For example, in an interleaved buffer this region can be used to access a single interleaved component as if the data was contiguous. """ def __init__(self, region, size, component_count, component_stride): """Wrap a buffer region. Use the `component_count` and `component_stride` parameters to specify the data layout of the encapsulated region. For example, if RGBA data is to be accessed as if it were packed RGB, ``component_count`` would be set to 3 and ``component_stride`` to 4. If the region contains 10 RGBA tuples, the ``size`` parameter is ``3 * 10 = 30``. :Parameters: `region` : `AbstractBufferRegion` The region with interleaved data `size` : int The number of elements that this region will provide access to. `component_count` : int The number of elements that are contiguous before some must be skipped. `component_stride` : int The number of elements of interleaved data separating the contiguous sections. """ self.region = region self.size = size self.count = component_count self.stride = component_stride self.array = self def __repr__(self): return 'IndirectArrayRegion(size=%d, count=%d, stride=%d)' % ( self.size, self.count, self.stride) def __getitem__(self, index): count = self.count if not isinstance(index, slice): elem = index // count j = index % count return self.region.array[elem * self.stride + j] start = index.start or 0 stop = index.stop step = index.step or 1 if start < 0: start = self.size + start if stop is None: stop = self.size elif stop < 0: stop = self.size + stop assert step == 1 or step % count == 0, 'Step must be multiple of component count' data_start = (start // count) * self.stride + start % count data_stop = (stop // count) * self.stride + stop % count data_step = step * self.stride # TODO stepped getitem is probably wrong, see setitem for correct. value_step = step * count value = [0] * ((stop - start) // step) stride = self.stride for i in range(count): value[i::value_step] = self.region.array[data_start + i:data_stop + i:data_step] return value def __setitem__(self, index, value): count = self.count if not isinstance(index, slice): elem = index // count j = index % count self.region.array[elem * self.stride + j] = value return start = index.start or 0 stop = index.stop step = index.step or 1 if start < 0: start = self.size + start if stop is None: stop = self.size elif stop < 0: stop = self.size + stop assert step == 1 or step % count == 0, 'Step must be multiple of component count' data_start = (start // count) * self.stride + start % count data_stop = (stop // count) * self.stride + stop % count if step == 1: data_step = self.stride value_step = count for i in range(count): self.region.array[data_start + i:data_stop + i:data_step] = value[i::value_step] else: data_step = (step // count) * self.stride self.region.array[data_start:data_stop:data_step] = value def invalidate(self): self.region.invalidate()