# ---------------------------------------------------------------------------- # pyglet # Copyright (c) 2006-2008 Alex Holkner # 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. # ---------------------------------------------------------------------------- # $Id:$ '''Low-level graphics rendering. This module provides an efficient low-level abstraction over OpenGL. It gives very good performance for rendering OpenGL primitives; far better than the typical immediate-mode usage and, on modern graphics cards, better than using display lists in many cases. The module is used internally by other areas of pyglet. See the Programming Guide for details on how to use this graphics API. Batches and groups ================== Without even needing to understand the details on how to draw primitives with the graphics API, developers can make use of `Batch` and `Group` objects to improve performance of sprite and text rendering. The `Sprite`, `Label` and `TextLayout` classes all accept a ``batch`` and ``group`` parameter in their constructors. A batch manages a set of objects that will be drawn all at once, and a group describes the manner in which an object is drawn. The following example creates a batch, adds two sprites to the batch, and then draws the entire batch:: batch = pyglet.graphics.Batch() car = pyglet.sprite.Sprite(car_image, batch=batch) boat = pyglet.sprite.Sprite(boat_image, batch=batch) def on_draw() batch.draw() Drawing a complete batch is much faster than drawing the items in the batch individually, especially when those items belong to a common group. Groups describe the OpenGL state required for an item. This is for the most part managed by the sprite and text classes, however you can also use groups to ensure items are drawn in a particular order. For example, the following example adds a background sprite which is guaranteed to be drawn before the car and the boat:: batch = pyglet.graphics.Batch() background = pyglet.graphics.OrderedGroup(0) foreground = pyglet.graphics.OrderedGroup(1) background = pyglet.sprite.Sprite(background_image, batch=batch, group=background) car = pyglet.sprite.Sprite(car_image, batch=batch, group=foreground) boat = pyglet.sprite.Sprite(boat_image, batch=batch, group=foreground) def on_draw() batch.draw() It's preferable to manage sprites and text objects within as few batches as possible. If the drawing of sprites or text objects need to be interleaved with other drawing that does not use the graphics API, multiple batches will be required. Data item parameters ==================== Many of the functions and methods in this module accept any number of ``data`` parameters as their final parameters. In the documentation these are notated as ``*data`` in the formal parameter list. A data parameter describes a vertex attribute format and an optional sequence to initialise that attribute. Examples of common attribute formats are: ``"v3f"`` Vertex position, specified as three floats. ``"c4B"`` Vertex color, specifed as four unsigned bytes. ``"t2f"`` Texture coordinate, specified as two floats. See `pyglet.graphics.vertexattribute` for the complete syntax of the vertex format string. When no initial data is to be given, the data item is just the format string. For example, the following creates a 2 element vertex list with position and color attributes:: vertex_list = pyglet.graphics.vertex_list(2, 'v2f', 'c4B') When initial data is required, wrap the format string and the initial data in a tuple, for example:: vertex_list = pyglet.graphics.vertex_list(2, ('v2f', (0.0, 1.0, 1.0, 0.0)), ('c4B', (255, 255, 255, 255) * 2)) Drawing modes ============= Methods in this module that accept a ``mode`` parameter will accept any value in the OpenGL drawing mode enumeration; for example, ``GL_POINTS``, ``GL_LINES``, ``GL_TRIANGLES``, etc. Because of the way the graphics API renders multiple primitives with shared state, ``GL_POLYGON``, ``GL_LINE_LOOP`` and ``GL_TRIANGLE_FAN`` cannot be used --- the results are undefined. When using ``GL_LINE_STRIP``, ``GL_TRIANGLE_STRIP`` or ``GL_QUAD_STRIP`` care must be taken to insert degenrate vertices at the beginning and end of each vertex list. For example, given the vertex list:: A, B, C, D the correct vertex list to provide the vertex list is:: A, A, B, C, D, D Alternatively, the ``NV_primitive_restart`` extension can be used if it is present. This also permits use of ``GL_POLYGON``, ``GL_LINE_LOOP`` and ``GL_TRIANGLE_FAN``. Unfortunatley the extension is not provided by older video drivers, and requires indexed vertex lists. :since: pyglet 1.1 ''' __docformat__ = 'restructuredtext' __version__ = '$Id: $' import ctypes import pyglet from pyglet.gl import * from pyglet import gl from pyglet.graphics import vertexbuffer, vertexattribute, vertexdomain _debug_graphics_batch = pyglet.options['debug_graphics_batch'] def draw(size, mode, *data): '''Draw a primitive immediately. :Parameters: `size` : int Number of vertices given `mode` : int OpenGL drawing mode, e.g. ``GL_TRIANGLES`` `data` : data items Attribute formats and data. See the module summary for details. ''' glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT) buffers = [] for format, array in data: attribute = vertexattribute.create_attribute(format) assert size == len(array) // attribute.count, \ 'Data for %s is incorrect length' % format buffer = vertexbuffer.create_mappable_buffer( size * attribute.stride, vbo=False) attribute.set_region(buffer, 0, size, array) attribute.enable() attribute.set_pointer(buffer.ptr) buffers.append(buffer) glDrawArrays(mode, 0, size) glFlush() glPopClientAttrib() def draw_indexed(size, mode, indices, *data): '''Draw a primitive with indexed vertices immediately. :Parameters: `size` : int Number of vertices given `mode` : int OpenGL drawing mode, e.g. ``GL_TRIANGLES`` `indices` : sequence of int Sequence of integers giving indices into the vertex list. `data` : data items Attribute formats and data. See the module summary for details. ''' glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT) buffers = [] for format, array in data: attribute = vertexattribute.create_attribute(format) assert size == len(array) // attribute.count, \ 'Data for %s is incorrect length' % format buffer = vertexbuffer.create_mappable_buffer( size * attribute.stride, vbo=False) attribute.set_region(buffer, 0, size, array) attribute.enable() attribute.set_pointer(buffer.ptr) buffers.append(buffer) if size <= 0xff: index_type = GL_UNSIGNED_BYTE index_c_type = ctypes.c_ubyte elif size <= 0xffff: index_type = GL_UNSIGNED_SHORT index_c_type = ctypes.c_ushort else: index_type = GL_UNSIGNED_INT index_c_type = ctypes.c_uint index_array = (index_c_type * len(indices))(*indices) glDrawElements(mode, len(indices), index_type, index_array) glFlush() glPopClientAttrib() def _parse_data(data): '''Given a list of data items, returns (formats, initial_arrays).''' assert data, 'No attribute formats given' # Return tuple (formats, initial_arrays). formats = [] initial_arrays = [] for i, format in enumerate(data): if isinstance(format, tuple): format, array = format initial_arrays.append((i, array)) formats.append(format) formats = tuple(formats) return formats, initial_arrays def _get_default_batch(): shared_object_space = gl.current_context.object_space try: return shared_object_space.pyglet_graphics_default_batch except AttributeError: shared_object_space.pyglet_graphics_default_batch = Batch() return shared_object_space.pyglet_graphics_default_batch def vertex_list(count, *data): '''Create a `VertexList` not associated with a batch, group or mode. :Parameters: `count` : int The number of vertices in the list. `data` : data items Attribute formats and initial data for the vertex list. See the module summary for details. :rtype: `VertexList` ''' # Note that mode=0 because the default batch is never drawn: vertex lists # returned from this function are drawn directly by the app. return _get_default_batch().add(count, 0, None, *data) def vertex_list_indexed(count, indices, *data): '''Create an `IndexedVertexList` not associated with a batch, group or mode. :Parameters: `count` : int The number of vertices in the list. `indices` : sequence Sequence of integers giving indices into the vertex list. `data` : data items Attribute formats and initial data for the vertex list. See the module summary for details. :rtype: `IndexedVertexList` ''' # Note that mode=0 because the default batch is never drawn: vertex lists # returned from this function are drawn directly by the app. return _get_default_batch().add_indexed(count, 0, None, indices, *data) class Batch(object): '''Manage a collection of vertex lists for batched rendering. Vertex lists are added to a `Batch` using the `add` and `add_indexed` methods. An optional group can be specified along with the vertex list, which gives the OpenGL state required for its rendering. Vertex lists with shared mode and group are allocated into adjacent areas of memory and sent to the graphics card in a single operation. Call `VertexList.delete` to remove a vertex list from the batch. ''' def __init__(self): '''Create a graphics batch.''' # Mapping to find domain. # group -> (attributes, mode, indexed) -> domain self.group_map = {} # Mapping of group to list of children. self.group_children = {} # List of top-level groups self.top_groups = [] self._draw_list = [] self._draw_list_dirty = False def add(self, count, mode, group, *data): '''Add a vertex list to the batch. :Parameters: `count` : int The number of vertices in the list. `mode` : int OpenGL drawing mode enumeration; for example, one of ``GL_POINTS``, ``GL_LINES``, ``GL_TRIANGLES``, etc. See the module summary for additional information. `group` : `Group` Group of the vertex list, or ``None`` if no group is required. `data` : data items Attribute formats and initial data for the vertex list. See the module summary for details. :rtype: `VertexList` ''' formats, initial_arrays = _parse_data(data) domain = self._get_domain(False, mode, group, formats) domain.__formats = formats # Create vertex list and initialize vlist = domain.create(count) for i, array in initial_arrays: vlist._set_attribute_data(i, array) return vlist def add_indexed(self, count, mode, group, indices, *data): '''Add an indexed vertex list to the batch. :Parameters: `count` : int The number of vertices in the list. `mode` : int OpenGL drawing mode enumeration; for example, one of ``GL_POINTS``, ``GL_LINES``, ``GL_TRIANGLES``, etc. See the module summary for additional information. `group` : `Group` Group of the vertex list, or ``None`` if no group is required. `indices` : sequence Sequence of integers giving indices into the vertex list. `data` : data items Attribute formats and initial data for the vertex list. See the module summary for details. :rtype: `IndexedVertexList` ''' formats, initial_arrays = _parse_data(data) domain = self._get_domain(True, mode, group, formats) # Create vertex list and initialize vlist = domain.create(count, len(indices)) start = vlist.start vlist._set_index_data(map(lambda i: i + start, indices)) for i, array in initial_arrays: vlist._set_attribute_data(i, array) return vlist def migrate(self, vertex_list, mode, group, batch): '''Migrate a vertex list to another batch and/or group. `vertex_list` and `mode` together identify the vertex list to migrate. `group` and `batch` are new owners of the vertex list after migration. The results are undefined if `mode` is not correct or if `vertex_list` does not belong to this batch (they are not checked and will not necessarily throw an exception immediately). `batch` can remain unchanged if only a group change is desired. :Parameters: `vertex_list` : `VertexList` A vertex list currently belonging to this batch. `mode` : int The current GL drawing mode of the vertex list. `group` : `Group` The new group to migrate to. `batch` : `Batch` The batch to migrate to (or the current batch). ''' formats = vertex_list.domain.__formats domain = batch._get_domain(False, mode, group, formats) vertex_list.migrate(domain) def _get_domain(self, indexed, mode, group, formats): if group is None: group = null_group # Batch group if group not in self.group_map: self._add_group(group) domain_map = self.group_map[group] # Find domain given formats, indices and mode key = (formats, mode, indexed) try: domain = domain_map[key] except KeyError: # Create domain if indexed: domain = vertexdomain.create_indexed_domain(*formats) else: domain = vertexdomain.create_domain(*formats) domain_map[key] = domain self._draw_list_dirty = True return domain def _add_group(self, group): self.group_map[group] = {} if group.parent is None: self.top_groups.append(group) else: if group.parent not in self.group_map: self._add_group(group.parent) if group.parent not in self.group_children: self.group_children[group.parent] = [] self.group_children[group.parent].append(group) self._draw_list_dirty = True def _update_draw_list(self): '''Visit group tree in preorder and create a list of bound methods to call. ''' def visit(group): draw_list = [] # Draw domains using this group domain_map = self.group_map[group] for (formats, mode, indexed), domain in list(domain_map.items()): # Remove unused domains from batch if domain._is_empty(): del domain_map[(formats, mode, indexed)] continue draw_list.append( (lambda d, m: lambda: d.draw(m))(domain, mode)) # Sort and visit child groups of this group children = self.group_children.get(group) if children: children.sort() for child in list(children): draw_list.extend(visit(child)) if children or domain_map: return [group.set_state] + draw_list + [group.unset_state] else: # Remove unused group from batch del self.group_map[group] if group.parent: self.group_children[group.parent].remove(group) try: del self.group_children[group] except KeyError: pass try: self.top_groups.remove(group) except ValueError: pass return [] self._draw_list = [] self.top_groups.sort() for group in list(self.top_groups): self._draw_list.extend(visit(group)) self._draw_list_dirty = False if _debug_graphics_batch: self._dump_draw_list() def _dump_draw_list(self): def dump(group, indent=''): print indent, 'Begin group', group domain_map = self.group_map[group] for _, domain in domain_map.items(): print indent, ' ', domain for start, size in zip(*domain.allocator.get_allocated_regions()): print indent, ' ', 'Region %d size %d:' % (start, size) for key, attribute in domain.attribute_names.items(): print indent, ' ', try: region = attribute.get_region(attribute.buffer, start, size) print key, region.array[:] except: print key, '(unmappable)' for child in self.group_children.get(group, ()): dump(child, indent + ' ') print indent, 'End group', group print 'Draw list for %r:' % self for group in self.top_groups: dump(group) def draw(self): '''Draw the batch. ''' if self._draw_list_dirty: self._update_draw_list() for func in self._draw_list: func() def draw_subset(self, vertex_lists): '''Draw only some vertex lists in the batch. The use of this method is highly discouraged, as it is quite inefficient. Usually an application can be redesigned so that batches can always be drawn in their entirety, using `draw`. The given vertex lists must belong to this batch; behaviour is undefined if this condition is not met. :Parameters: `vertex_lists` : sequence of `VertexList` or `IndexedVertexList` Vertex lists to draw. ''' # Horrendously inefficient. def visit(group): group.set_state() # Draw domains using this group domain_map = self.group_map[group] for (_, mode, _), domain in domain_map.items(): for list in vertex_lists: if list.domain is domain: list.draw(mode) # Sort and visit child groups of this group children = self.group_children.get(group) if children: children.sort() for child in children: visit(child) group.unset_state() self.top_groups.sort() for group in self.top_groups: visit(group) class Group(object): '''Group of common OpenGL state. Before a vertex list is rendered, its group's OpenGL state is set; as are that state's ancestors' states. This can be defined arbitrarily on subclasses; the default state change has no effect, and groups vertex lists only in the order in which they are drawn. ''' def __init__(self, parent=None): '''Create a group. :Parameters: `parent` : `Group` Group to contain this group; its state will be set before this state's. ''' self.parent = parent def set_state(self): '''Apply the OpenGL state change. The default implementation does nothing.''' pass def unset_state(self): '''Repeal the OpenGL state change. The default implementation does nothing.''' pass def set_state_recursive(self): '''Set this group and its ancestry. Call this method if you are using a group in isolation: the parent groups will be called in top-down order, with this class's `set` being called last. ''' if self.parent: self.parent.set_state_recursive() self.set_state() def unset_state_recursive(self): '''Unset this group and its ancestry. The inverse of `set_state_recursive`. ''' self.unset_state() if self.parent: self.parent.unset_state_recursive() class NullGroup(Group): '''The default group class used when ``None`` is given to a batch. This implementation has no effect. ''' pass #: The default group. #: #: :type: `Group` null_group = NullGroup() class TextureGroup(Group): '''A group that enables and binds a texture. Texture groups are equal if their textures' targets and names are equal. ''' # Don't use this, create your own group classes that are more specific. # This is just an example. def __init__(self, texture, parent=None): '''Create a texture group. :Parameters: `texture` : `Texture` Texture to bind. `parent` : `Group` Parent group. ''' super(TextureGroup, self).__init__(parent) self.texture = texture def set_state(self): glEnable(self.texture.target) glBindTexture(self.texture.target, self.texture.id) def unset_state(self): glDisable(self.texture.target) def __hash__(self): return hash((self.texture.target, self.texture.id, self.parent)) def __eq__(self, other): return (self.__class__ is other.__class__ and self.texture.target == other.texture.target and self.texture.id == other.texture.id and self.parent == other.parent) def __repr__(self): return '%s(id=%d)' % (self.__class__.__name__, self.texture.id) class OrderedGroup(Group): '''A group with partial order. Ordered groups with a common parent are rendered in ascending order of their ``order`` field. This is a useful way to render multiple layers of a scene within a single batch. ''' # This can be useful as a top-level group, or as a superclass for other # groups that need to be ordered. # # As a top-level group it's useful because graphics can be composited in a # known order even if they don't know about each other or share any known # group. def __init__(self, order, parent=None): '''Create an ordered group. :Parameters: `order` : int Order of this group. `parent` : `Group` Parent of this group. ''' super(OrderedGroup, self).__init__(parent) self.order = order def __cmp__(self, other): if isinstance(other, OrderedGroup): return cmp(self.order, other.order) return -1 def __eq__(self, other): return (self.__class__ is other.__class__ and self.order == other.order and self.parent == other.parent) def __hash__(self): return hash((self.order, self.parent)) def __repr__(self): return '%s(%d)' % (self.__class__.__name__, self.order)