def copy_from_buffer(self, source: "Buffer", size=-1, offset=0, source_offset=0):
"""Copy data into this buffer from another buffer
:param Buffer source: The buffer to copy from
:param int size: The amount of bytes to copy
:param int offset: The byte offset to write the data in this buffer
:param int source_offset: The byte offset to read from the source buffer
"""
# Read the entire source buffer into this buffer
if size == -1:
size = source.size
# TODO: Check buffer bounds
if size + source_offset > source.size:
raise ValueError("Attempting to read outside the source buffer")
if size + offset > self._size:
raise ValueError("Attempting to write outside the buffer")
gl.glBindBuffer(gl.GL_COPY_READ_BUFFER, source.glo)
gl.glBindBuffer(gl.GL_COPY_WRITE_BUFFER, self._glo)
gl.glCopyBufferSubData(
gl.GL_COPY_READ_BUFFER,
gl.GL_COPY_WRITE_BUFFER,
gl.GLintptr(source_offset), # readOffset
gl.GLintptr(offset), # writeOffset
size, # size (number of bytes to copy)
)
def _refresh_shape(self, group):
# Create a buffer large enough to hold all the shapes buffers
batch = self.batches[group]
total_vbo_bytes = sum(s.vbo.size for s in batch.items)
vbo = shader.Buffer.create_with_size(total_vbo_bytes)
offset = 0
gl.glBindBuffer(gl.GL_COPY_WRITE_BUFFER, vbo.buffer_id)
# Copy all the shapes buffer in our own vbo
for shape in batch.items:
gl.glBindBuffer(gl.GL_COPY_READ_BUFFER, shape.vbo.buffer_id)
gl.glCopyBufferSubData(
gl.GL_COPY_READ_BUFFER,
gl.GL_COPY_WRITE_BUFFER,
gl.GLintptr(0),
gl.GLintptr(offset),
shape.vbo.size)
offset += shape.vbo.size
# Create an index buffer object. It should count starting from 0. We need to
# use a reset_idx to indicate that a new shape will start.
reset_idx = 2 ** 32 - 1
indices = []
counter = itertools.count()
for shape in batch.items:
indices.extend(itertools.islice(counter, shape.vao.num_vertices))
indices.append(reset_idx)
del indices[-1]
indices = np.array(indices)
ibo = shader.Buffer(indices.astype('i4').tobytes())
vao_content = [
shader.BufferDescription(
vbo,
'2f 4B',
('in_vert', 'in_color'),
normalized=['in_color']
)
]
vao = shader.vertex_array(self.program, vao_content, ibo)
with self.program:
self.program['Projection'] = get_projection().flatten()
self.program['Position'] = [self.center_x, self.center_y]
self.program['Angle'] = self.angle
batch.shape.vao = vao
batch.shape.vbo = vbo
batch.shape.ibo = ibo
batch.shape.program = self.program
mode, line_width = group
batch.shape.mode = mode
batch.shape.line_width = line_width
def _read(self, size):
""" Debug method to read data from the buffer. """
gl.glBindBuffer(gl.GL_ARRAY_BUFFER, self.buffer_id)
ptr = gl.glMapBufferRange(gl.GL_ARRAY_BUFFER, gl.GLintptr(0), size,
gl.GL_MAP_READ_BIT)
print(f"Reading back from buffer:\n{string_at(ptr, size=size)}")
gl.glUnmapBuffer(gl.GL_ARRAY_BUFFER)
def write(self, data: Any, offset: int = 0):
"""Write byte data to the buffer.
:param bytes data: The byte data to write. This can be bytes or any object supporting the buffer protocol.
:param int offset: The byte offset
"""
gl.glBindBuffer(gl.GL_ARRAY_BUFFER, self._glo)
size, data = data_to_ctypes(data)
gl.glBufferSubData(gl.GL_ARRAY_BUFFER, gl.GLintptr(offset), size, data)
def write(self, data: bytes, offset: int = 0):
gl.glBindBuffer(gl.GL_ARRAY_BUFFER, self.buffer_id)
gl.glBufferSubData(gl.GL_ARRAY_BUFFER, gl.GLintptr(offset), len(data),
data)
