def __init__(self, sizes, surface_type, filter=GL_LINEAR, wrap=GL_CLAMP_TO_EDGE):
""" where sizes is a dict some_key -> Size2
textures and surfaces are later accessed by this key """
assert len(sizes)
self.surftype = surface_type
self.frontbuf, self.backbuf = glGenBuffers(2)
self.store = {}
self.surfaces = {}
offset = 0
self.texnames = tuple(glGenTextures(len(sizes)))
texnames = list(self.texnames)
for some_key, size in sizes.items():
texname = texnames.pop(0)
glBindTexture(GL_TEXTURE_2D, texname)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrap)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrap)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter)
self.store[some_key] = ( texname, size, offset )
offset += size.w*size.h*4
self.bufsize = offset
glBindTexture(GL_TEXTURE_2D, 0)
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, self.backbuf)
glBufferData(GL_PIXEL_UNPACK_BUFFER, self.bufsize, gl_off_t(0), GL_STREAM_DRAW)
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, self.frontbuf)
glBufferData(GL_PIXEL_UNPACK_BUFFER, self.bufsize, gl_off_t(0), GL_STREAM_DRAW)
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0)
self.swap() # initializes self.surfaces.
def upload(self):
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, self.frontbuf)
glUnmapBuffer(GL_PIXEL_UNPACK_BUFFER)
for texname, size, offset in self.store.values():
glBindTexture(GL_TEXTURE_2D, texname)
glTexImage2D(GL_TEXTURE_2D, 0, self.surftype.gl_internal_fmt,
size.w, size.h, 0, self.surftype.gl_data_fmt,
self.surftype.gl_data_type, gl_off_t(offset))
self.swap()
