entropy.rs - source

Files

ab_glyph_rasterizer

geometry.rs lib.rs raster.rs

adler

adler32

andrew

shapes

mod.rs rectangle.rs

text

fontconfig.rs mod.rs

bitflags

bytemuck

contiguous.rs lib.rs offset_of.rs pod.rs transparent.rs zeroable.rs

byteorder

calloop

sources

channel.rs generic.rs mod.rs ping.rs signals.rs timer.rs

sys

epoll.rs mod.rs

lib.rs list.rs loop_logic.rs

cfg_if

color_quant

crc32fast

specialized

mod.rs pclmulqdq.rs

baseline.rs combine.rs lib.rs table.rs

crossbeam_channel

flavors

array.rs at.rs list.rs mod.rs never.rs tick.rs zero.rs

channel.rs context.rs counter.rs err.rs lib.rs select.rs select_macro.rs utils.rs waker.rs

crossbeam_deque

deque.rs lib.rs

crossbeam_epoch

sync

list.rs mod.rs queue.rs

atomic.rs collector.rs default.rs deferred.rs epoch.rs guard.rs internal.rs lib.rs

crossbeam_utils

atomic

atomic_cell.rs consume.rs mod.rs seq_lock.rs

sync

mod.rs parker.rs sharded_lock.rs wait_group.rs

backoff.rs cache_padded.rs lib.rs thread.rs

deflate

dlib

downcast_rs

draw_state

lib.rs preset.rs state.rs target.rs

either

event_loop

float

fnv

gfx

macros

mod.rs pso.rs structure.rs

pso

buffer.rs bundle.rs mod.rs resource.rs target.rs

encoder.rs factory.rs lib.rs shade.rs slice.rs

gfx_core

buffer.rs command.rs dummy.rs factory.rs format.rs handle.rs lib.rs mapping.rs memory.rs pso.rs shade.rs texture.rs

gfx_device_gl

command.rs factory.rs info.rs lib.rs shade.rs state.rs tex.rs

gfx_gl

gfx_graphics

back_end.rs lib.rs

gfx_texture

gif

reader

decoder.rs mod.rs

common.rs encoder.rs lib.rs traits.rs

gl

glutin

api

egl

make_current_guard.rs mod.rs

glx

make_current_guard.rs mod.rs

osmesa

dlloader.rs mod.rs

platform

platform_impl

unix

x11

mod.rs wayland.rs x11.rs

context.rs lib.rs windowed.rs

glutin_egl_sys

glutin_glx_sys

glutin_window

graphics

graphics_api_version

image

input

after_render.rs button.rs close.rs controller.rs cursor.rs event_id.rs focus.rs generic_event.rs idle.rs keyboard.rs lib.rs mouse.rs render.rs resize.rs text.rs touch.rs update.rs

instant

lib.rs native.rs

interpolation

ease.rs lerp.rs lib.rs

iovec

sys

jpeg_decoder

worker

immediate.rs mod.rs multithreaded.rs

decoder.rs error.rs huffman.rs idct.rs lib.rs marker.rs parser.rs upsampler.rs

lazy_static

inline_lazy.rs lib.rs

lazycell

libc

unix

linux_like

linux

arch

generic

gnu

b64

x86_64

align.rs mod.rs not_x32.rs

align.rs mod.rs

align.rs mod.rs

align.rs mod.rs

fixed_width_ints.rs lib.rs macros.rs

libloading

os

unix

consts.rs mod.rs

changelog.rs error.rs lib.rs util.rs

lock_api

lib.rs mutex.rs remutex.rs rwlock.rs

log

lib.rs macros.rs

maybe_uninit

memchr

x86

fallback.rs iter.rs lib.rs naive.rs

memmap2

memoffset

lib.rs offset_of.rs raw_field.rs span_of.rs

miniz_oxide

deflate

buffer.rs core.rs mod.rs stream.rs

inflate

core.rs mod.rs output_buffer.rs stream.rs

lib.rs shared.rs

mio

mio_extras

channel.rs lib.rs timer.rs

net2

sys

unix

impls.rs mod.rs

ext.rs lib.rs socket.rs tcp.rs udp.rs unix.rs utils.rs

nix

nom

bits

complete.rs macros.rs mod.rs streaming.rs

branch

macros.rs mod.rs

bytes

complete.rs macros.rs mod.rs streaming.rs

character

complete.rs macros.rs mod.rs streaming.rs

combinator

macros.rs mod.rs

multi

macros.rs mod.rs

number

complete.rs macros.rs mod.rs streaming.rs

sequence

macros.rs mod.rs

error.rs internal.rs lib.rs str.rs traits.rs util.rs

num_cpus

lib.rs linux.rs

num_integer

average.rs lib.rs roots.rs

num_iter

num_rational

num_traits

ops

checked.rs inv.rs mod.rs mul_add.rs overflowing.rs saturating.rs wrapping.rs

bounds.rs cast.rs float.rs identities.rs int.rs lib.rs macros.rs pow.rs real.rs sign.rs

once_cell

imp_std.rs lib.rs race.rs

osmesa_sys

owned_ttf_parser

convert.rs lib.rs owned.rs

parking_lot

condvar.rs deadlock.rs elision.rs fair_mutex.rs lib.rs mutex.rs once.rs raw_fair_mutex.rs raw_mutex.rs raw_rwlock.rs remutex.rs rwlock.rs util.rs

parking_lot_core

thread_parker

linux.rs mod.rs

lib.rs parking_lot.rs spinwait.rs util.rs word_lock.rs

percent_encoding

piston

piston_window

png

decoder

mod.rs stream.rs zlib.rs

chunk.rs common.rs encoder.rs filter.rs lib.rs traits.rs utils.rs

proc_macro2

detection.rs fallback.rs lib.rs marker.rs parse.rs wrapper.rs

quote

ext.rs format.rs ident_fragment.rs lib.rs runtime.rs spanned.rs to_tokens.rs

raw_window_handle

rayon

delegate.rs lib.rs math.rs option.rs par_either.rs prelude.rs private.rs range.rs range_inclusive.rs result.rs split_producer.rs str.rs string.rs vec.rs

rayon_core

compile_fail

mod.rs quicksort_race1.rs quicksort_race2.rs quicksort_race3.rs rc_return.rs rc_upvar.rs scope_join_bad.rs

join

scope

sleep

counters.rs mod.rs

spawn

thread_pool

job.rs latch.rs lib.rs log.rs private.rs registry.rs unwind.rs util.rs

read_color

rusttype

font.rs geometry.rs lib.rs outliner.rs

same_file

scoped_threadpool

scoped_tls

scopeguard

serde

de

ignored_any.rs impls.rs mod.rs seed.rs utf8.rs value.rs

private

de.rs doc.rs mod.rs ser.rs size_hint.rs

ser

fmt.rs impls.rs impossible.rs mod.rs

integer128.rs lib.rs macros.rs

serde_derive

internals

ast.rs attr.rs case.rs check.rs ctxt.rs mod.rs receiver.rs respan.rs symbol.rs

bound.rs de.rs dummy.rs fragment.rs lib.rs pretend.rs ser.rs try.rs

shader_version

glsl.rs lib.rs opengl.rs

shaders_graphics2d

colored

textured

textured_color

shared_library

dynamic_library.rs lib.rs

slab

smallvec

smithay_client_toolkit

data_device

device.rs mod.rs offer.rs source.rs

primary_selection

device.rs mod.rs offer.rs source.rs

seat

keyboard

ffi.rs keysyms.rs mod.rs state.rs

pointer

mod.rs theme.rs

shell

mod.rs wl.rs xdg.rs zxdg.rs

shm

mempool.rs mod.rs

window

concept_frame.rs mod.rs

environment.rs event_loop.rs lazy_global.rs lib.rs output.rs surface.rs

spin_sleep

lib.rs loop_helper.rs

syn

texture

tiff

decoder

ifd.rs mod.rs stream.rs

encoder

colortype.rs mod.rs writer.rs

bytecast.rs error.rs lib.rs tags.rs

ttf_parser

unicode_xid

lib.rs tables.rs

vecmath

lib.rs traits.rs

viewport

walkdir

dent.rs error.rs lib.rs util.rs

wayland_client

native_lib

display.rs event_queue.rs mod.rs proxy.rs

display.rs event_queue.rs globals.rs lib.rs proxy.rs

wayland_commons

debug.rs filter.rs lib.rs map.rs socket.rs user_data.rs wire.rs

wayland_cursor

wayland_egl

wayland_protocols

lib.rs misc.rs protocol_macro.rs stable.rs unstable.rs wlr.rs

wayland_sys

client.rs common.rs egl.rs lib.rs server.rs

weezl

decode.rs encode.rs error.rs lib.rs

window

lib.rs no_window.rs

winit

platform

mod.rs run_return.rs unix.rs

platform_impl

linux

wayland

event_loop

mod.rs proxy.rs sink.rs state.rs

seat

keyboard

handlers.rs keymap.rs mod.rs

pointer

data.rs handlers.rs mod.rs

text_input

handlers.rs mod.rs

touch

handlers.rs mod.rs

window

env.rs mod.rs output.rs

x11

dpi.rs error.rs event.rs event_loop.rs icon.rs lib.rs monitor.rs window.rs

x11_dl

xcursor

lib.rs parser.rs

xdg

xml

/// Given an array containing the number of codes of each code length,
/// this function generates the huffman codes lengths and their respective
/// code lengths as specified by the JPEG spec.
fn derive_codes_and_sizes(bits: &[u8; 16]) -> ([u8; 256], [u16; 256]) {
    let mut huffsize = [0u8; 256];
    let mut huffcode = [0u16; 256];

    let mut k = 0;

    // Annex C.2
    // Figure C.1
    // Generate table of individual code lengths
    for i in 0u8..16 {
        let mut j = 0;

        while j < bits[usize::from(i)] {
            huffsize[k] = i + 1;
            k += 1;
            j += 1;
        }
    }

    huffsize[k] = 0;

    // Annex C.2
    // Figure C.2
    // Generate table of huffman codes
    k = 0;
    let mut code = 0u16;
    let mut size = huffsize[0];

    while huffsize[k] != 0 {
        huffcode[k] = code;
        code += 1;
        k += 1;

        if huffsize[k] == size {
            continue;
        }

        // FIXME there is something wrong with this code
        let diff = huffsize[k].wrapping_sub(size);
        code = if diff < 16 { code << diff as usize } else { 0 };

        size = size.wrapping_add(diff);
    }

    (huffsize, huffcode)
}

pub(crate) fn build_huff_lut(bits: &[u8; 16], huffval: &[u8]) -> [(u8, u16); 256] {
    let mut lut = [(17u8, 0u16); 256];
    let (huffsize, huffcode) = derive_codes_and_sizes(bits);

    for (i, &v) in huffval.iter().enumerate() {
        lut[v as usize] = (huffsize[i], huffcode[i]);
    }

    lut
}