skia2/experimental/nanomsg/picture_demo.cpp
2016-03-24 11:05:29 -07:00

215 lines
6.5 KiB
C++

/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "nanomsg/src/nn.h"
#include "nanomsg/src/pipeline.h"
#include "nanomsg/src/reqrep.h"
#include "SkCanvas.h"
#include "SkCommandLineFlags.h"
#include "SkData.h"
#include "SkForceLinking.h"
#include "SkGraphics.h"
#include "SkImageEncoder.h"
#include "SkOSFile.h"
#include "SkPicture.h"
#include "SkRandom.h"
#include "SkStream.h"
__SK_FORCE_IMAGE_DECODER_LINKING;
// To keep things simple, PictureHeader is fixed-size POD.
struct PictureHeader {
SkMatrix matrix;
SkRect clip;
SkXfermode::Mode xfermode;
pid_t pid;
uint8_t alpha;
PictureHeader()
: matrix(SkMatrix::I())
, clip(SkRect::MakeLargest())
, xfermode(SkXfermode::kSrcOver_Mode)
, pid(getpid())
, alpha(0xFF) {}
};
// A little adaptor: nn_iovec wants a non-const pointer for no obvious reason.
static struct nn_iovec create_iov(const void* ptr, size_t size) {
struct nn_iovec iov = { const_cast<void*>(ptr), size };
return iov;
}
static void send_picture(int socket, const PictureHeader& header, const SkData& skp) {
// Vectored IO lets us send header and skp contiguously without first
// copying them to a contiguous buffer.
struct nn_iovec iov[] = {
create_iov(&header, sizeof(header)),
create_iov(skp.data(), skp.size()),
};
struct nn_msghdr msg;
sk_bzero(&msg, sizeof(msg));
msg.msg_iov = iov;
msg.msg_iovlen = SK_ARRAY_COUNT(iov);
nn_sendmsg(socket, &msg, 0/*flags*/);
}
static sk_sp<SkPicture> recv_picture(int socket, PictureHeader* header) {
static const size_t hSize = sizeof(*header); // It's easy to slip up and use sizeof(header).
void* msg;
int size = nn_recv(socket, &msg, NN_MSG, 0/*flags*/);
SkDebugf("%d bytes", size);
// msg is first a fixed-size header, then an .skp.
memcpy(header, msg, hSize);
SkMemoryStream stream((uint8_t*)msg + hSize, size - hSize);
sk_sp<SkPicture> pic = SkPicture::MakeFromStream(&stream);
SkDebugf(" from proccess %d:", header->pid);
nn_freemsg(msg);
return pic;
}
static void client(const char* skpPath, const char* dataEndpoint) {
// Read the .skp.
SkAutoTUnref<const SkData> skp(SkData::NewFromFileName(skpPath));
if (!skp) {
SkDebugf("Couldn't read %s\n", skpPath);
exit(1);
}
SkMemoryStream stream(skp->data(), skp->size());
sk_sp<SkPicture> picture(SkPicture::MakeFromStream(&stream));
PictureHeader header;
SkRandom rand(picture->cullRect().width() * picture->cullRect().height());
SkScalar r = rand.nextRangeScalar(0, picture->cullRect().width()),
b = rand.nextRangeScalar(0, picture->cullRect().height()),
l = rand.nextRangeScalar(0, r),
t = rand.nextRangeScalar(0, b);
header.clip.setLTRB(l,t,r,b);
header.matrix.setTranslate(-l, -t);
header.matrix.postRotate(rand.nextRangeScalar(-25, 25));
header.alpha = 0x7F;
//Clients use NN_REQ (request) type sockets.
int socket = nn_socket(AF_SP, NN_REQ);
// Clients connect a socket to an endpoint.
nn_connect(socket, dataEndpoint);
// Send the picture and its header.
SkDebugf("Sending %s (%d bytes)...", skpPath, skp->size());
send_picture(socket, header, *skp);
// Wait for ack.
uint8_t ack;
nn_recv(socket, &ack, sizeof(ack), 0/*flags*/);
SkDebugf(" ok.\n");
}
// Wait until socketA or socketB has something to tell us, and return which one.
static int poll_in(int socketA, int socketB) {
struct nn_pollfd polls[] = {
{ socketA, NN_POLLIN, 0 },
{ socketB, NN_POLLIN, 0 },
};
nn_poll(polls, SK_ARRAY_COUNT(polls), -1/*no timeout*/);
if (polls[0].revents & NN_POLLIN) { return socketA; }
if (polls[1].revents & NN_POLLIN) { return socketB; }
SkFAIL("unreachable");
return 0;
}
static void server(const char* dataEndpoint, const char* controlEndpoint, SkCanvas* canvas) {
// NN_REP sockets receive a request then make a reply. NN_PULL sockets just receive a request.
int data = nn_socket(AF_SP, NN_REP);
int control = nn_socket(AF_SP, NN_PULL);
// Servers bind a socket to an endpoint.
nn_bind(data, dataEndpoint);
nn_bind(control, controlEndpoint);
while (true) {
int ready = poll_in(data, control);
// If we got any message on the control socket, we can stop.
if (ready == control) {
break;
}
// We should have an .skp waiting for us on data socket.
PictureHeader header;
sk_sp<SkPicture> picture(recv_picture(data, &header));
SkPaint paint;
paint.setAlpha(header.alpha);
paint.setXfermodeMode(header.xfermode);
canvas->saveLayer(NULL, &paint);
canvas->concat(header.matrix);
canvas->clipRect(header.clip);
picture->playback(canvas);
canvas->restore();
SkDebugf(" drew");
// Send back an ack.
uint8_t ack = 42;
nn_send(data, &ack, sizeof(ack), 0/*flags*/);
SkDebugf(" and acked.\n");
}
}
static void stop(const char* controlEndpoint) {
// An NN_PUSH socket can send messages but not receive them.
int control = nn_socket(AF_SP, NN_PUSH);
nn_connect(control, controlEndpoint);
// Sending anything (including this 0-byte message) will tell server() to stop.
nn_send(control, NULL, 0, 0/*flags*/);
}
DEFINE_string2(skp, r, "", ".skp to send (as client)");
DEFINE_string2(png, w, "", ".png to write (as server)");
DEFINE_bool(stop, false, "If true, tell server to stop and write its canvas out as a .png.");
DEFINE_string(data, "ipc://nanomsg-picture-data", "Endpoint for sending pictures.");
DEFINE_string(control, "ipc://nanomsg-picture-control", "Endpoint for control channel.");
int main(int argc, char** argv) {
SkAutoGraphics ag;
SkCommandLineFlags::Parse(argc, argv);
if (FLAGS_stop) {
stop(FLAGS_control[0]);
}
if (!FLAGS_skp.isEmpty()) {
client(FLAGS_skp[0], FLAGS_data[0]);
}
if (!FLAGS_png.isEmpty()) {
SkBitmap bitmap;
bitmap.allocN32Pixels(1000, 1000);
SkCanvas canvas(bitmap);
canvas.clear(0xFFFFFFFF);
server(FLAGS_data[0], FLAGS_control[0], &canvas);
canvas.flush();
SkImageEncoder::EncodeFile(FLAGS_png[0], bitmap, SkImageEncoder::kPNG_Type, 100);
SkDebugf("Wrote %s.\n", FLAGS_png[0]);
}
return 0;
}