X-Git-Url: http://git.localhorst.tv/?a=blobdiff_plain;f=src%2Fnet%2Fnet.cpp;h=7de901e31f58b7f842461e2a2414e677db8ceca5;hb=56069d41c1553d87a8759713ef391d3a908adc0e;hp=4de800e2429eb4c1c65e4a87ef0ec17567692058;hpb=a957788426ff011acf662e29ec5fc0525c1a578f;p=blank.git

diff --git a/src/net/net.cpp b/src/net/net.cpp
index 4de800e..7de901e 100644
--- a/src/net/net.cpp
+++ b/src/net/net.cpp
@@ -5,6 +5,7 @@
 #include "Packet.hpp"
 
 #include "../app/init.hpp"
+#include "../geometry/const.hpp"
 #include "../model/Model.hpp"
 #include "../world/Entity.hpp"
 #include "../world/EntityState.hpp"
@@ -40,27 +41,36 @@ CongestionControl::CongestionControl()
 , packets_lost(0)
 , packets_received(0)
 , packet_loss(0.0f)
-, stamp_cursor(15)
 , stamp_last(0)
 , rtt(64.0f)
 , next_sample(1000)
 , tx_bytes(0)
 , rx_bytes(0)
 , tx_kbps(0.0f)
-, rx_kbps(0.0f) {
+, rx_kbps(0.0f)
+, mode(GOOD)
+// rtt > 75ms or packet loss > 5% is BAD
+, bad_rtt(75.0f)
+, bad_loss(0.05f)
+// rtt > 150ms or packet loss > 15% is UGLY
+, ugly_rtt(150.0f)
+, ugly_loss(0.15f)
+, mode_keep_time(1000) {
 	Uint32 now = SDL_GetTicks();
 	for (Uint32 &s : stamps) {
 		s = now;
 	}
 	next_sample += now;
+	mode_entered = now;
+	mode_reset = now;
+	mode_step = now;
 }
 
 void CongestionControl::PacketSent(uint16_t seq) noexcept {
 	if (!SamplePacket(seq)) {
 		return;
 	}
-	stamp_cursor = (stamp_cursor + 1) % 16;
-	stamps[stamp_cursor] = SDL_GetTicks();
+	stamps[SampleIndex(seq)] = SDL_GetTicks();
 	stamp_last = seq;
 }
 
@@ -85,24 +95,23 @@ void CongestionControl::UpdatePacketLoss() noexcept {
 	}
 }
 
-void CongestionControl::UpdateRTT(std::uint16_t seq) noexcept {
+void CongestionControl::UpdateRTT(uint16_t seq) noexcept {
 	if (!SamplePacket(seq)) return;
-	int diff = HeadDiff(seq);
-	if (diff > 0 || diff < -15) {
-		// packet outside observed time frame
+	int16_t diff = int16_t(stamp_last) - int16_t(seq);
+	if (diff < 0 || diff > int(15 * sample_skip)) {
+		// packet outside observed frame
 		return;
 	}
-	int cur_rtt = SDL_GetTicks() - stamps[(stamp_cursor + diff + 16) % 16];
+	int cur_rtt = SDL_GetTicks() - stamps[SampleIndex(seq)];
 	rtt += (cur_rtt - rtt) * 0.1f;
 }
 
-bool CongestionControl::SamplePacket(std::uint16_t seq) const noexcept {
+bool CongestionControl::SamplePacket(uint16_t seq) const noexcept {
 	return seq % sample_skip == 0;
 }
 
-int CongestionControl::HeadDiff(std::uint16_t seq) const noexcept {
-	int16_t diff = int16_t(seq) - int16_t(stamp_last);
-	return diff / sample_skip;
+size_t CongestionControl::SampleIndex(uint16_t seq) const noexcept {
+	return (seq / sample_skip) % 16;
 }
 
 void CongestionControl::PacketIn(const UDPpacket &pack) noexcept {
@@ -117,12 +126,71 @@ void CongestionControl::PacketOut(const UDPpacket &pack) noexcept {
 
 void CongestionControl::UpdateStats() noexcept {
 	Uint32 now = SDL_GetTicks();
-	if (now >= next_sample) {
-		tx_kbps = float(tx_bytes) * (1.0f / 1024.0f);
-		rx_kbps = float(rx_bytes) * (1.0f / 1024.0f);
-		tx_bytes = 0;
-		rx_bytes = 0;
-		next_sample += 1000;
+	if (now < next_sample) {
+		// not yet
+		return;
+	}
+	tx_kbps = float(tx_bytes) * (1.0f / 1024.0f);
+	rx_kbps = float(rx_bytes) * (1.0f / 1024.0f);
+	tx_bytes = 0;
+	rx_bytes = 0;
+	next_sample += 1000;
+	UpdateMode();
+}
+
+void CongestionControl::UpdateMode() noexcept {
+	Mode now_mode = Conditions();
+	if (now_mode > mode) {
+		ChangeMode(now_mode);
+	} else if (now_mode < mode) {
+		CheckUpgrade(now_mode);
+	} else {
+		KeepMode();
+	}
+}
+
+void CongestionControl::CheckUpgrade(Mode m) noexcept {
+	Uint32 now = SDL_GetTicks();
+	Uint32 time_in_mode = now - mode_entered;
+	if (time_in_mode < mode_keep_time) {
+		return;
+	}
+	ChangeMode(m);
+}
+
+void CongestionControl::ChangeMode(Mode m) noexcept {
+	Uint32 now = SDL_GetTicks();
+	if (m > mode) {
+		// changed to worse mode
+		// if we spent less than 10 seconds in better mode
+		// double keep time till up to 64 seconds
+		if (now - mode_entered < 10000) {
+			if (mode_keep_time < 64000) {
+				mode_keep_time *= 2;
+			}
+		}
+	}
+	mode = m;
+	mode_entered = now;
+	mode_reset = mode_entered;
+}
+
+void CongestionControl::KeepMode() noexcept {
+	mode_reset = SDL_GetTicks();
+	// if in good mode for 10 seconds, halve keep time till down to one second
+	if (mode == GOOD && mode_keep_time > 1000 && mode_step - mode_reset > 10000) {
+		mode_keep_time /= 2;
+		mode_step = mode_reset;
+	}
+}
+
+CongestionControl::Mode CongestionControl::Conditions() const noexcept {
+	if (rtt > ugly_rtt || packet_loss > ugly_loss) {
+		return UGLY;
+	} else if (rtt > bad_rtt || packet_loss > bad_loss) {
+		return BAD;
+	} else {
+		return GOOD;
 	}
 }
 
@@ -130,7 +198,9 @@ void CongestionControl::UpdateStats() noexcept {
 Connection::Connection(const IPaddress &addr)
 : handler(nullptr)
 , addr(addr)
-, send_timer(500)
+// make sure a packet is sent at least every 50ms since packets contains
+// acks that the remote end will use to measure RTT
+, send_timer(50)
 , recv_timer(10000)
 , ctrl_out{ 0, 0xFFFF, 0xFFFFFFFF }
 , ctrl_in{ 0, 0xFFFF, 0xFFFFFFFF }
@@ -364,23 +434,72 @@ void Packet::Payload::ReadString(string &dst, size_t off, size_t maxlen) const n
 }
 
 void Packet::Payload::Write(const glm::quat &val, size_t off) noexcept {
-	WritePackN(val.w, off);
-	WritePackN(val.x, off + 2);
-	WritePackN(val.y, off + 4);
-	WritePackN(val.z, off + 6);
+	// find the largest component
+	float largest = 0.0f;
+	int largest_index = -1;
+	for (int i = 0; i < 4; ++i) {
+		float iabs = abs(val[i]);
+		if (iabs > largest) {
+			largest = iabs;
+			largest_index = i;
+		}
+	}
+	// make sure it's positive
+	const glm::quat q(val[largest_index] < 0.0f ? -val : val);
+	// move index to the two most significant bits
+	uint64_t packed = uint64_t(largest_index) << 62;
+	// we have to map from [-0.7072,0.7072] to [-524287,524287] and move into positive range
+	constexpr float conv = 524287.0f / 0.7072f;
+	// if largest is 1, the other three are 0
+	// precision of comparison is the interval of our mapping
+	if (abs(1.0 - largest) < (1.0f / conv)) {
+		packed |= 0x7FFFF7FFFF7FFFF;
+	} else {
+		// pack the three smaller components into 20bit ints each
+		int shift = 40;
+		for (int i = 0; i < 4; ++i) {
+			if (i != largest_index) {
+				packed |= uint64_t(int(q[i] * conv) + 524287) << shift;
+				shift -= 20;
+			}
+		}
+	}
+	// and write it out
+	Write(packed, off);
 }
 
 void Packet::Payload::Read(glm::quat &val, size_t off) const noexcept {
-	ReadPackN(val.w, off);
-	ReadPackN(val.x, off + 2);
-	ReadPackN(val.y, off + 4);
-	ReadPackN(val.z, off + 6);
-	val = normalize(val);
+	// extract the 8 byte packed value
+	uint64_t packed = 0;
+	Read(packed, off);
+	// two most significant bits are the index of the largest (omitted) component
+	int largest_index = packed >> 62;
+	// if all other three are 0, largest is 1 and we can omit the conversion
+	if ((packed & 0xFFFFFFFFFFFFFFF) == 0x7FFFF7FFFF7FFFF) {
+		val = { 0.0f, 0.0f, 0.0f, 0.0f };
+		val[largest_index] = 1.0f;
+		return;
+	}
+	// we have to map from [-524287,524287] to [-0.7072,0.7072]
+	constexpr float conv = 0.7072f / 524287.0f;
+	int shift = 40;
+	for (int i = 0; i < 4; ++i) {
+		if (i != largest_index) {
+			val[i] = float(int((packed >> shift) & 0xFFFFF) - 524287) * conv;
+			shift -= 20;
+		} else {
+			// set to zero so the length of the other three can be determined
+			val[i] = 0.0f;
+		}
+	}
+	// omitted component squared is 1 - length squared of others
+	val[largest_index] = sqrt(1.0f - dot(val, val));
+	// and already normalized
 }
 
 void Packet::Payload::Write(const EntityState &state, size_t off) noexcept {
-	Write(state.chunk_pos, off);
-	WritePackU(state.block_pos * (1.0f / 16.0f), off + 12);
+	Write(state.pos.chunk, off);
+	WritePackU(state.pos.block * (1.0f / ExactLocation::fscale), off + 12);
 	Write(state.velocity, off + 18);
 	Write(state.orient, off + 30);
 	WritePackN(state.pitch * PI_0p5_inv, off + 38);
@@ -388,20 +507,20 @@ void Packet::Payload::Write(const EntityState &state, size_t off) noexcept {
 }
 
 void Packet::Payload::Read(EntityState &state, size_t off) const noexcept {
-	Read(state.chunk_pos, off);
-	ReadPackU(state.block_pos, off + 12);
+	Read(state.pos.chunk, off);
+	ReadPackU(state.pos.block, off + 12);
 	Read(state.velocity, off + 18);
 	Read(state.orient, off + 30);
 	ReadPackN(state.pitch, off + 38);
 	ReadPackN(state.yaw, off + 40);
-	state.block_pos *= 16.0f;
+	state.pos.block *= ExactLocation::fscale;
 	state.pitch *= PI_0p5;
 	state.yaw *= PI;
 }
 
 void Packet::Payload::Write(const EntityState &state, const glm::ivec3 &base, size_t off) noexcept {
-	WritePackB(state.chunk_pos - base, off);
-	WritePackU(state.block_pos * (1.0f / 16.0f), off + 3);
+	WritePackB(state.pos.chunk - base, off);
+	WritePackU(state.pos.block * (1.0f / ExactLocation::fscale), off + 3);
 	Write(state.velocity, off + 9);
 	Write(state.orient, off + 21);
 	WritePackN(state.pitch * PI_0p5_inv, off + 29);
@@ -409,14 +528,14 @@ void Packet::Payload::Write(const EntityState &state, const glm::ivec3 &base, si
 }
 
 void Packet::Payload::Read(EntityState &state, const glm::ivec3 &base, size_t off) const noexcept {
-	ReadPackB(state.chunk_pos, off);
-	ReadPackU(state.block_pos, off + 3);
+	ReadPackB(state.pos.chunk, off);
+	ReadPackU(state.pos.block, off + 3);
 	Read(state.velocity, off + 9);
 	Read(state.orient, off + 21);
 	ReadPackN(state.pitch, off + 29);
 	ReadPackN(state.yaw, off + 31);
-	state.chunk_pos += base;
-	state.block_pos *= 16.0f;
+	state.pos.chunk += base;
+	state.pos.block *= ExactLocation::fscale;
 	state.pitch *= PI_0p5;
 	state.yaw *= PI;
 }