From 1a7e79f2c9ccd119a3769bab1a18de07d2dce342 Mon Sep 17 00:00:00 2001
From: wheremyfoodat <44909372+wheremyfoodat@users.noreply.github.com>
Date: Sat, 8 Jul 2023 23:31:16 +0300
Subject: [PATCH] Bad-but-ok for now gyroscope implementation

---
 include/emulator.hpp                 |  4 ++++
 include/services/hid.hpp             |  5 +++++
 include/services/service_manager.hpp |  4 ++++
 src/core/services/hid.cpp            |  9 +++++++++
 src/emulator.cpp                     | 22 ++++++++++++++++++++++
 5 files changed, 44 insertions(+)

diff --git a/include/emulator.hpp b/include/emulator.hpp
index 33f1ae6e..e1684085 100644
--- a/include/emulator.hpp
+++ b/include/emulator.hpp
@@ -37,6 +37,10 @@ class Emulator {
 	bool keyboardAnalogX = false;
 	bool keyboardAnalogY = false;
 
+	// For tracking whether to update gyroscope
+	// We bind gyro to right click + mouse movement
+	bool holdingRightClick = false;
+
 	static constexpr u32 width = 400;
 	static constexpr u32 height = 240 * 2;  // * 2 because 2 screens
 	ROMType romType = ROMType::None;
diff --git a/include/services/hid.hpp b/include/services/hid.hpp
index 70bae750..6a3aab95 100644
--- a/include/services/hid.hpp
+++ b/include/services/hid.hpp
@@ -52,6 +52,7 @@ class HIDService {
 
 	s16 circlePadX, circlePadY;      // Circlepad state
 	s16 touchScreenX, touchScreenY;  // Touchscreen state
+	s16 roll, pitch, yaw;            // Gyroscope state
 
 	bool accelerometerEnabled;
 	bool eventsInitialized;
@@ -117,6 +118,10 @@ class HIDService {
 			newButtons |= 1 << 31;
 	}
 
+	void setRoll(s16 value) { roll = value; }
+	void setPitch(s16 value) { pitch = value; }
+	void setYaw(s16 value) { yaw = value; }
+
 	void updateInputs(u64 currentTimestamp);
 
 	void setSharedMem(u8* ptr) {
diff --git a/include/services/service_manager.hpp b/include/services/service_manager.hpp
index 3136408f..1d93641c 100644
--- a/include/services/service_manager.hpp
+++ b/include/services/service_manager.hpp
@@ -99,4 +99,8 @@ class ServiceManager {
 	void updateInputs(u64 currentTimestamp) { hid.updateInputs(currentTimestamp); }
 	void setTouchScreenPress(u16 x, u16 y) { hid.setTouchScreenPress(x, y); }
 	void releaseTouchScreen() { hid.releaseTouchScreen(); }
+
+	void setRoll(s16 roll) { hid.setRoll(roll); }
+	void setPitch(s16 pitch) { hid.setPitch(pitch); }
+	void setYaw(s16 yaw) { hid.setYaw(yaw); }
 };
diff --git a/src/core/services/hid.cpp b/src/core/services/hid.cpp
index 27a078f2..0c83487c 100644
--- a/src/core/services/hid.cpp
+++ b/src/core/services/hid.cpp
@@ -33,6 +33,7 @@ void HIDService::reset() {
 	newButtons = oldButtons = 0;
 	circlePadX = circlePadY = 0;
 	touchScreenX = touchScreenY = 0;
+	roll = pitch = yaw = 0;
 }
 
 void HIDService::handleSyncRequest(u32 messagePointer) {
@@ -182,6 +183,14 @@ void HIDService::updateInputs(u64 currentTick) {
 			writeSharedMem<u64>(0x160, readSharedMem<u64>(0x158)); // Copy previous tick count
 			writeSharedMem<u64>(0x158, currentTick);             // Write new tick count
 		}
+		const size_t gyroEntryOffset = 0x178 + (nextGyroIndex * 6);  // Offset in the array of 8 touchscreen entries
+		writeSharedMem<u16>(gyroEntryOffset, pitch);
+		writeSharedMem<u16>(gyroEntryOffset + 2, yaw);
+		writeSharedMem<u16>(gyroEntryOffset + 4, roll);
+
+		// Since gyroscope euler angles are relative, we zero them out here and the frontend will update them again when we receive a new rotation
+		roll = pitch = yaw = 0;
+
 		writeSharedMem<u32>(0x168, nextGyroIndex); // Index last updated by the HID module
 		nextGyroIndex = (nextGyroIndex + 1) % 32; // Move to next entry
 	}
diff --git a/src/emulator.cpp b/src/emulator.cpp
index 7ca9e26d..198c573d 100644
--- a/src/emulator.cpp
+++ b/src/emulator.cpp
@@ -192,6 +192,8 @@ void Emulator::run() {
 						} else {
 							srv.releaseTouchScreen();
 						}
+					} else if (event.button.button == SDL_BUTTON_RIGHT) {
+						holdingRightClick = true;
 					}
 					break;
 				}
@@ -199,6 +201,8 @@ void Emulator::run() {
 				case SDL_MOUSEBUTTONUP:
 					if (event.button.button == SDL_BUTTON_LEFT) {
 						srv.releaseTouchScreen();
+					} else if (event.button.button == SDL_BUTTON_RIGHT) {
+						holdingRightClick = false;
 					}
 					break;
 
@@ -244,6 +248,24 @@ void Emulator::run() {
 						}
 					}
 				}
+
+				// Detect mouse motion events for gyroscope emulation
+				case SDL_MOUSEMOTION: {
+					// We use right click to indicate we want to rotate the console. If right click is not held, then this is not a gyroscope rotation
+					if (!holdingRightClick) break;
+
+					// Relative motion since last mouse motion event
+					const s32 motionX = event.motion.xrel;
+					const s32 motionY = event.motion.yrel;
+
+					// The gyroscope involves lots of weird math I don't want to bother with atm
+					// So up until then, we will set the gyroscope euler angles to fixed values based on the direction of the relative motion
+					const s32 roll = motionX > 0 ? 0x7f : -0x7f;
+					const s32 pitch = motionY > 0 ? 0x7f : -0x7f;
+					srv.setRoll(roll);
+					srv.setPitch(pitch);
+					break;
+				}
 			}
 		}