Add experimental mouse API (#126)

* Add experimental mouse API

* Add aurora::core library for aurora::ms

* Add absl::flat_hash_map library for aurora::ms

* Add comment clarifying MS is an aurora extension

* Clear MSStatus::buttons to prevent spurious values

* Minor cleanup for MSRead and MS_BUTTON_* bits

* Switch to Poll -> Read paradigm

* Clear mouse scroll state before polling for events

CMakeLists.txt

@@ -61,6 +61,7 @@ if (AURORA_ENABLE_GX)
   include(cmake/aurora_gd.cmake)
 endif ()
 include(cmake/aurora_pad.cmake)
+include(cmake/aurora_ms.cmake)
 include(cmake/aurora_si.cmake)
 include(cmake/aurora_main.cmake)
 include(cmake/aurora_mtx.cmake)

cmake/aurora_ms.cmake

@@ -0,0 +1,7 @@
+add_library(aurora_ms STATIC lib/dolphin/ms/mouse.cpp)
+
+add_library(aurora::ms ALIAS aurora_ms)
+
+target_include_directories(aurora_ms PUBLIC include)
+target_link_libraries(aurora_ms PUBLIC aurora::core)
+target_link_libraries(aurora_ms PRIVATE absl::flat_hash_map)

include/dolphin/ms.h

@@ -0,0 +1,35 @@
+// Aurora exclusive API extension
+// While the GC and Wii could both technically support mice, they never received official libraries
+// This library is a theoretical implementation based loosely on PAD
+#ifndef DOLPHIN_MS_H
+#define DOLPHIN_MS_H
+#include "types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct MSStatus {
+  f32 x;
+  f32 y;
+  f32 xrel;
+  f32 yrel;
+  u32 buttons;
+  f32 scrollX;
+  f32 scrollY;
+} MSStatus;
+
+#define MS_BUTTON_LEFT (1 << 0)
+#define MS_BUTTON_MIDDLE (1 << 1)
+#define MS_BUTTON_RIGHT (1 << 2)
+#define MS_BUTTON_X1 (1 << 3)
+#define MS_BUTTON_X2 (1 << 4)
+
+void MSPoll();
+void MSRead(MSStatus* status);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // DUSK_MS_H

lib/dolphin/ms/mouse.cpp

@@ -0,0 +1,33 @@
+#include "dolphin/ms.h"
+#include <SDL3/SDL_mouse.h>
+
+#include "../../input.hpp"
+
+extern "C" {
+static MSStatus gStatus{};
+
+void MSPoll() {
+  const uint32_t buttons = SDL_GetGlobalMouseState(&gStatus.x, &gStatus.y);
+  SDL_GetRelativeMouseState(&gStatus.xrel, &gStatus.yrel);
+  aurora::input::get_mouse_scroll(&gStatus.scrollX, &gStatus.scrollY);
+
+  gStatus.buttons = 0;
+  if (buttons & SDL_BUTTON_LEFT) {
+    gStatus.buttons |= MS_BUTTON_LEFT;
+  }
+  if (buttons & SDL_BUTTON_MIDDLE) {
+    gStatus.buttons |= MS_BUTTON_MIDDLE;
+  }
+  if (buttons & SDL_BUTTON_RIGHT) {
+    gStatus.buttons |= MS_BUTTON_RIGHT;
+  }
+  if (buttons & SDL_BUTTON_X1) {
+    gStatus.buttons |= MS_BUTTON_X1;
+  }
+  if (buttons & SDL_BUTTON_X2) {
+    gStatus.buttons |= MS_BUTTON_X2;
+  }
+}
+
+void MSRead(MSStatus* status) { *status = gStatus; }
+}

lib/input.cpp

@@ -138,4 +138,22 @@ void initialize() noexcept {
   ASSERT(SDL_Init(SDL_INIT_HAPTIC | SDL_INIT_JOYSTICK | SDL_INIT_GAMEPAD), "Failed to initialize SDL subsystems: {}",
          SDL_GetError());
 }
+
+struct MouseScrollStatus {
+  float scrollX;
+  float scrollY;
+};
+
+static MouseScrollStatus g_MouseStatus;
+
+void set_mouse_scroll(const float scrollX, const float scrollY) noexcept {
+  g_MouseStatus.scrollX = scrollX;
+  g_MouseStatus.scrollY = scrollY;
+}
+
+void get_mouse_scroll(float* scrollX, float* scrollY) noexcept {
+  *scrollX = g_MouseStatus.scrollX;
+  *scrollY = g_MouseStatus.scrollY;
+}
+
 } // namespace aurora::input

lib/input.hpp

@@ -53,4 +53,7 @@ void controller_rumble(uint32_t instance, uint16_t low_freq_intensity, uint16_t
 uint32_t controller_count() noexcept;
 void initialize() noexcept;
 extern absl::flat_hash_map<Uint32, GameController> g_GameControllers;
+
+void set_mouse_scroll(float scrollX, float scrollY) noexcept;
+void get_mouse_scroll(float* scrollX, float* scrollY) noexcept;
 } // namespace aurora::input

lib/window.cpp

@@ -74,6 +74,8 @@ const AuroraEvent* poll_events() {
   g_events.clear();
 
   SDL_Event event;
+  // Clear out the previous scroll values to prevent ghost input
+  input::set_mouse_scroll(0, 0);
   while (SDL_PollEvent(&event)) {
 #ifdef AURORA_ENABLE_GX
     imgui::process_event(event);
@@ -154,6 +156,9 @@ const AuroraEvent* poll_events() {
       });
       break;
     }
+    case SDL_EVENT_MOUSE_WHEEL:
+      input::set_mouse_scroll(event.wheel.x, event.wheel.y);
+      break;
     case SDL_EVENT_QUIT:
       g_events.push_back(AuroraEvent{
           .type = AURORA_EXIT,
@@ -334,7 +339,8 @@ AuroraWindowSize get_window_size() {
   int native_fb_w = 0;
   int native_fb_h = 0;
   ASSERT(SDL_GetWindowSize(g_window, &width, &height), "Failed to get window size: {}", SDL_GetError());
-  ASSERT(SDL_GetWindowSizeInPixels(g_window, &native_fb_w, &native_fb_h), "Failed to get window size in pixels: {}", SDL_GetError());
+  ASSERT(SDL_GetWindowSizeInPixels(g_window, &native_fb_w, &native_fb_h), "Failed to get window size in pixels: {}",
+         SDL_GetError());
 
   int fb_w = native_fb_w;
   int fb_h = native_fb_h;
@@ -385,7 +391,8 @@ void set_window_position(uint32_t x, uint32_t y) {
 }
 
 void center_window() {
-  TRY_WARN(SDL_SetWindowPosition(g_window, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED), "Failed to center window: {}", SDL_GetError());
+  TRY_WARN(SDL_SetWindowPosition(g_window, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED),
+           "Failed to center window: {}", SDL_GetError());
 }
 
 static void push_future_resize_event() {