[nostalgia/core/gba] Add user input support

src/nostalgia/core/CMakeLists.txt

@@ -28,6 +28,7 @@ install(
 		context.hpp
 		core.hpp
 		gfx.hpp
+		input.hpp
 		media.hpp
 		mem.hpp
 	DESTINATION

src/nostalgia/core/gba/addresses.hpp

@@ -62,6 +62,11 @@ using interrupt_handler = void (*)(void);
 #define REG_BG2VOFS *reinterpret_cast<volatile uint32_t*>(0x0400001a)
 #define REG_BG3VOFS *reinterpret_cast<volatile uint32_t*>(0x0400001e)
 
+/////////////////////////////////////////////////////////////////
+// User Input
+
+#define REG_GAMEPAD *reinterpret_cast<volatile uint16_t*>(0x04000130)
+
 /////////////////////////////////////////////////////////////////
 // Memory Addresses
 

src/nostalgia/core/gba/core.cpp

@@ -8,6 +8,7 @@
 
 #include <nostalgia/core/config.hpp>
 #include <nostalgia/core/core.hpp>
+#include <nostalgia/core/input.hpp>
 
 #include "addresses.hpp"
 #include "bios.hpp"
@@ -54,4 +55,8 @@ uint64_t ticksMs() {
 	return g_timerMs;
 }
 
+bool buttonDown(Key k) {
+	return !(REG_GAMEPAD & k);
+}
+
 }

src/nostalgia/core/input.hpp

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2016 - 2020 gary@drinkingtea.net
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#pragma once
+
+namespace nostalgia::core {
+
+enum Key {
+	// GBA implementation currently relies on GamePad entry order
+	GamePad_A      =   1,
+	GamePad_B      =   2,
+	GamePad_Select =   4,
+	GamePad_Start  =   8,
+	GamePad_Right  =  16,
+	GamePad_Left   =  32,
+	GamePad_Up     =  64,
+	GamePad_Down   = 128,
+	GamePad_R      = 256,
+	GamePad_L      = 512,
+};
+
+[[nodiscard]] bool buttonDown(Key);
+
+}

src/nostalgia/core/sdl/core.cpp

@@ -9,6 +9,7 @@
 #include <SDL.h>
 
 #include <nostalgia/core/gfx.hpp>
+#include <nostalgia/core/input.hpp>
 #include <nostalgia/core/core.hpp>
 
 namespace nostalgia::core {
@@ -52,4 +53,8 @@ uint64_t ticksMs() {
 	return SDL_GetTicks();;
 }
 
+bool buttonDown(Key) {
+	return false;
+}
+
 }