@@ -5,6 +5,7 @@ * 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/. */
 #include "gui-runner.h"
 
+#include "gba/interface.h"
 #include "gba/serialize.h"
 #include "util/gui/file-select.h"
 #include "util/gui/font.h"
@@ -36,9 +37,26 @@ gbaBackground->p->drawFrame(gbaBackground->p, true);
 	}
 }
 
+static void _updateLux(struct GBALuminanceSource* lux) {
+	UNUSED(lux);
+}
+
+static uint8_t _readLux(struct GBALuminanceSource* lux) {
+	struct GBAGUIRunnerLux* runnerLux = (struct GBAGUIRunnerLux*) lux;
+	int value = 0x16;
+	if (runnerLux->luxLevel > 0) {
+		value += GBA_LUX_LEVELS[runnerLux->luxLevel - 1];
+	}
+	return 0xFF - value;
+}
+
 void GBAGUIInit(struct GBAGUIRunner* runner, const char* port) {
 	GUIInit(&runner->params);
 	GBAContextInit(&runner->context, port);
+	runner->luminanceSource.d.readLuminance = _readLux;
+	runner->luminanceSource.d.sample = _updateLux;
+	runner->luminanceSource.luxLevel = 0;
+	runner->context.gba->luminanceSource = &runner->luminanceSource.d;
 	runner->background.d.draw = _drawBackground;
 	runner->background.p = runner;
 	if (runner->setup) {
@@ -139,10 +157,21 @@ }
 		bool running = true;
 		while (running) {
 			while (true) {
-				int guiKeys = runner->params.pollInput();
+				uint32_t guiKeys;
+				GUIPollInput(&runner->params, &guiKeys, 0);
 				if (guiKeys & (1 << GUI_INPUT_CANCEL)) {
 					break;
 				}
+				if (guiKeys & (1 << GBA_GUI_INPUT_INCREASE_BRIGHTNESS)) {
+					if (runner->luminanceSource.luxLevel < 10) {
+						++runner->luminanceSource.luxLevel;
+					}
+				}
+				if (guiKeys & (1 << GBA_GUI_INPUT_DECREASE_BRIGHTNESS)) {
+					if (runner->luminanceSource.luxLevel > 0) {
+						--runner->luminanceSource.luxLevel;
+					}
+				}
 				uint16_t keys = runner->pollGameInput(runner);
 				if (runner->prepareForFrame) {
 					runner->prepareForFrame(runner);
@@ -156,7 +185,7 @@ }
 			}
 
 			GUIInvalidateKeys(&runner->params);
-			int keys = -1; // Huge hack to avoid an extra variable!
+			uint32_t keys = 0xFFFFFFFF; // Huge hack to avoid an extra variable!
 			struct GUIMenuItem item;
 			enum GUIMenuExitReason reason = GUIShowMenu(&runner->params, &pauseMenu, &item);
 			if (reason == GUI_MENU_EXIT_ACCEPT) {

@@ -9,17 +9,27 @@
 #include "gba/context/context.h"
 #include "util/gui.h"
 
+enum GBAGUIInput {
+	GBA_GUI_INPUT_INCREASE_BRIGHTNESS = GUI_INPUT_USER_START,
+	GBA_GUI_INPUT_DECREASE_BRIGHTNESS
+};
 
 struct GBAGUIBackground {
 	struct GUIBackground d;
 	struct GBAGUIRunner* p;
 };
 
+struct GBAGUIRunnerLux {
+	struct GBALuminanceSource d;
+	int luxLevel;
+};
+
 struct GBAGUIRunner {
 	struct GBAContext context;
 	struct GUIParams params;
 
 	struct GBAGUIBackground background;
+	struct GBAGUIRunnerLux luminanceSource;
 
 	void (*setup)(struct GBAGUIRunner*);
 	void (*teardown)(struct GBAGUIRunner*);

@@ -126,9 +126,9 @@ activeKeys |= activeKeys >> 24;
 	return activeKeys;
 }
 
-static int _pollInput(void) {
+static uint32_t _pollInput(void) {
 	hidScanInput();
-	int keys = 0;
+	uint32_t keys = 0;
 	int activeKeys = hidKeysHeld();
 	if (activeKeys & KEY_X) {
 		keys |= 1 << GUI_INPUT_CANCEL;
@@ -150,6 +150,12 @@ keys |= 1 << GUI_INPUT_UP;
 	}
 	if (activeKeys & KEY_DOWN) {
 		keys |= 1 << GUI_INPUT_DOWN;
+	}
+	if (activeKeys & KEY_CSTICK_UP) {
+		keys |= 1 << GBA_GUI_INPUT_INCREASE_BRIGHTNESS;
+	}
+	if (activeKeys & KEY_CSTICK_DOWN) {
+		keys |= 1 << GBA_GUI_INPUT_DECREASE_BRIGHTNESS;
 	}
 	return keys;
 }

@@ -30,7 +30,7 @@ vita2d_end_drawing();
 	vita2d_swap_buffers();
 }
 
-static int _pollInput(void) {
+static uint32_t _pollInput(void) {
 	SceCtrlData pad;
 	sceCtrlPeekBufferPositive(0, &pad, 1);
 	int input = 0;

@@ -33,7 +33,7 @@ static int32_t _readGyroZ(struct GBARotationSource* source);
 
 static void _drawStart(void);
 static void _drawEnd(void);
-static int _pollInput(void);
+static uint32_t _pollInput(void);
 static void _guiPrepare(void);
 static void _guiFinish(void);
 
@@ -224,7 +224,7 @@ VIDEO_SetNextFramebuffer(framebuffer[whichFb]);
 	VIDEO_Flush();
 }
 
-static int _pollInput(void) {
+static uint32_t _pollInput(void) {
 	PAD_ScanPads();
 	u16 padkeys = PAD_ButtonsHeld(0);
 

@@ -10,9 +10,9 @@ memset(params->inputHistory, 0, sizeof(params->inputHistory));
 	strncpy(params->currentPath, params->basePath, PATH_MAX);
 }
 
-void GUIPollInput(struct GUIParams* params, int* newInputOut, int* heldInput) {
-	int input = params->pollInput();
-	int newInput = 0;
+void GUIPollInput(struct GUIParams* params, uint32_t* newInputOut, uint32_t* heldInput) {
+	uint32_t input = params->pollInput();
+	uint32_t newInput = 0;
 	for (int i = 0; i < GUI_INPUT_MAX; ++i) {
 		if (input & (1 << i)) {
 			++params->inputHistory[i];

@@ -23,7 +23,9 @@ GUI_INPUT_DOWN,
 	GUI_INPUT_LEFT,
 	GUI_INPUT_RIGHT,
 
-	GUI_INPUT_MAX
+	GUI_INPUT_USER_START = 0x10,
+
+	GUI_INPUT_MAX = 0x20
 };
 
 struct GUIBackground {
@@ -38,7 +40,7 @@ const char* basePath;
 
 	void (*drawStart)(void);
 	void (*drawEnd)(void);
-	int (*pollInput)(void);
+	uint32_t (*pollInput)(void);
 	void (*guiPrepare)(void);
 	void (*guiFinish)(void);
 
@@ -53,7 +55,7 @@
 #define GUI_PARAMS_TRAIL {}, "", 0
 
 void GUIInit(struct GUIParams* params);
-void GUIPollInput(struct GUIParams* params, int* newInput, int* heldInput);
+void GUIPollInput(struct GUIParams* params, uint32_t* newInput, uint32_t* heldInput);
 void GUIInvalidateKeys(struct GUIParams* params);
 
 #endif

@@ -56,7 +56,7 @@ struct VDirEntry* de;
 	while ((de = dir->listNext(dir))) {
 		++i;
 		if (!(i % SCANNING_THRESHOLD)) {
-			int input = 0;
+			uint32_t input = 0;
 			GUIPollInput(params, &input, 0);
 			if (input & (1 << GUI_INPUT_CANCEL)) {
 				return false;

@@ -21,7 +21,7 @@ }
 
 	GUIInvalidateKeys(params);
 	while (true) {
-		int newInput = 0;
+		uint32_t newInput = 0;
 		GUIPollInput(params, &newInput, 0);
 
 		if (newInput & (1 << GUI_INPUT_UP) && menu->index > 0) {