GB MBC: Pocket Cam support

CHANGES

@@ -1,6 +1,7 @@
 0.7.0: (Future)
 Features:
  - ELF support
+ - Game Boy Camera support
 Bugfixes:
  - GB Audio: Make audio unsigned with bias (fixes mgba.io/i/749)
  - Python: Fix importing .gb or .gba before .core

include/mgba/core/interface.h

@@ -61,6 +61,7 @@ struct mKeyCallback {
 enum mPeripheral {
 	mPERIPH_ROTATION = 1,
 	mPERIPH_RUMBLE,
+	mPERIPH_IMAGE_SOURCE,
 	mPERIPH_CUSTOM = 0x1000
 };
 
@@ -82,6 +83,12 @@ struct mRTCSource {
 	bool (*deserialize)(struct mRTCSource*, const struct mStateExtdataItem*);
 };
 
+struct mImageSource {
+	void (*startRequestImage)(struct mImageSource*);
+	void (*stopRequestImage)(struct mImageSource*);
+	void (*requestImage)(struct mImageSource*, unsigned w, unsigned h, const uint32_t** buffer, size_t* stride);
+};
+
 enum mRTCGenericType {
 	RTC_NO_OVERRIDE,
 	RTC_FIXED,

include/mgba/internal/gb/mbc.h

@@ -21,6 +21,11 @@ void GBMBCSwitchBank(struct GB* gb, int bank);
 void GBMBCSwitchBank0(struct GB* gb, int bank);
 void GBMBCSwitchSramBank(struct GB* gb, int bank);
 
+enum GBCam {
+	GBCAM_WIDTH = 128,
+	GBCAM_HEIGHT = 112
+};
+
 struct GBMBCRTCSaveBuffer {
 	uint32_t sec;
 	uint32_t min;

include/mgba/internal/gb/memory.h

@@ -117,6 +117,7 @@ struct GBMBC7State {
 
 struct GBPocketCamState {
 	bool registersActive;
+	uint8_t registers[0x36];
 };
 
 struct GBTAMA5State {
@@ -179,6 +180,7 @@ struct GBMemory {
 	struct mRTCSource* rtc;
 	struct mRotationSource* rotation;
 	struct mRumble* rumble;
+	struct mImageSource* cam;
 };
 
 struct LR35902Core;

src/gb/core.c

@@ -479,6 +479,9 @@ static void _GBCoreSetPeripheral(struct mCore* core, int type, void* periph) {
 	case mPERIPH_RUMBLE:
 		gb->memory.rumble = periph;
 		break;
+	case mPERIPH_IMAGE_SOURCE:
+		gb->memory.cam = periph;
+		break;
 	default:
 		return;
 	}

src/gb/gb.c

@@ -294,6 +294,9 @@ void GBUnloadROM(struct GB* gb) {
 	}
 	gb->sramRealVf = NULL;
 	gb->sramVf = NULL;
+	if (gb->memory.cam && gb->memory.cam->stopRequestImage) {
+		gb->memory.cam->stopRequestImage(gb->memory.cam);
+	}
 }
 
 void GBSynthesizeROM(struct VFile* vf) {

src/gb/mbc.c

@@ -37,6 +37,7 @@ static void _GBMBC7Write(struct GBMemory* memory, uint16_t address, uint8_t valu
 static uint8_t _GBTAMA5Read(struct GBMemory*, uint16_t address);
 
 static uint8_t _GBPocketCamRead(struct GBMemory*, uint16_t address);
+static void _GBPocketCamCapture(struct GBMemory*);
 
 void GBMBCSwitchBank(struct GB* gb, int bank) {
 	size_t bankStart = bank * GB_SIZE_CART_BANK0;
@@ -242,6 +243,9 @@ void GBMBCInit(struct GB* gb) {
 	case GB_POCKETCAM:
 		gb->memory.mbcWrite = _GBPocketCam;
 		gb->memory.mbcRead = _GBPocketCamRead;
+		if (gb->memory.cam && gb->memory.cam->startRequestImage) {
+			gb->memory.cam->startRequestImage(gb->memory.cam);
+		}
 		break;
 	}
 
@@ -757,6 +761,16 @@ void _GBPocketCam(struct GB* gb, uint16_t address, uint8_t value) {
 			memory->mbcState.pocketCam.registersActive = true;
 		}
 		break;
+	case 0x5:
+		address &= 0x7F;
+		if (address == 0 && value & 1) {
+			value &= 6; // TODO: Timing
+			_GBPocketCamCapture(memory);
+		}
+		if (address < sizeof(memory->mbcState.pocketCam.registers)) {
+			memory->mbcState.pocketCam.registers[address] = value;
+		}
+		break;
 	default:
 		mLOG(GB_MBC, STUB, "Pocket Cam unknown address: %04X:%02X", address, value);
 		break;
@@ -765,11 +779,53 @@ void _GBPocketCam(struct GB* gb, uint16_t address, uint8_t value) {
 
 uint8_t _GBPocketCamRead(struct GBMemory* memory, uint16_t address) {
 	if (memory->mbcState.pocketCam.registersActive) {
+		if ((address & 0x7F) == 0) {
+			return memory->mbcState.pocketCam.registers[0];
+		}
 		return 0;
 	}
 	return memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)];
 }
 
+void _GBPocketCamCapture(struct GBMemory* memory) {
+	if (!memory->cam) {
+		return;
+	}
+	const uint32_t* image = NULL;
+	size_t stride;
+	memory->cam->requestImage(memory->cam, GBCAM_WIDTH, GBCAM_HEIGHT, &image, &stride);
+	if (!image) {
+		return;
+	}
+	memset(&memory->sram[0x100], 0, GBCAM_HEIGHT * GBCAM_WIDTH / 4);
+	struct GBPocketCamState* pocketCam = &memory->mbcState.pocketCam;
+	size_t x, y;
+	for (y = 0; y < GBCAM_HEIGHT; ++y) {
+		for (x = 0; x < GBCAM_WIDTH; ++x) {
+			uint32_t color = image[y * stride + x];
+			uint32_t gray = ((color & 0xFF) + ((color >> 8) & 0xFF) + ((color >> 16) & 0xFF));
+			uint16_t exposure = (pocketCam->registers[2] << 8) | (pocketCam->registers[3]);
+			gray = (gray + 1) * exposure / 0x300;
+			// TODO: Additional processing
+			int matrixEntry = 3 * ((x & 3) + 4 * (y & 3));
+			if (gray < pocketCam->registers[matrixEntry + 6]) {
+				gray = 0x101;
+			} else if (gray < pocketCam->registers[matrixEntry + 7]) {
+				gray = 0x100;
+			} else if (gray < pocketCam->registers[matrixEntry + 8]) {
+				gray = 0x001;
+			} else {
+				gray = 0;
+			}
+			int coord = (((x >> 3) & 0xF) * 8 + (y & 0x7)) * 2 + (y & ~0x7) * 0x20;
+			uint16_t existing;
+			LOAD_16LE(existing, coord + 0x100, memory->sram);
+			existing |= gray << (7 - (x & 7));
+			STORE_16LE(existing, coord + 0x100, memory->sram);
+		}
+	}
+}
+
 void _GBTAMA5(struct GB* gb, uint16_t address, uint8_t value) {
 	struct GBMemory* memory = &gb->memory;
 	struct GBTAMA5State* tama5 = &memory->mbcState.tama5;

src/gb/memory.c

@@ -105,6 +105,7 @@ void GBMemoryInit(struct GB* gb) {
 	gb->memory.rtc = NULL;
 	gb->memory.rotation = NULL;
 	gb->memory.rumble = NULL;
+	gb->memory.cam = NULL;
 
 	GBIOInit(gb);
 }

src/platform/qt/CoreController.cpp

@@ -47,8 +47,6 @@ CoreController::CoreController(mCore* core, QObject* parent)
 
 	m_threadContext.startCallback = [](mCoreThread* context) {
 		CoreController* controller = static_cast<CoreController*>(context->userData);
-		context->core->setPeripheral(context->core, mPERIPH_ROTATION, controller->m_inputController->rotationSource());
-		context->core->setPeripheral(context->core, mPERIPH_RUMBLE, controller->m_inputController->rumble());
 
 		switch (context->core->platform(context->core)) {
 #ifdef M_CORE_GBA
@@ -285,6 +283,9 @@ void CoreController::setOverride(std::unique_ptr<Override> override) {
 
 void CoreController::setInputController(InputController* inputController) {
 	m_inputController = inputController;
+	m_threadContext.core->setPeripheral(m_threadContext.core, mPERIPH_ROTATION, m_inputController->rotationSource());
+	m_threadContext.core->setPeripheral(m_threadContext.core, mPERIPH_RUMBLE, m_inputController->rumble());
+	m_threadContext.core->setPeripheral(m_threadContext.core, mPERIPH_IMAGE_SOURCE, m_inputController->imageSource());
 }
 
 void CoreController::setLogger(LogController* logger) {

src/platform/qt/InputController.cpp

@@ -78,6 +78,27 @@ InputController::InputController(int playerId, QWidget* topLevel, QObject* paren
 	};
 	setLuminanceLevel(0);
 #endif
+
+	m_image.startRequestImage = [](mImageSource* context) {
+		InputControllerImage* image = static_cast<InputControllerImage*>(context);
+		image->image.load(":/res/no-cam.png");
+	};
+	m_image.stopRequestImage = nullptr;
+	m_image.requestImage = [](mImageSource* context, unsigned w, unsigned h, const uint32_t** buffer, size_t* stride) {
+		InputControllerImage* image = static_cast<InputControllerImage*>(context);
+		image->resizedImage = image->image.scaled(w, h, Qt::KeepAspectRatioByExpanding);
+		image->resizedImage = image->resizedImage.convertToFormat(QImage::Format_RGB32);
+		const uint32_t* bits = reinterpret_cast<const uint32_t*>(image->resizedImage.constBits());
+		QSize size = image->resizedImage.size();
+		if (size.width() > w) {
+			bits += size.width() / 2;
+		}
+		if (size.height() > h) {
+			bits += (size.height() / 2) * size.width();
+		}
+		*buffer = bits;
+		*stride = size.width();
+	};
 }
 
 InputController::~InputController() {

src/platform/qt/InputController.h

@@ -9,6 +9,7 @@
 #include "GamepadAxisEvent.h"
 #include "GamepadHatEvent.h"
 
+#include <QImage>
 #include <QObject>
 #include <QSet>
 #include <QTimer>
@@ -82,6 +83,7 @@ public:
 
 	mRumble* rumble();
 	mRotationSource* rotationSource();
+	mImageSource* imageSource() { return &m_image; }
 	GBALuminanceSource* luminance() { return &m_lux; }
 
 signals:
@@ -115,6 +117,12 @@ private:
 	uint8_t m_luxValue;
 	int m_luxLevel;
 
+	struct InputControllerImage : mImageSource {
+		InputController* p;
+		QImage image;
+		QImage resizedImage;
+	} m_image;
+
 	mInputMap m_inputMap;
 	ConfigController* m_config = nullptr;
 	int m_playerId;

src/platform/qt/resources.qrc

@@ -3,5 +3,6 @@
      <file>../../../res/mgba-1024.png</file>
      <file>../../../res/keymap.qpic</file>
      <file>../../../res/patrons.txt</file>
+     <file>../../../res/no-cam.png</file>
  </qresource>
  </RCC>