Added ergodox hid manager

Makefile

@@ -22,22 +22,31 @@ libs: $(BUILD_DIR)/hid.o
 # Flags and autodetection
 
 # -MMD and -MP generate makefiles with extension .d.
-CPPFLAGS := -Wall -MMD -MP -I src -I libs/hidapi/hidapi
+CPPFLAGS := -MMD -MP \
+	-Wall \
+	-I src \
+	-I libs/hidapi/hidapi
+
+# udev: required by hidapi
 LDFLAGS := -l fftw3 -l udev
 
 # Find all cpp files in source dirs
 SRCS := $(shell find $(SRC_DIRS) -name '*.cpp')
-# Turns ./build/a.cpp into ./build/a.cpp.o
-OBJS := $(SRCS:%=$(BUILD_DIR)/%.o)
+# Turns src/a.cpp into build/src/a.cpp.o
+SRC_OBJS := $(SRCS:%=$(BUILD_DIR)/%.o)
 LIB_OBJS := $(BUILD_DIR)/hid.o
-# Turns ./build/a.cpp.o into ./build/a.cpp.d
+OBJS = $(SRC_OBJS) $(LIB_OBJS)
+# Turns build/a.cpp.o into build/a.cpp.d
 DEPS := $(OBJS:.o=.d)
 
 #################################################
 # Build targets
 
-HIDAPI_PATH := libs/hidapi
+
+### Libraries
+
 # Build hidapi
+HIDAPI_PATH := libs/hidapi
 $(BUILD_DIR)/hid.o:
 	@mkdir -p $(BUILD_DIR)
 
@@ -49,15 +58,18 @@ $(BUILD_DIR)/hid.o:
 		$(HIDAPI_PATH)/linux/hid.c \
 		-o $(BUILD_DIR)/hid.o
 
+
+### Source
+
 # C++ build step
-$(BUILD_DIR)/%.cpp.o: %.cpp $(BUILD_DIR)/hid.o
+$(BUILD_DIR)/%.cpp.o: %.cpp
 	mkdir -p $(dir $@)
 	g++ $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
 
 
 # Final build step
 $(TARGET_EXEC) : $(OBJS)
-	g++ $(OBJS) $(LIB_OBJS) -o $@ $(LDFLAGS)
+	g++ $(OBJS) -o $@ $(LDFLAGS)
 
 
 

src/ergodox.cpp

@@ -0,0 +1,118 @@
+#include "ergodox.hpp"
+
+
+
+Ergodox::Ergodox(
+	unsigned short vendor_id,
+	unsigned short product_id,
+	unsigned short usage,
+	unsigned short usage_page
+) :
+	vendor_id(vendor_id),
+	product_id(product_id),
+	usage(usage),
+	usage_page(usage_page),
+	handle(NULL)
+{
+	hid_init();
+	open();
+}
+
+
+
+/*
+Initialize Ergodox interface.
+
+Should be called once at start of execution. Arguments are the USB parameters of the keyboard.
+
+Returns instance of singleton.
+*/
+Ergodox& Ergodox::init(
+	unsigned short vendor_id,
+	unsigned short product_id,
+	unsigned short usage,
+	unsigned short usage_page
+) {
+	static bool has_been_initialized = false;
+	static Ergodox Instance(
+		vendor_id,
+		product_id,
+		usage,
+		usage_page
+	);
+
+	// This isn't strictly necessary, but there is no reason
+	// to call init() twice.
+	if (has_been_initialized) {
+		has_been_initialized = true;
+		throw std::runtime_error("Ergodox has already been initialized!");
+	}
+
+	return Instance;
+}
+
+Ergodox::~Ergodox() {
+	close();
+	hid_exit();
+}
+
+
+/*
+Try to open this keyboard's hid device.
+Throws a runtime error if device is already open,
+or if we can't find a device with the given params.
+*/
+void Ergodox::open() {
+	if (handle != NULL) {
+		throw std::runtime_error("Device already open");
+	}
+
+	struct hid_device_info *devs, *cur_dev;
+	const char *path_to_open = NULL;
+
+	devs = hid_enumerate(vendor_id, product_id);
+	cur_dev = devs;
+	while (cur_dev) {
+		if (cur_dev->vendor_id == vendor_id &&
+			cur_dev->product_id == product_id &&
+			cur_dev->usage == usage &&
+			cur_dev->usage_page == usage_page
+		) {
+			path_to_open = cur_dev->path;
+			break;
+		}
+		cur_dev = cur_dev->next;
+	}
+
+	if (path_to_open) {
+		handle = hid_open_path(path_to_open);
+		hid_free_enumeration(devs);
+	} else {
+		hid_free_enumeration(devs);
+		throw std::runtime_error("Could not open hid device");
+	}
+}
+
+
+// Close hid device if it is open.
+void Ergodox::close() {
+	if (handle != NULL) {
+		hid_close(handle);
+	}
+}
+
+
+/*
+Send data to Ergodox.
+
+@param data Data to send
+@param length How many bytes to send
+@returns Actual number of bytes written, or -1 on error.
+*/
+int Ergodox::write(uint8_t* data, size_t length) const {
+	if (handle == NULL) {
+		throw std::runtime_error("Cannot write, device is not open!");
+	}
+
+	return hid_write(handle, data, length);
+}

src/ergodox.hpp

@@ -0,0 +1,54 @@
+#pragma once
+
+#include <stdexcept>
+#include <cstdint>
+#include <wchar.h>
+#include "hidapi.h"
+
+/*
+A singleton Ergodox interface. Wraps all hidapi methods, including
+hid_init() and hid_exit().
+*/
+class Ergodox {
+	public:
+		static Ergodox& init(
+			unsigned short vendor_id,
+			unsigned short product_id,
+			unsigned short usage,
+			unsigned short usage_page
+		);
+
+		~Ergodox();
+
+		int write(
+			uint8_t* data,
+			size_t length
+		) const;
+
+
+	private:
+		Ergodox(
+			unsigned short vendor_id,
+			unsigned short product_id,
+			unsigned short usage,
+			unsigned short usage_page
+		);
+
+		// Disable copy and assignment
+		//Ergodox(void);
+		//Ergodox(Ergodox& other);
+		//Ergodox& operator=(Ergodox& other);
+
+		void open();
+		void close();
+
+		// USB Device paramaters
+		const unsigned short vendor_id;
+		const unsigned short product_id;
+		const unsigned short usage;
+		const unsigned short usage_page;
+
+		// HID device.
+		// NULL if not opened.
+		hid_device* handle;
+};

src/test.cpp

@@ -1,27 +1,17 @@
 #include <stdio.h>
 #include <cstdint>
 #include <vector>
+#include <stdexcept>
 
 // For reading FIFO
 #include <fcntl.h>
 #include <unistd.h>
-// Math libs
-#include <math.h>
-#include <fftw3.h>
-// HIDapi
-#include <wchar.h>
-#include "hidapi.h"
 
 // Local files
 #include "utility/bitmap.hpp"
 #include "utility/buffer.hpp"
 #include "signal_processing/fft.hpp"
-
-
-#define HID_VEND 0x3297
-#define HID_PROD 0x4976
-#define HID_USAGE 0x61
-#define HID_PAGE 0xff60
+#include "ergodox.hpp"
 
 
 // TODO:
@@ -37,36 +27,6 @@
 // beat detection
 
 
-hid_device* get_keyboard() {
-	struct hid_device_info *devs, *cur_dev;
-	const char *path_to_open = NULL;
-	hid_device *handle = NULL;
-
-	devs = hid_enumerate(HID_VEND, HID_PROD);
-	cur_dev = devs;
-	while (cur_dev) {
-		if (cur_dev->vendor_id == HID_VEND &&
-			cur_dev->product_id == HID_PROD &&
-			cur_dev->usage == HID_USAGE&&
-			cur_dev->usage_page == HID_PAGE
-		) {
-			path_to_open = cur_dev->path;
-			break;
-		}
-		cur_dev = cur_dev->next;
-	}
-
-	if (path_to_open) {
-		handle = hid_open_path(path_to_open);
-	} else {
-		wprintf(L"Could not find device, exiting.\n");
-		exit(1);
-	}
-	hid_free_enumeration(devs);
-	return handle;
-}
-
-
 void draw_spectrum_bitmap(
 	const std::vector<size_t>& waveform,
 	Bitmap& bitmap
@@ -84,15 +44,13 @@ const size_t height = 150;
 
 int main(int argc, char *argv[]) {
 
-
-	// HID connect
-	int res;
-	uint8_t hid_buf[65];
-	hid_device *handle;
-	// Initialize the hidapi library
-	hid_init();
-	// Get Ergodox
-	handle = get_keyboard();
+	uint8_t hid_buf[20];
+	Ergodox Dox = Ergodox::init(
+		0x3297,
+		0x4976,
+		0x61,
+		0xFF60
+	);
 
 	// buffer size for waveform:
 	// (44100 / fps * 10), make 10 bigger for slower scrolling
@@ -132,12 +90,7 @@ int main(int argc, char *argv[]) {
 			hid_buf[i + 2] = h;
 		}
 
-		res = hid_write(handle, hid_buf, 12);
+		Dox.write(hid_buf, 12);
 	}
-
-	// Close the device
-	hid_close(handle);
-	// Finalize the hidapi library
-	hid_exit();
 	return 0;
 }