From 4eff7eb2772fe0158b2488593c7e71bb234e01c6 Mon Sep 17 00:00:00 2001
From: Mark <mark@betalupi.com>
Date: Sat, 25 Jun 2022 19:12:01 -0700
Subject: [PATCH] Added basic HID intervace

---
 .gitmodules  |  3 ++
 Makefile     | 28 +++++++++++++++----
 libs/hidapi  |  1 +
 src/test.cpp | 77 ++++++++++++++++++++++++++++++++++++++++++++++++----
 4 files changed, 98 insertions(+), 11 deletions(-)
 create mode 100644 .gitmodules
 create mode 160000 libs/hidapi

diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..b67db5d
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "libs/hidapi"]
+	path = libs/hidapi
+	url = ssh://git@git.betalupi.com:33/mirrors-libs/hidapi.git
diff --git a/Makefile b/Makefile
index 6d924df..41b2856 100644
--- a/Makefile
+++ b/Makefile
@@ -13,34 +13,52 @@ clean:
 	-rm -r $(BUILD_DIR)
 	@echo ""
 
-.PHONY: clean all run
+
+libs: $(BUILD_DIR)/hid.o
+
+.PHONY: clean all run libs
 
 #################################################
 # Flags and autodetection
 
 # -MMD and -MP generate makefiles with extension .d.
-CPPFLAGS := -Wall -MMD -MP -I src
-LDFLAGS := -l fftw3
+CPPFLAGS := -Wall -MMD -MP -I src -I libs/hidapi/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)
+LIB_OBJS := $(BUILD_DIR)/hid.o
 # Turns ./build/a.cpp.o into ./build/a.cpp.d
 DEPS := $(OBJS:.o=.d)
 
 #################################################
 # Build targets
 
+HIDAPI_PATH := libs/hidapi
+# Build hidapi
+$(BUILD_DIR)/hid.o:
+	@mkdir -p $(BUILD_DIR)
+
+	@echo "Compiling hid.o"
+	@gcc -Wall -g -fpic -c \
+		-I $(HIDAPI_PATH)/hidapi \
+		`pkg-config libusb-1.0 --cflags` \
+		\
+		$(HIDAPI_PATH)/linux/hid.c \
+		-o $(BUILD_DIR)/hid.o
+
 # C++ build step
-$(BUILD_DIR)/%.cpp.o: %.cpp
+$(BUILD_DIR)/%.cpp.o: %.cpp $(BUILD_DIR)/hid.o
 	mkdir -p $(dir $@)
 	g++ $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
 
 
 # Final build step
 $(TARGET_EXEC) : $(OBJS)
-	g++ $(OBJS) -o $@ $(LDFLAGS)
+	g++ $(OBJS) $(LIB_OBJS) -o $@ $(LDFLAGS)
+
 
 
 # Include generated makefiles
diff --git a/libs/hidapi b/libs/hidapi
new file mode 160000
index 0000000..eaa5c7c
--- /dev/null
+++ b/libs/hidapi
@@ -0,0 +1 @@
+Subproject commit eaa5c7c6f13e212b1936c2d4a7dc372b289aa9e0
diff --git a/src/test.cpp b/src/test.cpp
index bfc6d37..c993ceb 100644
--- a/src/test.cpp
+++ b/src/test.cpp
@@ -8,6 +8,9 @@
 // Math libs
 #include <math.h>
 #include <fftw3.h>
+// HIDapi
+#include <wchar.h>
+#include "hidapi.h"
 
 // Local files
 #include "utility/bitmap.hpp"
@@ -15,6 +18,12 @@
 #include "signal_processing/fft.hpp"
 
 
+#define HID_VEND 0x3297
+#define HID_PROD 0x4976
+#define HID_USAGE 0x61
+#define HID_PAGE 0xff60
+
+
 // TODO:
 // stereo support (and maybe different bitrates?)
 // Optimization: don't copy filename in buffer?
@@ -28,6 +37,34 @@
 // 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(
@@ -41,12 +78,22 @@ void draw_spectrum_bitmap(
 	}
 }
 
-const size_t width = 300;
-const size_t height = 100;
+const size_t width = 12;
+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();
+
 	// buffer size for waveform:
 	// (44100 / fps * 10), make 10 bigger for slower scrolling
 	//
@@ -54,7 +101,7 @@ int main(int argc, char *argv[]) {
 
 	FFT_Visualizer fft = FFT_Visualizer(
 		width, height,
-		20, 20000
+		100, 10000
 	);
 
 	std::vector<size_t> waveform;
@@ -62,6 +109,7 @@ int main(int argc, char *argv[]) {
 
 	Buffer buf = Buffer(
 		"/tmp/mpd.fifo",
+		//"/home/mark/Workbench/sospi/pulse.fifo",
 		44100 / 2, // Keep 500ms of data in buffer
 		fft.compute_buffer_output_size()
 	);
@@ -69,10 +117,27 @@ int main(int argc, char *argv[]) {
 	Bitmap b = Bitmap(width, height);
 
 	while (1) {
-		b.clear();
+		//b.clear();
 		buf.update();
 		fft.update(buf);
-		draw_spectrum_bitmap(fft.get_output(), b);
-		b.save("/tmp/o.bmp");
+		//draw_spectrum_bitmap(fft.get_output(), b);
+		//b.save("/tmp/o.bmp");
+
+		hid_buf[0] = 0x01;
+		hid_buf[1] = 0x02;
+		for (size_t i = 0; i < 10; i++) {
+			ssize_t h = fft.get_output()[i + 1] - 10;
+			h = h>100 ? 100 : h;
+			h = h<0 ? 0 : h;
+			hid_buf[i + 2] = h;
+		}
+
+		res = hid_write(handle, hid_buf, 12);
 	}
+
+	// Close the device
+	hid_close(handle);
+	// Finalize the hidapi library
+	hid_exit();
+	return 0;
 }
\ No newline at end of file