WIP: WebHID support through Emscripten

Unfinished.

Author: ruevs

CMakeLists.txt

@@ -20,12 +20,22 @@ cmake_minimum_required(VERSION 3.1...3.19)
 project(
   libspnavdev
   VERSION 0.1
-  LANGUAGES C)
+)
 
 if(WIN32)
   set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
 endif()
 
+if(EMSCRIPTEN)
+  set (CMAKE_CXX_STANDARD 11)
+  set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+  SET_SOURCE_FILES_PROPERTIES(
+    src/serdev.c
+    src/spnavdev.c
+    src/usbdev.c
+    PROPERTIES LANGUAGE CXX )
+endif()
+
 add_library(spnavdev
   src/serdev.c
   src/spnavdev.c
@@ -42,12 +52,15 @@ else()
   )
 endif()
 
-if(WIN32 OR APPLE OR EMSCRIPTEN)
+if(WIN32 OR APPLE)
   set(HAVE_HIDAPI TRUE)
   set(BUILD_SHARED_LIBS FALSE)
   add_subdirectory(extlib/hidapi)
   target_link_libraries(spnavdev PRIVATE hidapi::hidapi)
   target_include_directories(spnavdev PRIVATE ${CMAKE_BINARY_DIR}/extlib/hidapi/hidapi)
+elseif(EMSCRIPTEN)
+  set(HAVE_WEBHIDAPI TRUE)
+  set(BUILD_SHARED_LIBS FALSE)
 else()
   find_package(hidapi)
   if(hidapi_FOUND)
@@ -66,6 +79,8 @@ if(CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
   # We are our own project, not a subproject
   if(WIN32)
     add_subdirectory(examples/win32)
+  elseif(EMSCRIPTEN)
+    add_subdirectory(examples/web)
   else()
     add_subdirectory(examples/unix)
   endif()

config.h.in

@@ -18,4 +18,5 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifndef SPNAVDEV_CONFIG_H_
 #define SPNAVDEV_CONFIG_H_
 #cmakedefine HAVE_HIDAPI
+#cmakedefine HAVE_WEBHIDAPI
 #endif

examples/web/CMakeLists.txt

@@ -0,0 +1,36 @@
+# libspnavdev - direct 6dof device handling library
+# Copyright (C) 2021 Collabora, Ltd.
+#
+# SPDX-License-Identifier: GPL-3-or-later
+# 
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+add_executable(test test.c)
+target_link_libraries(test PRIVATE spnavdev)
+
+if(EMSCRIPTEN)
+    set(M_LIBRARY "" CACHE STRING "libm (not necessary)" FORCE)
+
+#	set(CMAKE_EXECUTABLE_SUFFIX ".html")
+
+    set(SHELL ${CMAKE_CURRENT_SOURCE_DIR}/test.html)
+
+    set_target_properties(test PROPERTIES LINK_FLAGS
+		"--bind
+		--no-heap-copy -s ALLOW_MEMORY_GROWTH=1 -s WASM=1 -s ASYNCIFY=1
+		-s DYNCALLS=1 -s ASSERTIONS=1
+		-s EXPORTED_RUNTIME_METHODS=ccall,cwrap
+		-s EXPORTED_FUNCTIONS=_test,_main
+		-s TOTAL_STACK=33554432 -s TOTAL_MEMORY=134217728")
+endif()

examples/web/test.c

@@ -0,0 +1,68 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <errno.h>
+#include "spnavdev.h"
+
+static struct spndev *dev;
+static int quit = 0;
+
+extern int test()
+{
+	int fd;
+	union spndev_event ev;
+	const char *s;
+	int led=0;
+
+	if(!(dev = spndev_open(0))) {
+		fprintf(stderr, "Failed to open 6dof device\n");
+		return 1;
+	}
+	fd = spndev_fd(dev);
+
+	printf("Monitoring device, ctrl-c to quit\n");
+
+	return 0;
+	while(!quit) {
+
+		if (spndev_process(dev, &ev)) {
+			switch (ev.type) {
+			case SPNDEV_MOTION:
+				printf("motion: T[%+6d %+6d %+6d]  R[%+6d %+6d %+6d]\n",
+					ev.mot.v[0], ev.mot.v[1], ev.mot.v[2], ev.mot.v[3],
+					ev.mot.v[4], ev.mot.v[5]);
+				break;
+
+			case SPNDEV_BUTTON:
+				if ((s = spndev_button_name(dev, ev.bn.num))) {
+					printf("button %d (\"%s\") ", ev.bn.num, s);
+				} else {
+					printf("button %d ", ev.bn.num);
+				}
+				puts(ev.bn.press ? "pressed" : "released");
+
+				if (ev.bn.press) {
+					spndev_set_led(dev, led);
+					spndev_write_lcd(dev, 0xAA);
+					spndev_set_lcd_bl(dev, led);
+					led = !led;
+				}
+
+				break;
+
+			default:
+				break;
+			}
+		}
+
+	}
+
+	spndev_close(dev);
+	return 0;
+}
+
+int main(int argc, char** argv) {
+	printf("Press the button to test\n");
+	return 0;
+}