build: Refactor flags and definitions (and fix fallout)

Defines:
* XRT_HAVE_[name] is a external dep indicator.
* XRT_DRIVER_[name] if a internal driver is built.

CMake variables:
* BUILD_WITH_[name] is a external dep indicator.
* BUILD_DRIVER_[name] tells if we should build a specific driver.

CMakeLists.txt

@@ -26,26 +26,15 @@ find_package(HIDAPI)
 find_package(OpenHMD)
 find_package(OpenCV)
 
-# Export OpenCV definition if found
-if(OpenCV_FOUND)
-	add_definitions(-DXRT_HAVE_OPENCV)
-endif()
-
 # @TODO Turn into a find_package LIBUSB-1.0 file.
 pkg_check_modules(LIBUSB REQUIRED libusb-1.0)
-add_definitions(-DXRT_HAVE_LIBUSB)
 
 # @TODO Turn into a find_package LIBUVC file.
 pkg_check_modules(LIBUVC libuvc)
-if(LIBUVC_FOUND)
-	add_definitions(-DXRT_HAVE_LIBUVC)
-endif()
 
 # @TODO Turn into a find_package FFMPEG file.
 pkg_check_modules(FFMPEG libavcodec)
-if(FFMPEG_FOUND)
-	add_definitions(-DXRT_HAVE_FFMPEG)
-endif()
+
 
 if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
 	find_package(X11)
@@ -53,11 +42,21 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
 	pkg_check_modules(XCB xcb xcb-randr)
 endif()
 
-cmake_dependent_option(BUILD_WITH_OPENHMD "Enable OpenHMD driver" ON "OPENHMD_FOUND" OFF)
-cmake_dependent_option(BUILD_WITH_HIDAPI "Enable HIDAPI-based OSVR HDK driver" ON "HIDAPI_FOUND" OFF)
 cmake_dependent_option(BUILD_WITH_WAYLAND "Enable Wayland support" ON "WAYLAND_FOUND" OFF)
 cmake_dependent_option(BUILD_WITH_XLIB "Enable xlib support" ON "X11_FOUND" OFF)
-cmake_dependent_option(BUILD_WITH_OPENGL "Enable OpenGL Graphics API support?" ON "OPENGL_FOUND" OFF)
+cmake_dependent_option(BUILD_WITH_OPENGL "Enable OpenGL Graphics API support" ON "OPENGL_FOUND" OFF)
+
+set(BUILD_WITH_LIBUSB TRUE)
+cmake_dependent_option(BUILD_WITH_OPENCV "Enable OpenCV backend" ON "OpenCV_FOUND" OFF)
+cmake_dependent_option(BUILD_WITH_LIBUVC "Enable libuvc video driver" ON "LIBUVC_FOUND" OFF)
+cmake_dependent_option(BUILD_WITH_FFMPEG "Enable ffmpeg testing video driver" ON "FFMPEG_FOUND" OFF)
+cmake_dependent_option(BUILD_WITH_HIDAPI "Enable HIDAPI-based driver(s) (OSVR HDK)" ON "HIDAPI_FOUND" OFF)
+cmake_dependent_option(BUILD_WITH_OPENHMD "Enable OpenHMD driver" ON "OPENHMD_FOUND" OFF)
+
+
+###
+# Error checking
+###
 
 if(NOT BUILD_WITH_OPENHMD AND NOT BUILD_WITH_HIDAPI)
 	message(FATAL_ERROR "You must enable at least one driver: either provide OpenHMD and enable BUILD_WITH_OPENHMD (for a variety of devices via OpenHMD), or provide HIDAPI and enable BUILD_WITH_HIDAPI (for the HDK driver)")
@@ -68,6 +67,38 @@ endif()
 # Flags
 ###
 
+if(BUILD_WITH_LIBUSB)
+	add_definitions(-DXRT_HAVE_LIBUSB)
+endif()
+
+if(BUILD_WITH_OPENCV)
+	add_definitions(-DXRT_HAVE_OPENCV)
+endif()
+
+if(BUILD_WITH_LIBUVC)
+	add_definitions(-DXRT_HAVE_LIBUVC)
+endif()
+
+if(BUILD_WITH_FFMPEG)
+	add_definitions(-DXRT_HAVE_FFMPEG)
+endif()
+
+if(BUILD_WITH_OPENHMD)
+	add_definitions(-DXRT_HAVE_OPENHMD)
+
+	# Drivers enabled with OpenHMD.
+	add_definitions(-DXRT_BUILD_OHMD)
+	set(BUILD_DRIVER_OHMD TRUE)
+endif()
+
+if(BUILD_WITH_HIDAPI)
+	add_definitions(-DXRT_HAVE_HIDAPI)
+
+	# Drivers enabled with hidapi.
+	add_definitions(-DXRT_BUILD_HDK)
+	set(BUILD_DRIVER_HDK TRUE)
+endif()
+
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pedantic -Wall -Wextra -Wno-unused-parameter")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wno-unused-parameter")
 

src/xrt/auxiliary/util/u_meta_prober.h

@@ -12,11 +12,11 @@
 #include <stdlib.h>
 #include "xrt/xrt_prober.h"
 
-#ifdef XRT_HAVE_OHMD
+#ifdef XRT_BUILD_OHMD
 #include "ohmd/oh_interface.h"
 #endif
 
-#ifdef XRT_HAVE_HDK
+#ifdef XRT_BUILD_HDK
 #include "hdk/hdk_interface.h"
 #endif
 
@@ -29,12 +29,12 @@ extern "C" {
 typedef struct xrt_prober *(*prober_creator)();
 
 static const prober_creator DRIVERS[] = {
-#ifdef XRT_HAVE_HDK
+#ifdef XRT_BUILD_HDK
     // Returns NULL if none found, so OK to go first.
     hdk_create_prober,
 #endif
 
-#ifdef XRT_HAVE_OHMD
+#ifdef XRT_BUILD_OHMD
     oh_create_prober,
 #endif
 

src/xrt/drivers/CMakeLists.txt

 # Copyright 2019, Collabora, Ltd.
 # SPDX-License-Identifier: BSL-1.0
 
+
 include_directories(
 	${CMAKE_CURRENT_SOURCE_DIR}/../include
 	${CMAKE_CURRENT_SOURCE_DIR}/../auxiliary
 	)
 
-set(OHMD_SOURCE_FILES
-	ohmd/oh_device.c
-	ohmd/oh_device.h
-	ohmd/oh_interface.h
-	ohmd/oh_prober.c
-	)
 
-# Use OBJECT to not create a archive, since it just gets in the way.
-add_library(drv_ohmd OBJECT ${OHMD_SOURCE_FILES})
-set_property(TARGET drv_ohmd PROPERTY POSITION_INDEPENDENT_CODE ON)
-target_include_directories(drv_ohmd SYSTEM
-	PRIVATE ${OPENHMD_INCLUDE_DIRS}
-	)
-
-if(BUILD_WITH_HIDAPI)
+if(BUILD_DRIVER_HDK)
 	set(HDK_SOURCE_FILES
 		hdk/hdk_device.cpp
 		hdk/hdk_device.h
@@ -35,3 +23,20 @@ if(BUILD_WITH_HIDAPI)
 		PRIVATE ${HIDAPI_INCLUDE_DIRS}
 		)
 endif()
+
+
+if(BUILD_DRIVER_OHMD)
+	set(OHMD_SOURCE_FILES
+		ohmd/oh_device.c
+		ohmd/oh_device.h
+		ohmd/oh_interface.h
+		ohmd/oh_prober.c
+		)
+
+	# Use OBJECT to not create a archive, since it just gets in the way.
+	add_library(drv_ohmd OBJECT ${OHMD_SOURCE_FILES})
+	set_property(TARGET drv_ohmd PROPERTY POSITION_INDEPENDENT_CODE ON)
+	target_include_directories(drv_ohmd SYSTEM
+		PRIVATE ${OPENHMD_INCLUDE_DIRS}
+		)
+endif()

src/xrt/targets/openxr/CMakeLists.txt

@@ -76,16 +76,14 @@ target_link_libraries(${RUNTIME_TARGET}
 	)
 
 
-if(BUILD_WITH_OPENHMD)
+if(BUILD_DRIVER_OHMD)
 	target_sources(${RUNTIME_TARGET} PRIVATE $<TARGET_OBJECTS:drv_ohmd>)
-	target_compile_definitions(${RUNTIME_TARGET} PRIVATE XRT_HAVE_OHMD)
 	target_link_libraries(${RUNTIME_TARGET} PRIVATE OpenHMD::OpenHMD)
 endif()
 
-if(BUILD_WITH_HIDAPI)
+if(BUILD_DRIVER_HDK)
 	target_sources(${RUNTIME_TARGET} PRIVATE $<TARGET_OBJECTS:drv_hdk>)
 	target_link_libraries(${RUNTIME_TARGET} PUBLIC ${HIDAPI_LIBRARIES})
-	target_compile_definitions(${RUNTIME_TARGET} PRIVATE XRT_HAVE_HDK)
 endif()
 
 if(CMAKE_SYSTEM_NAME STREQUAL "Linux")