Remove CMake compiling redundancies

- set OBJECT targets for osd cpu & gpu libs, and use the obj target for
  static and dynamic linking

- add a new examples_common_obj OBJECT target
- replace direct source dependencies to obj target in all examples CMakeLists

This change makes it possible to not re-compile the same source files
multiple times when they are used in multiple targets. Thanks to jcowles
for uncovering the CMake functionality.

Note: it seems that multi-process build is working again (gmake -j <x>)

examples/CMakeLists.txt

@@ -23,23 +23,31 @@
 #
 
 if( OPENGL_FOUND AND (GLEW_FOUND AND GLFW_FOUND) OR (APPLE AND GLFW_FOUND))
+
+    add_subdirectory(common)
+    
     add_subdirectory(glViewer)
     add_subdirectory(glBatchViewer)
     add_subdirectory(glStencilViewer)
     add_subdirectory(simpleCpu)
     add_subdirectory(limitEval)
     add_subdirectory(tessellateObjFile)
+
     if (NOT APPLE)
         add_subdirectory(uvViewer)
     endif()
+
     if(OPENGL_4_3_FOUND AND (NOT APPLE))
         # the paintTest example requires GL functionality not available on OSX
         add_subdirectory(paintTest)
     endif()
+
     if(PTEX_FOUND)
         add_subdirectory(ptexViewer)
     endif()
+
 else()
+
     set(MISSING "")
 
     if (NOT OPENGL_FOUND)
@@ -70,6 +78,7 @@ if(DXSDK_FOUND)
    if(PTEX_FOUND)
        add_subdirectory(dxPtexViewer)
    endif()
+
 endif()
 
 
@@ -79,8 +88,7 @@ if(MAYA_FOUND)
     # manuelk: the following plugins are disabled until further notice
 
     #add_subdirectory(mayaViewer)
-
+    #if(PTEX_FOUND)
-    if(PTEX_FOUND)
         #add_subdirectory(mayaPtexViewer)
-    endif()
+    #endif()
 endif()

examples/dxPtexViewer/CMakeLists.txt

@@ -42,9 +42,6 @@ include_directories(
 )
 
 set(SOURCE_FILES
-    ../common/font_image.cpp
-    ../common/hud.cpp
-    ../common/d3d11_hud.cpp
     dxPtexViewer.cpp
 )
 
@@ -74,6 +71,7 @@ _add_possibly_cuda_executable(dxPtexViewer WIN32
     ${SOURCE_FILES}
     ${SHADER_FILES}
     ${INC_FILES}
+    $<TARGET_OBJECTS:examples_common_obj>
 )
 
 target_link_libraries(dxPtexViewer

examples/dxViewer/CMakeLists.txt

@@ -40,9 +40,6 @@ include_directories(
 )
 
 set(SOURCE_FILES
-    ../common/font_image.cpp
-    ../common/hud.cpp
-    ../common/d3d11_hud.cpp
     dxViewer.cpp
 )
 
@@ -72,6 +69,7 @@ _add_possibly_cuda_executable(dxViewer WIN32
     ${SOURCE_FILES}
     ${SHADER_FILES}
     ${INC_FILES}
+    $<TARGET_OBJECTS:examples_common_obj>
 )
 
 target_link_libraries(dxViewer

examples/glBatchViewer/CMakeLists.txt

@@ -73,12 +73,9 @@ _add_glfw_executable(glBatchViewer
     delegate.cpp
     effect.cpp
     effectRegistry.cpp
-    ../common/font_image.cpp
-    ../common/hud.cpp
-    ../common/patchColors.cpp
-    ../common/gl_hud.cpp
     ${SHADER_FILES}
     ${INC_FILES}
+    $<TARGET_OBJECTS:examples_common_obj>
 )
 
 target_link_libraries(glBatchViewer

examples/glStencilViewer/CMakeLists.txt

@@ -42,10 +42,8 @@ endif()
 
 _add_glfw_executable(glStencilViewer
     main.cpp
-    ../common/font_image.cpp
-    ../common/hud.cpp
-    ../common/gl_hud.cpp
     ${INC_FILES}
+    $<TARGET_OBJECTS:examples_common_obj>
 )
 
 target_link_libraries(glStencilViewer

examples/glViewer/CMakeLists.txt

@@ -70,12 +70,9 @@ endforeach()
 
 _add_glfw_executable(glViewer
     viewer.cpp
-    ../common/font_image.cpp
-    ../common/hud.cpp
-    ../common/gl_hud.cpp
-    ../common/patchColors.cpp
     ${SHADER_FILES}
     ${INC_FILES}
+    $<TARGET_OBJECTS:examples_common_obj>
 )
 
 target_link_libraries(glViewer

examples/limitEval/CMakeLists.txt

@@ -42,10 +42,8 @@ endif()
 
 _add_glfw_executable(limitEval
     main.cpp
-    ../common/font_image.cpp
-    ../common/hud.cpp
-    ../common/gl_hud.cpp
     ${INC_FILES}
+    $<TARGET_OBJECTS:examples_common_obj>
 )
 
 target_link_libraries(limitEval

examples/paintTest/CMakeLists.txt

@@ -67,11 +67,9 @@ endforeach()
 
 _add_glfw_executable(paintTest
     main.cpp
-    ../common/font_image.cpp
-    ../common/hud.cpp
-    ../common/gl_hud.cpp
     ${SHADER_FILES}
     ${INC_FILES}
+    $<TARGET_OBJECTS:examples_common_obj>
 )
 
 target_link_libraries(paintTest

examples/ptexViewer/CMakeLists.txt

@@ -79,13 +79,9 @@ endforeach()
 #-------------------------------------------------------------------------------
 _add_glfw_executable(ptexViewer
     viewer.cpp
-   ../common/font_image.cpp
-   ../common/hud.cpp
-   ../common/patchColors.cpp
-   ../common/gl_hud.cpp
-   ../common/hdr_reader.cpp
     ${SHADER_FILES}
     ${INC_FILES}
+    $<TARGET_OBJECTS:examples_common_obj>
 )
 
 target_link_libraries(ptexViewer

examples/uvViewer/CMakeLists.txt

@@ -69,11 +69,9 @@ endforeach()
 
 _add_glfw_executable(uvViewer
     viewer.cpp
-    ../common/font_image.cpp
-    ../common/hud.cpp
-    ../common/gl_hud.cpp
     ${SHADER_FILES}
     ${INC_FILES}
+    $<TARGET_OBJECTS:examples_common_obj>
 )
 
 target_link_libraries(uvViewer

opensubdiv/osd/CMakeLists.txt

@@ -466,15 +466,25 @@ source_group("Inc" FILES ${INC_FILES})
 
 if (NOT NO_LIB)
 
-    add_library(osd_static_cpu_obj
+    # Compile objs first for both the CPU and GPU libs -----
+    add_library(osd_cpu_obj
         OBJECT
             ${CPU_SOURCE_FILES}
             ${PRIVATE_HEADER_FILES}
             ${PUBLIC_HEADER_FILES}
     )
+
+    add_library(osd_gpu_obj
+        OBJECT
+            ${GPU_SOURCE_FILES}
+            ${PRIVATE_HEADER_FILES}
+            ${PUBLIC_HEADER_FILES}
+    )
+
+    # Build static libs ------------------------------------
     add_library(osd_static_cpu
         STATIC
-        $<TARGET_OBJECTS:osd_static_cpu_obj>
+        $<TARGET_OBJECTS:osd_cpu_obj>
     )
     set_target_properties(osd_static_cpu PROPERTIES OUTPUT_NAME osdCPU CLEAN_DIRECT_OUTPUT 1)
 
@@ -482,11 +492,11 @@ if (NOT NO_LIB)
         ${PLATFORM_CPU_LIBRARIES}
     )
 
+    # this macro uses FindCUDA.cmake to compile .cu kernel files
+    # the target then adds the other obj dependencies and include files
     _add_possibly_cuda_library(osd_static_gpu
         STATIC
-            ${GPU_SOURCE_FILES}
+            $<TARGET_OBJECTS:osd_gpu_obj>
-            ${PRIVATE_HEADER_FILES}
-            ${PUBLIC_HEADER_FILES}
             ${KERNEL_FILES}
             ${INC_FILES}
     )
@@ -499,10 +509,10 @@ if (NOT NO_LIB)
     install( TARGETS osd_static_cpu DESTINATION ${CMAKE_LIBDIR_BASE} )
     install( TARGETS osd_static_gpu DESTINATION ${CMAKE_LIBDIR_BASE} )
 
+    # Build dynamic libs  ----------------------------------
     if (NOT WIN32 AND NOT IOS)
 
         # Evaluate 'soname' from OSD version
-
             # replace '_' with '.'
             string(REGEX REPLACE "(_)" "." OSD_SONAME ${OpenSubdiv_VERSION})
 
@@ -512,9 +522,7 @@ if (NOT NO_LIB)
         # generate dynamic-link targets
         add_library(osd_dynamic_cpu
             SHARED
-                ${CPU_SOURCE_FILES}
+            $<TARGET_OBJECTS:osd_cpu_obj>
-                ${PRIVATE_HEADER_FILES}
-                ${PUBLIC_HEADER_FILES}
         )
 
         set_target_properties(osd_dynamic_cpu
@@ -530,9 +538,7 @@ if (NOT NO_LIB)
 
         _add_possibly_cuda_library(osd_dynamic_gpu
             SHARED
-                ${GPU_SOURCE_FILES}
+                $<TARGET_OBJECTS:osd_gpu_obj>
-                ${PRIVATE_HEADER_FILES}
-                ${PUBLIC_HEADER_FILES}
                 ${KERNEL_FILES}
                 ${INC_FILES}
         )