set backend at runtime, hide windows on init, missing include (#50)

* set backend at init time

* glfw hide windows on init(), no focus on show()

* bugfix: missing include

* include Windows in CI

.travis.yml

@@ -11,7 +11,11 @@ os:
 compiler:
   - gcc
   - clang
-
+
+jobs:
+  include:
+    - os: windows
+
 addons:
   apt:
     packages:
@@ -22,10 +26,22 @@ before_script:
   - cd test 
   - mkdir build
   - cd build
-  - cmake -DCMAKE_BUILD_TYPE=Debug -DPOLYSCOPE_BACKEND=MOCK_OPENGL ..
+  - cmake -DCMAKE_BUILD_TYPE=Debug -DPOLYSCOPE_BACKEND_OPENGL3_GLFW=ON -DPOLYSCOPE_BACKEND_OPENGL_MOCK=ON ..
 
 script: 
-  - make 
-  - ./bin/polyscope-test --gtest_catch_exceptions=0 
-  - cmake -DCMAKE_BUILD_TYPE=Debug -DPOLYSCOPE_BACKEND=OPENGL3_GLFW ..
-  - make 
+  - |
+    if [ "$TRAVIS_OS_NAME" = "linux" ]; then 
+      make 
+      ./bin/polyscope-test --gtest_catch_exceptions=0 backend=openGL_mock
+    fi
+  - |
+    if [ "$TRAVIS_OS_NAME" = "osx" ]; then 
+      make 
+      ./bin/polyscope-test --gtest_catch_exceptions=0 backend=openGL_mock
+    fi
+  - |
+    if [ "$TRAVIS_OS_NAME" = "windows" ]; then 
+      cmake --build "."
+      ls
+      ./bin/Debug/polyscope-test.exe --gtest_catch_exceptions=0 backend=openGL_mock
+    fi

CMakeLists.txt

@@ -8,15 +8,8 @@ cmake_policy(SET CMP0054 NEW)   # don't implicitly dereference inside if()
 ## Project options
 
 # Backend
-set(POLYSCOPE_BACKEND "OPENGL3_GLFW" CACHE STRING "Which graphics and windowing backend to use")
-set_property(CACHE POLYSCOPE_BACKEND PROPERTY STRINGS "OPENGL3_GLFW" "MOCK_OPENGL")
-if("${POLYSCOPE_BACKEND}" STREQUAL "OPENGL3_GLFW")
-  message("Using polyscope backend: ${POLYSCOPE_BACKEND}")
-elseif("${POLYSCOPE_BACKEND}" STREQUAL "MOCK_OPENGL")
-  message("Using polyscope backend: ${POLYSCOPE_BACKEND}")
-else()
-  message(FATAL_ERROR "Unrecognized polyscope backend from POLYSCOPE_BACKEND option, value is [${POLYSCOPE_BACKEND}]" )
-endif()
+set(POLYSCOPE_BACKEND_OPENGL3_GLFW "ON" CACHE BOOL "Enable openGL3_glfw backend")
+set(POLYSCOPE_BACKEND_OPENGL_MOCK "ON" CACHE BOOL "Enable openGL_mock backend")
 
 ### Do anything needed for dependencies and bring their stuff in to scope
 add_subdirectory(deps)

deps/CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 2.8.9)
 
-if("${POLYSCOPE_BACKEND}" STREQUAL "OPENGL3_GLFW")
+if("${POLYSCOPE_BACKEND_OPENGL3_GLFW}")
 
   ## Glad
   add_subdirectory(glad)
@@ -11,8 +11,9 @@ if("${POLYSCOPE_BACKEND}" STREQUAL "OPENGL3_GLFW")
   set(GLFW_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
   set(GLFW_INSTALL OFF CACHE BOOL "" FORCE)
   add_subdirectory(glfw)
+endif()
 
-elseif("${POLYSCOPE_BACKEND}" STREQUAL "MOCK_OPENGL")
+if("${POLYSCOPE_BACKEND_OPENGL_MOCK}")
 endif()
 
 ## Imgui

deps/imgui/CMakeLists.txt

@@ -12,7 +12,7 @@ if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang" OR "${CMAKE_CXX_COMPILER_ID}" STR
 endif()
 
 
-if("${POLYSCOPE_BACKEND}" STREQUAL "OPENGL3_GLFW")
+if("${POLYSCOPE_BACKEND_OPENGL3_GLFW}")
 
   set(SRCS imgui/imgui.cpp imgui/imgui_draw.cpp imgui/imgui_widgets.cpp imgui/imgui_demo.cpp imgui/examples/imgui_impl_glfw.cpp imgui/examples/imgui_impl_opengl3.cpp)
 
@@ -32,7 +32,7 @@ if("${POLYSCOPE_BACKEND}" STREQUAL "OPENGL3_GLFW")
     add_definitions(-DIMGUI_IMPL_OPENGL_LOADER_GLAD)
   endif()
 
-elseif("${POLYSCOPE_BACKEND}" STREQUAL "MOCK_OPENGL")
+elseif("${POLYSCOPE_BACKEND_OPENGL_MOCK}")
 
   # Disable every platform-specific thing I can find in imgui
   add_definitions(-DIMGUI_DISABLE_OSX_FUNCTIONS)

include/polyscope/polyscope.h

@@ -19,10 +19,10 @@ namespace polyscope {
 // forward declarations
 class Structure;
 
-// Initialize polyscope, including windowing system and openGL. Should be
-// called exactly once at the beginning of a program. If initialization
-// fails in any way, an exception will be thrown.
-void init();
+// Initialize polyscope, including windowing system and openGL. Should be called exactly once at the beginning of a
+// program. If initialization fails in any way, an exception will be thrown.
+// The backend string sets which rendering backend to use. If "", a reasonable default backend will be chosen.
+void init(std::string backend = "");
 
 // Give control to the polyscope GUI. Blocks until the user returns control via
 // the GUI, possibly by exiting the window.

include/polyscope/render/engine.h

@@ -322,6 +322,7 @@ class Engine {
 
   // === Windowing and framework things
   virtual void makeContextCurrent() = 0;
+  virtual void showWindow() = 0;
   virtual void updateWindowSize(bool force = false) = 0;
   virtual std::tuple<int, int> getWindowPos() = 0;
   virtual bool windowRequestsClose() = 0;
@@ -450,7 +451,8 @@ inline void ShaderProgram::setAttribute(std::string name, const std::vector<std:
 // Callers should basically only interact via these methods and variables
 
 // Call once to initialize
-void initializeRenderEngine();
+// (see render/initialize_backend.cpp)
+void initializeRenderEngine(std::string backend="");
 
 // The global render engine
 // Gets initialized by initializeRenderEngine() in polyscope::init();

include/polyscope/render/mock_opengl/mock_gl_engine.h

@@ -7,11 +7,9 @@
 
 // A fake version of the opengl engine, with all of the actual gl calls stubbed out. Useful for testing.
 
-// Macro to construct shader strings. Unforunately, it eats line numbers.
-#define POLYSCOPE_GLSL(version, shader) "#version " #version "\n" #shader
-
 namespace polyscope {
 namespace render {
+namespace backend_openGL_mock {
 
 class GLTextureBuffer : public TextureBuffer {
 public:
@@ -216,6 +214,7 @@ class MockGLEngine : public Engine {
 
   // === Windowing and framework things
   void makeContextCurrent() override;
+  void showWindow() override;
   void updateWindowSize(bool force = false) override;
   std::tuple<int, int> getWindowPos() override;
   bool windowRequestsClose() override;
@@ -261,5 +260,6 @@ class MockGLEngine : public Engine {
 protected:
 };
 
+}
 } // namespace render
 } // namespace polyscope

include/polyscope/render/opengl/gl_engine.h

@@ -33,6 +33,7 @@
 
 namespace polyscope {
 namespace render {
+namespace backend_openGL3_glfw {
 
 // Some very nice typdefs
 typedef GLuint TextureBufferHandle;
@@ -262,6 +263,7 @@ class GLEngine : public Engine {
 
   // === Windowing and framework things
   void makeContextCurrent() override;
+  void showWindow() override;
   void updateWindowSize(bool force = false) override;
   std::tuple<int, int> getWindowPos() override;
   bool windowRequestsClose() override;
@@ -312,5 +314,6 @@ class GLEngine : public Engine {
   GLFWwindow* mainWindow = nullptr;
 };
 
+} // namespace backend_openGL3_glfw
 } // namespace render
 } // namespace polyscope

include/polyscope/utilities.h

@@ -9,6 +9,7 @@
 #include <random>
 #include <sstream>
 #include <string>
+#include <tuple>
 
 
 #include <glm/glm.hpp>

src/CMakeLists.txt

@@ -7,10 +7,20 @@ endif()
 
 SET(INCLUDE_ROOT "${CMAKE_CURRENT_SOURCE_DIR}/../include/polyscope/")
 
+# Lists that will be populated for the render backend
+
+# Add the main _engine file no matter what. All of the interesting parts are ifdef'd out, and this
+# allows us to resolve stubs.
+list (APPEND BACKEND_SRCS
+		render/opengl/gl_engine.cpp  
+		render/mock_opengl/mock_gl_engine.cpp  
+)
+
 # Configure the render backend
-if("${POLYSCOPE_BACKEND}" STREQUAL "OPENGL3_GLFW")
+if("${POLYSCOPE_BACKEND_OPENGL3_GLFW}")
+  message("Polyscope backend openGL3_glfw enabled")
 
-	SET(BACKEND_SRCS
+  list (APPEND BACKEND_SRCS
 		render/opengl/gl_engine.cpp  
 		render/opengl/shaders/texture_draw_shaders.cpp  
 		render/opengl/shaders/lighting_shaders.cpp  
@@ -23,18 +33,18 @@ if("${POLYSCOPE_BACKEND}" STREQUAL "OPENGL3_GLFW")
 		render/opengl/shaders/cylinder_shaders.cpp  
 	)
 
-	SET(BACKEND_HEADERS
+  list(APPEND BACKEND_HEADERS
 		${INCLUDE_ROOT}render/opengl/gl_engine.h
 		${INCLUDE_ROOT}render/opengl/shaders/common.h
 	)
 
-	SET(BACKEND_INCLUDE_DIRS
+  list(APPEND BACKEND_INCLUDE_DIRS
 		${CMAKE_CURRENT_SOURCE_DIR}/../deps/glad/include
 		${CMAKE_CURRENT_SOURCE_DIR}/../deps/glfw/include
 	)
 
 	# Link settings
-	SET(BACKEND_LIBS
+  list(APPEND BACKEND_LIBS
 		glfw ${GLFW_LIBRARIES}
 	)
 
@@ -51,10 +61,14 @@ if("${POLYSCOPE_BACKEND}" STREQUAL "OPENGL3_GLFW")
 	else()
 			list(APPEND BACKEND_LIBS glad)
 	endif()
+
+  add_definitions(-DPOLYSCOPE_BACKEND_OPENGL3_GLFW_ENABLED)  
+endif()
 
-elseif("${POLYSCOPE_BACKEND}" STREQUAL "MOCK_OPENGL")
+if("${POLYSCOPE_BACKEND_OPENGL_MOCK}")
+  message("Polyscope backend openGL_mock enabled")
 
-	SET(BACKEND_SRCS
+  list (APPEND BACKEND_SRCS
 		render/mock_opengl/mock_gl_engine.cpp  
 		render/opengl/shaders/texture_draw_shaders.cpp  
 		render/opengl/shaders/lighting_shaders.cpp  
@@ -67,18 +81,19 @@ elseif("${POLYSCOPE_BACKEND}" STREQUAL "MOCK_OPENGL")
 		render/opengl/shaders/cylinder_shaders.cpp  
 	)
 
-	SET(BACKEND_HEADERS
+  list(APPEND BACKEND_HEADERS
 		${INCLUDE_ROOT}render/mock_opengl/mock_gl_engine.h
 		${INCLUDE_ROOT}render/opengl/shaders/common.h
 	)
 
-	SET(BACKEND_INCLUDE_DIRS
+  list(APPEND BACKEND_INCLUDE_DIRS
 	)
 
 	# Link settings
-	SET(BACKEND_LIBS
+  list(APPEND BACKEND_LIBS
 	)
 
+add_definitions(-DPOLYSCOPE_BACKEND_OPENGL_MOCK_ENABLED)  
 endif()
 
 
@@ -98,6 +113,7 @@ SET(SRCS
   render/color_maps.cpp
   render/ground_plane.cpp
   render/materials.cpp
+  render/initialize_backend.cpp  
 
   # General utilities
   disjoint_sets.cpp

src/polyscope.cpp

@@ -137,7 +137,7 @@ void writePrefsFile() {
 
 // === Core global functions
 
-void init() {
+void init(std::string backend) {
   if (state::initialized) {
     throw std::logic_error(options::printPrefix + "Initialize called twice");
   }
@@ -147,7 +147,7 @@ void init() {
   }
 
   // Initialize the rendering engine
-  render::initializeRenderEngine();
+  render::initializeRenderEngine(backend);
 
   // Initialie ImGUI
   IMGUI_CHECKVERSION();
@@ -602,6 +602,8 @@ void show(size_t forFrames) {
                            "must initialize Polyscope with polyscope::init() before calling polyscope::show().");
   }
 
+  render::engine->showWindow();
+
   // Main loop
   while (!render::engine->windowRequestsClose() && forFrames > 0) {
     mainLoopIteration();

src/render/initialize_backend.cpp

@@ -0,0 +1,51 @@
+#include "polyscope/render/engine.h"
+
+namespace polyscope {
+namespace render {
+
+// Storage for the global engine pointer
+Engine* engine = nullptr;
+
+// Forward-declaration of initialize routines
+// we don't want to just include the appropriate headers, because they may define conflicting symbols
+namespace backend_openGL3_glfw {
+void initializeRenderEngine();
+}
+namespace backend_openGL_mock {
+void initializeRenderEngine();
+}
+// void initializeRenderEngine_openGL_mock();
+
+void initializeRenderEngine(std::string backend) {
+
+  // Handle default backends
+  // (the string is getting overwritten, so lower on the list means higher priority)
+  if (backend == "") {
+
+#ifdef POLYSCOPE_BACKEND_OPENGL_MOCK_ENABLED
+    // Don't set it one by default, since it's probably a mistake; better to throw the exception below.
+    // backend = "mock_openGL";
+#endif
+
+#ifdef POLYSCOPE_BACKEND_OPENGL3_GLFW_ENABLED
+    backend = "openGL3_glfw";
+#endif
+
+    if (backend == "") {
+      throw std::runtime_error("no Polyscope backends available");
+    }
+  }
+
+  // Initialize the appropriate backend
+  if (backend == "openGL3_glfw") {
+    backend_openGL3_glfw::initializeRenderEngine();
+  } else if (backend == "openGL_mock") {
+    backend_openGL_mock::initializeRenderEngine();
+  } else {
+    throw std::runtime_error("unrecognized Polyscope backend " + backend);
+  }
+}
+
+} // namespace render
+} // namespace polyscope
+