Provide Build Script, Minor Performance Improvement for the X3D Output, Add Emscripten as a target

.gitignore

@@ -0,0 +1,5 @@
+build/
+
+# CLion
+cmake-build-*/
+.idea/

CMakeLists.txt

@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 3.4 FATAL_ERROR)
+project(tgen)
+
+set(CMAKE_CXX_STANDARD_REQUIRED 11)
+set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
+
+if(EMSCRIPTEN)
+	option(TGEN_WEBASSEMBLY "Generate WebAssembly instead of asm.js" OFF)
+	if(TGEN_WEBASSEMBLY)
+		set(CMAKE_CXX_FLAGS "-s WASM=1 ${CMAKE_CXX_FLAGS}")
+	endif()
+
+	# For some reason CMAKE_CXX_STANDARD_REQUIRED does not work for emscripten
+	set(CMAKE_CXX_FLAGS  "--bind -std=c++11 ${CMAKE_CXX_FLAGS}")
+else()
+	option(TGEN_SHARED_LIBRARY "Build tgen as a shared library" OFF)
+endif()
+
+add_subdirectory(src bin)

README.md

@@ -7,17 +7,35 @@ Current Features:
 * Generation of per-corner tangents for triangle data with UVs
 * Computation of per-wedge / per-UV-vertex tangent spaces
 * Tangent frame orthogonalization
-* Encoding of 4-component tangents (with "flip factor") for avoiding explicit binormals
+* Encoding of 4-component tangents (with "flip factor") for avoiding explicit bitangents
 * Simple C++ implementation, no dependencies
+* Compilable to asm.js and WebAssembly (right now, only the functions are exported, there is no web demo yet)
 
 The code consists basically of one header + .cpp file.
 For debugging and visualization, there is also a simple X3D exporter in a separate file, which was used to generate the 3D visualizations shown below.
 The baked tangent-space normal maps are just provided for demonstration purposes, the actual baking code is not part of this repository.
 
-So far, the C++ code from this project has just been compiled and tested with VS 2015.
+So far, the C++ code from this project has been compiled and tested with VS 2015, gcc 6.3 / 7.0 trunk, clang 5.0 trunk and emscripten 1.37 (clang 3.9).
 
 Feedback and contributions are always welcome. 
 
+## Building and installing
+
+TGen has no external dependencies and can be built using CMake 3.4 or newer:
+```
+cd <this-repo>
+mkdir build
+cd build
+
+# Native targets
+cmake .. [-DCMAKE_BUILD_TYPE=Release] [-DTGEN_STATIC_LIBRARY=0] # Default is building as a shared library
+cmake --build . [--target install]
+
+# Emscripten
+emconfigure cmake .. [-DCMAKE_BUILD_TYPE=Release] [-DTGEN_WEBASSEMBLY=1] # Default is asm.js instead of WebAssembly
+cmake --build .
+emrun --port 8080 bin
+```
 
 ## Results
 

src/CMakeLists.txt

@@ -0,0 +1,37 @@
+set(SOURCE_FILES
+		tgen.h tgen.cpp
+		tgen_debug.h tgen_debug.cpp
+		)
+
+if(TGEN_SHARED_LIBRARY)
+	add_library(tgen SHARED ${SOURCE_FILES})
+else()
+	add_library(tgen STATIC ${SOURCE_FILES})
+endif()
+
+if(EMSCRIPTEN)
+	add_executable(tgen_driver EmscriptenMain.cpp)
+else()
+	add_executable(tgen_driver main.cpp)
+endif()
+
+target_link_libraries(tgen_driver PRIVATE tgen)
+set_target_properties(tgen_driver PROPERTIES OUTPUT_NAME tgen)
+
+install(TARGETS tgen_driver
+		RUNTIME DESTINATION bin
+)
+
+install(TARGETS tgen
+		RUNTIME DESTINATION bin
+		ARCHIVE DESTINATION lib
+		LIBRARY DESTINATION lib
+		)
+
+install(DIRECTORY . DESTINATION include
+		FILES_MATCHING PATTERN "*.h"
+)
+
+if(EMSCRIPTEN)
+	configure_file(webdemo.html index.html COPYONLY)
+endif()

src/EmscriptenMain.cpp

@@ -0,0 +1,27 @@
+/**
+ * TGen - Simple Tangent Generator
+ *
+ * 2016 by Max Limper, Fraunhofer IGD
+ *
+ * This code is public domain.
+ *
+ */
+
+#include <emscripten/bind.h>
+#include "tgen.h"
+
+using namespace emscripten;
+
+int add(int a, int b)
+{
+	return a + b;
+}
+
+EMSCRIPTEN_BINDINGS(tgen)
+{
+		function("computeCornerTSpace", &tgen::computeCornerTSpace);
+		function("computeVertexTSpace", &tgen::computeVertexTSpace);
+		function("orthogonalizeTSpace", &tgen::orthogonalizeTSpace);
+		function("computeTangent4D", &tgen::computeTangent4D);
+		function("add", &add);
+}

src/main.cpp

@@ -0,0 +1,12 @@
+#include "tgen.h"
+#include "tgen_debug.h"
+#include <iostream>
+
+int main(int argc, char ** argv)
+{
+	if(argc != 3)
+	{
+		std::cout << "Usage: " << argv[0] << " input.gltf output.gltf\n";
+		std::exit(EXIT_FAILURE);
+	}
+}

src/tgen_debug.cpp

@@ -103,20 +103,20 @@ namespace
                              double                           vScale,
                              std::stringstream              & ss       )
     {
-        ss << "    <Shape>" << std::endl;
-        ss << "      <Appearance>" << std::endl;
+        ss << "    <Shape>" << '\n';
+        ss << "      <Appearance>" << '\n';
         ss << "        <Material emissiveColor=\"" << colorStr << "\"/>"
-                            << std::endl;                
-        ss << "      </Appearance>" << std::endl;
+                            << '\n';                
+        ss << "      </Appearance>" << '\n';
         ss << "      <LineSet vertexCount=\"";
                             writeX3DLinesVCount(pos3D.size() / 3, ss);
                             ss << "\" >"
-                            << std::endl;
+                            << '\n';
         ss << "        <Coordinate point=\"";
                             writeX3DVecFieldLineData(pos3D, dir3D, vScale, ss);
-                            ss << "\"/>" << std::endl;
-        ss << "      </LineSet>" << std::endl;
-        ss << "    </Shape>" << std::endl;
+                            ss << "\"/>" << '\n';
+        ss << "      </LineSet>" << '\n';
+        ss << "    </Shape>" << '\n';
     }
 
     //-------------------------------------------------------------------------
@@ -178,52 +178,52 @@ namespace tgen
         std::stringstream sstr;
 
         // prologue
-        sstr << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" << std::endl;
+        sstr << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" << '\n';
         sstr << "<!DOCTYPE X3D PUBLIC \"ISO//Web3D//DTD X3D 3.0//EN\" "
              <<   "\"http://www.web3d.org/specifications/x3d-3.0.dtd\">"
-             << std::endl;
-        sstr << "<X3D>" << std::endl;
-        sstr << "  <Scene>" << std::endl;
+             << '\n';
+        sstr << "<X3D>" << '\n';
+        sstr << "  <Scene>" << '\n';
 
         // textured object
-        sstr << "    <Shape>" << std::endl;
-        sstr << "      <Appearance>" << std::endl;
-        sstr << "        <Material/>" << std::endl;        
-        sstr << "        <ImageTexture url=\"checker.png\">" << std::endl;
-        sstr << "          <TextureProperties magnificationFilter=\"NEAREST_PIXEL\"/>" << std::endl;
-        sstr << "        </ImageTexture>" << std::endl;
-        sstr << "      </Appearance>" << std::endl;
-        sstr << "      <IndexedFaceSet solid=\"false\"" << std::endl;
+        sstr << "    <Shape>" << '\n';
+        sstr << "      <Appearance>" << '\n';
+        sstr << "        <Material/>" << '\n';        
+        sstr << "        <ImageTexture url=\"checker.png\">" << '\n';
+        sstr << "          <TextureProperties magnificationFilter=\"NEAREST_PIXEL\"/>" << '\n';
+        sstr << "        </ImageTexture>" << '\n';
+        sstr << "      </Appearance>" << '\n';
+        sstr << "      <IndexedFaceSet solid=\"false\"" << '\n';
         sstr << "                      coordIndex   =\"";
                                             writeX3DTriIndexArray(triIndicesPos, sstr);
-                                            sstr << "\"" << std::endl;
+                                            sstr << "\"" << '\n';
         sstr << "                      texCoordIndex=\"";
                                             writeX3DTriIndexArray(triIndicesUV, sstr);
-                                            sstr << "\">" << std::endl;
+                                            sstr << "\">" << '\n';
         sstr << "        <Coordinate        point=\"";
                                             writeX3DArray(positions3D, sstr);
-                                            sstr << "\"/>" << std::endl;
+                                            sstr << "\"/>" << '\n';
         sstr << "        <Normal            vector=\"";
                                             writeX3DArray(normals3D, sstr);
-                                            sstr << "\"/>" << std::endl;
+                                            sstr << "\"/>" << '\n';
         sstr << "        <TextureCoordinate point=\"";
                                             writeX3DArray(uvs2D, sstr);
-                                            sstr << "\"/>" << std::endl;
-        sstr << "      </IndexedFaceSet>" << std::endl;
-        sstr << "    </Shape>" << std::endl;
+                                            sstr << "\"/>" << '\n';
+        sstr << "      </IndexedFaceSet>" << '\n';
+        sstr << "    </Shape>" << '\n';
 
         // vector field visualizations
         writeX3DVecFieldVis(positions3D, normals3D,    "0 0 1", vScale, sstr);
         writeX3DVecFieldVis(positions3D, tangents3D,   "1 0 0", vScale, sstr);
         writeX3DVecFieldVis(positions3D, bitangents3D, "0 1 0", vScale, sstr);
 
         // epilogue
-        sstr << "  </Scene>" << std::endl;
-        sstr << "</X3D>"     << std::endl;
+        sstr << "  </Scene>" << '\n';
+        sstr << "</X3D>"     << '\n';
 
 
-        std::ofstream fstr("tangents.x3d");
-        fstr << sstr.str() << std::endl;
+        std::ofstream fstr(filename);
+        fstr << sstr.str() << '\n';
     }
 
     //-------------------------------------------------------------------------    

src/tgen_debug.h

@@ -38,7 +38,7 @@ namespace tgen
                       const std::vector<tgen::RealT>   & uvs2D,
                       const std::vector<tgen::RealT>   & tangents3D,
                       const std::vector<tgen::RealT>   & bitangents3D,
-                      const char                       * filename      );
+                      const char                       * filename = "tangents.x3d");
 
     //-------------------------------------------------------------------------
 

src/webdemo.html

@@ -0,0 +1,31 @@
+<!doctype html>
+<html>
+	<body>
+		<script>
+			var run = function() {
+				let res = Module.add(42, 23)
+				console.log(res)
+			}
+
+			var Module = {}
+			let xhr = new XMLHttpRequest()
+			xhr.open('GET', 'tgen.wasm')
+			xhr.responseType = 'arraybuffer'
+			xhr.onload = function() {
+				if(xhr.status == 404) {
+					console.log("wasm module not found - continuing with assumption that tgen has been compiled to asm.js")
+				}
+				else {
+					Module.wasmBinary = xhr.response
+				}
+
+				let script = document.createElement('script')
+				script.src = "tgen.js"
+				document.body.appendChild(script)
+
+				script.onload = run
+			}
+			xhr.send(null)
+		</script>
+	</body>
+</html>