Try to clean up asset folders for sample apps. (#128)

* Try to clean up asset folders for sample apps.

This removes the build step where we copy a subset of assets, and makes
it so that FilamentApp hands out a "root path" for assets. For now this
is determined based on the location of the executable. This allows
developers to launch samples from any CWD.

Closes #11

* Restore asset copy to build.

libs/filagui/include/filagui/ImGuiHelper.h

@@ -28,6 +28,8 @@
 #include <filament/VertexBuffer.h>
 #include <filament/View.h>
 
+#include <utils/Path.h>
+
 struct ImDrawData;
 
 namespace filagui {
@@ -42,7 +44,7 @@ class ImGuiHelper {
     using Callback = std::function<void(filament::Engine*, filament::View*)>;
 
     // The constructor creates its own Scene and places it in the given View.
-    ImGuiHelper(filament::Engine* engine, filament::View* view);
+    ImGuiHelper(filament::Engine* engine, filament::View* view, const utils::Path& fontPath);
     ~ImGuiHelper();
 
     // Informs ImGui of the current display size, as well as the pixel ratio for high DPI displays.

libs/filagui/src/ImGuiHelper.cpp

@@ -31,7 +31,6 @@
 #include <filament/Texture.h>
 #include <filament/TransformManager.h>
 #include <utils/EntityManager.h>
-#include <utils/Path.h>
 
 using namespace math;
 using namespace filament;
@@ -43,14 +42,14 @@ static const uint8_t UI_BLIT_PACKAGE[] = {
     #include "generated/material/uiBlit.inc"
 };
 
-ImGuiHelper::ImGuiHelper(Engine* engine, filament::View* view) : mEngine(engine), mView(view) {
+ImGuiHelper::ImGuiHelper(Engine* engine, filament::View* view, const Path& fontPath) :
+        mEngine(engine), mView(view) {
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO();
 
-    // Try loading Roboto from assets/fonts (relative to the executable).  If this fails, ImGui
-    // will silently fall back to proggy.
-    std::string fpath = Path::getCurrentExecutable().getParent() + "assets/fonts/Roboto-Medium.ttf";
-    io.Fonts->AddFontFromFileTTF(fpath.c_str(), 16.0f);
+    // If the given font path is invalid, ImGui will silently fall back to proggy, which is a
+    // tiny "pixel art" texture that is compiled into the library.
+    io.Fonts->AddFontFromFileTTF(fontPath.c_str(), 16.0f);
 
     // Create the grayscale texture that ImGui uses for its glyph atlas.
     static unsigned char* pixels;

libs/utils/include/utils/Path.h

@@ -108,6 +108,12 @@ class Path {
      */
     Path getParent() const;
 
+    /**
+     * Returns ancestor path where "0" is the immediate parent.
+     * @return a new path containing the ancestor of this path
+     */
+    Path getAncestor(int n) const;
+
     /**
      * Returns the name of the file or directory represented by
      * this abstract pathname.

libs/utils/src/Path.cpp

@@ -131,6 +131,14 @@ Path Path::getParent() const {
     return getCanonicalPath(result);
 }
 
+Path Path::getAncestor(int n) const {
+    Path result = getParent();
+    while (n--) {
+        result = result.getParent();
+    }
+    return result;
+}
+
 std::string Path::getName() const {
     if (isEmpty()) return "";
 

samples/CMakeLists.txt

@@ -191,6 +191,15 @@ endif()
 
 # ==================================================================================================
 # Copy Assets
+#
+# This creates a structure like:
+#
+#    /lightbulb (etc)  sample app executable
+#    /assets/fonts     copied from REPO/assets
+#    /assets/models    copied from REPO/assets
+#    /textures         copied from REPO/third_party
+#    /envs             copied from REPO/samples/envs
+#
 # ==================================================================================================
 
 file(COPY ../third_party/textures DESTINATION ${PROJECT_BINARY_DIR})
@@ -202,3 +211,7 @@ file(COPY ../assets DESTINATION ${PROJECT_BINARY_DIR}
         PATTERN "environments" EXCLUDE)
 add_custom_target(assets ALL DEPENDS assets)
 add_dependencies(filament assets)
+
+file(COPY ../samples/envs DESTINATION ${PROJECT_BINARY_DIR})
+add_custom_target(envs ALL DEPENDS envs)
+add_dependencies(filament envs)

samples/app/FilamentApp.cpp

@@ -155,7 +155,8 @@ void FilamentApp::run(const Config& config,SetupCallback setupCallback,
     setupCallback(mEngine, window->mMainView->getView(), mScene);
 
     if (imguiCallback) {
-        mImGuiHelper = std::make_unique<ImGuiHelper>(mEngine, window->mUiView->getView());
+        mImGuiHelper = std::make_unique<ImGuiHelper>(mEngine, window->mUiView->getView(),
+            getRootPath() + "assets/fonts/Roboto-Medium.ttf");
         ImGuiIO& io = ImGui::GetIO();
         #ifdef WIN32
             SDL_SysWMinfo wmInfo;

samples/app/FilamentApp.h

@@ -27,6 +27,8 @@
 #include <filament/Engine.h>
 #include <filament/Viewport.h>
 
+#include <utils/Path.h>
+
 #include "CameraManipulator.h"
 #include "Config.h"
 #include "IBL.h"
@@ -77,6 +79,13 @@ class FilamentApp {
     FilamentApp& operator=(const FilamentApp& rhs) = delete;
     FilamentApp& operator=(FilamentApp&& rhs) = delete;
 
+    // Returns the path to the Filament root for loading assets. This is determined from the
+    // executable folder, which allows users to launch samples from any folder.
+    static const utils::Path& getRootPath() {
+        static const utils::Path root = utils::Path::getCurrentExecutable().getParent();
+        return root;
+    }
+
 private:
     FilamentApp();
 

samples/vk_hellopbr.cpp

@@ -36,14 +36,14 @@ struct App {
     mat4f transform;
 };
 
-static const char* MODEL_FILE = "samples/assets/models/monkey/monkey.obj";
-static const char* IBL_FOLDER = "../samples/envs/office";
+static const char* MODEL_FILE = "assets/models/monkey/monkey.obj";
+static const char* IBL_FOLDER = "envs/office";
 
 int main(int argc, char** argv) {
     Config config;
     config.title = "hellopbr";
     config.backend = Backend::VULKAN;
-    config.iblDirectory = IBL_FOLDER;
+    config.iblDirectory = FilamentApp::getRootPath() + IBL_FOLDER;
 
     App app;
     auto setup = [config, &app](Engine* engine, View* view, Scene* scene) {
@@ -53,7 +53,7 @@ int main(int argc, char** argv) {
 
         // Add geometry into the scene.
         app.meshes = new MeshAssimp(*engine);
-        app.meshes->addFromFile(MODEL_FILE, app.materials);
+        app.meshes->addFromFile(FilamentApp::getRootPath() + MODEL_FILE, app.materials);
         auto ti = tcm.getInstance(app.meshes->getRenderables()[0]);
         app.transform = mat4f{ mat3f(1), float3(0, 0, -4) } * tcm.getWorldTransform(ti);
         for (auto renderable : app.meshes->getRenderables()) {

samples/vk_shadowtest.cpp

@@ -47,8 +47,8 @@ struct App {
     GroundPlane plane;
 };
 
-static const char* MODEL_FILE = "samples/assets/models/monkey/monkey.obj";
-static const char* IBL_FOLDER = "../samples/envs/office";
+static const char* MODEL_FILE = "assets/models/monkey/monkey.obj";
+static const char* IBL_FOLDER = "envs/office";
 
 static constexpr bool ENABLE_SHADOWS = true;
 static constexpr uint8_t GROUND_SHADOW_PACKAGE[] = {
@@ -59,7 +59,7 @@ static GroundPlane createGroundPlane(Engine* engine);
 
 static const Config config {
     .title = "shadowtest",
-    .iblDirectory = IBL_FOLDER,
+    .iblDirectory = FilamentApp::getRootPath() + IBL_FOLDER,
     .scale = 1,
     .splitView = false,
     .backend = Backend::VULKAN,
@@ -75,7 +75,7 @@ int main(int argc, char** argv) {
 
         // Add geometry into the scene.
         app.meshes = new MeshAssimp(*engine);
-        app.meshes->addFromFile(MODEL_FILE, app.materials);
+        app.meshes->addFromFile(FilamentApp::getRootPath() + MODEL_FILE, app.materials);
         auto ti = tcm.getInstance(app.meshes->getRenderables()[0]);
         app.transform = mat4f{ mat3f(1), float3(0, 0, -4) } * tcm.getWorldTransform(ti);
         for (auto renderable : app.meshes->getRenderables()) {

samples/vk_texturedquad.cpp

@@ -81,14 +81,13 @@ int main() {
     auto setup = [&app](Engine* engine, View* view, Scene* scene) {
 
         // Load texture
-        Path path = Path::getCurrentExecutable().getParent() +
-                "textures/Moss_01/Moss_01_Color.png";
+        Path path = FilamentApp::getRootPath() + "third_party/textures/Moss_01/Moss_01_Color.png";
         if (!path.exists()) {
             std::cerr << "The texture " << path << " does not exist" << std::endl;
             exit(1);
         }
         int w, h, n;
-        unsigned char* data = stbi_load(path.getAbsolutePath().c_str(), &w, &h, &n, 4);
+        unsigned char* data = stbi_load(path.c_str(), &w, &h, &n, 4);
         if (data == nullptr) {
             std::cerr << "The texture " << path << " could not be loaded" << std::endl;
             exit(1);