Add Scenegraph Primitives Example

An example showing using primitives and the SceneGraph, as mentioned in: mosra/magnum#102

Implements DrawableObject subclass of Drawable3D, demonstrates parenting objects to the scene and to other objects, and shows local object transformations and camera transformations using left and right click respectively

CMakeLists.txt

@@ -52,6 +52,7 @@ cmake_dependent_option(WITH_MOTIONBLUR_EXAMPLE "Build Motion Blur example" OFF "
 option(WITH_OVR_EXAMPLE "Build OVR example" OFF)
 option(WITH_PICKING_EXAMPLE "Build Picking example" OFF)
 option(WITH_PRIMITIVES_EXAMPLE "Build Primitives example" OFF)
+option(WITH_PRIMITIVES_SCENEGRAPH_EXAMPLE "Build Primitives SceneGraph example" OFF)
 option(WITH_SHADOWS_EXAMPLE "Build Shadow Mapping example" OFF)
 option(WITH_TEXT_EXAMPLE "Build Text example (requires some TTF font plugin)" OFF)
 cmake_dependent_option(WITH_TEXTUREDTRIANGLE_EXAMPLE "Build TexturedTriangle example (requires some TGA importer plugin)" OFF "NOT MAGNUM_TARGET_GLES" OFF)

src/CMakeLists.txt

@@ -107,6 +107,10 @@ if(WITH_PRIMITIVES_EXAMPLE)
     add_subdirectory(primitives)
 endif()
 
+if(WITH_PRIMITIVES_SCENEGRAPH_EXAMPLE)
+    add_subdirectory(primitives-scenegraph)
+endif()
+
 if(WITH_SHADOWS_EXAMPLE)
     add_subdirectory(shadows)
 endif()

src/primitives-scenegraph/CMakeLists.txt

@@ -0,0 +1,64 @@
+#
+#   This file is part of Magnum.
+#
+#   Original authors — credit is appreciated but not required:
+#
+#       2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 —
+#           Vladimír Vondruš <mosra@centrum.cz>
+#
+#   This is free and unencumbered software released into the public domain.
+#
+#   Anyone is free to copy, modify, publish, use, compile, sell, or distribute
+#   this software, either in source code form or as a compiled binary, for any
+#   purpose, commercial or non-commercial, and by any means.
+#
+#   In jurisdictions that recognize copyright laws, the author or authors of
+#   this software dedicate any and all copyright interest in the software to
+#   the public domain. We make this dedication for the benefit of the public
+#   at large and to the detriment of our heirs and successors. We intend this
+#   dedication to be an overt act of relinquishment in perpetuity of all
+#   present and future rights to this software under copyright law.
+#
+#   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+#   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+#   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+#   THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+#   IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+#   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+cmake_minimum_required(VERSION 3.4)
+
+project(MagnumPrimitivesSceneGraphExample CXX)
+
+# Add module path in case this is project root
+if(PROJECT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
+    set(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/../../modules/" ${CMAKE_MODULE_PATH})
+endif()
+
+find_package(Corrade REQUIRED Main)
+find_package(Magnum REQUIRED
+    GL
+    MeshTools
+    Primitives
+    Shaders
+	SceneGraph
+    Sdl2Application)
+
+set_directory_properties(PROPERTIES CORRADE_USE_PEDANTIC_FLAGS ON)
+
+add_executable(magnum-primitives-scenegraph WIN32 PrimitivesSceneGraphExample.cpp)
+target_link_libraries(magnum-primitives-scenegraph PRIVATE
+    Corrade::Main
+    Magnum::Application
+    Magnum::GL
+    Magnum::Magnum
+    Magnum::MeshTools
+    Magnum::Primitives
+	Magnum::SceneGraph
+    Magnum::Shaders)
+
+install(TARGETS magnum-primitives-scenegraph DESTINATION ${MAGNUM_BINARY_INSTALL_DIR})
+
+# Make the executable a default target to build & run in Visual Studio
+set_property(DIRECTORY ${PROJECT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT magnum-primitives-scenegraph)

src/primitives-scenegraph/PrimitivesSceneGraphExample.cpp

@@ -0,0 +1,207 @@
+/*
+    This file is part of Magnum.
+
+    Original authors — credit is appreciated but not required:
+
+        2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 —
+            Vladimír Vondruš <mosra@centrum.cz>
+
+    This is free and unencumbered software released into the public domain.
+
+    Anyone is free to copy, modify, publish, use, compile, sell, or distribute
+    this software, either in source code form or as a compiled binary, for any
+    purpose, commercial or non-commercial, and by any means.
+
+    In jurisdictions that recognize copyright laws, the author or authors of
+    this software dedicate any and all copyright interest in the software to
+    the public domain. We make this dedication for the benefit of the public
+    at large and to the detriment of our heirs and successors. We intend this
+    dedication to be an overt act of relinquishment in perpetuity of all
+    present and future rights to this software under copyright law.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+    THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+    IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+    CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#include <Magnum/GL/Buffer.h>
+#include <Magnum/GL/DefaultFramebuffer.h>
+#include <Magnum/GL/Mesh.h>
+#include <Magnum/GL/Renderer.h>
+#include <Magnum/Math/Color.h>
+#include <Magnum/Math/Matrix4.h>
+#include <Magnum/MeshTools/Compile.h>
+#include <Magnum/Platform/Sdl2Application.h>
+#include <Magnum/Primitives/Cube.h>
+#include <Magnum/Primitives/UVSphere.h>
+#include <Magnum/Primitives/Plane.h>
+#include <Magnum/Shaders/Phong.h>
+#include <Magnum/Trade/MeshData.h>
+#include <Magnum/SceneGraph/Scene.h>
+#include <Magnum/SceneGraph/MatrixTransformation3D.h>
+#include <Magnum/SceneGraph/Camera.h>
+#include <Magnum/SceneGraph/Drawable.h>
+
+namespace Magnum { namespace Examples {
+
+using namespace Magnum::Math::Literals;
+
+typedef SceneGraph::Object<SceneGraph::MatrixTransformation3D> Object3D;
+typedef SceneGraph::Scene<SceneGraph::MatrixTransformation3D> Scene3D;
+
+class DrawableObject : public Object3D, SceneGraph::Drawable3D {
+	public:
+		explicit DrawableObject(Shaders::Phong& shader, const Color3& color, GL::Mesh& mesh, Object3D& parent, SceneGraph::DrawableGroup3D& drawables) : Object3D{ &parent }, SceneGraph::Drawable3D{ *this, &drawables }, _shader(shader), _color{ color }, _mesh(mesh) {}
+
+		void setColor(Color3 color) { _color = color; }
+		Color3 getColor() { return _color; }
+
+	private:
+		virtual void draw(const Matrix4& transformationMatrix, SceneGraph::Camera3D& camera) {
+			_shader.setTransformationMatrix(transformationMatrix)
+				.setNormalMatrix(transformationMatrix.normalMatrix())
+				.setProjectionMatrix(camera.projectionMatrix())
+				.setAmbientColor(_color*0.3f)
+				.setDiffuseColor(_color)
+				/* relative to the camera */
+				.setLightPosition({ 13.0f, 2.0f, 5.0f })
+				.draw(_mesh);
+		}
+
+		GL::Mesh& _mesh;
+		Shaders::Phong& _shader;
+		Color3 _color;
+};
+
+
+class PrimitivesSceneGraphExample: public Platform::Application {
+    public:
+        explicit PrimitivesSceneGraphExample(const Arguments& arguments);
+
+    private:
+        void drawEvent() override;
+        void mousePressEvent(MouseEvent& event) override;
+        void mouseReleaseEvent(MouseEvent& event) override;
+        void mouseMoveEvent(MouseMoveEvent& event) override;
+
+		Scene3D _scene;
+		Object3D* _cameraObject;
+		SceneGraph::Camera3D* _camera;
+		SceneGraph::DrawableGroup3D _drawables;
+
+		Shaders::Phong _shader;
+		GL::Mesh _cube, _plane, _sphere, _sphereWireframe;
+
+		enum { ObjectCount = 4 };
+		DrawableObject* _objects[ObjectCount];
+
+        Matrix4 _transformation, _projection;
+		Vector2i _previousMousePosition, _mousePressPosition;
+};
+
+
+
+PrimitivesSceneGraphExample::PrimitivesSceneGraphExample(const Arguments& arguments):
+    Platform::Application{arguments, Configuration{}
+        .setTitle("Magnum Primitives SceneGraph Example")}
+{
+	/* Global renderer configuration */
+    GL::Renderer::enable(GL::Renderer::Feature::DepthTest);
+    GL::Renderer::enable(GL::Renderer::Feature::FaceCulling);
+
+	/* Set up meshes */
+	_cube = MeshTools::compile(Primitives::cubeSolid());
+	_sphere = MeshTools::compile(Primitives::uvSphereSolid(16, 32));
+	_sphereWireframe = MeshTools::compile(Primitives::uvSphereWireframe(16, 32));
+	_plane = MeshTools::compile(Primitives::planeSolid());
+
+    _projection =
+        Matrix4::perspectiveProjection(
+            35.0_degf, Vector2{windowSize()}.aspectRatio(), 0.01f, 100.0f)*
+        Matrix4::translation(Vector3::zAxis(-10.0f));
+
+	/* Set up objects*/
+	(*(_objects[0] = new DrawableObject{_shader, 0x3bd267_rgbf, _cube, _scene, _drawables }))
+		.rotateZ(45.0_degf)
+		.rotateX(-45.0_degf)
+		.translate({ 0.5f, 0.0f, -2.0f });
+
+	(*(_objects[1] = new DrawableObject{_shader, 0x2f83cc_rgbf, _sphere, _scene, _drawables }))
+		.scale(Vector3(0.75f))
+		.translate({ -1.2f, -0.3f, -0.2f });
+
+	/* This uvSphereWireframe object has its parent set to the uvSphereSolid object, rather than
+		the _scene*/
+	(*(_objects[2] = new DrawableObject{ _shader, 0x2f83cc_rgbf, _sphereWireframe, (*_objects[1]), _drawables }))
+		.scale(Vector3(1.01f));
+
+	(*(_objects[3] = new DrawableObject{_shader, 0xcd3431_rgbf, _plane, _scene, _drawables }))
+		.rotate(30.0_degf, Vector3(1.0f).normalized())
+		.rotateX(-30.0_degf)
+		.scale(Vector3(2.0f))
+		.translate({ 0.0f, -0.30f, -3.3f });
+
+	/* Configure camera */
+	_cameraObject = new Object3D{ &_scene };
+	_cameraObject->translate(Vector3::zAxis(8.0f));
+	_camera = new SceneGraph::Camera3D{ *_cameraObject };
+	_camera->setAspectRatioPolicy(SceneGraph::AspectRatioPolicy::Extend)
+		.setProjectionMatrix(Matrix4::perspectiveProjection(35.0_degf, 4.0f / 3.0f, 0.001f, 100.0f))
+		.setViewport(GL::defaultFramebuffer.viewport().size());
+}
+
+void PrimitivesSceneGraphExample::drawEvent() {
+    GL::defaultFramebuffer.clear(
+        GL::FramebufferClear::Color|GL::FramebufferClear::Depth);
+
+	_camera->draw(_drawables);
+    swapBuffers();
+}
+
+void PrimitivesSceneGraphExample::mousePressEvent(MouseEvent& event) {
+    if(event.button() != MouseEvent::Button::Left) return;
+
+	_previousMousePosition = _mousePressPosition = event.position();
+    event.setAccepted();
+}
+
+void PrimitivesSceneGraphExample::mouseReleaseEvent(MouseEvent& event) {	
+	if (event.button() != MouseEvent::Button::Left || _mousePressPosition != event.position()) return;
+	//Change the color of each object
+	for (auto* o : _objects) o->setColor(Color3::fromHsv({ o->getColor().hue() + 50.0_degf, 1.0f, 1.0f }));
+
+    event.setAccepted();
+    redraw();
+}
+
+void PrimitivesSceneGraphExample::mouseMoveEvent(MouseMoveEvent& event) {
+	/* We have to take window size, not framebuffer size, since the position is
+	in window coordinates and the two can be different on HiDPI systems */
+	const Vector2 delta = 3.0f*
+		Vector2{ event.position() - _previousMousePosition } /
+		Vector2{ windowSize() };
+
+	//
+	if ((event.buttons() & MouseMoveEvent::Button::Right)) {
+		(*_cameraObject)
+			.rotate(Rad{ -delta.y() }, _cameraObject->transformation().right().normalized())
+			.rotateY(Rad{ -delta.x() });
+	}
+
+	if ((event.buttons() & MouseMoveEvent::Button::Left)) {
+		for (auto* o : _objects) {
+			(*o).transformLocal(Matrix4::rotationX(Rad{ delta.y() }) * Matrix4::rotationY(Rad{ delta.x() }));
+		}
+	}
+
+	_previousMousePosition = event.position();
+	event.setAccepted();
+	redraw();
+}
+
+}}
+
+MAGNUM_APPLICATION_MAIN(Magnum::Examples::PrimitivesSceneGraphExample)