10/12/2023

CMakeLists.txt

@@ -29,6 +29,8 @@ set(SRC_FILES
 	"src/imgui/imstb_textedit.h"
 	"src/input_manager.cpp"
 	"src/libs/json.hpp"
+	"src/libs/mikktspace.c"
+	"src/libs/mikktspace.h"
 	"src/libs/stb_impl.cpp"
 	"src/libs/tiny_gltf.h"
 	"src/libs/tiny_gltf_impl.cpp"

src/application.cpp

@@ -231,7 +231,7 @@ void Application::GameLoop()
         ImGui::NewFrame();
 
         if (debug_menu_state.menu_active) {
-            if (ImGui::Begin("debugMenu")) {
+            if (ImGui::Begin("debugMenu", 0)) {
                 ImGui::Text("Test!");
                 ImGui::Text("FPS: %.3f", std::roundf(avg_fps));
             }

src/libs/mikktspace.h

@@ -0,0 +1,145 @@
+/** \file mikktspace/mikktspace.h
+ *  \ingroup mikktspace
+ */
+/**
+ *  Copyright (C) 2011 by Morten S. Mikkelsen
+ *
+ *  This software is provided 'as-is', without any express or implied
+ *  warranty.  In no event will the authors be held liable for any damages
+ *  arising from the use of this software.
+ *
+ *  Permission is granted to anyone to use this software for any purpose,
+ *  including commercial applications, and to alter it and redistribute it
+ *  freely, subject to the following restrictions:
+ *
+ *  1. The origin of this software must not be misrepresented; you must not
+ *     claim that you wrote the original software. If you use this software
+ *     in a product, an acknowledgment in the product documentation would be
+ *     appreciated but is not required.
+ *  2. Altered source versions must be plainly marked as such, and must not be
+ *     misrepresented as being the original software.
+ *  3. This notice may not be removed or altered from any source distribution.
+ */
+
+#ifndef __MIKKTSPACE_H__
+#define __MIKKTSPACE_H__
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Author: Morten S. Mikkelsen
+ * Version: 1.0
+ *
+ * The files mikktspace.h and mikktspace.c are designed to be
+ * stand-alone files and it is important that they are kept this way.
+ * Not having dependencies on structures/classes/libraries specific
+ * to the program, in which they are used, allows them to be copied
+ * and used as is into any tool, program or plugin.
+ * The code is designed to consistently generate the same
+ * tangent spaces, for a given mesh, in any tool in which it is used.
+ * This is done by performing an internal welding step and subsequently an order-independent evaluation
+ * of tangent space for meshes consisting of triangles and quads.
+ * This means faces can be received in any order and the same is true for
+ * the order of vertices of each face. The generated result will not be affected
+ * by such reordering. Additionally, whether degenerate (vertices or texture coordinates)
+ * primitives are present or not will not affect the generated results either.
+ * Once tangent space calculation is done the vertices of degenerate primitives will simply
+ * inherit tangent space from neighboring non degenerate primitives.
+ * The analysis behind this implementation can be found in my master's thesis
+ * which is available for download --> http://image.diku.dk/projects/media/morten.mikkelsen.08.pdf
+ * Note that though the tangent spaces at the vertices are generated in an order-independent way,
+ * by this implementation, the interpolated tangent space is still affected by which diagonal is
+ * chosen to split each quad. A sensible solution is to have your tools pipeline always
+ * split quads by the shortest diagonal. This choice is order-independent and works with mirroring.
+ * If these have the same length then compare the diagonals defined by the texture coordinates.
+ * XNormal which is a tool for baking normal maps allows you to write your own tangent space plugin
+ * and also quad triangulator plugin.
+ */
+
+
+typedef int tbool;
+typedef struct SMikkTSpaceContext SMikkTSpaceContext;
+
+typedef struct {
+	// Returns the number of faces (triangles/quads) on the mesh to be processed.
+	int (*m_getNumFaces)(const SMikkTSpaceContext * pContext);
+
+	// Returns the number of vertices on face number iFace
+	// iFace is a number in the range {0, 1, ..., getNumFaces()-1}
+	int (*m_getNumVerticesOfFace)(const SMikkTSpaceContext * pContext, const int iFace);
+
+	// returns the position/normal/texcoord of the referenced face of vertex number iVert.
+	// iVert is in the range {0,1,2} for triangles and {0,1,2,3} for quads.
+	void (*m_getPosition)(const SMikkTSpaceContext * pContext, float fvPosOut[], const int iFace, const int iVert);
+	void (*m_getNormal)(const SMikkTSpaceContext * pContext, float fvNormOut[], const int iFace, const int iVert);
+	void (*m_getTexCoord)(const SMikkTSpaceContext * pContext, float fvTexcOut[], const int iFace, const int iVert);
+
+	// either (or both) of the two setTSpace callbacks can be set.
+	// The call-back m_setTSpaceBasic() is sufficient for basic normal mapping.
+
+	// This function is used to return the tangent and fSign to the application.
+	// fvTangent is a unit length vector.
+	// For normal maps it is sufficient to use the following simplified version of the bitangent which is generated at pixel/vertex level.
+	// bitangent = fSign * cross(vN, tangent);
+	// Note that the results are returned unindexed. It is possible to generate a new index list
+	// But averaging/overwriting tangent spaces by using an already existing index list WILL produce INCRORRECT results.
+	// DO NOT! use an already existing index list.
+	void (*m_setTSpaceBasic)(const SMikkTSpaceContext * pContext, const float fvTangent[], const float fSign, const int iFace, const int iVert);
+
+	// This function is used to return tangent space results to the application.
+	// fvTangent and fvBiTangent are unit length vectors and fMagS and fMagT are their
+	// true magnitudes which can be used for relief mapping effects.
+	// fvBiTangent is the "real" bitangent and thus may not be perpendicular to fvTangent.
+	// However, both are perpendicular to the vertex normal.
+	// For normal maps it is sufficient to use the following simplified version of the bitangent which is generated at pixel/vertex level.
+	// fSign = bIsOrientationPreserving ? 1.0f : (-1.0f);
+	// bitangent = fSign * cross(vN, tangent);
+	// Note that the results are returned unindexed. It is possible to generate a new index list
+	// But averaging/overwriting tangent spaces by using an already existing index list WILL produce INCRORRECT results.
+	// DO NOT! use an already existing index list.
+	void (*m_setTSpace)(const SMikkTSpaceContext * pContext, const float fvTangent[], const float fvBiTangent[], const float fMagS, const float fMagT,
+						const tbool bIsOrientationPreserving, const int iFace, const int iVert);
+} SMikkTSpaceInterface;
+
+struct SMikkTSpaceContext
+{
+	SMikkTSpaceInterface * m_pInterface;	// initialized with callback functions
+	void * m_pUserData;						// pointer to client side mesh data etc. (passed as the first parameter with every interface call)
+};
+
+// these are both thread safe!
+tbool genTangSpaceDefault(const SMikkTSpaceContext * pContext);	// Default (recommended) fAngularThreshold is 180 degrees (which means threshold disabled)
+tbool genTangSpace(const SMikkTSpaceContext * pContext, const float fAngularThreshold);
+
+
+// To avoid visual errors (distortions/unwanted hard edges in lighting), when using sampled normal maps, the
+// normal map sampler must use the exact inverse of the pixel shader transformation.
+// The most efficient transformation we can possibly do in the pixel shader is
+// achieved by using, directly, the "unnormalized" interpolated tangent, bitangent and vertex normal: vT, vB and vN.
+// pixel shader (fast transform out)
+// vNout = normalize( vNt.x * vT + vNt.y * vB + vNt.z * vN );
+// where vNt is the tangent space normal. The normal map sampler must likewise use the
+// interpolated and "unnormalized" tangent, bitangent and vertex normal to be compliant with the pixel shader.
+// sampler does (exact inverse of pixel shader):
+// float3 row0 = cross(vB, vN);
+// float3 row1 = cross(vN, vT);
+// float3 row2 = cross(vT, vB);
+// float fSign = dot(vT, row0)<0 ? -1 : 1;
+// vNt = normalize( fSign * float3(dot(vNout,row0), dot(vNout,row1), dot(vNout,row2)) );
+// where vNout is the sampled normal in some chosen 3D space.
+//
+// Should you choose to reconstruct the bitangent in the pixel shader instead
+// of the vertex shader, as explained earlier, then be sure to do this in the normal map sampler also.
+// Finally, beware of quad triangulations. If the normal map sampler doesn't use the same triangulation of
+// quads as your renderer then problems will occur since the interpolated tangent spaces will differ
+// eventhough the vertex level tangent spaces match. This can be solved either by triangulating before
+// sampling/exporting or by using the order-independent choice of diagonal for splitting quads suggested earlier.
+// However, this must be used both by the sampler and your tools/rendering pipeline.
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

src/util/gltf_loader.cpp

@@ -3,14 +3,83 @@
 #include "log.h"
 #include "util/files.h"
 
+#include "libs/mikktspace.h"
 #include "libs/tiny_gltf.h"
 
 #include "components/mesh_renderable.h"
+#include <components/transform.h>
 
 namespace tg = tinygltf;
 
 namespace engine::util {
 
+static void DecomposeTransform(glm::mat4 transform, glm::vec3& pos, glm::quat& rot, glm::vec3& scale)
+{
+    // get position
+    pos.x = transform[3][0];
+    pos.y = transform[3][1];
+    pos.z = transform[3][2];
+
+    // remove position from matrix
+    transform[3][0] = 0.0f;
+    transform[3][1] = 0.0f;
+    transform[3][2] = 0.0f;
+
+    // get scale
+    scale.x = sqrtf(transform[0][0] * transform[0][0] + transform[0][1] * transform[0][1] + transform[0][2] * transform[0][2]);
+    scale.y = sqrtf(transform[1][0] * transform[1][0] + transform[1][1] * transform[1][1] + transform[1][2] * transform[1][2]);
+    scale.z = sqrtf(transform[2][0] * transform[2][0] + transform[2][1] * transform[2][1] + transform[2][2] * transform[2][2]);
+
+    // remove scaling from matrix
+    for (int row = 0; row < 3; row++) {
+        transform[0][row] /= scale.x;
+        transform[1][row] /= scale.y;
+        transform[2][row] /= scale.z;
+    }
+
+    // get rotation
+    rot = glm::quat_cast(transform);
+}
+
+static glm::mat4 MatFromDoubleArray(const std::vector<double>& arr)
+{
+    glm::mat4 mat{};
+    for (int i = 0; i < 4; ++i) {
+        mat[i][0] = static_cast<float>(arr[i * 4 + 0]);
+        mat[i][1] = static_cast<float>(arr[i * 4 + 1]);
+        mat[i][2] = static_cast<float>(arr[i * 4 + 2]);
+        mat[i][3] = static_cast<float>(arr[i * 4 + 3]);
+    }
+    return mat;
+}
+
+static void CreateNodes(engine::Scene& app_scene, const tg::Scene& gl_scene, const tg::Model& gl_model, engine::Entity parent_entity,
+                        const tg::Node& node)
+{
+    static int node_uuid = 0;
+
+    const glm::mat4 matrix = MatFromDoubleArray(node.matrix);
+    glm::vec3 pos;
+    glm::quat rot;
+    glm::vec3 scale;
+    DecomposeTransform(matrix, pos, rot, scale);
+
+    engine::Entity entity = app_scene.CreateEntity(std::string("test_node") + std::to_string(node_uuid), parent_entity, pos, rot, scale);
+
+    if (node.mesh >= 0) {
+        const tg::Mesh& mesh = gl_model.meshes.at(node.mesh);
+        const tg::Primitive& prim = mesh.primitives.front();
+        const tg::Accessor& indices_accessor = gl_model.accessors.at(prim.indices);
+        const tg::BufferView& indices_bufferview = gl_model.bufferViews.at(indices_accessor.bufferView);
+    }
+
+    for (const int node : node.children) {
+        CreateNodes(app_scene, gl_scene, gl_model, entity, gl_model.nodes.at(node));
+    }
+
+    ++node_uuid;
+}
+
 engine::Entity LoadGLTF(Scene& scene, const std::string& path, bool isStatic)
 {
 
@@ -45,31 +114,16 @@ engine::Entity LoadGLTF(Scene& scene, const std::string& path, bool isStatic)
     int scene_index = 0;
     if (model.defaultScene != -1) scene_index = model.defaultScene;
 
-    tg::Scene& s = model.scenes.at(scene_index);
+    const tg::Scene& s = model.scenes.at(scene_index);
 
-    if (s.nodes.size() < 1) {
+    const Entity parent =
-        throw std::runtime_error("Need at least 1 node in the scene");
+        scene.CreateEntity("test_node", 0, glm::vec3{}, glm::quat{glm::one_over_root_two<float>(), glm::one_over_root_two<float>(), 0.0f, 0.0f});
+
+    for (int node : s.nodes) {
+        CreateNodes(scene, s, model, parent, model.nodes.at(node));
     }
 
-    const tg::Node& node = model.nodes.at(s.nodes[0]);
+    return parent;
-
-    const Entity e = scene.CreateEntity("test_node", 0);
-
-    //const tg::Mesh& gt_mesh = model.meshes.at(0);
-
-    //std::vector<uint32_t> indices;
-
-    //model.buffers[0].
-
-    //auto mesh = std::make_unique<Mesh>(scene.app()->renderer()->GetDevice(), vertices, indices);
-
-    //auto mr = scene.AddComponent<MeshRenderableComponent>(e);
-    
-
-
-    // if (node.mesh)
-
-    return static_cast<Entity>(0u);
 }
 
 } // namespace engine::util

test/src/game.cpp

@@ -184,12 +184,6 @@ void PlayGame(GameSettings settings)
 
             wall_renderable->material->SetAlbedoTexture(albedo_texture);
             wall_renderable->material->SetNormalTexture(normal_texture);
-
-            auto custom = scene2->AddComponent<engine::CustomComponent>(wall2);
-            custom->onInit = []() {};
-            custom->onUpdate = [&](float dt) {
-                scene2->GetComponent<engine::TransformComponent>(pivot)->rotation *= glm::angleAxis(dt * 0.03f, glm::normalize(glm::vec3{0.0f, 0.0f, 1.0f}));
-            };
         }
 
         { /* light */