Redo the normal map lighting to be done in tangent space and with blinn-phong lighing

.clang-tidy

@@ -1,37 +1,39 @@
 ---
-Checks:          'clang-diagnostic-*,clang-analyzer-*,cppcoreguidelines-*,modernize-*,-modernize-use-trailing-return-type'
+Checks: "clang-diagnostic-*,clang-analyzer-*,cppcoreguidelines-*,modernize-*,-modernize-use-trailing-return-type"
 WarningsAsErrors: true
-HeaderFilterRegex: ''
+HeaderFilterRegex: ""
 AnalyzeTemporaryDtors: false
-FormatStyle:     google
+FormatStyle: google
 CheckOptions:
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+  - key: cert-dcl16-c.NewSuffixes
-    value:           'L;LL;LU;LLU'
+    value: "L;LL;LU;LLU"
-  - key:             cert-oop54-cpp.WarnOnlyIfThisHasSuspiciousField
+  - key: cert-oop54-cpp.WarnOnlyIfThisHasSuspiciousField
-    value:           '0'
+    value: "0"
-  - key:             cppcoreguidelines-explicit-virtual-functions.IgnoreDestructors
+  - key: cppcoreguidelines-explicit-virtual-functions.IgnoreDestructors
-    value:           '1'
+    value: "1"
-  - key:             cppcoreguidelines-non-private-member-variables-in-classes.IgnoreClassesWithAllMemberVariablesBeingPublic
+  - key: cppcoreguidelines-non-private-member-variables-in-classes.IgnoreClassesWithAllMemberVariablesBeingPublic
-    value:           '1'
+    value: "1"
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+  - key: google-readability-namespace-comments.SpacesBeforeComments
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+    value: "2"
-  - key:             modernize-loop-convert.MaxCopySize
+  - key: modernize-loop-convert.MaxCopySize
-    value:           '16'
+    value: "16"
-  - key:             modernize-loop-convert.MinConfidence
+  - key: modernize-loop-convert.MinConfidence
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+    value: reasonable
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+  - key: modernize-loop-convert.NamingStyle
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+    value: CamelCase
-  - key:             modernize-pass-by-value.IncludeStyle
+  - key: modernize-pass-by-value.IncludeStyle
-    value:           llvm
+    value: llvm
-  - key:             modernize-replace-auto-ptr.IncludeStyle
+  - key: modernize-replace-auto-ptr.IncludeStyle
-    value:           llvm
+    value: llvm
-  - key:             modernize-use-nullptr.NullMacros
+  - key: modernize-use-nullptr.NullMacros
-    value:           'NULL'
+    value: "NULL"
-...
+  - key: readability-magic-numbers
+    value: "0"
+---
 

examples/dev_testing/src/main.cpp

@@ -179,7 +179,7 @@ int main(int argc, char *argv[]) {
     // entity.add_component<se::ModelComponent>("examples/dev_testing/resources/paradigm/paradigm.fbx");
     // entity.add_component<se::RotatingComponent>();
     auto &transform_comp = entity.add_component<se::TransformComponent>();
-    transform_comp.translate(7.f, 0.f, 0.f);
+    transform_comp.translate(4.f, 0.f, 0.f);
     // transform_comp.scale(0.05f);
     // transform_comp.rotate_z(-90.f);
     // transform_comp.rotate_y(-90.f);
@@ -197,7 +197,7 @@ int main(int argc, char *argv[]) {
     auto camera = std::make_shared<se::Camera>(game.get_window(), core_shader, 70, glm::vec3(0, 0, 0));
     game.add_event(camera);
 
-    auto light = std::make_shared<se::gfx::Light>(core_shader, glm::vec3(-10.f, 0.f, 0.f), glm::vec3(1.f, 1.f, 1.f));
+    auto light = std::make_shared<se::gfx::Light>(core_shader, glm::vec3(0.f, 0.f, 0.f), glm::vec3(1.f, 1.f, 1.f));
     game.add_event(light);
 
     auto fps_counter = std::make_shared<FPSCounterEvent>();

include/simpleengine/gfx/material.h

@@ -32,7 +32,7 @@ namespace simpleengine::gfx {
          */
         float shine_factor;
 
-        Material(std::unordered_map<aiTextureType, std::vector<std::shared_ptr<Texture>>> textures, float shine = 1.f, float specular_scalar = 1.f, float ambient_scalar = 0.2f, float diffuse_scalar = 1.f) :
+        Material(std::unordered_map<aiTextureType, std::vector<std::shared_ptr<Texture>>> textures, float shine = 1.f, float specular_scalar = 1.f, float ambient_scalar = 1.f, float diffuse_scalar = 1.f) :
                 textures(textures), ambient_strength(ambient_scalar), diffuse_strength(diffuse_scalar), specular_strength(specular_scalar),
                 shine_factor(shine) {
 

include/simpleengine/gfx/mesh.h

@@ -25,22 +25,16 @@ namespace simpleengine::gfx {
         std::vector<GLuint> indicies;
 
         std::vector<simpleengine::Vectorf> tangents;
-        std::vector<simpleengine::Vectorf> bitangents;
+        gfx::VBO tangent_vbo;
 
         bool are_buffers_created = false;
         gfx::VBO ebo;
         gfx::VBO vbo;
         gfx::VAO vao;
 
-        gfx::VBO tangent_vbo;
-        //gfx::VAO tangent_vao;
-
-        gfx::VBO bitangent_vbo;
-        //gfx::VAO bitangent_vao;
-
         Mesh(std::vector<LitVertex> vertices, std::vector<GLuint> indicies, Material material);
         Mesh(std::vector<LitVertex> vertices, std::vector<GLuint> indicies = std::vector<GLuint>(), std::optional<Material> material = std::nullopt);
-        Mesh(std::vector<LitVertex> vertices, std::vector<GLuint> indicies, Material material, gfx::VBO ebo, gfx::VBO vbo, gfx::VAO vao, gfx::VBO tangent_vbo, gfx::VBO bitangent_vbo);
+        Mesh(std::vector<LitVertex> vertices, std::vector<GLuint> indicies, Material material, gfx::VBO ebo, gfx::VBO vbo, gfx::VAO vao, gfx::VBO tangent_vbo);
 
         virtual void destroy() override;
 

resources/shaders/core/3d/fragment_core.glsl

@@ -12,7 +12,11 @@ in vec3 vs_view_pos;
 in vec3 vs_light_pos;
 in vec3 vs_frag_pos;
 
-in mat3 vs_tbn;
+//in mat3 vs_tbn;
+
+in vec3 vs_tangent_light_pos;
+in vec3 vs_tangent_view_pos;
+in vec3 vs_tangent_frag_pos;
 
 const int SAMP_DIFFUSE = 0;
 const int SAMP_SPECULAR = 1;
@@ -50,31 +54,33 @@ void main() {
 }
 
 vec3 calculate_lighting() {
-    // Ambient
+    vec3 normal = vec3(0.f, 0.f, 1.f); // default tangent-space normal
-    //float ambient_strength = 0.1;
-    vec3 ambient = u_material.ambient_strength * u_light_color;
-
-    vec3 normal = vs_world_normal;
     
     // Check if the normal map is set before trying to apply it.
     if (u_material.has_normal_map) {
         normal = texture(u_material.normal_map, vs_texcoord).rgb;
-        normal = normal * 2.0 - 1.0;
+
-        normal = normalize(vs_tbn * normal);
+        // transform normal vector to range [-1,1]
+        normal = normalize(normal * 2.f - 1.f);  // this normal is in tangent space
     }
    
-    // Diffuse
+    // Get diffuse color
-    vec3 norm = normalize(normal);
+    vec3 diffuse_map = texture(u_material.diffuse, vs_texcoord).rgb;
-    vec3 light_dir = normalize(vs_light_pos - vs_frag_pos);
-    float diff = max(dot(norm, light_dir), 0.f);
-    vec3 diffuse = (diff * u_material.diffuse_strength) * u_light_color;
     
-    // Specular
+    // Ambient lighting
-    float specular_strength = 0.5;
+    vec3 ambient = 0.1f * u_material.ambient_strength * diffuse_map;
-    vec3 view_dir = normalize(vs_view_pos - vs_frag_pos);
+    
-    vec3 reflect_dir = reflect(-light_dir, norm);
+    // Diffuse lighting
-    float spec = pow(max(dot(view_dir, reflect_dir), -0.f), 32 * u_material.shine_factor);
+    vec3 light_dir = normalize(vs_tangent_light_pos - vs_tangent_frag_pos);
-    vec3 specular = specular_strength * (spec * u_material.specular_strength) * u_light_color;
+    float diff = max(dot(light_dir, normal), 0.f);
+    vec3 diffuse = diff * u_material.diffuse_strength * diffuse_map;
+    
+    // Specular lighting
+    vec3 view_dir = normalize(vs_tangent_view_pos - vs_tangent_frag_pos);
+    vec3 reflect_dir = reflect(-light_dir, normal);
+    vec3 halfway_dir = normalize(light_dir + view_dir);  
+    float spec = pow(max(dot(normal, halfway_dir), 0.f), 32.f * u_material.shine_factor);
+    vec3 specular = vec3(0.2f * u_material.specular_strength) * spec;
     
     // Check if the specular map is set before trying to apply it.
     if (u_material.has_specular_map) {

resources/shaders/core/3d/vertex_core.glsl

@@ -6,7 +6,6 @@ layout (location = 2) in vec3 vertex_normal;
 layout (location = 3) in vec2 vertex_texcoord;
 // TODO: Make these optional
 layout (location = 4) in vec3 vertex_tangent;
-layout (location = 5) in vec3 vertex_bitangent;
 
 out vec3 vs_position;
 out vec3 vs_color;
@@ -20,7 +19,11 @@ out vec3 vs_view_pos;
 out vec3 vs_light_pos;
 out vec3 vs_frag_pos;
 
-out mat3 vs_tbn;
+//out mat3 vs_tbn;
+
+out vec3 vs_tangent_light_pos;
+out vec3 vs_tangent_view_pos;
+out vec3 vs_tangent_frag_pos;
 
 uniform mat4 u_transform_matrix;
 uniform mat4 u_view_matrix;
@@ -40,6 +43,7 @@ void main() {
 
     gl_Position = u_projection_matrix * u_view_matrix * world_pos;
     
+    // Apply transform matrix to normal.
     vs_normal = (u_transform_matrix * vec4(vertex_normal, 0.f)).xyz;
     
     vs_view_pos = u_view_pos;
@@ -47,9 +51,15 @@ void main() {
     vs_frag_pos = vec3(u_transform_matrix * vec4(vertex_position, 1.f));
     vs_world_normal = mat3(transpose(inverse(u_transform_matrix))) * vertex_normal; // TODO: Do this calculation on the CPU then send to GPU via a uniform
 
-    // Calculate the TBN (Tangent, Bi-tangent, and normal matrix)
+    // Calculate tangent space stuff.
-    vec3 T = normalize(vec3(u_transform_matrix * vec4(vertex_tangent, 1.f)));
+    mat3 normal_matrix = transpose(inverse(mat3(u_transform_matrix)));
-    vec3 B = normalize(vec3(u_transform_matrix * vec4(vertex_bitangent, 1.f)));
+    vec3 T = normalize(normal_matrix * vertex_tangent);
-    vec3 N = normalize(vec3(u_transform_matrix * vec4(vertex_normal, 1.f)));
+    vec3 N = normalize(normal_matrix * vertex_normal);
-    vs_tbn = mat3(T, B, N);
+    T = normalize(T - dot(T, N) * N);
+    vec3 B = cross(N, T);
+    
+    mat3 TBN = transpose(mat3(T, B, N));    
+    vs_tangent_light_pos = TBN * u_light_position;
+    vs_tangent_view_pos  = TBN * u_view_pos;
+    vs_tangent_frag_pos  = TBN * vs_frag_pos;
 }

src/gfx/mesh.cpp

@@ -7,20 +7,20 @@ namespace simpleengine::gfx {
     Mesh::Mesh(std::vector<LitVertex> vertices, std::vector<GLuint> indicies, Material material) :
             material(std::make_optional(material)), vertices(vertices), indicies(indicies),
            vbo(gfx::VBO::init(GL_ARRAY_BUFFER, false)), ebo(gfx::VBO::init(GL_ELEMENT_ARRAY_BUFFER, false)),
-           vao(gfx::VAO::init()), tangent_vbo(gfx::VBO::init(GL_ARRAY_BUFFER, false)), bitangent_vbo(gfx::VBO::init(GL_ARRAY_BUFFER, false)) {
+           vao(gfx::VAO::init()), tangent_vbo(gfx::VBO::init(GL_ARRAY_BUFFER, false)) {
 
     }
 
     Mesh::Mesh(std::vector<LitVertex> vertices, std::vector<GLuint> indicies, std::optional<Material> material) :
             material(material), vertices(vertices), indicies(indicies),
             vbo(gfx::VBO::init(GL_ARRAY_BUFFER, false)), ebo(gfx::VBO::init(GL_ELEMENT_ARRAY_BUFFER, false)),
-            vao(gfx::VAO::init()), tangent_vbo(gfx::VBO::init(GL_ARRAY_BUFFER, false)), bitangent_vbo(gfx::VBO::init(GL_ARRAY_BUFFER, false)) {
+            vao(gfx::VAO::init()), tangent_vbo(gfx::VBO::init(GL_ARRAY_BUFFER, false)) {
 
     }
 
     Mesh::Mesh(std::vector<LitVertex> vertices, std::vector<GLuint> indicies, Material material, gfx::VBO ebo, gfx::VBO vbo, gfx::VAO vao,
-            gfx::VBO tangent_vbo, gfx::VBO bitangent_vbo) :
+            gfx::VBO tangent_vbo) :
-            vertices(vertices), indicies(indicies), material(material), ebo(ebo), vbo(vbo), vao(vao), tangent_vbo(tangent_vbo), bitangent_vbo(bitangent_vbo) {
+            vertices(vertices), indicies(indicies), material(material), ebo(ebo), vbo(vbo), vao(vao), tangent_vbo(tangent_vbo) {
 
     }
 
@@ -81,13 +81,9 @@ namespace simpleengine::gfx {
     }
 
     void Mesh::calculate_tangents() {
-        // Resize the tangent and bitangents
+        // Resize the tangents vector, they will overwritten,
-        //tangents.clear();
+        // so no need to clear the vector.
         tangents.resize(vertices.size());
-        //bitangents.clear();
-        bitangents.resize(vertices.size());
-        /* std::vector<simpleengine::Vectorf> tangents;
-        std::vector<simpleengine::Vectorf> bitangents; */
 
         for (int i = 0; i < indicies.size(); i += 3) {
             int index0 = indicies[i];
@@ -111,20 +107,12 @@ namespace simpleengine::gfx {
             glm::vec2 delta_uv2 = lit_vertex2.tex_coord - lit_vertex0.tex_coord;
 
             float r = 1.0f / (delta_uv1.x * delta_uv2.y - delta_uv1.y * delta_uv2.x);
-            glm::vec3 tangent = (delta_pos1 * delta_uv2.y   - delta_pos2 * delta_uv1.y)*r;
+            glm::vec3 tangent = (delta_pos1 * delta_uv2.y - delta_pos2 * delta_uv1.y)*r;
-            glm::vec3 bitangent = (delta_pos2 * delta_uv1.x   - delta_pos1 * delta_uv2.x)*r;
+            //glm::vec3 bitangent = (delta_pos2 * delta_uv1.x - delta_pos1 * delta_uv2.x)*r;
 
             tangents[index0] = tangent;
             tangents[index1] = tangent;
             tangents[index2] = tangent;
-
-            bitangents[index0] = bitangent;
-            bitangents[index1] = bitangent;
-            bitangents[index2] = bitangent;
         }
-
-        /* this->tangents = std::optional<std::pair<std::vector<simpleengine::Vectorf>, std::vector<simpleengine::Vectorf>>>(
-            {tangents, bitangents}
-        ); */
     }
 }

src/gfx/model.cpp

@@ -28,18 +28,17 @@ namespace simpleengine::gfx {
         if (model_processing_flags & ModelProcessingFlags::MdlProcFlag_FLIP_TEX_COORDS_HORIZONTALLY) {
             horizontally_flip_tex_coords();
         }
-
-        if (model_processing_flags & ModelProcessingFlags::MdlProcFlag_CALCULATE_TANGENT_SPACE) {
-            calculate_tangents();
-        }
     }
 
     void Model::load_model(std::string path) {
         Assimp::Importer importer;
 
+        if (model_processing_flags & ModelProcessingFlags::MdlProcFlag_CALCULATE_TANGENT_SPACE) {
+            additional_assimp_flags |= aiProcess_CalcTangentSpace;
+        }
+
         // assimp post processing options: http://assimp.sourceforge.net/lib_html/postprocess_8h.html
-        const aiScene *scene = importer.ReadFile(path, additional_assimp_flags | aiProcess_Triangulate | aiProcess_FlipUVs
+        const aiScene *scene = importer.ReadFile(path, additional_assimp_flags | aiProcess_Triangulate | aiProcess_FlipUVs);
-            | aiProcess_CalcTangentSpace);
 
         if (!scene || scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE || !scene->mRootNode) {
             std::cout << "ERROR::ASSIMP::" << importer.GetErrorString() << std::endl;
@@ -70,6 +69,7 @@ namespace simpleengine::gfx {
     gfx::Mesh Model::process_mesh(std::unordered_map<aiTextureType, std::vector<std::shared_ptr<Texture>>>& processed_textures, aiMesh* mesh, const aiScene* scene) {
         std::vector<LitVertex> vertices;
         std::vector<unsigned int> indicies;
+        std::vector<Vectorf> tangents;
 
         for (unsigned int i = 0; i < mesh->mNumVertices; i++) {
             LitVertex vertex;
@@ -91,6 +91,10 @@ namespace simpleengine::gfx {
                 vertex.tex_coord = tex_coord;
             }
 
+            if (mesh->HasTangentsAndBitangents()) {
+                tangents.emplace_back(mesh->mTangents[i].x, mesh->mTangents[i].y, mesh->mTangents[i].z);
+            }
+
             vertices.push_back(vertex);
         }
 
@@ -173,6 +177,10 @@ namespace simpleengine::gfx {
             se_mesh.calculate_normals();
         }
 
+        if (mesh->HasTangentsAndBitangents()) {
+            se_mesh.tangents = tangents;
+        }
+
         return se_mesh;
     }
 

src/gfx/renderer.cpp

@@ -64,9 +64,6 @@ namespace simpleengine::gfx {
             rendering_mesh.tangent_vbo.buffer(rendering_mesh.tangents.data(), 0, rendering_mesh.tangents.size() * sizeof(Vectorf));
             vao.enable_attrib(rendering_mesh.tangent_vbo, 4, 3, GL_FLOAT, sizeof(Vectorf), 0, false);
 
-            rendering_mesh.bitangent_vbo.buffer(rendering_mesh.bitangents.data(), 0, rendering_mesh.bitangents.size() * sizeof(Vectorf));
-            vao.enable_attrib(rendering_mesh.bitangent_vbo, 5, 3, GL_FLOAT, sizeof(Vectorf), 0, false);
-
             vbo.unbind();
             vao.unbind();