glTF loader start working

5 files changed, 92 insertions, 21 deletions

diff --git a/src/app.cpp b/src/app.cpp
index 11a219d..2fd7c31 100644
--- a/src/app.cpp
+++ b/src/app.cpp
@@ -1,4 +1,6 @@
 #include "imgui.h"
+#include "render_assets.h"
+#include "gltf_loader.h"
 #include "vulkan_swapchain.h"
 
 #include "imgui_impl_vulkan.h"
@@ -22,10 +24,15 @@ int main(int argc, char** argv) {
     argparse::ArgumentParser program("Iris Renderer");
     program.add_argument("width")
         .help("display width of the window")
+        .default_value(1920)
         .scan<'i', int>();
     program.add_argument("height")
         .help("display height of the window")
+        .default_value(1080)
         .scan<'i', int>();
+    program.add_argument("scene")
+        .help("path to the scene file")
+        .default_value("assets/Box/Box.gltf");
     
     try {
         program.parse_args(argc, argv);
@@ -37,6 +44,7 @@ int main(int argc, char** argv) {
 
     int window_width = program.get<int>("width");
     int window_height = program.get<int>("height");
+    std::string scene_path = program.get<std::string>("scene");
 
     if (!glfwInit()) {
         const char* description = nullptr;
@@ -72,6 +80,11 @@ int main(int argc, char** argv) {
             .flags = VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT,
             .usage = VMA_MEMORY_USAGE_AUTO,
         });
+    iris::Scene scene;
+    if (!load_gltf(scene_path, scene)) {
+        spdlog::critical("Failed to load glTF file");
+        abort();
+    }
     // end load debug image
 
     auto swapchain = iris::Swapchain(window, device, window_width, window_height);
diff --git a/src/gltf_loader.cpp b/src/gltf_loader.cpp
index bf64740..684fa7f 100644
--- a/src/gltf_loader.cpp
+++ b/src/gltf_loader.cpp
@@ -1,4 +1,5 @@
 #include "gltf_loader.h"
+#include "render_assets.h"
 #include "spdlog/spdlog.h"
 #include <cstdint>
 
@@ -75,15 +76,26 @@ bool load_gltf(const std::string_view path, iris::Scene &scene) {
         model.scenes.size(),
         model.lights.size());
 
+    
     for (const auto &mesh : model.meshes) {
-        iris::Mesh iris_mesh {
-            .name = mesh.name,
-            .vertices = {},
-            .normals = {},
-            .texcoords = {},
-            .indices = {},
-        };
+        auto mesh_primitive_counter = 0u;
+        const std::string mesh_name = mesh.name == "" ? "mesh" : mesh.name;
+        
+        // TODO: A Mesh in glTF can have multiple primitives, each with its own set of attributes
+        // But our current abstract doesn't support multiple primitives within a mesh, so we load
+        // each primitive as a separate mesh instead. This is a temporary solution and should be fixed.
         for (const auto &primitive : mesh.primitives) {
+            std::string name = mesh_name + "_" + std::to_string(mesh_primitive_counter++);
+            spdlog::info("loading mesh primitive: {}", name);
+            iris::Mesh iris_mesh {
+                .name = mesh.name,
+                .vertices = {},
+                .normals = {},
+                .texcoords = {},
+                .indices = {},
+                .material_index = primitive.material,
+            };
+
             const auto &index_accessor = model.accessors[primitive.indices];
             const auto &index_buffer_view = model.bufferViews[index_accessor.bufferView];
             const auto &index_buffer = model.buffers[index_buffer_view.buffer];
@@ -144,15 +156,14 @@ bool load_gltf(const std::string_view path, iris::Scene &scene) {
                             return *typed_data;
                         };
 
-                        // TODO: support other types. Currently only float3 is supported
-                        if (accessor.type != TINYGLTF_TYPE_VEC3 || accessor.componentType != TINYGLTF_COMPONENT_TYPE_FLOAT) {
-                            spdlog::error("Unsupported POSITION type: {}, {}", accessor.type, accessor.componentType);
-                            return false;
-                        }
-
                         // spdlog::info("attribute: {}, count: {}", attrib_name, accessor.count);
                         if (attrib_name == "POSITION") {
                             spdlog::info("loading POSITION, count {}", accessor.count);
+                            // TODO: support other types. Currently only float3 is supported
+                            if (accessor.type != TINYGLTF_TYPE_VEC3 || accessor.componentType != TINYGLTF_COMPONENT_TYPE_FLOAT) {
+                                spdlog::error("Field {} type unsupported: {}, {}", attrib_name, accessor.type, accessor.componentType);
+                                continue;
+                            }
                             iris_mesh.p_min = glm::vec3(accessor.minValues[0], accessor.minValues[1], accessor.minValues[2]);
                             iris_mesh.p_max = glm::vec3(accessor.maxValues[0], accessor.maxValues[1], accessor.maxValues[2]);
                             for (size_t i = 0; i < accessor.count; i++) {
@@ -160,26 +171,65 @@ bool load_gltf(const std::string_view path, iris::Scene &scene) {
                             }
                         } else if (attrib_name == "NORMAL") {
                             spdlog::info("loading NORMAL, count {}", accessor.count);
+                            // TODO: support other types. Currently only float3 is supported
+                            if (accessor.type != TINYGLTF_TYPE_VEC3 || accessor.componentType != TINYGLTF_COMPONENT_TYPE_FLOAT) {
+                                spdlog::error("Field {} type unsupported: {}, {}", attrib_name, accessor.type, accessor.componentType);
+                                continue;
+                            }
                             for (size_t i = 0; i < accessor.count; i++) {
                                 iris_mesh.normals.push_back(extract_data.operator()<glm::vec3>());
                             }
                         } else if (attrib_name == "TEXCOORD_0") {
                             spdlog::info("loading TEXCOORD_0, count {}", accessor.count);
+                            // TODO: support other types. Currently only float2 is supported
+                            if (accessor.type != TINYGLTF_TYPE_VEC2 || accessor.componentType != TINYGLTF_COMPONENT_TYPE_FLOAT) {
+                                spdlog::error("Field {} type unsupported: {}, {}", attrib_name, accessor.type, accessor.componentType);
+                                continue;
+                            }
                             for (size_t i = 0; i < accessor.count; i++) {
                                 iris_mesh.texcoords.push_back(extract_data.operator()<glm::vec2>());
                             }
+                        } else if (attrib_name == "TANGENT") {
+                            spdlog::info("loading TANGENT, count {}", accessor.count);
+                            // TODO: support other types. Currently only float4 is supported
+                            if (accessor.type != TINYGLTF_TYPE_VEC4 || accessor.componentType != TINYGLTF_COMPONENT_TYPE_FLOAT) {
+                                spdlog::error("Field {} type unsupported: {}, {}", attrib_name, accessor.type, accessor.componentType);
+                                continue;
+                            }
+                            for (size_t i = 0; i < accessor.count; i++) {
+                                iris_mesh.tangents.push_back(extract_data.operator()<glm::vec4>());
+                            }
                         } else {
                             spdlog::warn("Unsupported attribute: {}", attrib_name);
                         }
                     }
+                    break;
                 }
                 // TODO add support for other modes
                 default:
                     spdlog::error("Unsupported primitive mode: {}", primitive.mode);
                     return false;
             }
+            scene.meshes.push_back(iris_mesh);
         }
-        scene.meshes.push_back(iris_mesh);
+    }
+
+    for (const tinygltf::Material &material : model.materials) {
+        const std::string material_name = material.name == "" ? "material" : material.name;
+        const auto &pbr = material.pbrMetallicRoughness;
+        iris::Material iris_material {
+            .name = material_name,
+            .base_color = glm::vec4(
+                pbr.baseColorFactor[0],
+                pbr.baseColorFactor[1],
+                pbr.baseColorFactor[2],
+                pbr.baseColorFactor[3]),
+            .metallic = float(pbr.metallicFactor),
+            .roughness = float(pbr.roughnessFactor),
+        };
+        
+        // TODO: load texture information, skip for now
+        spdlog::info("Material: {}", material_name);
     }
 
     // TODO load materials and textures
diff --git a/src/gltf_loader.h b/src/gltf_loader.h
index c239bb2..4b3190b 100644
--- a/src/gltf_loader.h
+++ b/src/gltf_loader.h
@@ -1,11 +1,9 @@
-#pragma once
+#ifndef GLTF_LOADER_H
 
+#define GLTF_LOADER_H
 #include <string_view>
 #include "render_assets.h"
-
-#define TINYGLTF_IMPLEMENTATION
-#define STB_IMAGE_IMPLEMENTATION
-#define STB_IMAGE_WRITE_IMPLEMENTATION
 #include "tiny_gltf.h"
 
-bool load_gltf(const std::string_view path, iris::Scene &scene);
\ No newline at end of file
+bool load_gltf(const std::string_view path, iris::Scene &scene);
+#endif
\ No newline at end of file
diff --git a/src/render_assets.h b/src/render_assets.h
index 8c28ead..113084a 100644
--- a/src/render_assets.h
+++ b/src/render_assets.h
@@ -12,7 +12,10 @@ struct Mesh {
     std::vector<glm::vec3> vertices;
     std::vector<glm::vec3> normals;
     std::vector<glm::vec2> texcoords;
+    // Note: w component is a sign, 1.0 or -1.0
+    std::vector<glm::vec4> tangents;
     std::vector<uint32_t> indices;
+    int32_t material_index;
 
     // AABB
     glm::vec3 p_min;
@@ -20,7 +23,10 @@ struct Mesh {
 };
 
 struct Material {
-
+    std::string name;
+    glm::vec4 base_color;
+    float metallic;
+    float roughness;
 };
 
 struct Texture {
diff --git a/src/vulkan_swapchain.cpp b/src/vulkan_swapchain.cpp
index 4e08049..b93b8a9 100644
--- a/src/vulkan_swapchain.cpp
+++ b/src/vulkan_swapchain.cpp
@@ -1,5 +1,9 @@
 #include "vulkan_swapchain.h"
 
+#define TINYGLTF_IMPLEMENTATION
+#define STB_IMAGE_IMPLEMENTATION
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#include "tiny_gltf.h"
 #include "GLFW/glfw3.h"
 #include "imgui.h"
 #include "imgui_impl_glfw.h"