From 2a5560279b85cd79c5aa1b4d85588ff326ee5140 Mon Sep 17 00:00:00 2001
From: Razakhel <romain.milbert@gmail.com>
Date: Sun, 24 Dec 2023 11:42:26 +0100
Subject: [PATCH] [Data/GltfLoad] Texcoords are normalized

- They can be outside the [0; 1] range, and are wrapped according to the REPEAT mode
---
 src/RaZ/Data/GltfLoad.cpp         | 21 ++++++++++++++++-----
 tests/src/RaZ/Data/GltfFormat.cpp |  8 ++++----
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/src/RaZ/Data/GltfLoad.cpp b/src/RaZ/Data/GltfLoad.cpp
index 1ada0909..02ff52b2 100644
--- a/src/RaZ/Data/GltfLoad.cpp
+++ b/src/RaZ/Data/GltfLoad.cpp
@@ -60,12 +60,23 @@ void loadVertices(const fastgltf::Primitive& primitive,
     vert.position = Vec3f(data[0], data[1], data[2]);
   });
 
-  // The tangent's input W component (data[3]) is either 1 or -1 and represents the handedness
-  // See: https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#meshes-overview
   constexpr std::array<std::pair<std::string_view, void (*)(Vertex&, const float*)>, 3> attributes = {{
-    { "TEXCOORD_0", [] (Vertex& vert, const float* data) { vert.texcoords = Vec2f(data[0], data[1]); } },
-    { "NORMAL",     [] (Vertex& vert, const float* data) { vert.normal    = Vec3f(data[0], data[1], data[2]); } },
-    { "TANGENT",    [] (Vertex& vert, const float* data) { vert.tangent   = Vec3f(data[0], data[1], data[2]) * data[3]; } }
+    { "TEXCOORD_0", [] (Vertex& vert, const float* data) {
+      // The texcoords can be outside the [0; 1] range; they're normalized according to the REPEAT mode. This may be subject to change
+      //   See: https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#_wrapping
+      vert.texcoords = Vec2f(data[0], data[1]);
+
+      for (float& elt : vert.texcoords.getData()) {
+        if (elt < -1.f || elt > 1.f) elt = std::fmod(elt, 1.f);
+        if (elt < 0.f) elt += 1.f;
+      }
+    }},
+    { "NORMAL",  [] (Vertex& vert, const float* data) { vert.normal = Vec3f(data[0], data[1], data[2]); } },
+    { "TANGENT", [] (Vertex& vert, const float* data) {
+      // The tangent's input W component (data[3]) is either 1 or -1 and represents the handedness
+      //   See: https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#meshes-overview
+      vert.tangent = Vec3f(data[0], data[1], data[2]) * data[3];
+    }}
   }};
 
   for (auto&& [attribName, callback] : attributes) {
diff --git a/tests/src/RaZ/Data/GltfFormat.cpp b/tests/src/RaZ/Data/GltfFormat.cpp
index ee72e12b..8892b630 100644
--- a/tests/src/RaZ/Data/GltfFormat.cpp
+++ b/tests/src/RaZ/Data/GltfFormat.cpp
@@ -17,10 +17,10 @@ TEST_CASE("GltfFormat load glTF") {
   CHECK(mesh.getSubmeshes()[1].getTriangleIndexCount() == 36);
   CHECK(mesh.recoverTriangleCount() == 24); // 72 / 3
 
-  CHECK(mesh.getSubmeshes()[0].getVertices()[0]  == Raz::Vertex{ Raz::Vec3f(1.f, -1.f, 1.f),        Raz::Vec2f(0.f, 0.f),  -Raz::Axis::Y, -Raz::Axis::X });
-  CHECK(mesh.getSubmeshes()[0].getVertices()[1]  == Raz::Vertex{ Raz::Vec3f(-1.f, -1.f, -1.f),      Raz::Vec2f(-1.f, 1.f), -Raz::Axis::Y, -Raz::Axis::X });
-  CHECK(mesh.getSubmeshes()[0].getVertices()[17] == Raz::Vertex{ Raz::Vec3f(1.f, 1.f, -0.9999989f), Raz::Vec2f(0.f, 1.f),  -Raz::Axis::Z, -Raz::Axis::X });
-  CHECK(mesh.getSubmeshes()[0].getVertices()[35] == Raz::Vertex{ Raz::Vec3f(-1.f, 1.f, -1.f),       Raz::Vec2f(-1.f, 1.f), -Raz::Axis::Z, -Raz::Axis::X });
+  CHECK(mesh.getSubmeshes()[0].getVertices()[0]  == Raz::Vertex{ Raz::Vec3f(1.f, -1.f, 1.f),        Raz::Vec2f(0.f, 0.f), -Raz::Axis::Y, -Raz::Axis::X });
+  CHECK(mesh.getSubmeshes()[0].getVertices()[1]  == Raz::Vertex{ Raz::Vec3f(-1.f, -1.f, -1.f),      Raz::Vec2f(0.f, 1.f), -Raz::Axis::Y, -Raz::Axis::X });
+  CHECK(mesh.getSubmeshes()[0].getVertices()[17] == Raz::Vertex{ Raz::Vec3f(1.f, 1.f, -0.9999989f), Raz::Vec2f(0.f, 1.f), -Raz::Axis::Z, -Raz::Axis::X });
+  CHECK(mesh.getSubmeshes()[0].getVertices()[35] == Raz::Vertex{ Raz::Vec3f(-1.f, 1.f, -1.f),       Raz::Vec2f(0.f, 1.f), -Raz::Axis::Z, -Raz::Axis::X });
 
   REQUIRE(meshRenderer.getSubmeshRenderers().size() == 2);
   CHECK(meshRenderer.getSubmeshRenderers()[0].getRenderMode() == Raz::RenderMode::TRIANGLE);