Various small things

Author: appgurueu

irr/include/WeightBuffer.h

@@ -20,8 +20,9 @@ struct WeightBuffer
 	// ID-weight pairs for a joint
 	struct VertexWeights {
 		std::array<u16, MAX_WEIGHTS_PER_VERTEX> joint_ids = {};
-		std::array<f32, MAX_WEIGHTS_PER_VERTEX> strengths = {};
+		std::array<f32, MAX_WEIGHTS_PER_VERTEX> weights = {};
 		void addWeight(u16 joint_id, f32 weight);
+		/// Transform given position and normal with these weights
 		void skinVertex(core::vector3df &pos, core::vector3df &normal,
 				const std::vector<core::matrix4> &joint_transforms) const;
 	};
@@ -40,13 +41,14 @@ struct WeightBuffer
 	{ return weights[vertex_id].joint_ids; }
 
 	const std::array<f32, MAX_WEIGHTS_PER_VERTEX> &getWeights(u32 vertex_id) const
-	{ return weights[vertex_id].strengths; }
+	{ return weights[vertex_id].weights; }
 
 	size_t size() const
 	{ return weights.size(); }
 
 	void addWeight(u32 vertex_id, u16 joint_id, f32 weight);
 
+	/// Transform position and normal using the weights of the given vertex
 	void skinVertex(u32 vertex_id, core::vector3df &pos, core::vector3df &normal,
 			const std::vector<core::matrix4> &joint_transforms) const;
 

irr/src/SkinnedMesh.cpp

@@ -276,21 +276,21 @@ void SkinnedMesh::calculateJointBoundingBoxes()
 		if (!weights)
 			continue;
 		for (u32 vert_id : weights->animated_vertices.value()) {
+			const auto pos = buf->getVertex(vert_id)->Pos;
 			for (u16 j = 0; j < WeightBuffer::MAX_WEIGHTS_PER_VERTEX; j++) {
-				const auto joint_id = weights->getJointIds(vert_id)[j];
-				const auto *joint = AllJoints[joint_id];
-				const auto strength = weights->getWeights(vert_id)[j];
-				if (core::equals(strength, 0.0f))
+				const u16 joint_id = weights->getJointIds(vert_id)[j];
+				const SJoint *joint = AllJoints[joint_id];
+				const f32 weight = weights->getWeights(vert_id)[j];
+				if (core::equals(weight, 0.0f))
 					continue;
-				auto pos = buf->getVertex(vert_id)->Pos;
-				joint->GlobalInversedMatrix.value().transformVect(pos);
+				auto trans_pos = pos;
+				joint->GlobalInversedMatrix.value().transformVect(trans_pos);
 				if (joint_boxes[joint_id]) {
-					joint_boxes[joint_id]->addInternalPoint(pos);
+					joint_boxes[joint_id]->addInternalPoint(trans_pos);
 				} else {
-					joint_boxes[joint_id] = core::aabbox3df{pos};
+					joint_boxes[joint_id] = core::aabbox3df{trans_pos};
 				}
 			}
-			weights->getWeights(vert_id);
 		}
 	}
 	for (u16 joint_id = 0; joint_id < AllJoints.size(); joint_id++) {
@@ -317,7 +317,7 @@ void SkinnedMesh::recalculateBaseBoundingBoxes() {
 void SkinnedMeshBuilder::topoSortJoints()
 {
 	auto &joints = getJoints();
-	size_t n = joints.size();
+	const size_t n = joints.size();
 
 	std::vector<u16> new_to_old_id;
 
@@ -365,6 +365,9 @@ SkinnedMesh *SkinnedMeshBuilder::finalize() &&
 {
 	os::Printer::log("Skinned Mesh - finalize", ELL_DEBUG);
 
+	// Topologically sort the joints such that parents come before their children.
+	// From this point on, transformations can be calculated in linear order.
+	// (see e.g. SkinnedMesh::calculateGlobalMatrices)
 	topoSortJoints();
 
 	mesh->prepareForSkinning();

irr/src/WeightBuffer.cpp

@@ -11,12 +11,12 @@ namespace scene {
 void WeightBuffer::VertexWeights::addWeight(u16 joint_id, f32 weight)
 {
 	assert(weight >= 0.0f);
-	auto min_weight = std::min_element(strengths.begin(), strengths.end());
+	auto min_weight = std::min_element(weights.begin(), weights.end());
 	if (*min_weight > weight)
 		return;
 
 	*min_weight = weight;
-	joint_ids[std::distance(strengths.begin(), min_weight)] = joint_id;
+	joint_ids[std::distance(weights.begin(), min_weight)] = joint_id;
 }
 
 void WeightBuffer::addWeight(u32 vertex_id, u16 joint_id, f32 weight)
@@ -31,8 +31,8 @@ void WeightBuffer::VertexWeights::skinVertex(core::vector3df &pos, core::vector3
 	core::vector3df skinned_pos;
 	core::vector3df skinned_normal;
 	for (u16 i = 0; i < MAX_WEIGHTS_PER_VERTEX; ++i) {
-		u16 joint_id = joint_ids[i];
-		f32 weight = strengths[i];
+		const u16 joint_id = joint_ids[i];
+		const f32 weight = weights[i];
 		if (core::equals(weight, 0.0f))
 			continue;
 
@@ -81,16 +81,16 @@ void WeightBuffer::finalize()
 	assert(!animated_vertices.has_value());
 	animated_vertices.emplace();
 	for (u32 i = 0; i < size(); ++i) {
-		auto &strengths = weights[i].strengths;
-		f32 total_weight = std::accumulate(strengths.begin(), strengths.end(), 0.0f);
+		auto &weights_i = weights[i].weights;
+		f32 total_weight = std::accumulate(weights_i.begin(), weights_i.end(), 0.0f);
 		if (core::equals(total_weight, 0.0f)) {
-			std::fill(strengths.begin(), strengths.end(), 0.0f);
+			std::fill(weights_i.begin(), weights_i.end(), 0.0f);
 			continue;
 		}
 		animated_vertices->emplace_back(i);
 		if (core::equals(total_weight, 1.0f))
 			continue;
-		for (auto &strength : strengths)
+		for (auto &strength : weights_i)
 			strength /= total_weight;
 	}
 	animated_vertices->shrink_to_fit();