X-Git-Url: https://git.lukelau.me/?p=opengl.git;a=blobdiff_plain;f=model.cpp;h=4192645c9c003d2de7d490897ff0ca02a1897b46;hp=f4fc307ebca7db0515ce0af40bc74d916ccc2021;hb=b472351f3c80cec8c7e9ec30cb4c113c947c0ff7;hpb=ba6e56681d4083a4c4009d5e754828d89d1ba7ec

diff --git a/model.cpp b/model.cpp
index f4fc307..4192645 100644
--- a/model.cpp
+++ b/model.cpp
@@ -2,11 +2,10 @@
 #include <iostream>
 #include <assimp/quaternion.h>
 #include <glm/gtc/type_ptr.hpp>
+#include <glm/gtx/closest_point.hpp>
 #include "util.hpp"
 
-
-Model::Mesh::Mesh(const aiMesh *aiMesh, GLuint progId) {
-
+Model::Mesh::Mesh(const aiMesh *aiMesh, GLuint progId) : ai(*aiMesh) {
 	std::vector<glm::vec3> vertices, normals, tangents, bitangents;
 	std::vector<glm::vec2> texCoords;
 
@@ -404,3 +403,36 @@ Model::Node* Model::Node::findNode(const aiNode &aiNode) {
 bool Model::Node::operator==(const Model::Node &rhs) const {
 	return &ai == &rhs.ai;
 }
+
+// Returns closest vertex in world space and distance
+// a and b define the line in 3d space
+std::pair<glm::vec3, float> Model::closestVertex(Model::Node &n, glm::vec3 a, glm::vec3 b, glm::mat4 parentTrans) const {
+	float shortestDist = FLT_MAX;
+	glm::vec3 closest;
+	for (int i = 0; i < n.ai.mNumMeshes; i++) {
+		int meshIdx = n.ai.mMeshes[i];
+		const aiMesh &mesh = meshes[meshIdx].ai;
+
+		for (int j = 0; j < mesh.mNumVertices; j++) {
+			glm::vec4 vPos = glm::vec4(aiVector3DToMat4(mesh.mVertices[j]), 1);
+			// Move from model space -> world space
+			vPos = parentTrans * aiMatrixToMat4(n.ai.mTransformation) * vPos;
+			float dist = glm::distance(glm::vec3(vPos),
+							glm::closestPointOnLine(glm::vec3(vPos), a, b));
+			if (dist < shortestDist) {
+				closest = glm::vec3(vPos);
+				shortestDist = dist;
+			}
+		}
+	}
+	
+	for (auto child: n.getChildren()) {
+		auto res = closestVertex(*child, a, b, parentTrans * aiMatrixToMat4(n.ai.mTransformation));
+		if (res.second < shortestDist) {
+			closest = res.first;
+			shortestDist = res.second;
+		}
+	}
+
+	return { closest, shortestDist };
+}