+glm::mat4 lerpPosition(const aiNodeAnim *anim, const float tick) {
+ if (anim->mNumPositionKeys == 0) return glm::mat4(1.f);
+
+ int yIndex = -1;
+ for (int i = 0; i < anim->mNumPositionKeys; i++) {
+ aiVectorKey vk = anim->mPositionKeys[i];
+ if (vk.mTime > tick) {
+ yIndex = i;
+ break;
+ }
+ }
+ aiVector3D lerpPos;
+ if (yIndex == 0) {
+ lerpPos = anim->mPositionKeys[0].mValue;
+ } else if (yIndex == -1) {
+ lerpPos = anim->mPositionKeys[anim->mNumPositionKeys - 1].mValue;
+ } else {
+ auto X = anim->mPositionKeys[yIndex - 1];
+ auto Y = anim->mPositionKeys[yIndex];
+
+ lerpPos = (X.mValue * (float)(Y.mTime - tick) + Y.mValue * (float)(tick - X.mTime)) / (float)(Y.mTime - X.mTime);
+ }
+ aiMatrix4x4 result;
+ aiMatrix4x4::Translation(lerpPos, result);
+ return aiMatrixToMat4(result);
+}
+
+glm::mat4 lerpRotation(const aiNodeAnim *anim, const float tick) {
+ int yIndex = -1;
+ for (int i = 0; i < anim->mNumRotationKeys; i++) {
+ aiQuatKey vk = anim->mRotationKeys[i];
+ if (vk.mTime > tick) {
+ yIndex = i;
+ break;
+ }
+ }
+
+ aiQuaternion result;
+ if (yIndex < 1) {
+ result = anim->mRotationKeys[0].mValue;
+ } else if (yIndex == -1) {
+ result = anim->mRotationKeys[anim->mNumRotationKeys - 1].mValue;
+ } else {
+
+ auto X = anim->mRotationKeys[yIndex - 1];
+ auto Y = anim->mRotationKeys[yIndex];
+
+ float mix = (tick - X.mTime) / (Y.mTime - X.mTime);
+
+ aiQuaternion::Interpolate(result, X.mValue, Y.mValue, mix);
+
+ }
+ return aiMatrixToMat4(aiMatrix4x4(result.GetMatrix()));
+}
+
+glm::mat4 lerpScaling(const aiNodeAnim *anim, const float tick) {
+ int yIndex = -1;
+ for (int i = 0; i < anim->mNumScalingKeys; i++) {
+ aiVectorKey vk = anim->mScalingKeys[i];
+ if (vk.mTime > tick) {
+ yIndex = i;
+ break;
+ }
+ }
+
+ aiVector3D lerpPos;
+ if (yIndex < 1) {
+ lerpPos = anim->mScalingKeys[0].mValue;
+ } else {
+ auto X = anim->mScalingKeys[yIndex - 1];
+ auto Y = anim->mScalingKeys[yIndex];
+
+ lerpPos = (X.mValue * (float)(Y.mTime - tick) + Y.mValue * (float)(tick - X.mTime)) / (float)(Y.mTime - X.mTime);
+ }
+ aiMatrix4x4 result;
+ aiMatrix4x4::Scaling(lerpPos, result);
+ return aiMatrixToMat4(result);
+}
+
+void Model::Node::draw( const std::vector<Mesh> &meshes,
+ const std::vector<Material> &materials,
+ const Skybox skybox,
+ const float tick,
+ glm::mat4 parentTrans = glm::mat4(1),
+ BoneTransforms boneTransforms = BoneTransforms()) const {
+
+ GLuint modelLoc = glGetUniformLocation(progId, "model");
+
+ glm::mat4 animTrans(1.f);
+ if (animMap->count(std::string(ai.mName.C_Str()))) {
+ for (const Animation anim: animMap->at(std::string(ai.mName.C_Str()))) {
+ float t = fmod(tick, anim.duration);
+ for (const aiNodeAnim *nodeAnim: anim.nodeAnims) {
+ animTrans *= lerpPosition(nodeAnim, t);
+ animTrans *= lerpRotation(nodeAnim, t);
+ animTrans *= lerpScaling(nodeAnim, t);
+ }
+ }
+ }
+
+
+ glm::mat4 m = parentTrans * animTrans * aiMatrixToMat4(ai.mTransformation);
+
+ /* for (auto child: children) { */
+ /* boneTransforms[std::string(ai.mName.C_Str())] = m; */
+ /* } */
+
+ for (unsigned int i: meshIndices) {
+ const Mesh &mesh = meshes[i];
+ glBindVertexArray(mesh.vao);
+
+ // bones
+ std::vector<glm::mat4> idBones(17, glm::mat4(1.f));
+ glUniformMatrix4fv(glGetUniformLocation(progId, "bones"), 17, GL_FALSE, glm::value_ptr(idBones[0]));
+
+ for (std::pair<std::string, std::pair<unsigned int, glm::mat4>> pair: mesh.boneMap) {
+
+ std::string nodeName = pair.first;
+ unsigned int boneId = pair.second.first;
+ // This is actually an inverse-bind matrix
+ // i.e. position of the mesh in bone space
+ // so no need to inverse again!
+ // https://github.com/assimp/assimp/pull/1803/files
+ glm::mat4 boneOffset = pair.second.second;
+
+ glm::mat4 boneTrans(1.f);
+ /* if (boneTransforms.count(nodeName)) { */
+ /* std::cerr << "got bone transform from map" << std::endl; */
+ /* boneTrans = boneTransforms[nodeName]; */
+ /* } */
+ for (const Animation anim: animMap->at(nodeName)) {
+ float t = fmod(tick, anim.duration);
+ for (const aiNodeAnim *nodeAnim: anim.nodeAnims) {
+ boneTrans = boneTrans * lerpPosition(nodeAnim, t);
+ boneTrans = boneTrans * lerpRotation(nodeAnim, t);
+ boneTrans = boneTrans * lerpScaling(nodeAnim, t);
+ }
+ }
+
+ boneTrans = boneTrans * boneOffset;
+
+
+ std::string boneLocStr = "bones[" + std::to_string(boneId) + "]";
+ GLuint boneLoc = glGetUniformLocation(progId, boneLocStr.c_str());
+ glUniformMatrix4fv(boneLoc, 1, GL_FALSE, glm::value_ptr(boneTrans));
+ }
+
+ Material material = materials[mesh.materialIndex];
+ material.bind();
+
+ glUniform1i(glGetUniformLocation(progId, "irradianceMap"), 4);
+ glActiveTexture(GL_TEXTURE4);
+ glBindTexture(GL_TEXTURE_CUBE_MAP, skybox.getIrradianceMap());
+
+ glUniform1i(glGetUniformLocation(progId, "prefilterMap"), 5);
+ glActiveTexture(GL_TEXTURE5);
+ glBindTexture(GL_TEXTURE_CUBE_MAP, skybox.getPrefilterMap());
+
+ glUniform1i(glGetUniformLocation(progId, "brdfMap"), 6);
+ glActiveTexture(GL_TEXTURE6);
+ glBindTexture(GL_TEXTURE_2D, skybox.getBRDFMap());
+
+ glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(m));
+
+ glDrawElements(GL_TRIANGLES, mesh.numIndices, GL_UNSIGNED_INT, 0);
+ }
+ for (Node *child: children) child->draw(meshes, materials, skybox, tick, m, boneTransforms);
+}
+
+Model::Model(const aiScene *scene, Program p): program(p) {
+ glUseProgram(p.progId);
+