| /* |
| * Copyright (C) 2016 Google, Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <cassert> |
| #include <cmath> |
| #include <array> |
| #include <glm/gtc/matrix_transform.hpp> |
| #include "Simulation.h" |
| |
| namespace { |
| |
| class MeshPicker { |
| public: |
| MeshPicker() |
| : pattern_({{ |
| Meshes::MESH_PYRAMID, Meshes::MESH_ICOSPHERE, Meshes::MESH_TEAPOT, Meshes::MESH_PYRAMID, Meshes::MESH_ICOSPHERE, |
| Meshes::MESH_PYRAMID, Meshes::MESH_PYRAMID, Meshes::MESH_PYRAMID, Meshes::MESH_PYRAMID, Meshes::MESH_PYRAMID, |
| }}), |
| cur_(-1) {} |
| |
| Meshes::Type pick() { |
| cur_ = (cur_ + 1) % pattern_.size(); |
| return pattern_[cur_]; |
| } |
| |
| float scale(Meshes::Type type) const { |
| float base = 0.005f; |
| |
| switch (type) { |
| case Meshes::MESH_PYRAMID: |
| default: |
| return base * 1.0f; |
| case Meshes::MESH_ICOSPHERE: |
| return base * 3.0f; |
| case Meshes::MESH_TEAPOT: |
| return base * 10.0f; |
| } |
| } |
| |
| private: |
| const std::array<Meshes::Type, 10> pattern_; |
| int cur_; |
| }; |
| |
| class ColorPicker { |
| public: |
| ColorPicker(unsigned int rng_seed) : rng_(rng_seed), red_(0.0f, 1.0f), green_(0.0f, 1.0f), blue_(0.0f, 1.0f) {} |
| |
| glm::vec3 pick() { return glm::vec3{red_(rng_), green_(rng_), blue_(rng_)}; } |
| |
| private: |
| std::mt19937 rng_; |
| std::uniform_real_distribution<float> red_; |
| std::uniform_real_distribution<float> green_; |
| std::uniform_real_distribution<float> blue_; |
| }; |
| |
| } // namespace |
| |
| Animation::Animation(unsigned int rng_seed, float scale) : rng_(rng_seed), dir_(-1.0f, 1.0f), speed_(0.1f, 1.0f) { |
| float x = dir_(rng_); |
| float y = dir_(rng_); |
| float z = dir_(rng_); |
| if (std::abs(x) + std::abs(y) + std::abs(z) == 0.0f) x = 1.0f; |
| |
| current_.axis = glm::normalize(glm::vec3(x, y, z)); |
| |
| current_.speed = speed_(rng_); |
| current_.scale = scale; |
| |
| current_.matrix = glm::scale(glm::mat4(1.0f), glm::vec3(current_.scale)); |
| } |
| |
| glm::mat4 Animation::transformation(float t) { |
| current_.matrix = glm::rotate(current_.matrix, current_.speed * t, current_.axis); |
| |
| return current_.matrix; |
| } |
| |
| class Curve { |
| public: |
| virtual ~Curve() {} |
| virtual glm::vec3 evaluate(float t) = 0; |
| }; |
| |
| namespace { |
| |
| enum CurveType { |
| CURVE_RANDOM, |
| CURVE_CIRCLE, |
| CURVE_COUNT, |
| }; |
| |
| class RandomCurve : public Curve { |
| public: |
| RandomCurve(unsigned int rng_seed) |
| : rng_(rng_seed), |
| direction_(-0.3f, 0.3f), |
| duration_(1.0f, 5.0f), |
| segment_start_(0.0f), |
| segment_direction_(0.0f), |
| time_start_(0.0f), |
| time_duration_(0.0f) {} |
| |
| glm::vec3 evaluate(float t) { |
| if (t >= time_start_ + time_duration_) new_segment(t); |
| |
| pos_ += unit_dir_ * (t - last_); |
| last_ = t; |
| |
| return pos_; |
| } |
| |
| private: |
| void new_segment(float time_start) { |
| segment_start_ += segment_direction_; |
| segment_direction_ = glm::vec3(direction_(rng_), direction_(rng_), direction_(rng_)); |
| |
| time_start_ = time_start; |
| time_duration_ = duration_(rng_); |
| |
| unit_dir_ = segment_direction_ / time_duration_; |
| pos_ = segment_start_; |
| last_ = time_start_; |
| } |
| |
| std::mt19937 rng_; |
| std::uniform_real_distribution<float> direction_; |
| std::uniform_real_distribution<float> duration_; |
| |
| glm::vec3 segment_start_; |
| glm::vec3 segment_direction_; |
| float time_start_; |
| float time_duration_; |
| |
| glm::vec3 unit_dir_; |
| glm::vec3 pos_; |
| float last_; |
| }; |
| |
| class CircleCurve : public Curve { |
| public: |
| CircleCurve(float radius, glm::vec3 axis) : r_(radius) { |
| glm::vec3 a; |
| |
| if (axis.x != 0.0f) { |
| a.x = -axis.z / axis.x; |
| a.y = 0.0f; |
| a.z = 1.0f; |
| } else if (axis.y != 0.0f) { |
| a.x = 1.0f; |
| a.y = -axis.x / axis.y; |
| a.z = 0.0f; |
| } else { |
| a.x = 1.0f; |
| a.y = 0.0f; |
| a.z = -axis.x / axis.z; |
| } |
| |
| a_ = glm::normalize(a); |
| b_ = glm::normalize(glm::cross(a_, axis)); |
| } |
| |
| glm::vec3 evaluate(float t) { |
| return (a_ * (glm::vec3(std::cos(t)) - glm::vec3(1.0f)) + b_ * glm::vec3(std::sin(t))) * glm::vec3(r_); |
| } |
| |
| private: |
| float r_; |
| glm::vec3 a_; |
| glm::vec3 b_; |
| }; |
| |
| } // namespace |
| |
| Path::Path(unsigned int rng_seed) : rng_(rng_seed), type_(0, CURVE_COUNT - 1), duration_(5.0f, 20.0f) { |
| // trigger a subpath generation |
| current_.end = -1.0f; |
| current_.now = 0.0f; |
| } |
| |
| glm::vec3 Path::position(float t) { |
| current_.now += t; |
| |
| while (current_.now >= current_.end) generate_subpath(); |
| |
| return current_.origin + current_.curve->evaluate(current_.now - current_.start); |
| } |
| |
| void Path::generate_subpath() { |
| float duration = duration_(rng_); |
| CurveType type = static_cast<CurveType>(type_(rng_)); |
| |
| if (current_.curve) { |
| current_.origin += current_.curve->evaluate(current_.end - current_.start); |
| current_.start = current_.end; |
| } else { |
| std::uniform_real_distribution<float> origin(0.0f, 2.0f); |
| current_.origin = glm::vec3(origin(rng_), origin(rng_), origin(rng_)); |
| current_.start = current_.now; |
| } |
| |
| current_.end = current_.start + duration; |
| |
| Curve *curve; |
| |
| switch (type) { |
| case CURVE_RANDOM: |
| curve = new RandomCurve(rng_()); |
| break; |
| case CURVE_CIRCLE: { |
| std::uniform_real_distribution<float> dir(-1.0f, 1.0f); |
| glm::vec3 axis(dir(rng_), dir(rng_), dir(rng_)); |
| if (axis.x == 0.0f && axis.y == 0.0f && axis.z == 0.0f) axis.x = 1.0f; |
| |
| std::uniform_real_distribution<float> radius_(0.02f, 0.2f); |
| curve = new CircleCurve(radius_(rng_), axis); |
| } break; |
| default: |
| assert(!"unreachable"); |
| curve = nullptr; |
| break; |
| } |
| |
| current_.curve.reset(curve); |
| } |
| |
| Simulation::Simulation(int object_count) : random_dev_() { |
| MeshPicker mesh; |
| ColorPicker color(random_dev_()); |
| |
| objects_.reserve(object_count); |
| for (int i = 0; i < object_count; i++) { |
| Meshes::Type type = mesh.pick(); |
| float scale = mesh.scale(type); |
| |
| objects_.emplace_back(Object{ |
| type, glm::vec3(0.5f + 0.5f * (float)i / object_count), color.pick(), Animation(random_dev_(), scale), |
| Path(random_dev_()), |
| }); |
| } |
| } |
| |
| void Simulation::set_frame_data_size(uint32_t size) { |
| uint32_t offset = 0; |
| for (auto &obj : objects_) { |
| obj.frame_data_offset = offset; |
| offset += size; |
| } |
| } |
| |
| void Simulation::update(float time, int begin, int end) { |
| for (int i = begin; i < end; i++) { |
| auto &obj = objects_[i]; |
| |
| glm::vec3 pos = obj.path.position(time); |
| glm::mat4 trans = obj.animation.transformation(time); |
| obj.model = glm::translate(glm::mat4(1.0f), pos) * trans; |
| } |
| } |