/* Quirky Quad Trees Part #1 - Static Quad Tree Implementation "War... huh... What is it good for? Absolutely nothin..." - javidx9 License (OLC-3) ~~~~~~~~~~~~~~~ Copyright 2018 - 2022 OneLoneCoder.com Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions or derivations of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions or derivative works in binary form must reproduce the above copyright notice. This list of conditions and the following disclaimer must be reproduced in the documentation and/or other materials provided with the distribution. 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Video: ~~~~~~ https://youtu.be/ASAowY6yJII Pan & Zoom with middle mouse, TAB to switch between methods Links ~~~~~ YouTube: https://www.youtube.com/javidx9 https://www.youtube.com/javidx9extra Discord: https://discord.gg/WhwHUMV Twitter: https://www.twitter.com/javidx9 Twitch: https://www.twitch.tv/javidx9 GitHub: https://www.github.com/onelonecoder Homepage: https://www.onelonecoder.com Author ~~~~~~ David Barr, aka javidx9, �OneLoneCoder 2019, 2020, 2021, 2022 */ #define OLC_PGE_APPLICATION #include "pixelGameEngine.h" #define OLC_PGEX_TRANSFORMEDVIEW #include "transformedView.h" #include "quadtree.h" // The Example! class Example_StaticQuadTree : public olc::PixelGameEngine { public: Example_StaticQuadTree() { sAppName = "Static QuadTree"; } protected: olc::TransformedView tv; // An example object of something in 2D space struct SomeObjectWithArea { olc::vf2d vPos; olc::vf2d vVel; olc::vf2d vSize; olc::Pixel colour; }; // A regular list of the objects std::list vecObjects; // An equivalent quad tree of the objects olc::utils::QuadTreeContainer treeObjects; // The "length" of one side of the "world" the objects reside in float fArea = 100000.0f; bool bUseQuadTree = true; public: bool OnUserCreate() override { // Transform View - enables Pan & Zoom tv.Initialise({ ScreenWidth(), ScreenHeight() }); // Create the tree, and size it to the world treeObjects.resize(olc::utils::geom2d::rect({ 0.0f, 0.0f }, { fArea, fArea })); // Dirty random float generator auto rand_float = [](const float a, const float b) { return float(rand()) / float(RAND_MAX) * (b - a) + a; }; // Create 1,000,000 objects, push into both containers (so 2,000,000 I suppose :P ) for (int i = 0; i < 1000000; i++) { SomeObjectWithArea ob; ob.vPos = { rand_float(0.0f, fArea), rand_float(0.0f, fArea) }; ob.vSize = { rand_float(0.1f, 100.0f), rand_float(0.1f, 100.0f) }; ob.colour = olc::Pixel(rand() % 256, rand() % 256, rand() % 256); treeObjects.insert(ob, olc::utils::geom2d::rect(ob.vPos, ob.vSize)); vecObjects.push_back(ob); } return true; } bool OnUserUpdate(float fElapsedTime) override { // Tab switches between modes if (GetKey(olc::Key::TAB).bPressed) bUseQuadTree = !bUseQuadTree; tv.HandlePanAndZoom(); // Get rectangle that equates to screen in world space olc::utils::geom2d::rect rScreen = { tv.GetWorldTL(), tv.GetWorldBR() - tv.GetWorldTL() }; size_t nObjectCount = 0; if (bUseQuadTree) { // QUAD TREE MODE auto tpStart = std::chrono::system_clock::now(); // Use search function to return list of pointers to objects in that area for (const auto& object : treeObjects.search(rScreen)) { tv.FillRectDecal(object->item.vPos, object->item.vSize, object->item.colour); nObjectCount++; } std::chrono::duration duration = std::chrono::system_clock::now() - tpStart; std::string sOutput = "Quadtree " + std::to_string(nObjectCount) + "/" + std::to_string(vecObjects.size()) + " in " + std::to_string(duration.count()); DrawStringDecal({ 4, 4 }, sOutput, olc::BLACK, { 4.0f, 8.0f }); DrawStringDecal({ 2, 2 }, sOutput, olc::WHITE, { 4.0f, 8.0f }); } else { // LINEAR SEARCH MODE auto tpStart = std::chrono::system_clock::now(); // Blindly check all objects to see if they overlap with screen for (const auto& object : vecObjects) { if (olc::utils::geom2d::overlaps(rScreen,olc::utils::geom2d::rect{ object.vPos, object.vSize })) { tv.FillRectDecal(object.vPos, object.vSize, object.colour); nObjectCount++; } } std::chrono::duration duration = std::chrono::system_clock::now() - tpStart; std::string sOutput = "Linear " + std::to_string(nObjectCount) + "/" + std::to_string(vecObjects.size()) + " in " + std::to_string(duration.count()); DrawStringDecal({ 4, 4 }, sOutput, olc::BLACK, { 4.0f, 8.0f }); DrawStringDecal({ 2, 2 }, sOutput, olc::WHITE, { 4.0f, 8.0f }); } return true; } }; int main() { Example_StaticQuadTree demo; if (demo.Construct(1280, 960, 1, 1, false, false)) demo.Start(); return 0; }