Add kdtree -> Lines conversion

The kdtree can now be drawn!

ECS/Components/Lines.h

@@ -0,0 +1,44 @@
+#ifndef ECSGAME_LINES_H
+#define ECSGAME_LINES_H
+
+#include "../../Util/geometry.h"
+#include <GLFW/glfw3.h>
+#include <glad/glad.h>
+#include <glm/fwd.hpp>
+#include <vector>
+
+struct Lines {
+    explicit Lines(std::vector<Vector> lines) : vertex_count(lines.size()) {
+        GLfloat linearray[vertex_count * 3];
+        int pos = 0;
+
+        for (const Vector &vec : lines) {
+            linearray[pos++] = vec[0];
+            linearray[pos++] = vec[1];
+            linearray[pos++] = vec[2];
+        }
+
+        glGenVertexArrays(1, &lineVAO);
+        glGenBuffers(1, &lineVBO);
+        glBindVertexArray(lineVAO);
+        glBindBuffer(GL_ARRAY_BUFFER, lineVBO);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(linearray), &linearray, GL_STATIC_DRAW);
+        glEnableVertexAttribArray(0);
+        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), (void *)0);
+    }
+
+    void render() const {
+        // glEnable(GL_LINE_SMOOTH);
+        // glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);
+        glBindVertexArray(lineVAO);
+        glLineWidth(3.3f);
+        glDrawArrays(GL_LINES, 0, vertex_count);
+        glLineWidth(1.0f);
+    }
+
+  private:
+    GLuint lineVAO, lineVBO;
+    int vertex_count;
+};
+
+#endif // ECSGAME_LINES_H

ECS/Systems/RenderSystem.h

@@ -10,6 +10,7 @@
 #include "../Components/Camera.h"
 #include "../Components/DirectionalLight.h"
 #include "../Components/LODObjMesh.h"
+#include "../Components/Lines.h"
 #include "../Components/Mesh.h"
 #include "../Components/ObjMesh.h"
 #include "../Components/Texture.h"
@@ -226,7 +227,8 @@ class RenderSystem : public EntitySystem, public EventSubscriber<InputEvent> {
         glBindFramebuffer(GL_FRAMEBUFFER, 0);
     }
 
-    void render(World *pWorld, Shader normalShader, Shader shadowShader, Shader debugShader) {
+    void render(World *pWorld, Shader normalShader, Shader shadowShader, Shader debugShader,
+                Shader lineShader) {
         pWorld->each<Camera, Transform>([&](Entity *ent, ComponentHandle<Camera> camera,
                                             ComponentHandle<Transform> cameraTransform) {
             // Get render objects
@@ -306,6 +308,16 @@ class RenderSystem : public EntitySystem, public EventSubscriber<InputEvent> {
             glActiveTexture(GL_TEXTURE0);
             glBindTexture(GL_TEXTURE_2D, depthMap);
             // renderQuad();
+
+            // Draw lines
+            lineShader.use();
+            lineShader.setMat4("projection", camera->projection);
+            lineShader.setMat4("view", glm::inverse(view));
+            lineShader.setMat4("model",
+                               glm::mat4(1.0f)); // TODO: integrate cameraTransform->get_origin()
+
+            pWorld->each<Lines>(
+                [&](Entity *ent, ComponentHandle<Lines> lines) { lines->render(); });
         });
     }
 

Shaders/line-fragment.fs

@@ -0,0 +1,7 @@
+#version 330 core
+out vec4 FragColor;
+
+void main()
+{
+    FragColor = vec4(1.0); // white
+}

Shaders/line-vertex.vs

@@ -0,0 +1,11 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+    gl_Position = projection * view * model * vec4(aPos, 1.0);
+}

Util/geometry.h

@@ -1,3 +1,5 @@
+#pragma once
+
 #include <vector>
 
 // Forward declarations
@@ -24,7 +26,7 @@ struct Vector {
     }
 
     Vector cross(const Vector &other) {
-        return Vector(c[1] * other[2] - c[2] - other[1], c[2] * other[0] - c[0] * other[2],
+        return Vector(c[1] * other[2] - c[2] * other[1], c[2] * other[0] - c[0] * other[2],
                       c[0] * other[1] - c[1] * other[0]);
     }
 

Util/kdtree.h

@@ -11,7 +11,7 @@ class KDTree {
 
     ~KDTree() = default; // TODO: Delete all allocated Nodes
 
-    Triangle *intersect_ray(Ray ray) { return intersect_ray_recurse(ray, root, 1000.0); }
+    Triangle *intersect_ray(Ray ray) { return intersect_ray_recurse(ray, root, 1000.0, 0); }
 
     std::string to_string() {
         std::string str = "";
@@ -19,6 +19,16 @@ class KDTree {
         return str;
     }
 
+    std::vector<Vector> get_lines() {
+        std::vector<Vector> lines;
+        float mins[3] = {-1000, -1000, -1000};
+        float maxs[3] = {1000, 1000, 1000};
+
+        get_lines_recursive(lines, root, mins, maxs);
+
+        return lines;
+    }
+
   private:
     Node *root;
 
@@ -75,7 +85,7 @@ class KDTree {
                         build(right_of_median, depth + 1));
     }
 
-    Triangle *intersect_ray_recurse(Ray ray, Node *node, float max_distance) {
+    Triangle *intersect_ray_recurse(Ray ray, Node *node, float max_distance, int depth) {
         // Exit condition: There was no collision
         if (node == nullptr) { return nullptr; }
 
@@ -84,9 +94,6 @@ class KDTree {
             ray.origin[node->axis] > node->point->pos[node->axis] ? node->right : node->left;
         Node *far = near == node->right ? node->left : node->right;
 
-        std::cout << "Checking " << node->point->pos[0] << ", " << node->point->pos[1] << ", "
-                  << node->point->pos[2] << std::endl;
-
         // Check for collisions in this order (stopping if an intersection is found):
         // 1. In the nearer section
         // 2. With the point in this current node
@@ -98,7 +105,7 @@ class KDTree {
                       ? (node->point->pos[node->axis] - ray.origin[node->axis]) /
                             ray.direction[node->axis]
                       : max_distance;
-        Triangle *near_result = intersect_ray_recurse(ray, near, t);
+        Triangle *near_result = intersect_ray_recurse(ray, near, t, depth + 1);
 
         // If the nearer segment had a collision, we're done! We're only interested in the closest
         // collision.
@@ -117,7 +124,7 @@ class KDTree {
             // For this, calculate a new ray origin and continue towards that direction, but with
             // the new origin (we can leave behind what we already checked)
             return intersect_ray_recurse(Ray(ray.origin + ray.direction * t, ray.direction), far,
-                                         max_distance - t);
+                                         max_distance - t, depth + 1);
         }
 
         // If nothing worked, return a nullptr
@@ -136,4 +143,61 @@ class KDTree {
         to_string_recurse(str, node->left, depth + 1);
         to_string_recurse(str, node->right, depth + 1);
     }
+
+    void get_lines_recursive(std::vector<Vector> &lines, Node *node, float mins[3], float maxs[3]) {
+        if (node == nullptr) return;
+
+        int axis = node->axis;
+
+        // Add lines for this node
+        // We add a whole bounding box, so we need 8 points -> 12 lines
+        lines.emplace_back(Vector(mins[0], mins[1], mins[2]));
+        lines.emplace_back(Vector(maxs[0], mins[1], mins[2]));
+
+        lines.emplace_back(Vector(maxs[0], mins[1], mins[2]));
+        lines.emplace_back(Vector(maxs[0], maxs[1], mins[2]));
+
+        lines.emplace_back(Vector(maxs[0], maxs[1], mins[2]));
+        lines.emplace_back(Vector(mins[0], maxs[1], mins[2]));
+
+        lines.emplace_back(Vector(mins[0], maxs[1], mins[2]));
+        lines.emplace_back(Vector(mins[0], mins[1], mins[2]));
+
+        lines.emplace_back(Vector(mins[0], mins[1], maxs[2]));
+        lines.emplace_back(Vector(maxs[0], mins[1], maxs[2]));
+
+        lines.emplace_back(Vector(maxs[0], mins[1], maxs[2]));
+        lines.emplace_back(Vector(maxs[0], maxs[1], maxs[2]));
+
+        lines.emplace_back(Vector(maxs[0], maxs[1], maxs[2]));
+        lines.emplace_back(Vector(mins[0], maxs[1], maxs[2]));
+
+        lines.emplace_back(Vector(mins[0], maxs[1], maxs[2]));
+        lines.emplace_back(Vector(mins[0], mins[1], maxs[2]));
+
+        lines.emplace_back(Vector(mins[0], mins[1], mins[2]));
+        lines.emplace_back(Vector(mins[0], mins[1], maxs[2]));
+
+        lines.emplace_back(Vector(maxs[0], mins[1], mins[2]));
+        lines.emplace_back(Vector(maxs[0], mins[1], maxs[2]));
+
+        lines.emplace_back(Vector(mins[0], maxs[1], mins[2]));
+        lines.emplace_back(Vector(mins[0], maxs[1], maxs[2]));
+
+        lines.emplace_back(Vector(maxs[0], maxs[1], mins[2]));
+        lines.emplace_back(Vector(maxs[0], maxs[1], maxs[2]));
+
+        // TODO: We don't actually have to add all as some are always going to overlap with the
+        // previous lines...
+
+        // Recurse on the left
+        float new_maxs[3] = {maxs[0], maxs[1], maxs[2]}; // Copy initially
+        new_maxs[axis] = node->point->pos[axis];
+        get_lines_recursive(lines, node->left, mins, new_maxs);
+
+        // Recurse on the right
+        float new_mins[3] = {mins[0], mins[1], mins[2]}; // Copy initially
+        new_mins[axis] = node->point->pos[axis];
+        get_lines_recursive(lines, node->right, new_mins, maxs);
+    }
 };

main.cpp

@@ -3,6 +3,7 @@
 #include <iostream>
 
 #include "ECS/Components/DirectionalLight.h"
+#include "ECS/Components/Lines.h"
 #include "ECS/Components/ObjMesh.h"
 #include "ECS/Components/PathMove.h"
 #include "ECS/Components/SineAnimation.h"
@@ -196,12 +197,17 @@ int main(int argc, char **argv) {
     Entity *sun = world->create();
     sun->assign<DirectionalLight>(glm::normalize(glm::vec3(1.0, 1.0, 1.0)));
 
+    Entity *kdtree_vis = world->create();
+
     // We're done loading geometry -> build the collision structure
     collision_system->build();
 
+    kdtree_vis->assign<Lines>(collision_system->kdtree->get_lines());
+
     Shader defaultShader("Shaders/default-vertex.vs", "Shaders/default-fragment.fs");
     Shader shadowShader("Shaders/shadow-vertex.vs", "Shaders/shadow-fragment.fs");
     Shader debugShader("Shaders/debug-vertex.vs", "Shaders/debug-fragment.fs");
+    Shader lineShader("Shaders/line-vertex.vs", "Shaders/line-fragment.fs");
 
     double timeInLastFrame = glfwGetTime();
     double elapsed_time = 0.0;
@@ -214,7 +220,7 @@ int main(int argc, char **argv) {
         elapsed_time += delta;
 
         world->tick(delta);
-        renderSystem->render(world, defaultShader, shadowShader, debugShader);
+        renderSystem->render(world, defaultShader, shadowShader, debugShader, lineShader);
 
         ring->get<Transform>()->rotate(delta * 100.0, glm::vec3(0.0, 1.0, 0.0));
         sun->get<DirectionalLight>()->direction = glm::normalize(glm::vec3(