refac: clean working raycasting

src/Lighting.cpp

@@ -0,0 +1,81 @@
+#include "Lighting.hpp"
+#include <algorithm>
+#include <cmath>
+
+Lighting::Lighting() : rayVertices(sf::PrimitiveType::TriangleFan) {
+  lightColor = sf::Color(255, 255, 150, 50);
+};
+
+float Lighting::intersects(Ray ray, Wall wall) {
+  auto wallVector = wall.end - wall.start;
+  auto determinator =
+      (ray.direction.x * wallVector.y) - (ray.direction.y * wallVector.x);
+
+  if (determinator == 0)
+    return INFINITY;
+
+  auto rayDist = ((wall.start.x - ray.origin.x) * wallVector.y -
+                  (wall.start.y - ray.origin.y) * wallVector.x);
+  rayDist /= determinator;
+
+  auto wallDist = (wall.start.x - ray.origin.x) * ray.direction.y -
+                  (wall.start.y - ray.origin.y) * ray.direction.x;
+  wallDist /= determinator;
+
+  if (rayDist > 0 && wallDist >= 0 && wallDist <= 1) {
+    return rayDist;
+  }
+
+  return INFINITY;
+};
+
+sf::Vector2f Lighting::updateRay(Walls &walls, sf::Vector2f &origin,
+                                 sf::Vector2f &targetPoint, float offset) {
+  auto closestDist = 1.0f;
+  auto maxDist = 3000.0f;
+
+  float angle =
+      std::atan2(targetPoint.y - origin.y, targetPoint.x - origin.x) + offset;
+
+  sf::Vector2f direction = {std::cos(angle) * maxDist,
+                            std::sin(angle) * maxDist};
+  Ray ray = {origin, direction};
+
+  for (Wall wall : walls.get()) {
+    auto rayDist = intersects(ray, wall);
+    if (rayDist < closestDist) {
+      closestDist = rayDist;
+    };
+  }
+
+  return ray.origin + (ray.direction * closestDist);
+}
+
+void Lighting::update(double dt, sf::Vector2f &playerPosition, Walls &walls) {
+  rayVertices.clear();
+  hitPoints.clear();
+
+  for (sf::Vector2 targetPoint : walls.getPoints()) {
+    hitPoints.emplace_back(updateRay(walls, playerPosition, targetPoint, 0.f));
+    hitPoints.emplace_back(
+        updateRay(walls, playerPosition, targetPoint, 0.001f));
+    hitPoints.emplace_back(
+        updateRay(walls, playerPosition, targetPoint, -0.001f));
+  }
+  std::sort(hitPoints.begin(), hitPoints.end(),
+            [playerPosition](sf::Vector2f a, sf::Vector2f b) -> bool {
+              auto angleA =
+                  atan2(playerPosition.y - a.y, playerPosition.x - a.x);
+              auto angleB =
+                  atan2(playerPosition.y - b.y, playerPosition.x - b.x);
+              return angleA < angleB;
+            });
+
+  rayVertices.append({playerPosition, lightColor});
+  for (auto hitPoint : hitPoints) {
+    rayVertices.append({hitPoint, lightColor});
+  }
+  rayVertices.append({hitPoints[0], lightColor});
+}
+
+void Lighting::render(sf::RenderWindow &window) { window.draw(rayVertices); };