Basic hit detection

src/dawn/physics/2d/Box.cpp

@@ -12,4 +12,70 @@ bool_t boxIsPointInside(glm::vec2 point, glm::vec2 min, glm::vec2 max) {
     point.x >= min.x && point.x <= max.x &&
     point.y >= min.y && point.y <= max.y
   );
+}
+
+bool_t Dawn::boxCheckCollision(
+  glm::vec2 posA, glm::vec2 minA, glm::vec2 maxA,
+  glm::vec2 posB, glm::vec2 minB, glm::vec2 maxB,
+  glm::vec2 velocity,
+  glm::vec2 &normal,
+  float_t &entryTime,
+  float_t &exitTime,
+  glm::vec2 &entryPoint,
+  glm::vec2 &exitPoint
+) {
+  // Calculate the time intervals of overlap in the x and y axes
+  glm::vec2 invEntry = glm::vec2(0.0f);
+  glm::vec2 invExit = glm::vec2(0.0f);
+
+  if (velocity.x >= 0.0f) {
+    invEntry.x = ((minB.x + posB.x) - (maxA.x + posA.x)) / velocity.x;
+    invExit.x = ((maxB.x + posB.x) - (minA.x + posA.x)) / velocity.x;
+  } else {
+    invEntry.x = ((maxB.x + posB.x) - (minA.x + posA.x)) / velocity.x;
+    invExit.x = ((minB.x + posB.x) - (maxA.x + posA.x)) / velocity.x;
+  }
+
+
+  if (velocity.y >= 0.0f) {
+    invEntry.y = ((minB.y + posB.y) - (maxA.y + posA.y)) / velocity.y;
+    invExit.y = ((maxB.y + posB.y) - (minA.y + posA.y)) / velocity.y;
+  } else {
+    invEntry.y = ((maxB.y + posB.y) - (minA.y + posA.y)) / velocity.y;
+    invExit.y = ((minB.y + posB.y) - (maxA.y + posA.y)) / velocity.y;
+  }
+
+  // Calculate the time of entry and exit for each axis
+  glm::vec2 entry = glm::max(invEntry, glm::vec2(0.0f));
+  glm::vec2 exit = glm::min(invExit, glm::vec2(1.0f));
+
+  // Find the time of entry and exit
+  entryTime = glm::max(entry.x, entry.y);
+  exitTime = glm::min(exit.x, exit.y);
+
+  // If there is no overlap in either axis, there is no collision
+  if (entryTime > exitTime || entry.x < 0.0f && entry.y < 0.0f || entry.x > 1.0f || entry.y > 1.0f) {
+    return false;
+  }
+
+  // Calculate the normal of the collision
+  if (entry.x > entry.y) {
+    if (invEntry.x < 0.0f) {
+      normal = glm::vec2(1.0f, 0.0f);
+    } else {
+      normal = glm::vec2(-1.0f, 0.0f);
+    }
+  } else {
+    if (invEntry.y < 0.0f) {
+      normal = glm::vec2(0.0f, 1.0f);
+    } else {
+      normal = glm::vec2(0.0f, -1.0f);
+    }
+  }
+
+  // Calculate the entry and exit points
+  entryPoint = posA + velocity * entryTime;
+  exitPoint = posA + velocity * exitTime;
+
+  return true;
 }

src/dawn/physics/2d/Box.hpp

@@ -6,8 +6,20 @@
 #pragma once
 #include "dawnlibs.hpp"
 #include "assert/assert.hpp"
+#include "util/mathutils.hpp"
 
 namespace Dawn {
+  bool_t boxCheckCollision(
+    glm::vec2 posA, glm::vec2 minA, glm::vec2 maxA,
+    glm::vec2 posB, glm::vec2 minB, glm::vec2 maxB,
+    glm::vec2 velocity,
+    glm::vec2 &normal,
+    float_t &entryTime,
+    float_t &exitTime,
+    glm::vec2 &entryPoint,
+    glm::vec2 &exitPoint
+  );
+
   /**
    * Checks if a given point is within the 2D Boundaries of an object.
    * 

src/dawn/physics/2d/Ray2D.cpp

@@ -18,7 +18,7 @@ bool_t Ray2D::intersects(struct Ray2D ray, glm::vec2 *out) {
   float_t f = -ray.direction.x * direction.y + direction.x * ray.direction.y;
   float_t s = (-direction.y * j.x + direction.x * j.y) / f;
   float_t t = (ray.direction.x * j.y - ray.direction.y * j.x) / f;
-  if (s >= 0 && s <= 1 && t >= 0 && t <= 1) {
+  if(s >= 0 && s <= 1 && t >= 0 && t <= 1) {
     *out = position + (t * direction);
     return true;
   }

src/dawn/physics/3d/AABB3D.cpp

@@ -47,7 +47,7 @@ bool_t aabb3dSweep(
 
   // If the earliest time of overlap is greater than the length of the timestep, the cubes
   // will not collide during the timestep
-  if (tmin > 1.0f) {
+  if(tmin > 1.0f) {
     fraction = 1.0f;
     return false;
   }

src/dawn/physics/3d/Ray3D.cpp

@@ -187,9 +187,9 @@ bool_t Dawn::raytestQuad(
 
   // perform ray-quad intersection test
   float_t t = -localRayOrigin.z / localRayDirection.z; // intersection distance along ray
-  if (t < 0) return false; // intersection is behind the ray origin
+  if(t < 0) return false; // intersection is behind the ray origin
   glm::vec2 intersectionPoint = glm::vec2(localRayOrigin) + t * glm::vec2(localRayDirection);
-  if (
+  if(
     glm::any(glm::lessThan(intersectionPoint, min)) ||
     glm::any(glm::greaterThan(intersectionPoint, max))
   ) {