Added a (temp) collision solver for Axis-Aligned rectangles

Engine/utils.cpp

@@ -686,9 +686,87 @@ bool utils::IntersectRectLine(const Rectf& r, const Point2f& p1, const Point2f&
 	intersectMax = tMax;
 	return true;
 }
+bool utils::IsRectInRect(const Rectf& r1, const Rectf& r2) {
+	// the origin of both rectangles is in bottom left
+	return (r1.left < r2.left + r2.width && r1.left + r1.width > r2.left && r1.bottom < r2.bottom + r2.height && r1.bottom + r1.height > r2.bottom);
+}
+bool utils::RayVsRect(const Point2f& rayOrigin, const Point2f& rayDir, const Rectf& target,
+	Point2f& contactPoint, Point2f& contactNormal, float& t_hit_near) {
+	
+	Point2f t_near = Point2f{(target.BottomLeft() - rayOrigin).x / rayDir.x, (target.BottomLeft() - rayOrigin).y / rayDir.y};
+	Point2f t_far = Point2f{(target.BottomLeft() + Point2f{target.width, target.height} - rayOrigin).x / rayDir.x, (target.BottomLeft() + Point2f{target.width, target.height} - rayOrigin).y / rayDir.y};
 
+	if(std::isnan(t_far.y) || std::isnan(t_far.x)) return false;
+	if(std::isnan(t_near.y) || std::isnan(t_near.x)) return false;
+	
+	if (t_near.x > t_far.x) std::swap(t_near.x, t_far.x);
+	if (t_near.y > t_far.y) std::swap(t_near.y, t_far.y);
+
+	if (t_near.x > t_far.y || t_near.y > t_far.x) return false;
+
+	t_hit_near = std::max(t_near.x, t_near.y);
+	float t_hit_far = std::min(t_far.x, t_far.y);
+
+	if (t_hit_far < 0) return false;
+
+	contactPoint = rayOrigin + rayDir * t_hit_near;
+
+	if(t_near.x > t_near.y) {
+		if(rayDir.x < 0) {
+			contactNormal = Point2f{1, 0};
+		}else {
+			contactNormal = Point2f{-1, 0};
+		}
+	} else if(t_near.x < t_near.y) {
+		if(rayDir.y < 0) {
+			contactNormal = Point2f{0, 1};
+		}else {
+			contactNormal = Point2f{0, -1};
+		}
+	}
+
+	return true;
+}
+
+bool utils::DynamicRectVsRect(const MovingRectf& in, const Rectf& target, Point2f& contactPoint, Point2f& contactNormal, float& contactTime, float dt) {
+	if(in.velocity.x == 0 && in.velocity.y == 0) return false;
+
+
+	Rectf expanded_target{};
+	expanded_target.left = target.left - in.width / 2;
+	expanded_target.bottom = target.bottom - in.height / 2;
+	expanded_target.width = target.width + in.width;
+	expanded_target.height = target.height + in.height;
+	
+	if(RayVsRect(Point2f{in.bottomLeft.x + in.width / 2, in.bottomLeft.y + in.height / 2}, in.velocity * dt, expanded_target, contactPoint, contactNormal, contactTime)) {
+		if(contactTime <= 1.0f && contactTime >= 0.0f) {
+			return true;
+		}
+	}
+	return false;
+}
+float utils::DotProduct(const Point2f& a, const Point2f& b) {
+	return a.x * b.x + a.y * b.y;
+}
 #pragma endregion CollisionFunctionality
 
 int utils::randRange(int min, int max) {
 	return min + rand() % (( max + 1 ) - min);
 }
+bool utils::isKeyDown(int keycode) {
+	const Uint8* pStates = SDL_GetKeyboardState(nullptr);
+	if (pStates != nullptr)
+	{
+		if(pStates[keycode]) {
+			return true;
+		}
+	}
+	return false;
+}
+bool utils::isMouseDown(int button) {
+	const Uint32 pStates = SDL_GetMouseState(nullptr, nullptr);
+	if (pStates & SDL_BUTTON(button)) {
+		return true;
+	}
+	return false;
+}