add basic camera controls

include/td/Maths.h

@@ -183,6 +183,51 @@ T Lerp(T v0, T v1, T t) {
 
 }  // namespace maths
 
+template<typename T>
+Vec2<T> operator+(const Vec2<T>& vect, const Vec2<T>& other) {
+	return {vect.x + other.x, vect.y + other.y};
+}
+
+template<typename T>
+Vec2<T> operator- (const Vec2<T>& vect) {
+	return { -vect.x, -vect.y };
+}
+
+template<typename T>
+Vec2<T> operator- (const Vec2<T>& vect, const Vec2<T>& other) {
+	return vect + (-other);
+}
+
+template<typename T>
+Vec3<T> operator- (const Vec3<T>& vect) {
+	return { -vect.x, -vect.y, -vect.z };
+}
+
+template<typename T>
+Vec3<T> operator+ (const Vec3<T>& vect, const Vec3<T>& other) {
+	return { vect.x + other.x, vect.y + other.y, vect.z + other.z };
+}
+
+template<typename T>
+Vec3<T> operator- (const Vec3<T>& vect, const Vec3<T>& other) {
+	return vect + (-other);
+}
+
+template<typename T>
+Vec4<T> operator- (const Vec4<T>& vect) {
+	return { -vect.x, -vect.y, -vect.z, -vect.w };
+}
+
+template<typename T>
+Vec4<T> operator+ (const Vec4<T>& vect, const Vec4<T>& other) {
+	return { vect.x + other.x, vect.y + other.y, vect.z + other.z, vect.w + other.w };
+}
+
+template<typename T>
+Vec4<T> operator- (const Vec4<T>& vect, const Vec4<T>& other) {
+	return vect + (-other);
+}
+
 template <typename T>
 sp::DataBuffer& operator<<(sp::DataBuffer& a_Buffer, const Vec2<T>& a_Vec) {
 	return a_Buffer << a_Vec.x << a_Vec.y;

include/td/render/Camera.h

@@ -35,6 +35,7 @@ class Camera {
 	void UpdatePerspective(float a_AspectRatio);
 
 	void SetCamPos(const Vec3f& a_NewPos);
+	const Vec3f& GetCamPos() const;
 };
 
 }  // namespace render

include/td/render/renderer/WorldRenderer.h

@@ -17,6 +17,9 @@ class WorldRenderer : public Renderer<shader::WorldShader> {
 	virtual ~WorldRenderer();
 
 	virtual void Render(float a_Lerp) override;
+
+  private:
+	void UpdateControls();
 };
 
 }  // namespace render

src/td/render/Camera.cpp

@@ -1,3 +1,4 @@
+#include "td/Maths.h"
 #include <td/render/Camera.h>
 
 #include <cmath>
@@ -24,5 +25,9 @@ void Camera::SetCamPos(const Vec3f& a_NewPos) {
 	OnViewChange();
 }
 
+const Vec3f& Camera::GetCamPos() const {
+	return m_CamPos;
+}
+
 }  // namespace render
 }  // namespace td

src/td/render/renderer/WorldRenderer.cpp

@@ -1,3 +1,4 @@
+#include <td/Maths.h>
 #include <td/render/renderer/WorldRenderer.h>
 
 #include <td/render/loader/WorldLoader.h>
@@ -13,7 +14,17 @@ WorldRenderer::WorldRenderer(Camera& a_Camera, const game::WorldPtr& a_World) :
 
 WorldRenderer::~WorldRenderer() {}
 
+void WorldRenderer::UpdateControls() {
+	if (ImGui::IsMouseDown(ImGuiMouseButton_Left)) {
+		constexpr float sensitivity = 1.0f;
+		float delta = ImGui::GetIO().DeltaTime;
+		auto mouseDelta = ImGui::GetIO().MouseDelta;
+		m_Camera.SetCamPos(m_Camera.GetCamPos() + Vec3f{-mouseDelta.x * delta * sensitivity, 0, -mouseDelta.y * delta * sensitivity});
+	}
+}
+
 void WorldRenderer::Render(float a_Lerp) {
+	UpdateControls();
 	m_Shader->Start();
 	Renderer::Render(*m_WorldVao);
 }