camera notify

.gitignore

@@ -7,3 +7,5 @@ build/
 
 
 .vscode
+
+imgui.ini

imgui.ini

@@ -1,16 +0,0 @@
-[Window][Debug##Default]
-Pos=20,60
-Size=400,400
-
-[Window][Dear ImGui Demo]
-Pos=1116,220
-Size=927,695
-
-[Window][Dear ImGui Debug Log]
-Pos=60,60
-Size=670,354
-
-[Window][Example: Console]
-Pos=958,210
-Size=520,600
-

include/td/misc/ObjectNotifier.h

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <algorithm>
+#include <functional>
+#include <vector>
+
+namespace td {
+namespace utils {
+
+template <typename Listener>
+class ObjectNotifier {
+protected:
+	std::vector<Listener*> m_Listeners;
+
+public:
+	void BindListener(Listener* listener) {
+		m_Listeners.push_back(listener);
+	}
+
+	void UnbindListener(Listener* listener) {
+		auto iter = std::find(m_Listeners.begin(), m_Listeners.end(), listener);
+
+		if (iter == m_Listeners.end()) return;
+
+		m_Listeners.erase(iter);
+	}
+
+	template <typename Func, typename... Args>
+	void NotifyListeners(Func function, Args... args) {
+		for (Listener* listener : m_Listeners)
+			std::bind(function, listener, args...)();
+	}
+};
+
+} // namespace utils
+} // namespace td

include/td/render/Camera.h

@@ -1,11 +1,20 @@
 #pragma once
 
 #include <td/Maths.h>
+#include <td/misc/ObjectNotifier.h>
 
 namespace td {
 namespace render {
 
-class Camera {
+class ICameraListener {
+  public:
+	virtual void OnPerspectiveChange() {}
+	virtual void OnViewChange() {}
+};
+
+using CameraNotifier = utils::ObjectNotifier<ICameraListener>;
+
+class Camera : public CameraNotifier {
   private:
 	Mat4f m_ViewMatrix;
 	Mat4f m_ProjectionMatrix;

include/td/render/renderer/WorldRenderer.h

@@ -8,7 +8,7 @@
 namespace td {
 namespace render {
 
-class WorldRenderer : public Renderer {
+class WorldRenderer : public Renderer, public ICameraListener {
   private:
 	const game::World& m_World;
 	shader::WorldShader m_Shader;
@@ -19,6 +19,9 @@ class WorldRenderer : public Renderer {
 	virtual ~WorldRenderer();
 
 	virtual void Render() override;
+
+	virtual void OnPerspectiveChange() override;
+	virtual void OnViewChange() override;
 };
 
 }  // namespace render

src/main.cpp

@@ -194,12 +194,13 @@ int main(int argc, char** argv) {
 	td::Display display(1920, 1080, "Tower-Defense 2");
 
 	td::render::Camera cam;
-	cam.SetCamPos({77, 25, 13});
-	cam.UpdatePerspective(display.GetAspectRatio());
 
 	td::render::RenderPipeline renderer;
 	renderer.AddRenderer(std::make_unique<td::render::WorldRenderer>(cam, w));
 
+	cam.SetCamPos({77, 25, 13});
+	cam.UpdatePerspective(display.GetAspectRatio());
+
 	while (!display.IsCloseRequested()) {
 		display.PollEvents();
 		renderer.Render();

src/td/render/Camera.cpp

@@ -8,6 +8,7 @@ namespace render {
 void Camera::UpdatePerspective(float a_AspectRatio) {
 	m_ProjectionMatrix = maths::Perspective(80.0f / 180.0f * PI, a_AspectRatio, 0.1f, 160.0f);
 	m_InvProjectionMatrix = maths::Inverse(m_ProjectionMatrix);
+	NotifyListeners(&ICameraListener::OnPerspectiveChange);
 }
 
 void Camera::SetCamPos(const Vec3f& a_NewPos) {
@@ -20,6 +21,7 @@ void Camera::SetCamPos(const Vec3f& a_NewPos) {
 	m_CamPos = a_NewPos;
 	m_ViewMatrix = maths::Look(m_CamPos, front, { 0, 1, 0 });
 	m_InvViewMatrix = maths::Transpose(maths::Inverse(m_ViewMatrix));  // why transpose ? I don't know
+	NotifyListeners(&ICameraListener::OnViewChange);
 }
 
 }  // namespace render

src/td/render/renderer/WorldRenderer.cpp

@@ -7,20 +7,28 @@
 namespace td {
 namespace render {
 
-WorldRenderer::WorldRenderer(Camera& a_Camera, const game::World& a_World) : Renderer(a_Camera), m_World(a_World){
+WorldRenderer::WorldRenderer(Camera& a_Camera, const game::World& a_World) : Renderer(a_Camera), m_World(a_World) {
 	m_WorldVao = std::make_unique<GL::VertexArray>(std::move(WorldLoader::LoadWorldModel(&a_World)));
+	a_Camera.BindListener(this);
 }
 
 WorldRenderer::~WorldRenderer() {}
 
 void WorldRenderer::Render() {
 	m_Shader.Start();
-	m_Shader.SetProjectionMatrix(m_Camera.GetProjectionMatrix());
-	m_Shader.SetViewMatrix(m_Camera.GetViewMatrix());
 	Renderer::Render(*m_WorldVao);
 	ImGui::ShowDemoWindow();
 }
 
+void WorldRenderer::OnPerspectiveChange() {
+	m_Shader.Start();
+	m_Shader.SetProjectionMatrix(m_Camera.GetProjectionMatrix());
+}
+
+void WorldRenderer::OnViewChange() {
+	m_Shader.Start();
+	m_Shader.SetViewMatrix(m_Camera.GetViewMatrix());
+}
 
 }  // namespace render
 }  // namespace td