From 4ff75df1a78de5a33a2e990cde524f4950112194 Mon Sep 17 00:00:00 2001
From: Lightling <contactlightling@gmail.com>
Date: Sun, 13 Feb 2022 13:11:00 -0500
Subject: [PATCH] update buffer structs/shader to use view/projection and add
 camera to scene; fix compile error

---
 BufferStructs.h   | 2 ++
 Camera.cpp        | 5 ++++-
 Game.cpp          | 8 ++++++++
 Game.h            | 5 ++++-
 VertexShader.hlsl | 7 ++++++-
 5 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/BufferStructs.h b/BufferStructs.h
index a8951ce..9812303 100644
--- a/BufferStructs.h
+++ b/BufferStructs.h
@@ -6,4 +6,6 @@ struct VertexShaderExternalData
 {
 	DirectX::XMFLOAT4 colorTint;
 	DirectX::XMFLOAT4X4 world;
+	DirectX::XMFLOAT4X4 view;
+	DirectX::XMFLOAT4X4 projection;
 };
diff --git a/Camera.cpp b/Camera.cpp
index ccc36be..bf49309 100644
--- a/Camera.cpp
+++ b/Camera.cpp
@@ -28,7 +28,10 @@ void Camera::Update(float _dt)
 void Camera::UpdateViewMatrix()
 {
 	XMFLOAT3 worldUp = XMFLOAT3(0, 1, 0);
-	XMMATRIX view = XMMatrixLookToLH(XMLoadFloat3(&transform.GetPosition()), XMLoadFloat3(&transform.GetForward()), XMLoadFloat3(&worldUp));
+	XMFLOAT3 position = transform.GetPosition();
+	XMFLOAT3 forward = transform.GetForward();
+
+	XMMATRIX view = XMMatrixLookToLH(XMLoadFloat3(&position), XMLoadFloat3(&forward), XMLoadFloat3(&worldUp));
 	XMStoreFloat4x4(&viewMatrix, view);
 }
 
diff --git a/Game.cpp b/Game.cpp
index ed088cf..afd3244 100644
--- a/Game.cpp
+++ b/Game.cpp
@@ -32,6 +32,7 @@ Game::Game(HINSTANCE hInstance)
 	CreateConsoleWindow(500, 120, 32, 120);
 	printf("Console window created successfully.  Feel free to printf() here.\n");
 #endif
+	camera = std::make_shared<Camera>(0.0f, 0.0f, -5.0f, (float)width / height, 90, 0.01f, 1000.0f);
 }
 
 // --------------------------------------------------------
@@ -220,6 +221,9 @@ void Game::OnResize()
 {
 	// Handle base-level DX resize stuff
 	DXCore::OnResize();
+
+	// Ensure camera has its projection matrix updated when window size changes
+	camera->SetAspect((float)width / height);
 }
 
 // --------------------------------------------------------
@@ -231,6 +235,8 @@ void Game::Update(float deltaTime, float totalTime)
 	if (Input::GetInstance().KeyDown(VK_ESCAPE))
 		Quit();
 
+	camera->Update(deltaTime);
+
 	for (int i = 0; i < entities.size(); ++i)
 	{
 		entities[i]->GetTransform()->SetScale(0.1f * (i + 1), 0.1f * (i + 1), 0.1f * (i + 1));
@@ -277,6 +283,8 @@ void Game::Draw(float deltaTime, float totalTime)
 		VertexShaderExternalData vsData;
 		vsData.colorTint = XMFLOAT4(1.0f, 0.5f, 0.5f, 1.0f);
 		vsData.world = entity->GetTransform()->GetWorldMatrix();
+		vsData.view = camera->GetViewMatrix();
+		vsData.projection = camera->GetProjectionMatrix();
 
 		// copy constant buffer to resource
 		D3D11_MAPPED_SUBRESOURCE mappedBuffer = {};
diff --git a/Game.h b/Game.h
index 0aa6992..51cfa8d 100644
--- a/Game.h
+++ b/Game.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include "DXCore.h"
+#include "Camera.h"
 #include "Mesh.h"
 #include "Entity.h"
 #include <DirectXMath.h>
@@ -44,8 +45,10 @@ private:
 
 	// Temporary A2 shapes
 	std::vector<std::shared_ptr<Mesh>> shapes;
-	// Temporary A3 entities;
+	// Temporary A4 entities;
 	std::vector<std::shared_ptr<Entity>> entities;
+	// A5 Camera
+	std::shared_ptr<Camera> camera;
 
 	Microsoft::WRL::ComPtr<ID3D11Buffer> constantBufferVS;
 };
diff --git a/VertexShader.hlsl b/VertexShader.hlsl
index 17d8b36..dc17a70 100644
--- a/VertexShader.hlsl
+++ b/VertexShader.hlsl
@@ -2,6 +2,8 @@ cbuffer ExternalData : register(b0)
 {
 	float4 colorTint;
 	matrix world;
+	matrix view;
+	matrix projection;
 }
 
 // Struct representing a single vertex worth of data
@@ -48,6 +50,9 @@ VertexToPixel main( VertexShaderInput input )
 	// Set up output struct
 	VertexToPixel output;
 
+	// Convert vertex to world view projection
+	matrix worldViewProjection = mul(mul(projection, view), world);
+
 	// Here we're essentially passing the input position directly through to the next
 	// stage (rasterizer), though it needs to be a 4-component vector now.  
 	// - To be considered within the bounds of the screen, the X and Y components 
@@ -56,7 +61,7 @@ VertexToPixel main( VertexShaderInput input )
 	// - Each of these components is then automatically divided by the W component, 
 	//   which we're leaving at 1.0 for now (this is more useful when dealing with 
 	//   a perspective projection matrix, which we'll get to in the future).
-	output.screenPosition = mul(world, float4(input.localPosition, 1.0f));
+	output.screenPosition = mul(worldViewProjection, float4(input.localPosition, 1.0f));
 
 	// Pass the color through 
 	// - The values will be interpolated per-pixel by the rasterizer