From a812cc9577fd6bb409bb78c2404edab3d96d5a4d Mon Sep 17 00:00:00 2001
From: n-l-i <57808975+n-l-i@users.noreply.github.com>
Date: Mon, 9 Jan 2023 09:41:18 +0100
Subject: [PATCH 1/4] Make controls more intuitive

This changes the controls to be more similar to what you would see in most video games, i.e. the up-vector always points in the same direction, here in the +Y direction, and arrow keys only move in the xz-plane, not up and down. This also necessitates the introduction of dedicated up and down controls, here using the spacebar and shift keys correspondingly.
---
 common/controls.cpp | 47 +++++++++++++++++++++++++++++++--------------
 1 file changed, 33 insertions(+), 14 deletions(-)

diff --git a/common/controls.cpp b/common/controls.cpp
index fdf91b3d5..3943fd924 100644
--- a/common/controls.cpp
+++ b/common/controls.cpp
@@ -19,11 +19,12 @@ glm::mat4 getProjectionMatrix(){
 	return ProjectionMatrix;
 }
 
+const float PI = glm::pi<float>();
 
 // Initial position : on +Z
 glm::vec3 position = glm::vec3( 0, 0, 5 ); 
 // Initial horizontal angle : toward -Z
-float horizontalAngle = 3.14f;
+float horizontalAngle = PI;
 // Initial vertical angle : none
 float verticalAngle = 0.0f;
 // Initial Field of View
@@ -54,30 +55,39 @@ void computeMatricesFromInputs(){
 	horizontalAngle += mouseSpeed * float(1024/2 - xpos );
 	verticalAngle   += mouseSpeed * float( 768/2 - ypos );
 
+	if (verticalAngle < PI/2+0.01) {
+		verticalAngle = PI/2+0.01;
+	}
+	if (verticalAngle > 3*PI/2-0.01) {
+		verticalAngle = 3*PI/2-0.01;
+	}
+
 	// Direction : Spherical coordinates to Cartesian coordinates conversion
 	glm::vec3 direction(
 		cos(verticalAngle) * sin(horizontalAngle), 
 		sin(verticalAngle),
 		cos(verticalAngle) * cos(horizontalAngle)
 	);
-	
-	// Right vector
-	glm::vec3 right = glm::vec3(
-		sin(horizontalAngle - 3.14f/2.0f), 
-		0,
-		cos(horizontalAngle - 3.14f/2.0f)
-	);
-	
+
+	// Forwards vector
+	glm::vec3 forwards = glm::normalize(glm::vec3(direction.x,0,direction.z));
+	glm::vec3 backwards = (-1.0f)*forwards;
+
 	// Up vector
-	glm::vec3 up = glm::cross( right, direction );
+	glm::vec3 up = glm::vec3( 0, 1, 0 );
+	glm::vec3 down = (-1.0f)*up;
+
+	// Right vector
+	glm::vec3 right = glm::cross(forwards,up);
+	glm::vec3 left = (-1.0f)*right;
 
 	// Move forward
 	if (glfwGetKey( window, GLFW_KEY_UP ) == GLFW_PRESS){
-		position += direction * deltaTime * speed;
+		position += forwards * deltaTime * speed;
 	}
 	// Move backward
 	if (glfwGetKey( window, GLFW_KEY_DOWN ) == GLFW_PRESS){
-		position -= direction * deltaTime * speed;
+		position += backwards * deltaTime * speed;
 	}
 	// Strafe right
 	if (glfwGetKey( window, GLFW_KEY_RIGHT ) == GLFW_PRESS){
@@ -85,7 +95,16 @@ void computeMatricesFromInputs(){
 	}
 	// Strafe left
 	if (glfwGetKey( window, GLFW_KEY_LEFT ) == GLFW_PRESS){
-		position -= right * deltaTime * speed;
+		position += left * deltaTime * speed;
+	}
+	// Move up
+	if (glfwGetKey( window, GLFW_KEY_SPACE ) == GLFW_PRESS){
+		position += up * deltaTime * speed;
+	}
+	// Move down
+	if (glfwGetKey( window, GLFW_KEY_LEFT_SHIFT ) == GLFW_PRESS
+		|| glfwGetKey( window, GLFW_KEY_RIGHT_SHIFT) == GLFW_PRESS){
+		position += down * deltaTime * speed;
 	}
 
 	float FoV = initialFoV;// - 5 * glfwGetMouseWheel(); // Now GLFW 3 requires setting up a callback for this. It's a bit too complicated for this beginner's tutorial, so it's disabled instead.
@@ -101,4 +120,4 @@ void computeMatricesFromInputs(){
 
 	// For the next frame, the "last time" will be "now"
 	lastTime = currentTime;
-}
\ No newline at end of file
+}

From 026265eb33a37ad9dd35e41c45050621e3874cf7 Mon Sep 17 00:00:00 2001
From: n-l-i <57808975+n-l-i@users.noreply.github.com>
Date: Mon, 9 Jan 2023 09:41:25 +0100
Subject: [PATCH 2/4] Add WASD-controls as an alternative to arrow keys

---
 common/controls.cpp | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/common/controls.cpp b/common/controls.cpp
index 3943fd924..f7f7d5bd5 100644
--- a/common/controls.cpp
+++ b/common/controls.cpp
@@ -82,19 +82,23 @@ void computeMatricesFromInputs(){
 	glm::vec3 left = (-1.0f)*right;
 
 	// Move forward
-	if (glfwGetKey( window, GLFW_KEY_UP ) == GLFW_PRESS){
+	if (glfwGetKey( window, GLFW_KEY_UP ) == GLFW_PRESS
+		|| glfwGetKey( window, GLFW_KEY_W ) == GLFW_PRESS){
 		position += forwards * deltaTime * speed;
 	}
 	// Move backward
-	if (glfwGetKey( window, GLFW_KEY_DOWN ) == GLFW_PRESS){
+	if (glfwGetKey( window, GLFW_KEY_DOWN ) == GLFW_PRESS
+		|| glfwGetKey( window, GLFW_KEY_S ) == GLFW_PRESS){
 		position += backwards * deltaTime * speed;
 	}
 	// Strafe right
-	if (glfwGetKey( window, GLFW_KEY_RIGHT ) == GLFW_PRESS){
+	if (glfwGetKey( window, GLFW_KEY_RIGHT ) == GLFW_PRESS
+		|| glfwGetKey( window, GLFW_KEY_D ) == GLFW_PRESS){
 		position += right * deltaTime * speed;
 	}
 	// Strafe left
-	if (glfwGetKey( window, GLFW_KEY_LEFT ) == GLFW_PRESS){
+	if (glfwGetKey( window, GLFW_KEY_LEFT ) == GLFW_PRESS
+		|| glfwGetKey( window, GLFW_KEY_A ) == GLFW_PRESS){
 		position += left * deltaTime * speed;
 	}
 	// Move up

From f68cf8ec28640ff4492f4e806d94f7dcbcd0aa4f Mon Sep 17 00:00:00 2001
From: n-l-i <57808975+n-l-i@users.noreply.github.com>
Date: Mon, 9 Jan 2023 09:41:27 +0100
Subject: [PATCH 3/4] Invert vertical mouse movement

---
 common/controls.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/common/controls.cpp b/common/controls.cpp
index f7f7d5bd5..032499941 100644
--- a/common/controls.cpp
+++ b/common/controls.cpp
@@ -53,7 +53,7 @@ void computeMatricesFromInputs(){
 
 	// Compute new orientation
 	horizontalAngle += mouseSpeed * float(1024/2 - xpos );
-	verticalAngle   += mouseSpeed * float( 768/2 - ypos );
+	verticalAngle   -= mouseSpeed * float( 768/2 - ypos );
 
 	if (verticalAngle < PI/2+0.01) {
 		verticalAngle = PI/2+0.01;

From 58af56f53d008cc13ba33ec089d255ac8ed0b0c5 Mon Sep 17 00:00:00 2001
From: n-l-i <57808975+n-l-i@users.noreply.github.com>
Date: Mon, 9 Jan 2023 09:41:29 +0100
Subject: [PATCH 4/4] Fix camera direction bug

---
 common/controls.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/common/controls.cpp b/common/controls.cpp
index 032499941..c049977ab 100644
--- a/common/controls.cpp
+++ b/common/controls.cpp
@@ -33,8 +33,6 @@ float initialFoV = 45.0f;
 float speed = 3.0f; // 3 units / second
 float mouseSpeed = 0.005f;
 
-
-
 void computeMatricesFromInputs(){
 
 	// glfwGetTime is called only once, the first time this function is called
@@ -44,6 +42,14 @@ void computeMatricesFromInputs(){
 	double currentTime = glfwGetTime();
 	float deltaTime = float(currentTime - lastTime);
 
+	// First time this function is called, the cursor position is reset since
+	// an unintended movement will otherwise register on the first frame
+	static bool first_frame = true;
+    if (first_frame){
+        glfwSetCursorPos(window, 1024/2, 768/2);
+        first_frame  = false;
+    }
+
 	// Get mouse position
 	double xpos, ypos;
 	glfwGetCursorPos(window, &xpos, &ypos);