From: Luke Lau <luke_lau@icloud.com>
Date: Mon, 15 Oct 2018 22:21:27 +0000 (+0100)
Subject: Allow upside-down(ish) camera angles
X-Git-Tag: cs7gv3-a3~30
X-Git-Url: https://git.lukelau.me/?p=opengl.git;a=commitdiff_plain;h=da829a43b9ab76ce8830bd83760e59f016787727

Allow upside-down(ish) camera angles
---

diff --git a/main.cpp b/main.cpp
index 0b53eee..4c9171a 100644
--- a/main.cpp
+++ b/main.cpp
@@ -149,6 +149,7 @@ void drawTeapot(TeapotProjection proj, bool rotate, float d, glm::vec3 lightPos,
 }
 
 void display() {
+	glClearColor(0.5, 0.5, 0.5, 1);
 	glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
 	float d = (float)glutGet(GLUT_ELAPSED_TIME) * 0.001f;
 
@@ -531,6 +532,12 @@ void motion(int x, int y) {
 	front.y = sin(pitch);
 	front.z = cos(pitch) * sin(yaw);
 	camFront = glm::normalize(front);
+
+	if (pitch < -1.57079632679 || pitch >= 1.57079632679) {
+		camUp = glm::vec3(0, -1, 0);
+	} else {
+		camUp = glm::vec3(0, 1, 0);
+	}
 }
 
 void mouse(int button, int state, int x, int y) {