added orbiting camera

src/OrbitingCamera.cpp

@@ -0,0 +1,39 @@
+#include "OrbitingCamera.hpp"
+
+OrbitingCamera::OrbitingCamera(const glm::vec3& target, float distance, const glm::vec2& pitchRange) :
+	target(target), distance(distance), pitchRange(pitchRange)
+{
+	pitch = pitchRange.x + (pitchRange.y - pitchRange.x) / 2;
+	yaw = 0.0f;
+}
+
+void OrbitingCamera::Pan(float amount)
+{
+	yaw += amount;
+	if (yaw < 0.0f || yaw >= 360.0f)
+		yaw = 0.0f;
+
+	CalculateMatrix();
+}
+
+void OrbitingCamera::Tilt(float amount)
+{
+	pitch += amount;
+	if (pitch < pitchRange.x)
+		pitch = pitchRange.x;
+	else if (pitch > pitchRange.y)
+		pitch = pitchRange.y;
+
+	CalculateMatrix();
+}
+
+void OrbitingCamera::CalculateMatrix()
+{
+	glm::vec3 position = distance * glm::vec3(
+		cos(glm::radians(yaw)) * sin(glm::radians(pitch)),
+		cos(glm::radians(pitch)),
+		sin(glm::radians(yaw)) * sin(glm::radians(pitch))
+	);
+
+	transformation = glm::lookAt(position, target, glm::vec3(0.0f, 1.0f, 0.0f));
+}