1 files changed, 14 insertions, 0 deletions
diff --git a/camera.go b/camera.go
index 6cc3391..2992b02 100644
--- a/camera.go
+++ b/camera.go
@@ -1,11 +1,25 @@
 package main
 
+import "math"
+
 // Camera handle view position and screen
 type Camera struct {
 	lowerLeftCorner              Vec3D
 	origin, horizontal, vertical Vec3D
 }
 
+// NewCamera creates a new camera
+func NewCamera(vfov float64, aspect float64) Camera {
+	origin := Vec3D{0.0, 0.0, 0.0}
+	theta := DegreesToRadians(vfov)
+	halfHeight := math.Tan(theta / 2.0)
+	halfWidth := aspect * halfHeight
+	lowerLeftCorner := Vec3D{-halfWidth, -halfHeight, -1.0}
+	horizontal := Vec3D{2.0 * halfWidth, 0.0, 0.0}
+	vertical := Vec3D{0.0, 2.0 * halfHeight, 0.0}
+	return Camera{lowerLeftCorner, origin, horizontal, vertical}
+}
+
 // GetRay computes Ray given screen params
 func (camera Camera) GetRay(u float64, v float64) Ray {
 	return Ray{