Camera package+ rename asserts->assert

camera/camera.go

@@ -0,0 +1,96 @@
+package camera
+
+import (
+	"github.com/bloeys/gglm/gglm"
+)
+
+type Type int32
+
+const (
+	Type_Unknown Type = iota
+	Type_Perspective
+	Type_Orthographic
+)
+
+type Camera struct {
+	Type Type
+
+	Pos    gglm.Vec3
+	Target gglm.Vec3
+	// Forward gglm.Vec3
+	WorldUp gglm.Vec3
+
+	NearClip float32
+	FarClip  float32
+
+	// Perspective data
+	Fov         float32
+	AspectRatio float32
+
+	// Ortho data
+	Left, Right, Top, Bottom float32
+
+	// Matrices
+	ViewMat gglm.Mat4
+	ProjMat gglm.Mat4
+}
+
+// Update recalculates view and projection matrices
+func (c *Camera) Update() {
+
+	c.ViewMat = gglm.LookAt(&c.Pos, &c.Target, &c.WorldUp).Mat4
+
+	if c.Type == Type_Perspective {
+		c.ProjMat = *gglm.Perspective(c.Fov, c.AspectRatio, c.NearClip, c.FarClip)
+	} else {
+		c.ProjMat = gglm.Ortho(c.Left, c.Right, c.Top, c.Bottom, c.NearClip, c.FarClip).Mat4
+	}
+}
+
+func (c *Camera) LookAt(targetPos, worldUp *gglm.Vec3) {
+	c.Target = *targetPos
+	c.WorldUp = *worldUp
+	c.Update()
+}
+
+func NewPerspective(pos, targetPos, worldUp *gglm.Vec3, nearClip, farClip, fovRadians, aspectRatio float32) *Camera {
+
+	cam := &Camera{
+		Type: Type_Perspective,
+		Pos:  *pos,
+		// Forward: *gglm.NewVec3(0, 0, 1),
+		Target:  *targetPos,
+		WorldUp: *worldUp,
+
+		NearClip: nearClip,
+		FarClip:  farClip,
+
+		Fov:         fovRadians,
+		AspectRatio: aspectRatio,
+	}
+	cam.Update()
+
+	return cam
+}
+
+func NewOrthographic(pos, targetPos, worldUp *gglm.Vec3, nearClip, farClip, left, right, top, bottom float32) *Camera {
+
+	cam := &Camera{
+		Type: Type_Orthographic,
+		Pos:  *pos,
+		// Forward: *gglm.NewVec3(0, 0, 0),
+		Target:  *targetPos,
+		WorldUp: *worldUp,
+
+		NearClip: nearClip,
+		FarClip:  farClip,
+
+		Left:   left,
+		Right:  right,
+		Top:    top,
+		Bottom: bottom,
+	}
+	cam.Update()
+
+	return cam
+}