From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 10 Nov 2017 07:26:38 +0000 (+0200)
Subject: Derive Camera and Light from Placeable
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=05d70b38a546f35a7687cae6ae3fcd6ab78898b2;p=libs%2Fgl.git

Derive Camera and Light from Placeable
---

diff --git a/source/camera.cpp b/source/camera.cpp
index ae35f632..e7c925c9 100644
--- a/source/camera.cpp
+++ b/source/camera.cpp
@@ -85,6 +85,14 @@ void Camera::look_at(const Vector3 &p)
 	set_look_direction(p-position);
 }
 
+void Camera::set_object_matrix(const Matrix &m)
+{
+	position = m.column(3).slice<3>(0);
+	look_dir = normalize(-m.column(2).slice<3>(0));
+	up_dir = normalize(m.column(1).slice<3>(0));
+	update_object_matrix();
+}
+
 Vector3 Camera::project(const Vector4 &p) const
 {
 	Vector4 r = proj_matrix*(view_matrix*p);
@@ -99,7 +107,7 @@ Vector3 Camera::project(const Vector3 &p) const
 Vector4 Camera::unproject(const Vector4 &p) const
 {
 	Vector4 r = invert(proj_matrix)*Vector4(p.x, p.y, p.z, 1.0f);
-	r = object_matrix*Vector4(r.x/r.w, r.y/r.w, r.z/r.w, p.w);
+	r = matrix*Vector4(r.x/r.w, r.y/r.w, r.z/r.w, p.w);
 	return r;
 }
 
@@ -137,8 +145,8 @@ void Camera::update_object_matrix()
 	columns[1] = compose(cross(right_dir, look_dir), 0.0f);
 	columns[2] = compose(-look_dir, 0.0f);
 	columns[3] = compose(position, 1.0f);
-	object_matrix = Matrix::from_columns(columns);
-	view_matrix = invert(object_matrix);
+	matrix = Matrix::from_columns(columns);
+	view_matrix = invert(matrix);
 }
 
 } // namespace GL
diff --git a/source/camera.h b/source/camera.h
index 412d69ff..d96ada81 100644
--- a/source/camera.h
+++ b/source/camera.h
@@ -1,13 +1,12 @@
 #ifndef MSP_GL_CAMERA_H_
 #define MSP_GL_CAMERA_H_
 
-#include "matrix.h"
-#include "vector.h"
+#include "placeable.h"
 
 namespace Msp {
 namespace GL {
 
-class Camera
+class Camera: public Placeable
 {
 private:
 	Geometry::Angle<float> fov;
@@ -23,7 +22,6 @@ private:
 	Vector3 look_dir;
 	Vector3 up_dir;
 	Matrix view_matrix;
-	Matrix object_matrix;
 	Matrix proj_matrix;
 
 public:
@@ -52,13 +50,18 @@ public:
 	const Vector3 &get_look_direction() const { return look_dir; }
 	const Vector3 &get_up_direction() const { return up_dir; }
 
+	virtual void set_matrix(const Matrix &m) { set_object_matrix(m); }
+
+	/** Sets the position and orientation of the camera from an object matrix. */
+	void set_object_matrix(const Matrix &);
+
 	/** Returns the view matrix, used to transform coordinates from world space
 	to eye space. */
 	const Matrix &get_view_matrix() const { return view_matrix; }
 
 	/** Returns the object matrix, used to transform coordinates from eye space
 	to world space. */
-	const Matrix &get_object_matrix() const { return object_matrix; }
+	const Matrix &get_object_matrix() const { return matrix; }
 
 	/** Returns the projection matrix. */
 	const Matrix &get_projection_matrix() const { return proj_matrix; }
diff --git a/source/light.cpp b/source/light.cpp
index f74b3acb..aeb17c5b 100644
--- a/source/light.cpp
+++ b/source/light.cpp
@@ -63,6 +63,23 @@ void Light::update_parameter(int mask, int index) const
 	}
 }
 
+void Light::update_matrix()
+{
+	Vector3 up_dir;
+	if(20*abs(direction.z)>abs(direction.x)+abs(direction.y))
+		up_dir.y = 1;
+	else
+		up_dir.z = 1;
+	Vector3 right_dir = normalize(cross(direction, up_dir));
+
+	Vector4 columns[4];
+	columns[0] = compose(right_dir, 0.0f);
+	columns[1] = compose(cross(right_dir, direction), 0.0f);
+	columns[2] = compose(-direction, 0.0f);
+	columns[3] = position;
+	matrix = Matrix::from_columns(columns);
+}
+
 void Light::set_diffuse(const Color &c)
 {
 	diffuse = c;
@@ -75,16 +92,32 @@ void Light::set_specular(const Color &c)
 	update_parameter(SPECULAR);
 }
 
+void Light::set_matrix(const Matrix &m)
+{
+	Placeable::set_matrix(m);
+	position = matrix.column(3);
+	spot_dir = normalize(-matrix.column(2).slice<3>(0));
+	direction = (position.w ? spot_dir : normalize(-position.slice<3>(0)));
+	update_parameter(POSITION|SPOT_DIR);
+	update_matrix();
+}
+
 void Light::set_position(const Vector4 &p)
 {
 	position = p;
 	update_parameter(POSITION);
+	if(!position.w)
+		direction = normalize(-position.slice<3>(0));
+	update_matrix();
 }
 
 void Light::set_spot_direction(const Vector3 &d)
 {
 	spot_dir = normalize(d);
+	if(position.w)
+		direction = spot_dir;
 	update_parameter(SPOT_DIR);
+	update_matrix();
 }
 
 void Light::set_spot_exponent(float e)
diff --git a/source/light.h b/source/light.h
index b775a711..396e276d 100644
--- a/source/light.h
+++ b/source/light.h
@@ -3,7 +3,7 @@
 
 #include <vector>
 #include "color.h"
-#include "vector.h"
+#include "placeable.h"
 
 namespace Msp {
 namespace GL {
@@ -24,7 +24,7 @@ Pipeline::Pass.
 
 Lights do not cast shadows by themselves.  See ShadowMap for that.
 */
-class Light
+class Light: public Placeable
 {
 private:
 	enum ParameterMask
@@ -42,6 +42,7 @@ private:
 	Color specular;
 	Vector4 position;
 	Vector3 spot_dir;
+	Vector3 direction;
 	float spot_exp;
 	Geometry::Angle<float> spot_cutoff;
 	float attenuation[3];
@@ -52,6 +53,7 @@ public:
 
 private:
 	void update_parameter(int, int = -1) const;
+	void update_matrix();
 
 public:
 	/** Sets the diffuse (direction-independent) color of the Light.  Provided
@@ -65,6 +67,10 @@ public:
 	const Color &get_diffuse() const { return diffuse; }
 	const Color &get_specular() const { return specular; }
 
+	/** Sets the postion and orientation of the Light from a matrix.  Negative Z
+	axis is used as the spot direction, other axes are ignored. */
+	virtual void set_matrix(const Matrix &);
+
 	/** Sets the position of the Light.  For a directional light, set the xyz
 	components to a vector pointing towards the light and the w component to 0. */
 	void set_position(const Vector4 &);