Get Frustum Culling half-working

Source/audio/PerspectiveEffect.cpp

@@ -65,9 +65,14 @@ Point PerspectiveEffect::apply(int index, Point input, const std::vector<double>
 	double x3 = cosValue * x2 - sinValue * y2;
 	double y3 = sinValue * x2 + cosValue * y2;
 
+	Point p = Point(x3, y3, z3);
+
+	Frustum frustum = Frustum(focalLength, 1.0, 0.1, 1000);
+	frustum.clipToFrustum(p);
+
 	return Point(
-		(1 - effectScale) * input.x + effectScale * (x3 * focalLength / (z3 - depth)),
-		(1 - effectScale) * input.y + effectScale * (y3 * focalLength / (z3 - depth)),
+		(1 - effectScale) * input.x + effectScale * (p.x * focalLength / p.z),
+		(1 - effectScale) * input.y + effectScale * (p.y * focalLength / p.z),
 		0
 	);
 }

Source/audio/PerspectiveEffect.h

@@ -3,6 +3,7 @@
 #include "../shape/Point.h"
 #include "../audio/Effect.h"
 #include "../lua/LuaParser.h"
+#include "../obj/Frustum.h"
 
 class PerspectiveEffect : public EffectApplication {
 public:

Source/obj/Frustum.cpp

@@ -0,0 +1,46 @@
+// FROM https://cgvr.cs.uni-bremen.de/teaching/cg_literatur/lighthouse3d_view_frustum_culling/index.html
+
+#include "Frustum.h"
+
+void Frustum::setCameraInternals(float focalLength, float ratio, float nearDistance, float farDistance) {
+	// store the information
+	this->ratio = ratio;
+	this->nearDistance = nearDistance;
+	this->farDistance = farDistance;
+
+	// compute width and height of the near section
+	float fov = 2 * std::atan(1 / (focalLength * 2));
+	origin = Point(0, 0, -focalLength);
+	tang = (float) std::tan(fov * 0.5);
+	height = nearDistance * tang;
+	width = height * ratio;
+}
+
+void Frustum::clipToFrustum(Point &p) {
+	float pcz, pcx, pcy, aux;
+
+	// compute vector from camera position to p
+	Point v = p - origin;
+
+	// compute and test the Z coordinate
+	Point negZ = -Z;
+	pcz = v.innerProduct(Z);
+	pcz = juce::jlimit(nearDistance, farDistance, pcz);
+
+	// compute and test the Y coordinate
+	pcy = v.innerProduct(Y);
+	aux = pcz * tang;
+	pcy = juce::jlimit(-aux, aux, pcy);
+
+	// compute and test the X coordinate
+	pcx = v.innerProduct(X);
+	aux = aux * ratio;
+	pcx = juce::jlimit(-aux, aux, pcx);
+
+	// calculate the clipped point using the referential coordinates
+	Point x = X * pcx;
+	Point y = Y * pcy;
+	Point z = Z * pcz;
+
+	p = x + y + z;
+}

Source/obj/Frustum.h

@@ -0,0 +1,25 @@
+// FROM https://cgvr.cs.uni-bremen.de/teaching/cg_literatur/lighthouse3d_view_frustum_culling/index.html
+
+#pragma once
+
+#include <JuceHeader.h>
+#include "../shape/Point.h"
+
+class Frustum {
+public:
+	float ratio, nearDistance, farDistance, width, height, tang;
+
+	Point origin = Point(0, 0, 0);
+
+	Point X = Point(1, 0, 0);
+	Point Y = Point(0, 1, 0);
+	Point Z = Point(0, 0, 1);
+
+	Frustum(float fov, float ratio, float nearDistance, float farDistance) {
+        setCameraInternals(fov, ratio, nearDistance, farDistance);
+    }
+	~Frustum() {};
+
+	void setCameraInternals(float fov, float ratio, float nearD, float farD);
+	void clipToFrustum(Point &p);
+};

Source/shape/Point.cpp

@@ -32,6 +32,17 @@ void Point::rotate(double rotateX, double rotateY, double rotateZ) {
     y = sinValue * x2 + cosValue * y2;
 }
 
+void Point::normalize() {
+    double mag = magnitude();
+    x /= mag;
+    y /= mag;
+    z /= mag;
+}
+
+double Point::innerProduct(Point& other) {
+    return x * other.x + y * other.y + z * other.z;
+}
+
 void Point::scale(double x, double y, double z) {
 	this->x *= x;
 	this->y *= y;
@@ -49,7 +60,7 @@ double Point::length() {
 }
 
 double Point::magnitude() {
-	return sqrt(x * x * x + y * y * y + z * z * z);
+	return sqrt(x * x + y * y + z * z);
 }
 
 std::unique_ptr<Shape> Point::clone() {
@@ -66,3 +77,23 @@ Point& Point::operator=(const Point& other) {
 	z = other.z;
 	return *this;
 }
+
+Point Point::operator+(const Point& other) {
+    return Point(x + other.x, y + other.y, z + other.z);
+}
+
+Point Point::operator-(const Point& other) {
+    return Point(x - other.x, y - other.y, z - other.z);
+}
+
+Point Point::operator-() {
+    return Point(-x, -y, -z);
+}
+
+Point Point::operator*(const Point& other) {
+    return Point(x * other.x, y * other.y, z * other.z);
+}
+
+Point Point::operator*(double scalar) {
+    return Point(x * scalar, y * scalar, z * scalar);
+}

Source/shape/Point.h

@@ -20,9 +20,16 @@ public:
 	std::string type() override;
 
 	void rotate(double rotateX, double rotateY, double rotateZ);
+	void normalize();
+	double innerProduct(Point& other);
 
 	// copy assignment operator
 	Point& operator=(const Point& other);
+	Point operator+(const Point& other);
+	Point operator-(const Point& other);
+	Point operator-();
+	Point operator*(const Point& other);
+	Point operator*(double scalar);
 
 	double x, y, z;
 	

osci-render.jucer

@@ -393,6 +393,8 @@
             file="Source/MidiComponent.cpp"/>
       <FILE id="GJqoJa" name="MidiComponent.h" compile="0" resource="0" file="Source/MidiComponent.h"/>
       <GROUP id="{E6ED85A9-3843-825F-EF48-BCF81E38F8AD}" name="obj">
+        <FILE id="T6iC8q" name="Frustum.cpp" compile="1" resource="0" file="Source/obj/Frustum.cpp"/>
+        <FILE id="ky5ZfA" name="Frustum.h" compile="0" resource="0" file="Source/obj/Frustum.h"/>
         <FILE id="Yfpzzn" name="ObjectServer.cpp" compile="1" resource="0"
               file="Source/obj/ObjectServer.cpp"/>
         <FILE id="CqYgqM" name="ObjectServer.h" compile="0" resource="0" file="Source/obj/ObjectServer.h"/>