ported the University CGI demo from WINDOWS + GLUT + GLEW + GLU + OpenGL 4 to LINUX WAYLAND + EGL + GLES 2 with minimal cuts

GL_STUFF/SOURCES/CURVES/Bezier.cpp

@@ -0,0 +1,80 @@
+#include "../../HEADERS/CURVES/Bezier.hpp"
+#include "iostream"
+#define LERP(t,a,b) (1 - t) * a + t * b;
+
+Bezier::Bezier(unsigned int order, vector<glm::vec3> *points, vector<float> *intervals) : Curve{ points, intervals } {
+	this->order = order;
+}
+
+/*might be useless (using lerp based evaluation)*/
+float Bezier::evaluateBasisFunction(float at, int number, int order, float intervalLeft, float intervalRight) {
+	if (number < 0 || number > order) {
+		return 0;
+	}
+	else if (number == 0 && order == 0) {
+		return 1;
+	}
+	else {
+		return ((at - intervalLeft)/(intervalRight - intervalLeft)) * evaluateBasisFunction(at, number - 1, order - 1, intervalLeft, intervalRight) + ((intervalRight - at) / (intervalRight - intervalLeft)) * evaluateBasisFunction(at, number, order - 1, intervalLeft, intervalRight);
+	}
+}
+
+glm::vec3 Bezier::evaluate(float at) {
+	vector<glm::vec3>partials = vector<glm::vec3>();
+	for (const glm::vec3 point : *controlPoints)
+		partials.push_back(point);
+	int iter = partials.size() - 1;
+	while (iter > 0) {
+		for (int i = 0; i < iter; i++) {
+			partials[i] = LERP(at, partials[i], partials[i + 1]);
+		}
+		iter--;
+	}
+	return partials[0];
+}
+
+glm::vec3 Bezier::derivate(float at) {
+	return glm::vec3();
+}
+
+/*
+* takes as input a sequence of points 
+* to be interpreted as conjoined bezier segments of order 3
+*/
+Bezier3Segments::Bezier3Segments( vector<glm::vec3>* points, vector<float>* intervals) : Bezier { ((unsigned int) points->size() - 1 ) , points , intervals } {
+	int nPoints = points->size();
+	assert((nPoints % 4) == 0);
+}
+
+glm::vec3 Bezier3Segments::evaluate(float at) {
+	for (int interval = 0; interval < intervalBoundaries->size() - 1; interval++) {
+		if ((intervalBoundaries->operator[](interval) <= at) && (intervalBoundaries->operator[](interval + 1) >= at)) {
+			float normalizedAt = (at - intervalBoundaries->operator[](interval)) / (intervalBoundaries->operator[](interval + 1) - intervalBoundaries->operator[](interval));
+			vector<glm::vec3> partials;
+			for (int j = 0; j <= 3; j++) {
+				partials.push_back(controlPoints->operator[](4 * interval + j));
+			}
+			int count = 3;
+			while (count > 0) {
+				for (int j = 0; j < count; j++) {
+					partials[j] = LERP(normalizedAt, partials[j], partials[j + 1]);
+				}
+				count--;
+			}
+			return partials[0];
+		}
+	}
+	throw "Bezier3Segment evaluation out of range";
+}
+
+glm::vec3 Bezier3Segments::derivate(float at) {
+	return glm::vec3();
+}
+
+float Bezier3Segments::getLeftBound() {
+	return intervalBoundaries->front();
+}
+
+float Bezier3Segments::getRightBound() {
+	return intervalBoundaries->back();
+}