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#include "main/linearcurve.h"
#include "demolib_prefs.h"
#include "exception.h"
#include <stdio.h>
#if DEMOLIB_MAINLOOP
LinearCurve::LinearCurve()
{
this->num_points = 0;
}
LinearCurve::~LinearCurve() {}
void LinearCurve::add_curvepoint(float x, float y)
{
if (this->num_points == MAX_POINTS)
throw new FatalException("Maximum number of points reached!");
/* check better for dupes later */
this->x[this->num_points] = x;
this->y[this->num_points] = y;
this->num_points++;
this->pos_hint = 0;
}
void LinearCurve::end_curvepoints(float start, float length)
{
if (this->num_points == 0)
throw new FatalException("No points for linear movement!");
int i;
for (i = 0; i < this->num_points; i++) {
this->x[i] -= start;
this->x[i] /= length;
}
/* whee, O(n^2) bubblesort */
for (i = 0; i < this->num_points; i++) {
for (int j = i; j < this->num_points; j++) {
if (x[i] > x[j]) {
float xt = x[j];
float yt = y[j];
x[j] = x[i];
y[j] = y[i];
x[i] = xt;
y[i] = yt;
}
}
}
}
float LinearCurve::get_value(float x) {
if (this->num_points == 1) return this->y[0];
/* extrapolation to the left */
if (x < this->x[0]) {
return (this->x[0] - x) * (this->y[1] - this->y[0]) / (this->x[1] - this->x[0]);
}
float leftx = 0.0f, rightx = 0.1f, lefty = 0.0f, righty = 0.0f;
/*
* We have so many long linear curves we'll try to optimize this a bit:
* We check to see if the last used value is a usable starting point --
* if it is, we start from there, if not, we start from 0. we should
* also implement a binary search really soon. ;-) This will work real
* crappy if progress went backwards, but in 99% of the cases, it isn't. ;-)
*/
if (this->pos_hint == -1 || x > this->x[this->pos_hint]) {
this->pos_hint = 0;
}
for (int i = this->pos_hint; i < this->num_points - 1; i++) {
leftx = this->x[i];
rightx = this->x[i + 1];
lefty = this->y[i];
righty = this->y[i + 1];
if (x <= rightx) {
this->pos_hint = i - 1;
break;
}
}
float t = (x - leftx) / (rightx - leftx);
return lefty + (righty - lefty) * t;
}
#endif
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