Bake 200, more info

This commit is contained in:
vaxerski 2022-04-23 23:16:43 +02:00
parent 8f3b4aa89c
commit ad2c72a797
2 changed files with 27 additions and 10 deletions

View file

@ -3,6 +3,8 @@
void CBezierCurve::setup(std::vector<Vector2D>* pVec) { void CBezierCurve::setup(std::vector<Vector2D>* pVec) {
m_dPoints.clear(); m_dPoints.clear();
const auto BEGIN = std::chrono::high_resolution_clock::now();
m_dPoints.emplace_back(Vector2D(0,0)); m_dPoints.emplace_back(Vector2D(0,0));
for (auto& p : *pVec) { for (auto& p : *pVec) {
@ -13,11 +15,23 @@ void CBezierCurve::setup(std::vector<Vector2D>* pVec) {
RASSERT(m_dPoints.size() == 4, "CBezierCurve only supports cubic beziers! (points num: %i)", m_dPoints.size()); RASSERT(m_dPoints.size() == 4, "CBezierCurve only supports cubic beziers! (points num: %i)", m_dPoints.size());
// bake 100 points for faster lookups // bake BAKEDPOINTS points for faster lookups
// T -> X ( / 100 ) // T -> X ( / BAKEDPOINTS )
for (int i = 0; i < 100; ++i) { for (int i = 0; i < BAKEDPOINTS; ++i) {
m_aPointsBaked[i] = getXForT((i + 1) / 100.f); m_aPointsBaked[i] = getXForT((i + 1) / (float)BAKEDPOINTS);
} }
const auto ELAPSEDUS = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::high_resolution_clock::now() - BEGIN).count() / 1000.f;
const auto POINTSSIZE = m_aPointsBaked.size() * sizeof(m_aPointsBaked[0]) / 1000.f;
const auto BEGINCALC = std::chrono::high_resolution_clock::now();
for (float i = 0.1f; i < 1.f; i += 0.1f)
getYForPoint(i);
const auto ELAPSEDCALCAVG = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::high_resolution_clock::now() - BEGINCALC).count() / 1000.f / 10.f;
Debug::log(LOG, "Created a bezier curve, baked %i points, mem usage: %.2fkB, time to bake: %.2fµs. Estimated average calc time: %.2fµs.",
BAKEDPOINTS, POINTSSIZE, ELAPSEDUS, ELAPSEDCALCAVG);
} }
float CBezierCurve::getYForT(float t) { float CBezierCurve::getYForT(float t) {
@ -35,8 +49,8 @@ float CBezierCurve::getYForPoint(float x) {
float lowerX = 0; float lowerX = 0;
float mid = 0.5; float mid = 0.5;
while(std::abs(upperX - lowerX) > 0.01f) { while(std::abs(upperX - lowerX) > INVBAKEDPOINTS) {
if (m_aPointsBaked[((int)(mid * 100.f))] > x) { if (m_aPointsBaked[((int)(mid * (float)BAKEDPOINTS))] > x) {
upperX = mid; upperX = mid;
} else { } else {
lowerX = mid; lowerX = mid;
@ -46,10 +60,10 @@ float CBezierCurve::getYForPoint(float x) {
} }
// in the name of performance i shall make a hack // in the name of performance i shall make a hack
const auto PERCINDELTA = (x - m_aPointsBaked[(int)(100.f * lowerX)]) / (m_aPointsBaked[(int)(100.f * upperX)] - m_aPointsBaked[(int)(100.f * lowerX)]); const auto PERCINDELTA = (x - m_aPointsBaked[(int)((float)BAKEDPOINTS * lowerX)]) / (m_aPointsBaked[(int)((float)BAKEDPOINTS * upperX)] - m_aPointsBaked[(int)((float)BAKEDPOINTS * lowerX)]);
if (std::isnan(PERCINDELTA) || std::isinf(PERCINDELTA)) // can sometimes happen for VERY small x if (std::isnan(PERCINDELTA) || std::isinf(PERCINDELTA)) // can sometimes happen for VERY small x
return 0.f; return 0.f;
return getYForT(mid + PERCINDELTA * 0.01f); return getYForT(mid + PERCINDELTA * INVBAKEDPOINTS);
} }

View file

@ -3,6 +3,9 @@
#include "../defines.hpp" #include "../defines.hpp"
#include <deque> #include <deque>
constexpr int BAKEDPOINTS = 200;
constexpr float INVBAKEDPOINTS = 1.f / BAKEDPOINTS;
// an implementation of a cubic bezier curve // an implementation of a cubic bezier curve
// might do better later // might do better later
// TODO: n-point curves // TODO: n-point curves
@ -20,5 +23,5 @@ private:
// this INCLUDES the 0,0 and 1,1 points. // this INCLUDES the 0,0 and 1,1 points.
std::deque<Vector2D> m_dPoints; std::deque<Vector2D> m_dPoints;
std::array<float, 100> m_aPointsBaked; std::array<float, BAKEDPOINTS> m_aPointsBaked;
}; };