zgui/libs/node_editor/imgui_bezier_math.h

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//------------------------------------------------------------------------------
// VERSION 0.1
//
// LICENSE
// This software is dual-licensed to the public domain and under the following
// license: you are granted a perpetual, irrevocable license to copy, modify,
// publish, and distribute this file as you see fit.
//
// CREDITS
// Written by Michal Cichon
//------------------------------------------------------------------------------
# ifndef __IMGUI_BEZIER_MATH_H__
# define __IMGUI_BEZIER_MATH_H__
# pragma once
//------------------------------------------------------------------------------
# include "imgui_extra_math.h"
//------------------------------------------------------------------------------
template <typename T>
struct ImCubicBezierPointsT
{
T P0;
T P1;
T P2;
T P3;
};
using ImCubicBezierPoints = ImCubicBezierPointsT<ImVec2>;
//------------------------------------------------------------------------------
// Low-level Bezier curve sampling.
template <typename T> inline T ImLinearBezier(const T& p0, const T& p1, float t);
template <typename T> inline T ImLinearBezierDt(const T& p0, const T& p1, float t);
template <typename T> inline T ImQuadraticBezier(const T& p0, const T& p1, const T& p2, float t);
template <typename T> inline T ImQuadraticBezierDt(const T& p0, const T& p1, const T& p2, float t);
template <typename T> inline T ImCubicBezier(const T& p0, const T& p1, const T& p2, const T& p3, float t);
template <typename T> inline T ImCubicBezierDt(const T& p0, const T& p1, const T& p2, const T& p3, float t);
// High-level Bezier sampling, automatically collapse to lower level Bezier curves if control points overlap.
template <typename T> inline T ImCubicBezierSample(const T& p0, const T& p1, const T& p2, const T& p3, float t);
template <typename T> inline T ImCubicBezierSample(const ImCubicBezierPointsT<T>& curve, float t);
template <typename T> inline T ImCubicBezierTangent(const T& p0, const T& p1, const T& p2, const T& p3, float t);
template <typename T> inline T ImCubicBezierTangent(const ImCubicBezierPointsT<T>& curve, float t);
// Calculate approximate length of Cubic Bezier curve.
template <typename T> inline float ImCubicBezierLength(const T& p0, const T& p1, const T& p2, const T& p3);
template <typename T> inline float ImCubicBezierLength(const ImCubicBezierPointsT<T>& curve);
// Splits Cubic Bezier curve into two curves.
template <typename T>
struct ImCubicBezierSplitResultT
{
ImCubicBezierPointsT<T> Left;
ImCubicBezierPointsT<T> Right;
};
using ImCubicBezierSplitResult = ImCubicBezierSplitResultT<ImVec2>;
template <typename T> inline ImCubicBezierSplitResultT<T> ImCubicBezierSplit(const T& p0, const T& p1, const T& p2, const T& p3, float t);
template <typename T> inline ImCubicBezierSplitResultT<T> ImCubicBezierSplit(const ImCubicBezierPointsT<T>& curve, float t);
// Returns bounding rectangle of Cubic Bezier curve.
inline ImRect ImCubicBezierBoundingRect(const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3);
inline ImRect ImCubicBezierBoundingRect(const ImCubicBezierPoints& curve);
// Project point on Cubic Bezier curve.
struct ImProjectResult
{
ImVec2 Point; // Point on curve
float Time; // [0 - 1]
float Distance; // Distance to curve
};
inline ImProjectResult ImProjectOnCubicBezier(const ImVec2& p, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const int subdivisions = 100);
inline ImProjectResult ImProjectOnCubicBezier(const ImVec2& p, const ImCubicBezierPoints& curve, const int subdivisions = 100);
// Calculate intersection between line and a Cubic Bezier curve.
struct ImCubicBezierIntersectResult
{
int Count;
ImVec2 Points[3];
};
inline ImCubicBezierIntersectResult ImCubicBezierLineIntersect(const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& a0, const ImVec2& a1);
inline ImCubicBezierIntersectResult ImCubicBezierLineIntersect(const ImCubicBezierPoints& curve, const ImLine& line);
// Adaptive Cubic Bezier subdivision.
enum ImCubicBezierSubdivideFlags
{
ImCubicBezierSubdivide_None = 0,
ImCubicBezierSubdivide_SkipFirst = 1
};
struct ImCubicBezierSubdivideSample
{
ImVec2 Point;
ImVec2 Tangent;
};
using ImCubicBezierSubdivideCallback = void (*)(const ImCubicBezierSubdivideSample& p, void* user_pointer);
inline void ImCubicBezierSubdivide(ImCubicBezierSubdivideCallback callback, void* user_pointer, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, float tess_tol = -1.0f, ImCubicBezierSubdivideFlags flags = ImCubicBezierSubdivide_None);
inline void ImCubicBezierSubdivide(ImCubicBezierSubdivideCallback callback, void* user_pointer, const ImCubicBezierPoints& curve, float tess_tol = -1.0f, ImCubicBezierSubdivideFlags flags = ImCubicBezierSubdivide_None);
// F has signature void(const ImCubicBezierSubdivideSample& p)
template <typename F> inline void ImCubicBezierSubdivide(F& callback, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, float tess_tol = -1.0f, ImCubicBezierSubdivideFlags flags = ImCubicBezierSubdivide_None);
template <typename F> inline void ImCubicBezierSubdivide(F& callback, const ImCubicBezierPoints& curve, float tess_tol = -1.0f, ImCubicBezierSubdivideFlags flags = ImCubicBezierSubdivide_None);
// Fixed step Cubic Bezier subdivision.
struct ImCubicBezierFixedStepSample
{
float T;
float Length;
ImVec2 Point;
bool BreakSearch;
};
using ImCubicBezierFixedStepCallback = void (*)(ImCubicBezierFixedStepSample& sample, void* user_pointer);
inline void ImCubicBezierFixedStep(ImCubicBezierFixedStepCallback callback, void* user_pointer, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, float step, bool overshoot = false, float max_value_error = 1e-3f, float max_t_error = 1e-5f);
inline void ImCubicBezierFixedStep(ImCubicBezierFixedStepCallback callback, void* user_pointer, const ImCubicBezierPoints& curve, float step, bool overshoot = false, float max_value_error = 1e-3f, float max_t_error = 1e-5f);
// F has signature void(const ImCubicBezierFixedStepSample& p)
template <typename F> inline void ImCubicBezierFixedStep(F& callback, const ImVec2& p0, const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, float step, bool overshoot = false, float max_value_error = 1e-3f, float max_t_error = 1e-5f);
template <typename F> inline void ImCubicBezierFixedStep(F& callback, const ImCubicBezierPoints& curve, float step, bool overshoot = false, float max_value_error = 1e-3f, float max_t_error = 1e-5f);
//------------------------------------------------------------------------------
# include "imgui_bezier_math.inl"
//------------------------------------------------------------------------------
# endif // __IMGUI_BEZIER_MATH_H__