224 lines
6 KiB
C++
224 lines
6 KiB
C++
// Copyright (c) 2007, Rodrigo Braz Monteiro
|
|
// All rights reserved.
|
|
//
|
|
// Redistribution and use in source and binary forms, with or without
|
|
// modification, are permitted provided that the following conditions are met:
|
|
//
|
|
// * Redistributions of source code must retain the above copyright notice,
|
|
// this list of conditions and the following disclaimer.
|
|
// * Redistributions in binary form must reproduce the above copyright notice,
|
|
// this list of conditions and the following disclaimer in the documentation
|
|
// and/or other materials provided with the distribution.
|
|
// * Neither the name of the Aegisub Group nor the names of its contributors
|
|
// may be used to endorse or promote products derived from this software
|
|
// without specific prior written permission.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
// POSSIBILITY OF SUCH DAMAGE.
|
|
//
|
|
// Aegisub Project http://www.aegisub.org/
|
|
//
|
|
// $Id$
|
|
|
|
/// @file spline_curve.cpp
|
|
/// @brief Handle bicubic splines (Bezier curves) in vector drawings
|
|
/// @ingroup visual_ts
|
|
///
|
|
|
|
///////////
|
|
// Headers
|
|
#include "config.h"
|
|
|
|
#include "spline_curve.h"
|
|
#include "utils.h"
|
|
|
|
/// @brief Curve constructor
|
|
///
|
|
SplineCurve::SplineCurve() {
|
|
type = CURVE_INVALID;
|
|
}
|
|
|
|
/// @brief Split a curve in two using the de Casteljau algorithm
|
|
/// @param c1
|
|
/// @param c2
|
|
/// @param t
|
|
///
|
|
void SplineCurve::Split(SplineCurve &c1,SplineCurve &c2,float t) {
|
|
// Split a line
|
|
if (type == CURVE_LINE) {
|
|
c1.type = CURVE_LINE;
|
|
c2.type = CURVE_LINE;
|
|
c1.p1 = p1;
|
|
c2.p2 = p2;
|
|
c1.p2 = p1*(1-t)+p2*t;
|
|
c2.p1 = c1.p2;
|
|
}
|
|
|
|
// Split a bicubic
|
|
else if (type == CURVE_BICUBIC) {
|
|
c1.type = CURVE_BICUBIC;
|
|
c2.type = CURVE_BICUBIC;
|
|
|
|
// Sub-divisions
|
|
float u = 1-t;
|
|
Vector2D p12 = p1*u+p2*t;
|
|
Vector2D p23 = p2*u+p3*t;
|
|
Vector2D p34 = p3*u+p4*t;
|
|
Vector2D p123 = p12*u+p23*t;
|
|
Vector2D p234 = p23*u+p34*t;
|
|
Vector2D p1234 = p123*u+p234*t;
|
|
|
|
// Set points
|
|
c1.p1 = p1;
|
|
c2.p4 = p4;
|
|
c1.p2 = p12;
|
|
c1.p3 = p123;
|
|
c1.p4 = p1234;
|
|
c2.p1 = p1234;
|
|
c2.p2 = p234;
|
|
c2.p3 = p34;
|
|
}
|
|
}
|
|
|
|
/// @brief Based on http://antigrain.com/research/bezier_interpolation/index.html Smoothes the curve
|
|
/// @param P0
|
|
/// @param P3
|
|
/// @param smooth
|
|
/// @return
|
|
///
|
|
void SplineCurve::Smooth(Vector2D const& P0,Vector2D const& P3,float smooth) {
|
|
// Validate
|
|
if (type != CURVE_LINE) return;
|
|
if (p1 == p2) return;
|
|
smooth = MID(0.f,smooth,1.f);
|
|
|
|
// Get points
|
|
Vector2D P1 = p1;
|
|
Vector2D P2 = p2;
|
|
|
|
// Calculate intermediate points
|
|
Vector2D c1 = (P0+P1)/2.f;
|
|
Vector2D c2 = (P1+P2)/2.f;
|
|
Vector2D c3 = (P2+P3)/2.f;
|
|
float len1 = (P1-P0).Len();
|
|
float len2 = (P2-P1).Len();
|
|
float len3 = (P3-P2).Len();
|
|
float k1 = len1/(len1+len2);
|
|
float k2 = len2/(len2+len3);
|
|
Vector2D m1 = c1+(c2-c1)*k1;
|
|
Vector2D m2 = c2+(c3-c2)*k2;
|
|
|
|
// Set curve points
|
|
p4 = p2;
|
|
p2 = m1+(c2-m1)*smooth + P1 - m1;
|
|
p3 = m2+(c2-m2)*smooth + P2 - m2;
|
|
type = CURVE_BICUBIC;
|
|
}
|
|
|
|
/// @brief Get a point
|
|
/// @param t
|
|
/// @return
|
|
///
|
|
Vector2D SplineCurve::GetPoint(float t) const {
|
|
if (type == CURVE_POINT) return p1;
|
|
if (type == CURVE_LINE) {
|
|
return p1*(1.f-t) + p2*t;
|
|
}
|
|
if (type == CURVE_BICUBIC) {
|
|
float u = 1.f-t;
|
|
return p1*u*u*u + 3*p2*t*u*u + 3*p3*t*t*u + p4*t*t*t;
|
|
}
|
|
|
|
return Vector2D(0,0);
|
|
}
|
|
|
|
Vector2D& SplineCurve::EndPoint() {
|
|
switch (type) {
|
|
case CURVE_POINT: return p1;
|
|
case CURVE_LINE: return p2;
|
|
case CURVE_BICUBIC: return p4;
|
|
default: return p1;
|
|
}
|
|
}
|
|
|
|
/// @brief Get point closest to reference
|
|
/// @param ref
|
|
/// @return
|
|
///
|
|
Vector2D SplineCurve::GetClosestPoint(Vector2D const& ref) const {
|
|
return GetPoint(GetClosestParam(ref));
|
|
}
|
|
|
|
/// @brief Get value of parameter closest to point
|
|
/// @param ref
|
|
/// @return
|
|
///
|
|
float SplineCurve::GetClosestParam(Vector2D const& ref) const {
|
|
if (type == CURVE_LINE) {
|
|
return GetClosestSegmentPart(p1,p2,ref);
|
|
}
|
|
if (type == CURVE_BICUBIC) {
|
|
int steps = 100;
|
|
float bestDist = 80000000.f;
|
|
float bestT = 0.f;
|
|
for (int i=0;i<=steps;i++) {
|
|
float t = float(i)/float(steps);
|
|
float dist = (GetPoint(t)-ref).Len();
|
|
if (dist < bestDist) {
|
|
bestDist = dist;
|
|
bestT = t;
|
|
}
|
|
}
|
|
return bestT;
|
|
}
|
|
return 0.f;
|
|
}
|
|
|
|
/// @brief Quick distance
|
|
/// @param ref
|
|
/// @return
|
|
///
|
|
float SplineCurve::GetQuickDistance(Vector2D const& ref) const {
|
|
using std::min;
|
|
if (type == CURVE_BICUBIC) {
|
|
float len1 = GetClosestSegmentDistance(p1,p2,ref);
|
|
float len2 = GetClosestSegmentDistance(p2,p3,ref);
|
|
float len3 = GetClosestSegmentDistance(p3,p4,ref);
|
|
float len4 = GetClosestSegmentDistance(p4,p1,ref);
|
|
float len5 = GetClosestSegmentDistance(p1,p3,ref);
|
|
float len6 = GetClosestSegmentDistance(p2,p4,ref);
|
|
return min(min(min(len1,len2),min(len3,len4)),min(len5,len6));
|
|
}
|
|
|
|
// Something else
|
|
else return (GetClosestPoint(ref)-ref).Len();
|
|
}
|
|
|
|
/// @brief Closest t in segment p1-p2 to point p3
|
|
/// @param pt1
|
|
/// @param pt2
|
|
/// @param pt3
|
|
/// @return
|
|
///
|
|
float SplineCurve::GetClosestSegmentPart(Vector2D const& pt1,Vector2D const& pt2,Vector2D const& pt3) const {
|
|
return MID(0.f,(pt3-pt1).Dot(pt2-pt1)/(pt2-pt1).SquareLen(),1.f);
|
|
}
|
|
|
|
/// @brief Closest distance between p3 and segment p1-p2
|
|
/// @param pt1
|
|
/// @param pt2
|
|
/// @param pt3
|
|
///
|
|
float SplineCurve::GetClosestSegmentDistance(Vector2D const& pt1,Vector2D const& pt2,Vector2D const& pt3) const {
|
|
float t = GetClosestSegmentPart(pt1,pt2,pt3);
|
|
return (pt1*(1.f-t)+pt2*t-pt3).Len();
|
|
}
|