swf2ass/src/CubicCurveRecord.php

343 lines
12 KiB
PHP

<?php
namespace swf2ass;
/*
* Contains adapted code from http://antigrain.com/research/adaptive_bezier/index.html
* Anti-Grain Geometry (AGG) - Version 2.5
* A high quality rendering engine for C++
* Copyright (C) 2002-2006 Maxim Shemanarev
* Contact: mcseem@antigrain.com
* mcseemagg@yahoo.com
* http://antigrain.com
*
* AGG is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* AGG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
class CubicCurveRecord implements Record {
private const RECURSION_LIMIT = 32;
private const CURVE_COLLINEARITY_EPSILON = PHP_FLOAT_EPSILON; //1E-30?
private const CURVE_ANGLE_TOLERANCE_EPSILON = 0.01;
public Vector2 $start;
public Vector2 $control1;
public Vector2 $control2;
public Vector2 $anchor;
public function __construct(Vector2 $control1, Vector2 $control2, Vector2 $anchor, Vector2 $start) {
$this->control1 = $control1;
$this->control2 = $control2;
$this->anchor = $anchor;
$this->start = $start;
}
public function getStart(): Vector2 {
return $this->start;
}
public function getEnd(): Vector2 {
return $this->anchor;
}
public function reverse(): CubicCurveRecord {
return new CubicCurveRecord($this->control2, $this->control1, $this->start, $this->anchor);
}
public function applyMatrixTransform(MatrixTransform $transform, bool $applyTranslation = true): CubicCurveRecord {
return new CubicCurveRecord($transform->applyToVector($this->control1, $applyTranslation), $transform->applyToVector($this->control2, $applyTranslation), $transform->applyToVector($this->anchor, $applyTranslation), $transform->applyToVector($this->start, $applyTranslation));
}
public static function fromQuadraticRecord(QuadraticCurveRecord $q): CubicCurveRecord {
return new CubicCurveRecord(
$q->start->add($q->control->multiply(2))->divide(3),
$q->anchor->add($q->control->multiply(2))->divide(3),
$q->anchor,
$q->start
);
}
/**
* @return LineRecord[]
*/
public function toLineRecords(float $scale = 1.0) : array{
$points = [];
$distance_tolerance_square = 0.5 / $scale;
$distance_tolerance_square *= $distance_tolerance_square;
self::recursive_bezier($points, 0.0, 0.0, $distance_tolerance_square, $this->start, $this->control1, $this->control2, $this->anchor, 0);
$points[] = $this->anchor;
$result = [];
$current = $this->start;
foreach ($points as $point){
$result[] = new LineRecord($point, $current);
$current = $point;
}
return $result;
}
/**
* @param Vector2[] $points
* @param float $angle_tolerance
* @param float $distance_tolerance_square
* @param Vector2 $v1
* @param Vector2 $v2
* @param Vector2 $v3
* @param int $level
*/
private static function recursive_bezier(array &$points, float $cusp_limit, float $angle_tolerance, float $distance_tolerance_square, Vector2 $v1, Vector2 $v2, Vector2 $v3, Vector2 $v4, int $level){
if($level > self::RECURSION_LIMIT){
return;
}
// Calculate all the mid-points of the line segments
//----------------------
$x12 = ( $v1->x + $v2->x) / 2;
$y12 = ( $v1->y + $v2->y) / 2;
$x23 = ( $v2->x + $v3->x) / 2;
$y23 = ( $v2->y + $v3->y) / 2;
$x34 = ( $v3->x + $v4->x) / 2;
$y34 = ( $v3->y + $v4->y) / 2;
$x123 = ( $x12 + $x23) / 2;
$y123 = ( $y12 + $y23) / 2;
$x234 = ( $x23 + $x34) / 2;
$y234 = ( $y23 + $y34) / 2;
$x1234 = ( $x123 + $x234) / 2;
$y1234 = ( $y123 + $y234) / 2;
// Try to approximate the full cubic curve by a single straight line
//------------------
$dx = $v4->x- $v1->x;
$dy = $v4->y- $v1->y;
$d2 = abs((( $v2->x - $v4->x) * $dy - ( $v2->y - $v4->y) * $dx));
$d3 = abs((( $v3->x - $v4->x) * $dy - ( $v3->y - $v4->y) * $dx));
$da1 = $da2 = $k = null;
switch(((int)( $d2 > self::CURVE_COLLINEARITY_EPSILON) << 1) +
(int)( $d3 > self::CURVE_COLLINEARITY_EPSILON))
{
case 0:
// All collinear OR p1==p4
//----------------------
$k = $dx* $dx + $dy* $dy;
if($k == 0)
{
$d2 = $v1->distanceSquare($v2);
$d3 = $v4->distanceSquare($v3);
}
else
{
$k = 1 / $k;
$da1 = $v2->x - $v1->x;
$da2 = $v2->y - $v1->y;
$d2 = $k * ( $da1* $dx + $da2* $dy);
$da1 = $v3->x - $v1->x;
$da2 = $v3->y - $v1->y;
$d3 = $k * ( $da1* $dx + $da2* $dy);
if( $d2 > 0 && $d2 < 1 && $d3 > 0 && $d3 < 1)
{
// Simple collinear case, 1---2---3---4
// We can leave just two endpoints
return;
}
if( $d2 <= 0){
$d2 = $v2->distanceSquare($v1);
}
else if( $d2 >= 1) {
$d2 = $v2->distanceSquare($v4);
}
else {
$d2 = $v2->distanceSquare($v1->add(new Vector2($d2 * $dx, $d2 * $dy)));
}
if( $d3 <= 0) {
$d3 = $v3->distanceSquare($v1);
}
else if( $d3 >= 1) {
$d3 = $v3->distanceSquare($v4);
}
else {
$d3 = $v3->distanceSquare($v1->add(new Vector2($d2 * $dx, $d2 * $dy)));
}
}
if( $d2 > $d3)
{
if( $d2 < $distance_tolerance_square)
{
$points[] = $v2;
return;
}
}
else
{
if( $d3 < $distance_tolerance_square)
{
$points[] = $v3;
return;
}
}
break;
case 1:
// p1,p2,p4 are collinear, p3 is significant
//----------------------
if( $d3 * $d3 <= $distance_tolerance_square * ( $dx* $dx + $dy* $dy))
{
if($angle_tolerance < self::CURVE_ANGLE_TOLERANCE_EPSILON)
{
$points[] = new Vector2($x23, $y23);
return;
}
// Angle Condition
//----------------------
$da1 = abs(atan2( $v4->y - $v3->y, $v4->x - $v3->x) - atan2( $v3->y - $v2->y, $v3->x - $v2->x));
if( $da1 >= M_PI) {
$da1 = 2 * M_PI - $da1;
}
if( $da1 < $angle_tolerance)
{
$points[] = $v2;
$points[] = $v3;
return;
}
if($cusp_limit != 0.0)
{
if( $da1 > $cusp_limit)
{
$points[] = $v3;
return;
}
}
}
break;
case 2:
// p1,p3,p4 are collinear, p2 is significant
//----------------------
if( $d2 * $d2 <= $distance_tolerance_square * ( $dx* $dx + $dy* $dy))
{
if($angle_tolerance < self::CURVE_ANGLE_TOLERANCE_EPSILON)
{
$points[] = new Vector2($x23, $y23);
return;
}
// Angle Condition
//----------------------
$da1 = abs(atan2( $v3->y - $v2->y, $v3->x - $v2->x) - atan2( $v2->y - $v1->y, $v2->x - $v1->x));
if( $da1 >= M_PI) {
$da1 = 2 * M_PI - $da1;
}
if( $da1 < $angle_tolerance)
{
$points[] = $v2;
$points[] = $v3;
return;
}
if($cusp_limit != 0.0)
{
if( $da1 > $cusp_limit)
{
$points[] = $v2;
return;
}
}
}
break;
case 3:
// Regular case
//-----------------
if(( $d2 + $d3)*( $d2 + $d3) <= $distance_tolerance_square * ( $dx* $dx + $dy* $dy))
{
// If the curvature doesn't exceed the distance_tolerance value
// we tend to finish subdivisions.
//----------------------
if($angle_tolerance < self::CURVE_ANGLE_TOLERANCE_EPSILON)
{
$points[] = new Vector2($x23, $y23);
return;
}
// Angle & Cusp Condition
//----------------------
$k = atan2( $v3->y - $v2->y, $v3->x - $v2->x);
$da1 = abs($k - atan2( $v2->y - $v1->y, $v2->x - $v1->x));
$da2 = abs(atan2( $v4->y - $v3->y, $v4->x - $v3->x) - $k);
if( $da1 >= M_PI) {
$da1 = 2 * M_PI - $da1;
}
if( $da2 >= M_PI) {
$da2 = 2 * M_PI - $da2;
}
if( $da1 + $da2 < $angle_tolerance)
{
// Finally we can stop the recursion
//----------------------
$points[] = new Vector2($x23, $y23);
return;
}
if($cusp_limit != 0.0)
{
if( $da1 > $cusp_limit)
{
$points[] = $v2;
return;
}
if( $da2 > $cusp_limit)
{
$points[] = $v3;
return;
}
}
}
break;
}
// Continue subdivision
//----------------------
self::recursive_bezier( $points, $cusp_limit, $angle_tolerance, $distance_tolerance_square, $v1, new Vector2($x12, $y12), new Vector2($x123, $y123), new Vector2($x1234, $y1234),$level + 1);
self::recursive_bezier( $points, $cusp_limit, $angle_tolerance, $distance_tolerance_square, new Vector2($x1234, $y1234), new Vector2($x234, $y234), new Vector2($x34, $y34), $v4,$level + 1);
}
/**
* Finds if Cubic curve is a perfect fit of a Quadratic curve (aka, it was upconverted)
*
* @return ?QuadraticCurveRecord
*/
public function toSingleQuadraticRecord() : ?QuadraticCurveRecord{
$control1 = $this->control1->multiply(3)->sub($this->start)->divide(2);
$control2 = $this->control2->multiply(3)->sub($this->anchor)->divide(2);
if($control1->equals($control2)){
return new QuadraticCurveRecord($control1, $this->anchor, $this->start);
}
return null;
}
public function equals(Record $other): bool {
return $other instanceof $this and $this->start->equals($other->start) and $this->control1->equals($other->control1) and $this->control2->equals($other->control2) and $this->anchor->equals($other->anchor);
}
}