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//
// util.m
// TikZiT
//
// Copyright 2010 Aleks Kissinger. All rights reserved.
//
//
// This file is part of TikZiT.
//
// TikZiT 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 3 of the License, or
// (at your option) any later version.
//
// TikZiT 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.
//
#import "util.h"
#import "math.h"
NSRect NSRectAroundPointsWithPadding(NSPoint p1, NSPoint p2, float padding) {
return NSMakeRect(MIN(p1.x,p2.x)-padding,
MIN(p1.y,p2.y)-padding,
ABS(p2.x-p1.x)+(2.0f*padding),
ABS(p2.y-p1.y)+(2.0f*padding));
}
NSRect NSRectAroundPoints(NSPoint p1, NSPoint p2) {
return NSRectAroundPointsWithPadding(p1, p2, 0.0f);
}
NSRect NSRectAround4PointsWithPadding(NSPoint p1, NSPoint p2, NSPoint p3, NSPoint p4, float padding) {
float leftMost = MIN(p1.x, p2.x);
leftMost = MIN(leftMost, p3.x);
leftMost = MIN(leftMost, p4.x);
float rightMost = MAX(p1.x, p2.x);
rightMost = MAX(rightMost, p3.x);
rightMost = MAX(rightMost, p4.x);
float topMost = MIN(p1.y, p2.y);
topMost = MIN(topMost, p3.y);
topMost = MIN(topMost, p4.y);
float bottomMost = MAX(p1.y, p2.y);
bottomMost = MAX(bottomMost, p3.y);
bottomMost = MAX(bottomMost, p4.y);
return NSMakeRect(leftMost-padding,
topMost-padding,
(rightMost - leftMost)+(2.0f*padding),
(bottomMost - topMost)+(2.0f*padding));
}
NSRect NSRectAround4Points(NSPoint p1, NSPoint p2, NSPoint p3, NSPoint p4) {
return NSRectAround4PointsWithPadding(p1, p2, p3, p4, 0.0f);
}
float NSDistanceBetweenPoints(NSPoint p1, NSPoint p2) {
float dx = p2.x - p1.x;
float dy = p2.y - p1.y;
return sqrt(dx * dx + dy * dy);
}
float good_atan(float dx, float dy) {
if (dx > 0) {
return atan(dy/dx);
} else if (dx < 0) {
return M_PI + atan(dy/dx);
} else {
if (dy > 0) return 0.5 * M_PI;
else if (dy < 0) return 1.5 * M_PI;
else return 0;
}
}
// interpolate on a cubic bezier curve
float bezierInterpolate(float dist, float c0, float c1, float c2, float c3) {
float distp = 1 - dist;
return (distp*distp*distp) * c0 +
3 * (distp*distp) * dist * c1 +
3 * (dist*dist) * distp * c2 +
(dist*dist*dist) * c3;
}
void lineCoeffsFromPoints(NSPoint p1, NSPoint p2, float *A, float *B, float *C) {
*A = p2.y - p1.y;
*B = p1.x - p2.x;
*C = (*A) * p1.x + (*B) * p1.y;
}
static BOOL lineSegmentContainsPoint(NSPoint l1, NSPoint l2, float x, float y) {
float maxX = l1.x > l2.x ? l2.x : l1.x;
float minX = l1.x > l2.x ? l1.x : l2.x;
float maxY = l1.y > l2.y ? l2.y : l1.y;
float minY = l1.y > l2.y ? l1.y : l2.y;
return x >= minX && x <= maxX && y >= minY && y <= maxY;
}
BOOL lineSegmentsIntersect(NSPoint l1start, NSPoint l1end, NSPoint l2start, NSPoint l2end, NSPoint *result) {
// Ax + By = C
float A1, B1, C1;
lineCoeffsFromPoints(l1start, l1end, &A1, &B1, &C1);
float A2, B2, C2;
lineCoeffsFromPoints(l2start, l2end, &A2, &B2, &C2);
float det = A1*B2 - A2*B1;
if (det == 0.0f) {
// parallel
return NO;
} else {
float x = (B2*C1 - B1*C2)/det;
float y = (A1*C2 - A2*C1)/det;
if (lineSegmentContainsPoint(l1start, l1end, x, y) &&
lineSegmentContainsPoint(l2start, l2end, x, y)) {
if (result) {
(*result).x = x;
(*result).y = y;
}
return YES;
}
}
return NO;
}
BOOL lineSegmentIntersectsRect(NSPoint lineStart, NSPoint lineEnd, NSRect rect) {
const float rectMaxX = NSMaxX(rect);
const float rectMinX = NSMinX(rect);
const float rectMaxY = NSMaxY(rect);
const float rectMinY = NSMinY(rect);
// check if the segment is entirely to one side of the rect
if (lineStart.x > rectMaxX && lineEnd.x > rectMaxX) {
return NO;
}
if (lineStart.x < rectMinX && lineEnd.x < rectMinX) {
return NO;
}
if (lineStart.y > rectMaxY && lineEnd.y > rectMaxY) {
return NO;
}
if (lineStart.y < rectMinY && lineEnd.y < rectMinY) {
return NO;
}
// Now check whether the (infinite) line intersects the rect
// (if it does, so does the segment, due to above checks)
// Ax + By = C
float A, B, C;
lineCoeffsFromPoints(lineStart, lineEnd, &A, &B, &C);
const float tlVal = A * rectMinX + B * rectMaxY - C;
const float trVal = A * rectMaxX + B * rectMaxY - C;
const float blVal = A * rectMinX + B * rectMinY - C;
const float brVal = A * rectMaxX + B * rectMinY - C;
if (tlVal < 0 && trVal < 0 && blVal < 0 && brVal < 0) {
// rect below line
return NO;
}
if (tlVal > 0 && trVal > 0 && blVal > 0 && brVal > 0) {
// rect above line
return NO;
}
return YES;
}
float roundToNearest(float stepSize, float val) {
if (stepSize==0.0f) return val;
else return round(val/stepSize)*stepSize;
}
float radiansToDegrees (float radians) {
return (radians * 180.0f) / M_PI;
}
int normaliseAngleDeg (int degrees) {
while (degrees > 180) {
degrees -= 360;
}
while (degrees <= -180) {
degrees += 360;
}
return degrees;
}
static char ahex[] =
{'a','b','c','d','e','f','g','h','i','j',
'A','B','C','D','E','F'};
NSString *alphaHex(unsigned short sh) {
if (sh > 255) return @"!!";
return [NSString stringWithFormat:@"%c%c", ahex[sh/16], ahex[sh%16]];
}
// vi:ft=objc:noet:ts=4:sts=4:sw=4
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