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LUT1D.m
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LUT1D.m
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//
// LUT1D.m
// Pods
//
// Created by Greg Cotten and Wil Gieseler on 3/5/14.
//
//
#import "LUT1D.h"
@interface LUT1D ()
@property (strong) NSArray *redCurve;
@property (strong) NSArray *greenCurve;
@property (strong) NSArray *blueCurve;
@property NSUInteger size;
@end
@implementation LUT1D
+ (instancetype)LUT1DWithRedCurve:(NSArray *)redCurve greenCurve:(NSArray *)greenCurve blueCurve:(NSArray *)blueCurve{
return [[[self class] alloc] initWithRedCurve:redCurve greenCurve:greenCurve blueCurve:blueCurve];
}
- (instancetype)initWithRedCurve:(NSArray *)redCurve greenCurve:(NSArray *)greenCurve blueCurve:(NSArray *)blueCurve{
if (self = [super init]){
self.redCurve = redCurve;
self.greenCurve = greenCurve;
self.blueCurve = blueCurve;
NSAssert(redCurve.count == greenCurve.count && redCurve.count == blueCurve.count, @"Curves must be the same length.");
self.size = self.redCurve.count;
}
return self;
}
- (LUT1D *)LUT1DByResizingToSize:(NSUInteger)newSize {
if (newSize == self.size) {
return [self copy];
}
NSMutableArray *newRedCurve = [NSMutableArray array];
NSMutableArray *newGreenCurve = [NSMutableArray array];
NSMutableArray *newBlueCurve = [NSMutableArray array];
double ratio = ((double)self.size - 1.0) / ((float)newSize - 1.0);
for(int i = 0; i < newSize; i++){
double interpolatedIndex = (double)i * ratio;
NSUInteger bottomIndex = floor(interpolatedIndex);
NSUInteger topIndex = ceil(interpolatedIndex);
double interpolatedRedValue = lerp1d([self.redCurve[bottomIndex] doubleValue], [self.redCurve[topIndex] doubleValue], interpolatedIndex - (double)bottomIndex);
double interpolatedGreenValue = lerp1d([self.greenCurve[bottomIndex] doubleValue], [self.greenCurve[topIndex] doubleValue], interpolatedIndex - (double)bottomIndex);
double interpolatedBlueValue = lerp1d([self.blueCurve[bottomIndex] doubleValue], [self.blueCurve[topIndex] doubleValue], interpolatedIndex - (double)bottomIndex);
[newRedCurve addObject:@(interpolatedRedValue)];
[newGreenCurve addObject:@(interpolatedGreenValue)];
[newBlueCurve addObject:@(interpolatedBlueValue)];
}
return [LUT1D LUT1DWithRedCurve:newRedCurve greenCurve:newGreenCurve blueCurve:newBlueCurve];
}
- (LUT *)lutOfSize:(NSUInteger)size {
LUT1D *resized1DLUT = [self LUT1DByResizingToSize:size];
LUTLattice *lattice = [[LUTLattice alloc] initWithSize:size];
LUTConcurrentCubeLoop(lattice.size, ^(NSUInteger r, NSUInteger g, NSUInteger b) {
LUTColorValue rv = [resized1DLUT.redCurve[r] doubleValue];
LUTColorValue gv = [resized1DLUT.greenCurve[g] doubleValue];
LUTColorValue bv = [resized1DLUT.blueCurve[b] doubleValue];
[lattice setColor:[LUTColor colorWithRed:rv green:gv blue:bv] r:r g:g b:b];
});
return [[LUT LUTWithLattice:lattice] LUTByResizingToSize:size];
}
@end