Thanks for looking into this! Here's a demo method that demonstartes the issue:
- (void) testNoiseMap{
GKNoiseSource *theSource;
float freq = 1;
NSInteger octaves = 3;
float pers = 0.75;
float lacu = 4.2;
int32_t seed = 0;
theSource = [GKPerlinNoiseSource perlinNoiseSourceWithFrequency:freq octaveCount:octaves persistence:pers lacunarity:lacu seed:seed];
NSDictionary *theGrads;
theGrads = @{
@-1 : [[self color0] color], // black
@1 : [[self color1] color], // white
};
GKNoise *theNoise = [GKNoise noiseWithNoiseSource:theSource gradientColors:theGrads];
vector_double2 vSize;
vSize.x = 256;
vSize.y = 256;
vector_double2 vSizeFixed = {1.0, 1.0};
vector_int2 sampleSize = {vSize.x, vSize.y};
vector_double2 orig = {0, 0};
GKNoiseMap *theMap = [GKNoiseMap noiseMapWithNoise:theNoise
size:vSizeFixed
origin:orig
sampleCount:sampleSize
seamless:NO];
// this works: returns perlin values -1..+1
int x = 0;
while (x < 20) {
vector_int2 pos = {x, 0};
NSLog(@"sample val is %f", [theMap valueAtPosition:pos]);
x++;
}
// does NOT work
// always returns -1
x = 0;
while (x < 20) {
vector_float2 fpos = {x / 256.0, 0};
NSLog(@"sample val is %f", [theMap interpolatedValueAtPosition:fpos]);
x++;
}
}
When you run it, you'll see that the valueAtPosition works flawlessly, but sampling via interpolated always returns -1
020-04-06 19:54:15.658556+0200 noiseexplorer[1994:711977] sample val is 0.000000
2020-04-06 19:54:19.946082+0200 noiseexplorer[1994:711977] sample val is -0.031727
2020-04-06 19:54:21.450169+0200 noiseexplorer[1994:711977] sample val is -0.059578
2020-04-06 19:54:22.360135+0200 noiseexplorer[1994:711977] sample val is -0.083551
etc.
2020-04-06 19:54:46.453443+0200 noiseexplorer[1994:711977] sample val is -1.000000
2020-04-06 19:54:47.783488+0200 noiseexplorer[1994:711977] sample val is -1.000000
2020-04-06 19:54:48.541423+0200 noiseexplorer[1994:711977] sample val is -1.000000
2020-04-06 19:54:49.337322+0200 noiseexplorer[1994:711977] sample val is -1.000000
Thanks for any hints on what I'm doing wrong.
-ch
