我正在尝试让 CIColorCube 过滤器正常工作。然而,苹果文档仅提供了一个解释不清的参考示例:
// Allocate memory
const unsigned int size = 64;
float *cubeData = (float *)malloc (size * size * size * sizeof (float) * 4);
float rgb[3], hsv[3], *c = cubeData;
// Populate cube with a simple gradient going from 0 to 1
for (int z = 0; z < size; z++){
rgb[2] = ((double)z)/(size-1); // Blue value
for (int y = 0; y < size; y++){
rgb[1] = ((double)y)/(size-1); // Green value
for (int x = 0; x < size; x ++){
rgb[0] = ((double)x)/(size-1); // Red value
// Convert RGB to HSV
// You can find publicly available rgbToHSV functions on the Internet
rgbToHSV(rgb, hsv);
// Use the hue value to determine which to make transparent
// The minimum and maximum hue angle depends on
// the color you want to remove
float alpha = (hsv[0] > minHueAngle && hsv[0] < maxHueAngle) ? 0.0f: 1.0f;
// Calculate premultiplied alpha values for the cube
c[0] = rgb[0] * alpha;
c[1] = rgb[1] * alpha;
c[2] = rgb[2] * alpha;
c[3] = alpha;
c += 4; // advance our pointer into memory for the next color value
}
}
}
// Create memory with the cube data
NSData *data = [NSData dataWithBytesNoCopy:cubeData
length:cubeDataSize
freeWhenDone:YES];
CIColorCube *colorCube = [CIFilter filterWithName:@"CIColorCube"];
[colorCube setValue:@(size) forKey:@"inputCubeDimension"];
// Set data for cube
[colorCube setValue:data forKey:@"inputCubeData"];
所以我尝试将其转换为 Swift,如下所示:
var filter = CIFilter(name: "CIColorCube")
filter.setValue(ciImage, forKey: kCIInputImageKey)
filter.setDefaults()
var size: UInt = 64
var floatSize = UInt(sizeof(Float))
var cubeDataSize:size_t = size * size * size * floatSize * 4
var colorCubeData:Array<Float> = [
0,0,0,1,
0,0,0,1,
0,0,0,1,
0,0,0,1,
0,0,0,1,
0,0,0,1,
0,0,0,1,
0,0,0,1
]
var cubeData:NSData = NSData(bytesNoCopy: colorCubeData, length: cubeDataSize)
但是,在尝试创建多维数据集数据时出现错误:
"Extra argument 'bytesNoCopy' in call"
基本上我创建的cubeData是错误的。你能告诉我如何在 Swift 中正确创建cubeData 对象吗?
Thanks!