public_types.h

/*
Copyright [2024] [Yao Yao]

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

*/

//
// Created by yao on 1/05/18.
//

#pragma once

#include <cstdint>
#include <cuda_runtime_api.h>
#include <cuda_fp16.h>

struct alignas(16) KeyPoint{
    float2 location;// texture coordinates. (0,0) is at the upperleft corner, NOT the centre of the upperleft pixel. UpperLeft pixel is (0.5, 0.5)
    half size;
    half response;
    uint8_t angle;//fixed-point, value = (angle / 256.f) * 2 * M_PI
    int8_t octave;//can be -1 if up sampled
    uint8_t layer;//idx of DoG layer in the octave.
    int8_t layer_offset;//[-128, 127] mapped to [-(0.5-1/512), 0.5-1/512]; layer + (layer_offset + 0.5f)/256 falls in range [0, nbOctaveLayers+1], where nbOctaveLayers is 3.
};
static_assert(sizeof(KeyPoint) == 16, "fatal error");

// default width of descriptor histogram array
static const int sift_desc_width = 4;
// default number of bins per histogram in descriptor array
static const int sift_desc_hist_bins = 8;

struct alignas(128) SiftDescriptor{
    uint8_t data[sift_desc_width][sift_desc_width][sift_desc_hist_bins];
};
static_assert(sizeof(SiftDescriptor) == 128, "fatal error");

enum class DescType : int32_t {
    kSIFT,
    kRootSIFT,
    kSOSNet
};