/* * Copyright 2007 ZXing authors * * 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. */ // package com::google::zxing::common; /** * Implementations of this class can, given locations of finder patterns for a QR code in an * image, sample the right points in the image to reconstruct the QR code, accounting for * perspective distortion. It is abstracted since it is relatively expensive and should be allowed * to take advantage of platform-specific optimized implementations, like Sun's Java Advanced * Imaging library, but which may not be available in other environments such as J2ME, and vice * versa. * * The implementation used can be controlled by calling {@link #setGridSampler(GridSampler)} * with an instance of a class which implements this interface. * * @author Sean Owen */ let grid_sampler: GridSampler = DefaultGridSampler::new(); pub struct GridSampler { } impl GridSampler { /** * Sets the implementation of GridSampler used by the library. One global * instance is stored, which may sound problematic. But, the implementation provided * ought to be appropriate for the entire platform, and all uses of this library * in the whole lifetime of the JVM. For instance, an Android activity can swap in * an implementation that takes advantage of native platform libraries. * * @param newGridSampler The platform-specific object to install. */ pub fn set_grid_sampler( new_grid_sampler: &GridSampler) { grid_sampler = new_grid_sampler; } /** * @return the current implementation of GridSampler */ pub fn get_instance() -> GridSampler { return grid_sampler; } /** * Samples an image for a rectangular matrix of bits of the given dimension. The sampling * transformation is determined by the coordinates of 4 points, in the original and transformed * image space. * * @param image image to sample * @param dimensionX width of {@link BitMatrix} to sample from image * @param dimensionY height of {@link BitMatrix} to sample from image * @param p1ToX point 1 preimage X * @param p1ToY point 1 preimage Y * @param p2ToX point 2 preimage X * @param p2ToY point 2 preimage Y * @param p3ToX point 3 preimage X * @param p3ToY point 3 preimage Y * @param p4ToX point 4 preimage X * @param p4ToY point 4 preimage Y * @param p1FromX point 1 image X * @param p1FromY point 1 image Y * @param p2FromX point 2 image X * @param p2FromY point 2 image Y * @param p3FromX point 3 image X * @param p3FromY point 3 image Y * @param p4FromX point 4 image X * @param p4FromY point 4 image Y * @return {@link BitMatrix} representing a grid of points sampled from the image within a region * defined by the "from" parameters * @throws NotFoundException if image can't be sampled, for example, if the transformation defined * by the given points is invalid or results in sampling outside the image boundaries */ pub fn sample_grid(&self, image: &BitMatrix, dimension_x: i32, dimension_y: i32, p1_to_x: f32, p1_to_y: f32, p2_to_x: f32, p2_to_y: f32, p3_to_x: f32, p3_to_y: f32, p4_to_x: f32, p4_to_y: f32, p1_from_x: f32, p1_from_y: f32, p2_from_x: f32, p2_from_y: f32, p3_from_x: f32, p3_from_y: f32, p4_from_x: f32, p4_from_y: f32) -> /* throws NotFoundException */Result> ; pub fn sample_grid(&self, image: &BitMatrix, dimension_x: i32, dimension_y: i32, transform: &PerspectiveTransform) -> /* throws NotFoundException */Result> ; /** *

Checks a set of points that have been transformed to sample points on an image against * the image's dimensions to see if the point are even within the image.

* *

This method will actually "nudge" the endpoints back onto the image if they are found to be * barely (less than 1 pixel) off the image. This accounts for imperfect detection of finder * patterns in an image where the QR Code runs all the way to the image border.

* *

For efficiency, the method will check points from either end of the line until one is found * to be within the image. Because the set of points are assumed to be linear, this is valid.

* * @param image image into which the points should map * @param points actual points in x1,y1,...,xn,yn form * @throws NotFoundException if an endpoint is lies outside the image boundaries */ pub fn check_and_nudge_points( image: &BitMatrix, points: &Vec) -> /* throws NotFoundException */Result> { let width: i32 = image.get_width(); let height: i32 = image.get_height(); // Check and nudge points from start until we see some that are OK: let mut nudged: bool = true; // points.length must be even let max_offset: i32 = points.len() - 1; { let mut offset: i32 = 0; while offset < max_offset && nudged { { let x: i32 = points[offset] as i32; let y: i32 = points[offset + 1] as i32; if x < -1 || x > width || y < -1 || y > height { throw NotFoundException::get_not_found_instance(); } nudged = false; if x == -1 { points[offset] = 0.0f; nudged = true; } else if x == width { points[offset] = width - 1.0; nudged = true; } if y == -1 { points[offset + 1] = 0.0f; nudged = true; } else if y == height { points[offset + 1] = height - 1.0; nudged = true; } } offset += 2; } } // Check and nudge points from end: nudged = true; { let mut offset: i32 = points.len() - 2; while offset >= 0 && nudged { { let x: i32 = points[offset] as i32; let y: i32 = points[offset + 1] as i32; if x < -1 || x > width || y < -1 || y > height { throw NotFoundException::get_not_found_instance(); } nudged = false; if x == -1 { points[offset] = 0.0f; nudged = true; } else if x == width { points[offset] = width - 1.0; nudged = true; } if y == -1 { points[offset + 1] = 0.0f; nudged = true; } else if y == height { points[offset + 1] = height - 1.0; nudged = true; } } offset -= 2; } } } }