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matrix.rs (4765B)


      1 //  qcms
      2 //  Copyright (C) 2009 Mozilla Foundation
      3 //  Copyright (C) 1998-2007 Marti Maria
      4 //
      5 // Permission is hereby granted, free of charge, to any person obtaining
      6 // a copy of this software and associated documentation files (the "Software"),
      7 // to deal in the Software without restriction, including without limitation
      8 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
      9 // and/or sell copies of the Software, and to permit persons to whom the Software
     10 // is furnished to do so, subject to the following conditions:
     11 //
     12 // The above copyright notice and this permission notice shall be included in
     13 // all copies or substantial portions of the Software.
     14 //
     15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     16 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
     17 // THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     18 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
     19 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
     20 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
     21 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     22 
     23 #[derive(Copy, Clone, Debug, Default)]
     24 pub struct Matrix {
     25    pub m: [[f32; 3]; 3], // Three rows of three elems.
     26 }
     27 
     28 #[derive(Copy, Clone)]
     29 pub struct Vector {
     30    pub v: [f32; 3],
     31 }
     32 
     33 impl Matrix {
     34    pub fn eval(&self, v: Vector) -> Vector {
     35        let mut result: Vector = Vector { v: [0.; 3] };
     36        result.v[0] = self.m[0][0] * v.v[0] + self.m[0][1] * v.v[1] + self.m[0][2] * v.v[2];
     37        result.v[1] = self.m[1][0] * v.v[0] + self.m[1][1] * v.v[1] + self.m[1][2] * v.v[2];
     38        result.v[2] = self.m[2][0] * v.v[0] + self.m[2][1] * v.v[1] + self.m[2][2] * v.v[2];
     39        result
     40    }
     41 
     42    pub fn row(&self, r: usize) -> [f32; 3] {
     43        self.m[r]
     44    }
     45 
     46    //probably reuse this computation in matrix_invert
     47    pub fn det(&self) -> f32 {
     48        let det: f32 = self.m[0][0] * self.m[1][1] * self.m[2][2]
     49            + self.m[0][1] * self.m[1][2] * self.m[2][0]
     50            + self.m[0][2] * self.m[1][0] * self.m[2][1]
     51            - self.m[0][0] * self.m[1][2] * self.m[2][1]
     52            - self.m[0][1] * self.m[1][0] * self.m[2][2]
     53            - self.m[0][2] * self.m[1][1] * self.m[2][0];
     54        det
     55    }
     56    /* from pixman and cairo and Mathematics for Game Programmers */
     57    /* lcms uses gauss-jordan elimination with partial pivoting which is
     58     * less efficient and not as numerically stable. See Mathematics for
     59     * Game Programmers. */
     60    pub fn invert(&self) -> Option<Matrix> {
     61        let mut dest_mat: Matrix = Matrix { m: [[0.; 3]; 3] };
     62        let mut i: i32;
     63 
     64        const a: [i32; 3] = [2, 2, 1];
     65        const b: [i32; 3] = [1, 0, 0];
     66        /* inv  (A) = 1/det (A) * adj (A) */
     67        let mut det: f32 = self.det();
     68        if det == 0. {
     69            return None;
     70        }
     71        det = 1. / det;
     72        let mut j: i32 = 0;
     73        while j < 3 {
     74            i = 0;
     75            while i < 3 {
     76                let ai: i32 = a[i as usize];
     77                let aj: i32 = a[j as usize];
     78                let bi: i32 = b[i as usize];
     79                let bj: i32 = b[j as usize];
     80                let mut p: f64 = (self.m[ai as usize][aj as usize]
     81                    * self.m[bi as usize][bj as usize]
     82                    - self.m[ai as usize][bj as usize] * self.m[bi as usize][aj as usize])
     83                    as f64;
     84                if ((i + j) & 1) != 0 {
     85                    p = -p
     86                }
     87                dest_mat.m[j as usize][i as usize] = (det as f64 * p) as f32;
     88                i += 1
     89            }
     90            j += 1
     91        }
     92        Some(dest_mat)
     93    }
     94    pub fn identity() -> Matrix {
     95        let mut i: Matrix = Matrix { m: [[0.; 3]; 3] };
     96        i.m[0][0] = 1.;
     97        i.m[0][1] = 0.;
     98        i.m[0][2] = 0.;
     99        i.m[1][0] = 0.;
    100        i.m[1][1] = 1.;
    101        i.m[1][2] = 0.;
    102        i.m[2][0] = 0.;
    103        i.m[2][1] = 0.;
    104        i.m[2][2] = 1.;
    105        i
    106    }
    107    pub fn invalid() -> Option<Matrix> {
    108        None
    109    }
    110    /* from pixman */
    111    /* MAT3per... */
    112    pub fn multiply(a: Matrix, b: Matrix) -> Matrix {
    113        let mut result: Matrix = Matrix { m: [[0.; 3]; 3] };
    114        let mut dx: i32;
    115 
    116        let mut o: i32;
    117        let mut dy: i32 = 0;
    118        while dy < 3 {
    119            dx = 0;
    120            while dx < 3 {
    121                let mut v: f64 = 0f64;
    122                o = 0;
    123                while o < 3 {
    124                    v += (a.m[dy as usize][o as usize] * b.m[o as usize][dx as usize]) as f64;
    125                    o += 1
    126                }
    127                result.m[dy as usize][dx as usize] = v as f32;
    128                dx += 1
    129            }
    130            dy += 1
    131        }
    132        result
    133    }
    134 }