tesseract/classify/xform2d.cpp
theraysmith 694d3f2c20 Changes to classify for 3.00
git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk@291 d0cd1f9f-072b-0410-8dd7-cf729c803f20
2009-07-11 02:17:36 +00:00

121 lines
3.5 KiB
C++

/******************************************************************************
** Filename: xform2d.c
** Purpose: Library routines for performing 2D point transformations
** Author: Dan Johnson
** History: Fri Sep 22 09:54:17 1989, DSJ, Created.
**
** (c) Copyright Hewlett-Packard Company, 1988.
** 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.
******************************************************************************/
/**----------------------------------------------------------------------------
Include Files and Type Defines
----------------------------------------------------------------------------**/
#include "xform2d.h"
#include <math.h>
/**----------------------------------------------------------------------------
Public Code
----------------------------------------------------------------------------**/
void InitMatrix(MATRIX_2D *M) {
M->a = 1;
M->b = 0;
M->c = 0;
M->d = 1;
M->tx = 0;
M->ty = 0;
}
void CopyMatrix(MATRIX_2D *A, MATRIX_2D *B) {
B->a = A->a;
B->b = A->b;
B->c = A->c;
B->d = A->d;
B->tx = A->tx;
B->ty = A->ty;
}
void TranslateMatrix(MATRIX_2D *M, FLOAT32 X, FLOAT32 Y) {
M->tx += M->a * X + M->c * Y;
M->ty += M->b * X + M->d * Y;
}
void ScaleMatrix(MATRIX_2D *M, FLOAT32 X, FLOAT32 Y) {
M->a *= X;
M->b *= X;
M->c *= Y;
M->d *= Y;
}
void MirrorMatrixInX(MATRIX_2D *M) {ScaleMatrix(M, -1, 1);}
void MirrorMatrixInY(MATRIX_2D *M) {ScaleMatrix(M, 1, -1);}
void MirrorMatrixInXY(MATRIX_2D *M) {ScaleMatrix(M, -1, -1);}
FLOAT32 MapX(MATRIX_2D *M, FLOAT32 X, FLOAT32 Y) {
return M->a * (X) + (M)->c * (Y) + (M)->tx;
}
FLOAT32 MapY(MATRIX_2D *M, FLOAT32 X, FLOAT32 Y) {
return M->b * X + M->d * Y + M->ty;
}
void MapPoint(MATRIX_2D *M, const FPOINT &A, FPOINT* B) {
B->x = MapX(M, A.x, A.y);
B->y = MapY(M, A.x, A.y);
}
FLOAT32 MapDx(MATRIX_2D *M, FLOAT32 DX, FLOAT32 DY) {
return M->a * DX + M->c * DY;
}
FLOAT32 MapDy(MATRIX_2D *M, FLOAT32 DX, FLOAT32 DY) {
return M->b * DX + M->d * DY;
}
/*---------------------------------------------------------------------------*/
void RotateMatrix(MATRIX_2D_PTR Matrix, FLOAT32 Angle) {
/*
** Parameters:
** Matrix transformation matrix to rotate
** Angle angle to rotate matrix
** Globals: none
** Operation:
** Rotate the coordinate system (as specified by Matrix) about
** its origin by Angle radians. In matrix notation the
** effect is as follows:
**
** Matrix = R X Matrix
**
** where R is the following matrix
**
** cos Angle sin Angle 0
** -sin Angle cos Angle 0
** 0 0 1
** Return: none
** Exceptions: none
** History: 7/27/89, DSJ, Create.
*/
FLOAT32 Cos, Sin;
FLOAT32 NewA, NewB;
Cos = cos ((double) Angle);
Sin = sin ((double) Angle);
NewA = Matrix->a * Cos + Matrix->c * Sin;
NewB = Matrix->b * Cos + Matrix->d * Sin;
Matrix->c = Matrix->a * -Sin + Matrix->c * Cos;
Matrix->d = Matrix->b * -Sin + Matrix->d * Cos;
Matrix->a = NewA;
Matrix->b = NewB;
} /* RotateMatrix */