tesseract/ccstruct/points.cpp

105 lines
3.4 KiB
C++

/**********************************************************************
* File: points.c (Formerly coords.c)
* Description: Member functions for coordinate classes.
* Author: Ray Smith
* Created: Fri Mar 15 08:58:17 GMT 1991
*
* (C) Copyright 1991, Hewlett-Packard Ltd.
** 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 "mfcpch.h" //precompiled headers
#include <stdlib.h>
#include "helpers.h"
#include "ndminx.h"
#include "serialis.h"
#include "points.h"
ELISTIZE (ICOORDELT) //turn to list
bool FCOORD::normalise() { //Convert to unit vec
float len = length ();
if (len < 0.0000000001) {
return false;
}
xcoord /= len;
ycoord /= len;
return true;
}
// Set from the given x,y, shrinking the vector to fit if needed.
void ICOORD::set_with_shrink(int x, int y) {
// Fit the vector into an ICOORD, which is 16 bit.
int factor = 1;
int max_extent = MAX(abs(x), abs(y));
if (max_extent > MAX_INT16)
factor = max_extent / MAX_INT16 + 1;
xcoord = x / factor;
ycoord = y / factor;
}
// The fortran/basic sgn function returns -1, 0, 1 if x < 0, x == 0, x > 0
// respectively.
static int sign(int x) {
if (x < 0)
return -1;
else
return x > 0 ? 1 : 0;
}
// Writes to the given file. Returns false in case of error.
bool ICOORD::Serialize(FILE* fp) const {
if (fwrite(&xcoord, sizeof(xcoord), 1, fp) != 1) return false;
if (fwrite(&ycoord, sizeof(ycoord), 1, fp) != 1) return false;
return true;
}
// Reads from the given file. Returns false in case of error.
// If swap is true, assumes a big/little-endian swap is needed.
bool ICOORD::DeSerialize(bool swap, FILE* fp) {
if (fread(&xcoord, sizeof(xcoord), 1, fp) != 1) return false;
if (fread(&ycoord, sizeof(ycoord), 1, fp) != 1) return false;
if (swap) {
ReverseN(&xcoord, sizeof(xcoord));
ReverseN(&ycoord, sizeof(ycoord));
}
return true;
}
// Setup for iterating over the pixels in a vector by the well-known
// Bresenham rendering algorithm.
// Starting with major/2 in the accumulator, on each step add major_step,
// and then add minor to the accumulator. When the accumulator >= major
// subtract major and step a minor step.
void ICOORD::setup_render(ICOORD* major_step, ICOORD* minor_step,
int* major, int* minor) const {
int abs_x = abs(xcoord);
int abs_y = abs(ycoord);
if (abs_x >= abs_y) {
// X-direction is major.
major_step->xcoord = sign(xcoord);
major_step->ycoord = 0;
minor_step->xcoord = 0;
minor_step->ycoord = sign(ycoord);
*major = abs_x;
*minor = abs_y;
} else {
// Y-direction is major.
major_step->xcoord = 0;
major_step->ycoord = sign(ycoord);
minor_step->xcoord = sign(xcoord);
minor_step->ycoord = 0;
*major = abs_y;
*minor = abs_x;
}
}