window.c File Reference

Raster Library - Window functions. More...

#include <grass/gis.h>
#include <grass/raster.h>
#include <grass/glocale.h>
#include "R.h"

Include dependency graph for raster/window.c:

Go to the source code of this file.

Functions
void	Rast_get_window (struct Cell_head *window)
	Read the current window.
void	Rast_get_input_window (struct Cell_head *window)
	Read the current input window.
void	Rast_get_output_window (struct Cell_head *window)
	Read the current output window.
int	Rast_window_rows (void)
	Number of rows in active window.
int	Rast_window_cols (void)
	Number of columns in active window.
int	Rast_input_window_rows (void)
	Number of rows in active input window.
int	Rast_input_window_cols (void)
	Number of columns in active input window.
int	Rast_output_window_rows (void)
	Number of rows in active output window.
int	Rast_output_window_cols (void)
	Number of columns in active output window.
double	Rast_northing_to_row (double north, const struct Cell_head *window)
	Northing to row.
double	Rast_easting_to_col (double east, const struct Cell_head *window)
	Easting to column.
double	Rast_row_to_northing (double row, const struct Cell_head *window)
	Row to northing.
double	Rast_col_to_easting (double col, const struct Cell_head *window)
	Column to easting.

Detailed Description

Raster Library - Window functions.

SPDX-FileCopyrightText: 2001-2009 GRASS Development Team SPDX-License-Identifier: GPL-2.0-or-later

Author

Original author CERL

Definition in file raster/window.c.

Function Documentation

Rast_col_to_easting()

double Rast_col_to_easting	(	double	col,
		const struct Cell_head *	window
	)

Column to easting.

Converts a col relative to a window to an easting.

Note: col is a double:

• col+0.0 will return the easting for the western edge of the column.
• col+0.5 will return the easting for the center of the column.
• col+1.0 will return the easting for the eastern edge of the column.

Parameters

	col	column number
[in]	window	pointer to Cell_head

Returns

east coordinate

Definition at line 262 of file raster/window.c.

References Cell_head::ew_res, and Cell_head::west.

Referenced by P_Read_Raster_Region_Map(), and P_Regular_Points().

Rast_easting_to_col()

double Rast_easting_to_col	(	double	east,
		const struct Cell_head *	window
	)

Easting to column.

Converts east relative to a window to a column.

Note: The result is a double. Casting it to an int will give the column number.

Parameters

east	east coordinate
window	pointer to Cell_head

Returns

column number

Definition at line 219 of file raster/window.c.

References Cell_head::ew_res, G_adjust_easting(), and Cell_head::west.

Referenced by Rast_get_sample_bilinear(), Rast_get_sample_cubic(), and Rast_get_sample_nearest().

Rast_get_input_window()

void Rast_get_input_window

(

struct Cell_head *

window

)

Read the current input window.

Parameters

window

pointer to Cell_head

Definition at line 41 of file raster/window.c.

References Rast__init_window(), and R__::rd_window.

Rast_get_output_window()

void Rast_get_output_window

(

struct Cell_head *

window

)

Read the current output window.

Parameters

window

pointer to Cell_head

Definition at line 53 of file raster/window.c.

References Rast__init_window(), and R__::wr_window.

Rast_get_window()

void Rast_get_window

(

struct Cell_head *

window

)

Read the current window.

Parameters

window

pointer to Cell_head

Definition at line 23 of file raster/window.c.

References _, G_fatal_error(), Rast__init_window(), R__::split_window, and R__::wr_window.

Rast_input_window_cols()

int Rast_input_window_cols

(

void

)

Number of columns in active input window.

This routine returns the number of columns in the active input window.

Returns

number of columns

Definition at line 153 of file raster/window.c.

References Rast__init_window(), and R__::rd_window.

Referenced by Rast_allocate_c_input_buf(), Rast_allocate_d_input_buf(), Rast_allocate_f_input_buf(), Rast_allocate_input_buf(), Rast_allocate_null_input_buf(), and Rast_zero_input_buf().

Rast_input_window_rows()

int Rast_input_window_rows

(

void

)

Number of rows in active input window.

This routine returns the number of rows in the active input window.

Returns

number of rows

Definition at line 139 of file raster/window.c.

References Rast__init_window(), and R__::rd_window.

Rast_northing_to_row()

double Rast_northing_to_row	(	double	north,
		const struct Cell_head *	window
	)

Northing to row.

Converts a northing relative to a window to a row.

Note: The result is a double. Casting it to an integer will give the row number.

Parameters

north	northing value
window	pointer to Cell_head

Returns

row number

Definition at line 201 of file raster/window.c.

References Cell_head::north, and Cell_head::ns_res.

Referenced by Rast_get_sample_bilinear(), Rast_get_sample_cubic(), and Rast_get_sample_nearest().

Rast_output_window_cols()

int Rast_output_window_cols

(

void

)

Number of columns in active output window.

This routine returns the number of columns in the active output window.

Returns

number of columns

Definition at line 181 of file raster/window.c.

References Rast__init_window(), and R__::wr_window.

Referenced by Rast_allocate_c_output_buf(), Rast_allocate_d_output_buf(), Rast_allocate_f_output_buf(), Rast_allocate_null_output_buf(), Rast_allocate_output_buf(), and Rast_zero_output_buf().

Rast_output_window_rows()

int Rast_output_window_rows

(

void

)

Number of rows in active output window.

This routine returns the number of rows in the active output window.

Returns

number of rows

Definition at line 167 of file raster/window.c.

References Rast__init_window(), and R__::wr_window.

Rast_row_to_northing()

double Rast_row_to_northing	(	double	row,
		const struct Cell_head *	window
	)

Row to northing.

Converts a row relative to a window to a northing.

Note: row is a double:

• row+0.0 will return the northing for the northern edge of the row.
• row+0.5 will return the northing for the center of the row.
• row+1.0 will return the northing for the southern edge of the row.

Parameters

	row	row number
[in]	window	pointer to Cell_head

Returns

north coordinate

Definition at line 242 of file raster/window.c.

References Cell_head::north, and Cell_head::ns_res.

Referenced by P_Read_Raster_Region_Map(), and P_Regular_Points().

Rast_window_cols()

int Rast_window_cols

(

void

)

Number of columns in active window.

These routines return the number of rows and columns (respectively) in the active module region. Before raster maps can be read or written, it is necessary to known how many rows and columns are in the active region. For example:

int nrows, cols;
int row, col;
 
nrows = Rast_window_rows();
ncols = Rast_window_cols();
for (row = 0; row < nrows; row++) {
// read row ...
for (col = 0; col < ncols; col++) {
// process col ...
}
}

Returns

number of columns

Definition at line 119 of file raster/window.c.

References _, G_fatal_error(), Rast__init_window(), R__::split_window, and R__::wr_window.

Referenced by create_raster(), P_Aux_to_Raster(), Rast_allocate_buf(), Rast_allocate_c_buf(), Rast_allocate_d_buf(), Rast_allocate_f_buf(), Rast_allocate_null_buf(), Rast_get_row_colors(), Rast_get_sample_bilinear(), Rast_get_sample_cubic(), Rast_get_sample_nearest(), Rast_map_to_img_str(), and Rast_zero_buf().

Rast_window_rows()

int Rast_window_rows

(

void

)

Number of rows in active window.

This routine returns the number of rows in the active module window. Before raster files can be read or written, it is necessary to known how many rows are in the active window. For example:

int nrows, cols;
int row, col;
 
nrows = Rast_window_rows();
ncols = Rast_window_cols();
for (row = 0; row < nrows; row++) {
// read row ...
for (col = 0; col < ncols; col++) {
// process col ...
}
}

Returns

number of rows

Definition at line 82 of file raster/window.c.

References _, G_fatal_error(), Rast__init_window(), R__::split_window, and R__::wr_window.

Referenced by create_raster(), I_compute_scatts(), P_Aux_to_Raster(), Rast_get_sample_bilinear(), Rast_get_sample_cubic(), Rast_get_sample_nearest(), and Rast_map_to_img_str().