GRASS GIS 8 Programmer's Manual
8.2.2dev(2023)-3d2c704037
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GIS Library - Plotting functions. More...
Go to the source code of this file.
Macros | |
#define | POINT struct point |
#define | OK 0 |
#define | TOO_FEW_EDGES 2 |
#define | NO_MEMORY 1 |
#define | OUT_OF_SYNC -1 |
#define | X(e) (st->left + st->xconv * ((e) - st->window.west)) |
#define | Y(n) (st->top + st->yconv * (st->window.north - (n))) |
#define | EAST(x) (st->window.west + ((x)-st->left)/st->xconv) |
#define | NORTH(y) (st->window.north - ((y)-st->top)/st->yconv) |
Functions | |
void | G_setup_plot (double t, double b, double l, double r, int(*Move)(int, int), int(*Cont)(int, int)) |
Initialize plotting routines. More... | |
void | G_setup_fill (int gap) |
Set row_fill routine to row_solid_fill or row_dotted_fill. More... | |
void | G_plot_where_xy (double east, double north, int *x, int *y) |
Converts east,north to x,y. More... | |
void | G_plot_where_en (int x, int y, double *east, double *north) |
Converts x,y to east,north. More... | |
void | G_plot_point (double east, double north) |
Plot point. More... | |
void | G_plot_line (double east1, double north1, double east2, double north2) |
Plot line between latlon coordinates (fastline) More... | |
void | G_plot_line2 (double east1, double north1, double east2, double north2) |
Plot line between latlon coordinates (slowline) More... | |
int | G_plot_polygon (const double *x, const double *y, int n) |
Plot filled polygon with n vertices. More... | |
int | G_plot_area (double *const *xs, double *const *ys, int *rpnts, int rings) |
Plot multiple polygons. More... | |
void | G_plot_fx (double(*f)(double), double east1, double east2) |
Plot f(east1) to f(east2) More... | |
GIS Library - Plotting functions.
Plot lines and filled polygons. Input space is current window. Output space and output functions are user defined. Converts input east,north lines and polygons to output x,y and calls user supplied line drawing routines to do the plotting.
Handles global wrap-around for lat-lon locations.
Does not perform window clipping. Clipping must be done by the line draw routines supplied by the user.
Note: Hopefully, cartographic style projection plotting will be added later.
(C) 2001-2008, 2013 by the GRASS Development Team
This program is free software under the GNU General Public License (>=v2). Read the file COPYING that comes with GRASS for details.
Definition in file plot.c.
Definition at line 143 of file plot.c.
Referenced by G_plot_where_en().
Definition at line 144 of file plot.c.
Referenced by G_plot_where_en().
int G_plot_area | ( | double *const * | xs, |
double *const * | ys, | ||
int * | rpnts, | ||
int | rings | ||
) |
Plot multiple polygons.
Like G_plot_polygon(), except it takes a set of polygons, each with npts[i] vertices, where the number of polygons is specified with the rings argument. It is especially useful for plotting vector areas with interior islands.
xs | pointer to pointer for X's |
ys | pointer to pointer for Y's |
rpnts | array of ints w/ num points per ring |
rings | number of rings |
void G_plot_fx | ( | double(*)(double) | f, |
double | east1, | ||
double | east2 | ||
) |
Plot f(east1) to f(east2)
The function f(east) is plotted from east1 to east2. The function f(east) must return the map northing coordinate associated with east.
f | plotting function |
east1 | easting (first point) |
east2 | easting (second point) |
Definition at line 779 of file plot.c.
References G_plot_line().
void G_plot_line | ( | double | east1, |
double | north1, | ||
double | east2, | ||
double | north2 | ||
) |
Plot line between latlon coordinates (fastline)
A line from east1,north1 to east2,north2 is plotted in output x,y coordinates (e.g. pixels for graphics.) This routine handles global wrap-around for latitude-longitude databases.
east1,north1 | first point (start line node) |
east2,north2 | second point (end line node) |
Definition at line 207 of file plot.c.
Referenced by G_plot_fx().
void G_plot_line2 | ( | double | east1, |
double | north1, | ||
double | east2, | ||
double | north2 | ||
) |
Plot line between latlon coordinates (slowline)
A line from east1,north1 to east2,north2 is plotted in output x,y coordinates (e.g. pixels for graphics.) This routine handles global wrap-around for latitude-longitude databases.
east1,north1 | first point (start line node) |
east2,north2 | second point (end line node) |
void G_plot_point | ( | double | east, |
double | north | ||
) |
Plot point.
east | easting |
north | northing |
Definition at line 188 of file plot.c.
References G_plot_where_xy(), and x.
int G_plot_polygon | ( | const double * | x, |
const double * | y, | ||
int | n | ||
) |
Plot filled polygon with n vertices.
The polygon, described by the n vertices east,north, is plotted in the output x,y space as a filled polygon.
x | coordinates of vertices |
y | coordinates of vertices |
n | number of vertices |
void G_plot_where_en | ( | int | x, |
int | y, | ||
double * | east, | ||
double * | north | ||
) |
Converts x,y to east,north.
The pixel coordinates x,y are converted to map coordinates east,north.
x | x coordinate |
y | y coordinate |
east | easting |
north | northing |
Definition at line 176 of file plot.c.
References EAST, G_adjust_easting(), and NORTH.
void G_plot_where_xy | ( | double | east, |
double | north, | ||
int * | x, | ||
int * | y | ||
) |
Converts east,north to x,y.
The map coordinates east,north are converted to pixel coordinates x,y.
east | easting |
north | nothing |
x | x coordinate |
y | y coordinate |
Definition at line 158 of file plot.c.
Referenced by G_plot_point().
void G_setup_fill | ( | int | gap | ) |
Set row_fill routine to row_solid_fill or row_dotted_fill.
After calling this function, G_plot_polygon() and G_plot_area() fill shapes with solid or dotted lines. If gap is greater than zero, this value will be used for row_dotted_fill. Otherwise, row_solid_fill is used.
gap |
void G_setup_plot | ( | double | t, |
double | b, | ||
double | l, | ||
double | r, | ||
int(*)(int, int) | Move, | ||
int(*)(int, int) | Cont | ||
) |
Initialize plotting routines.
Initializes the plotting capability. This routine must be called once before calling the G_plot_*() routines described below. The parameters t, b, l, r are the top, bottom, left, and right of the output x,y coordinate space. They are not integers, but doubles to allow for subpixel registration of the input and output coordinate spaces. The input coordinate space is assumed to be the current GRASS region, and the routines supports both planimetric and latitude-longitude coordinate systems.
Move and Cont are subroutines that will draw lines in x,y space. They will be called as follows:
t,b,l,r | top, bottom, left, right |
move | Move function |
Cont | Cont function |
Definition at line 94 of file plot.c.
References b, G_get_set_window(), l, r, and t.