PROGRAMMING IN THE AUTON PROJECT AND SCHENLEY PARK RESEARCH

CONTENTS

INTRODUCTION
PICTURES
----- DRAWING FUNCTIONS:
----- COLOR FUNCTIONS:
----- NOW BACK TO APICTS
THE SIMPLEST FORM OF DRAWING DIRECTLY
----- Saving graphics to Postscript
----- Rescaling the drawing region.
2-d line and dot plotting (lingraphs)
3-d surface and dot plotting (surgraphs)

INTRODUCTION

PICTURES

      #include "apict.h"

The only abstract data type involved is called an apict. It represents a picture. Elements of these pictures may be circles, lines, strings, rectangles, and discs (solid circles).

To begin drawing a picture, call void apict_on(). Then you may use any of the following functions to draw into a global picture defined on a square area of width and height 512.0 units, in which coordinates are represented by (x,y) pairs. The origin (0,0) is the bottom left hand corner. x (a double) is the horizontal distance. y (also a double) is the vertical distance.

DRAWING FUNCTIONS:

      void ag_dot(double x, double y)
      void ag_line(double u, double v, double x, double y)
      void ag_circle(double x, double y, double r)
      void ag_box(double x_botleft, double y_botleft, double x_tr, double y_tr)
      double x_topright, double y_topright)
      void ag_disc(double x, double y, double r)
      void ag_print(double x, double y, char *s)

COLOR FUNCTIONS:

There are 16 colors which may be used (though that number may later be reduced to 8). The colors are represented by amut_colors, which are #defined integer constants from amxw.h. They have imaginative names like AG_RED.

      void ag_set_pen_color(int amut_col)
      int ag_pen_color()
      int ag_spectrum_color(double fract)

NOW BACK TO APICTS

To create an apict call

      apict_on()

      apict *apict_off()

To display the picture on Unix under X-windows, call render_apict(). On Windows NT under Visual C++, the top level user interface has its own methods of rendering apicts, and all you have to do is return those apicts to the top level user interface.

Here are other functions on apicts:

      void free_apict(apict *g)
      apict *mk_copy_apict(apict *ap)

There also exist apict_sets for people who wish to produce sequences of pictures. Andrew will document this (Andrew!)

THE SIMPLEST FORM OF DRAWING DIRECTLY

Instead of creating an apict and then rendering it, you can simply call

      ag_on("")

This (Under X) will pop up a square white window in the top left of the screen. Then commands like ag_line() ag_dot etc will draw within the window.

When you have finished drawing, we recommend you call ag_off(). The window won't disappear, but it is important if you want to save stuff to Postscript. You may call ag_on("") at any time. If you have previously called it, then all that will happen is that the square window will be blanked out.

Saving graphics to Postscript

Instead of calling ag_on(""), call ag_on("test.ps") (or a filename of your choice). Then when you next call ag_off() you'll find a file called test.ps has been created with the picture (and appropriate bounding boxes etc) defined. These pictures can be inserted directly into latex reports with \psfig.

Rescaling the drawing region.

By default, when you call ag_on(""), the bottom left hand of the image will correspond to coordinates (0,0) and the top right will be coordinates (512,512). If instead you wish the bottom left to be (xlo,ylo) and the top right to be (xhi,yhi) just call

      void set_ag_frame(double xlo,double ylo,double xhi,double yhi);

2-d line and dot plotting (lingraphs)

See lingraph.h in the draw library

3-d surface and dot plotting (surgraphs)

See drac.h in the draw library. Seach for "surgraph" and you can ignore all the low-level contour plotting stuff.