Richard Ellingworth / BarIndicator

Used to draw horizontal bar indicators using characters on a Gameduino display. Requires Gameduino library.

This is used to display moving bar style indicators on a Gameduino VGA display. You will require the Gameduino library in order to use this. The indicators are made up of a horizontal strip of characters. The left side of the indicator represents the minimum possible reading and the right side represents the maximum possible reading. When you draw the indicator you specify what reading to display and the code works out which characters to display so that a bar is drawn starting at the left and extending right up to an appropriate position. The BarIndicator class allows you to specify the location of the indicator on the screen, the length of the indicator (the number of characters to use) and the minimum and maximum values for the bar. You can also change which section of the character set to use when drawing the bar.

BarIndicator.cpp

Committer:
RichardE
Date:
2012-11-11
Revision:
3:6607ad01c5a1
Parent:
0:d4ba843a0e6a

File content as of revision 3:6607ad01c5a1:

/*
 * SOURCE FILE : BarIndicator.cpp
 *
 * Definition of class BarIndicator.
 *
 */

#include "BarIndicator.h"

/** Constructor.
 */
BarIndicator::BarIndicator() :
    startCode( 128 ),
    min( (float)0 ),
    max( (float)100 ),
    xco( 0 ),
    yco( 0 ),
    length( 10 )
{
}

/** Destructor.
 */
BarIndicator::~BarIndicator() {
}

/** Draw bar indicator.
 * Invalid readings are drawn using a greyed out indicator.
 * @param gd Pointer to Gameduino to use for drawing.
 * @param reading Reading to display on indicator.
 * @param valid True if reading is valid, False if not.
 */
void BarIndicator::Draw( Gameduino *gd, float reading, bool valid ) {
    char text[] = "X";
    if( valid ) {
        // Work out fraction of indicator link that is filled.
        float frac = ( reading - min ) / ( max - min );
        // Don't allow fraction to stray outside of range 0.0 to 1.0.
        if( frac < (float)0 ) {
          frac = (float)0;
        }
        else if( frac > (float)1 ) {
          frac = (float)1;
        }
        // Work out character position of character that is partially filled.
        UInt8 pos = (UInt8)( frac * (float)length );
        // Draw filled part of indicator.
        UInt8 x;
        text[ 0 ] = (char)( startCode + 8 );
        for( x = xco; x < xco + pos; ++x ) {
          gd->putstr( x, yco, text );
        }
        // Don't do rest if indicator is at maximum.
        if( pos < length ) {
            // Work out how much of next character needs to be filled.
            UInt8 rem = (UInt8)( (int)floor( frac * (float)length * (float)8 ) & 7 );
            // Draw partially filled character.
            text[ 0 ] = startCode + rem;
            gd->putstr( xco + pos, yco, text );
            // Draw unfilled characters for remainder of indicator.
            text[ 0 ] = (char)( startCode + 0 );
            for( x = xco + pos + 1; x < xco + length; ++x ) {
              gd->putstr( x, yco, text );
            }
        }
    }
    else {
        // Draw greyed out characters for whole indicator.
        text[ 0 ] = (char)( startCode + 9 );
        for( UInt8 x = xco; x < xco + length; ++x ) {
          gd->putstr( x, yco, text );
        }
    }
}