// EXAMPLE
// Color bead 0, 0 to red using default plane (0)

PS.color( 0, 0, PS.COLOR_RED );

// Change active plane to 1

PS.gridPlane( 1 );

// Set plane 1 to opaque and assign a new color
// This hides the red plane under the blue

PS.alpha( 0, 0, PS.ALPHA_OPAQUE );
PS.color( 0, 0, PS.COLOR_BLUE );

// Set plane 1 back to transparent
// to see the red plane again

PS.alpha( 0, 0, PS.ALPHA_TRANSPARENT );

var G; // establish global namespace

( function () {
 // Private variables and functions

 var grabX = 0; // current x-position
 var grabY = 0; // current y-position
 var score = 0; // current score
 var goldCount = 0; // number of pieces grabbed
 var goldMax = 10; // max number of gold pieces
 var goldValue = 10; // value of each gold piece

 var wallColor = PS.COLOR_BLACK;
 var archColor = 0x800000; // medium red
 var goldColor = PS.COLOR_YELLOW;
 var grabColor = PS.COLOR_GREEN;

 // Establish planes for geography, gold & grabber

 var floorPlane = 0;
 var goldPlane = 1;
 var grabPlane = 2;
 var archPlane = 3; // so grabber goes "under" arches

 // 15 x 15 map array
 // 0 = wall, 1 = floor, 2 = arch

 var map = [
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0,
 0, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 0,
 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0,
 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0,
 0, 1, 0, 2, 0, 1, 1, 1, 1, 1, 0, 2, 0, 1, 0,
 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0,
 0, 1, 0, 2, 0, 1, 1, 1, 1, 1, 0, 2, 0, 1, 0,
 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0,
 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0,
 0, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 0,
 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0,
 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 ];

 // Private variables and functions
 // This is where G is defined as an object,
 // and its properties initialized

 G = {
 width : 15, // width of grid
 height : 15, // height of grid

 // drawMap()
 // Scans the map data and draws geography,
 // randomly placing gold and grabber

 drawMap : function () {
 var ptr, x, y, data, val, i, loc;

 ptr = 0; // init data pointer
 for ( y = 0; y < G.height; y += 1 ) {
 for ( x = 0; x < G.width; x += 1 ) {
 data = map [ ptr ]; // get map data
 if ( data === 0 ) { // wall?
 PS.gridPlane( floorPlane );
 PS.color( x, y, wallColor );
 }
 else if ( data === 1 ) { // floor?
 PS.gridPlane( floorPlane );

 // Set floor to random gray

 val = ( PS.random(32) - 1 ) + 128;
 PS.color( x, y, val, val, val );
 }
 else if ( data === 2 ) { // arch?
 map[ ptr ] = 1; // change to floor
 PS.gridPlane( archPlane );
 PS.alpha( x, y, PS.ALPHA_OPAQUE );
 PS.color( x, y, archColor );
 }
 ptr += 1; // update pointer
 }
 }

 // Set entire grabber plane to gold
 // Only alpha will need to be manipulated

 PS.gridPlane( goldPlane );
 PS.color( PS.ALL, PS.ALL, goldColor );

 // Randomly place gold pieces on gold plane
 // Some pieces may end up beneath arches!

 for ( i = 0; i < goldMax; i += 1 ) {
 do {
 x = PS.random( 15 ) - 1;
 y = PS.random( 15 ) - 1;
 loc = ( y * G.width ) + x;
 data = map[ loc ]; // get map data
 } while ( data !== 1 ); // must be floor
 map[ loc ] = 4; // place gold in data
 PS.alpha( x, y, PS.ALPHA_OPAQUE );
 }

 // Set entire grabber plane to green
 // Only alpha will need to be manipulated

 PS.gridPlane( grabPlane );
 PS.color( PS.ALL, PS.ALL, grabColor );

 // Randomly place grabber on floor

 do {
 x = PS.random( 15 ) - 1;
 y = PS.random( 15 ) - 1;
 loc = ( y * G.width ) + x;
 data = map[ loc ]; // get map data
 } while ( data !== 1 ); // must be floor
 grabX = x; // save location
 grabY = y;
 PS.alpha( x, y, PS.ALPHA_OPAQUE );
 },

 // move( x, y )
 // Attempts to move grabber relative to
 // current position

 move : function ( x, y ) {
 var nx, ny, loc, data;

 // Calculate proposed new position

 nx = grabX + x;
 ny = grabY + y;

 // Is new location off the grid?
 // If so, return without moving

 if ( ( nx < 0 ) || ( nx >= G.width ) ||
 ( ny < 0 ) || ( ny >= G.height ) ) {
 return;
 }

 // Is there a wall in that location?
 // If map data = 0, it's a wall
 // so return without moving
 // If data = 4, it's gold, so update score

 loc = ( ny * G.width ) + nx;
 data = map[ loc ];
 if ( data === 0 ) {
 return;
 }
 if ( data === 4 ) {
 map[ loc ] = 1; // Change gold to floor
 PS.gridPlane( goldPlane );
 PS.alpha( nx, ny, PS.ALPHA_TRANSPARENT );
 PS.audioPlay( "fx_coin7" );
 score += goldValue;
 goldCount += 1;
 if ( goldCount >= goldMax ) {
 PS.statusText( "You win with $" +
 score + "!" );
 PS.audioPlay( "fx_tada" );
 }
 else {
 PS.statusText( "Score = $" + score );
 }
 }

 // Legal move, so erase grabber's current
 // location and move grabber

 PS.gridPlane( grabPlane );
 PS.alpha ( grabX, grabY, PS.ALPHA_TRANSPARENT );
 PS.alpha( nx, ny, PS.ALPHA_OPAQUE ); // new pos
 grabX = nx;
 grabY = ny;
 PS.audioPlay( "fx_click" );
 }
 };
}() );

PS.init = function( system, options ) {
 PS.gridSize( G.width, G.height ); // init grid
 PS.border( PS.ALL, PS.ALL, 0 ); // no borders
 G.drawMap(); // draws walls
 PS.audioLoad( "fx_click" );// preload sounds
 PS.audioLoad( "fx_coin7" );
 PS.statusText( "Use arrow/WASD keys to grab gold" );
};

PS.keyDown = function( key, shift, ctrl, options ) {
 switch ( key ) {
 case PS.KEY_ARROW_UP:
 case 119: // lower-case w
 case 87: // upper-case W
 {
 G.move( 0, -1 );
 break;
 }
 case PS.KEY_ARROW_DOWN:
 case 115: // lower-case s
 case 83: // upper-case S
 {
 G.move( 0, 1 );
 break;
 }
 case PS.KEY_ARROW_LEFT:
 case 97: // lower-case a
 case 65: // upper-case A
 {
 G.move( -1, 0 );
 break;
 }
 case PS.KEY_ARROW_RIGHT:
 case 100: // lower-case d
 case 68: // upper-case D
 {
 G.move( 1, 0 );
 break;
 }
 }
};