program animate;
uses sprites,pcmaudio;

type PictData = record
		magic,mode:integer;
		palette: array [0..15] of integer;
		pixeldata: array [0..31999] of integer;
     end;

     Sprite = record
     	x,y:integer;
     	xdelta,ydelta:integer;
     	curFrame:integer;
     	frameCount:integer;
     	frameTime:integer;
     	frameLeft:integer;
     	moveTime:integer;
     	moveLeft:integer;
     	changed:boolean;
     	frame:array [0..3] of SpritePixels;
    end;

var pic:PictData;
    infile:file;
    ch:char;
    stickMan:Sprite;
    rocket:Sprite;
    rocket2:Sprite;
    rocket3:Sprite;

    buf:SndBufPtr;


procedure WaitVSync; external;

function readAudioFile(fname:string):SndBufPtr;
var size:integer;
    buf:SndBufPtr;
    f:file;
begin
	open(f, fname, ModeReadOnly);
	size := FileSize(f);
	new(buf, size);

	ReadSample(f, buf);

	writeln;
	close(f);
	readAudioFile := buf;	
end;

procedure changePalette(var pic:PictData);
var i:integer;
begin
	for i := 0 to 15 do
		setpalette(i, pic.palette[i]);
end;

procedure showPic(var pic:PictData);
begin
	PutScreen(pic.pixeldata);
end;

procedure loadPic(filename:string;var pic:PictData);
var infile:file;
begin
        open(infile, filename, ModeReadonly);
        read(infile, pic);
        close(infile);

        writeln('magic: ', pic.magic, ' mode:', pic.mode);
end;

procedure loadSpriteFrame(var aSprite:Sprite;spriteIndex:integer;
		var sheetFile:file;sheetIndex:integer);
begin
	seek(sheetFile, 8 + sheetIndex * 512);
	read(sheetFile, aSprite.frame[spriteIndex]);
	if aSprite.frameCount <= spriteIndex then
		aSprite.frameCount := spriteIndex + 1;

	aSprite.curFrame := 0;
	writeln('loaded sprite frame ', spriteIndex, ' from ', sheetIndex);
end;

procedure animateSprite(var aSprite:Sprite);
var frameIndex:integer;
    frameTime,frameLeft:integer;
    moveTime,moveLeft:integer;
    ydelta:integer;
begin
	ydelta := aSprite.ydelta;
	frameIndex := aSprite.curFrame;
	frameTime := aSprite.frameTime;
	frameLeft := aSprite.frameLeft;
	moveTime := aSprite.moveTime;
	moveLeft := aSprite.moveLeft;

	frameLeft := frameLeft - 1;
	if frameLeft <= 0 then
	begin
		frameIndex := frameIndex + 1;
		frameLeft := frameTime;
		aSprite.curFrame := frameIndex;
		if frameIndex >= aSprite.frameCount then
			aSprite.curFrame := 0;
	end;

	moveLeft := moveLeft - 1;
	if moveLeft <= 0 then
	begin
		aSprite.x := aSprite.x + aSprite.xdelta;
		aSprite.y := aSprite.y + aSprite.ydelta;
		moveLeft := moveTime;

		if aSprite.x > 608 then aSprite.x := 0;

		if aSprite.ydelta <> 0 then
		begin
			if aSprite.y < 3 then
				aSprite.ydelta := -aSprite.ydelta
			else
			if aSprite.y > 130 then
				aSprite.ydelta := -aSprite.yDelta;
		end;
	end;
	
	aSprite.frameLeft := frameLeft;
	aSprite.moveLeft := moveLeft;
end;

procedure animLoop;
var i:integer;
    lastX,lastY:integer;
    rlastX,rlastY:integer;
    r2lastX,r2lastY:integer;
    r3lastX,r3lastY:integer;
begin
	stickMan.x := 0;
	stickMan.y := 205;
	stickMan.frameTime := 6;
	stickMan.frameLeft := stickMan.frameTime;
	stickMan.curFrame := 0;
	stickMan.xdelta := 2;
	stickMan.ydelta := 0;
	stickMan.moveTime := 2;
	stickman.moveLeft := stickMan.moveTime;

	rocket.x := 0;
	rocket.y := 50;
	rocket.frameTime := 5;
	rocket.frameLeft := rocket.frameTime;
	rocket.curFrame := 0;
	rocket.xdelta := 3;
	rocket.ydelta := 1;
	rocket.moveTime := 1;
	rocket.moveLeft := rocket.moveTime;

	rocket2.x := 50;
	rocket2.y := 190;
	rocket2.frameTime := 5;
	rocket2.frameLeft := rocket2.frameTime;
	rocket2.curFrame := 1;
	rocket2.xdelta := 3;
	rocket2.ydelta := 0;
	rocket2.moveTime := 1;
	rocket2.moveLeft := rocket2.moveTime;

	rocket3.x :=100;
	rocket3.y := 90;
	rocket3.frameTime := 5;
	rocket3.frameLeft := rocket3.frameTime;
	rocket3.curFrame := 2;
	rocket3.xdelta := 3;
	rocket3.ydelta := -1;
	rocket3.moveTime := 1;
	rocket3.moveLeft := rocket3.moveTime;

	while not ConAvail do
	begin
		lastX := stickMan.x;
		lastY := stickMan.y;

		rlastX := rocket.x;
		rlastY := rocket.y;

		r2lastX := rocket2.x;
		r2lastY := rocket2.y;

		r3lastX := rocket3.x;
		r3lastY := rocket3.y;

		PutSprite(rlastX, rlastY, rocket.frame[rocket.curFrame]);
		PutSprite(r2lastX, r2lastY, rocket2.frame[rocket2.curFrame]);
		PutSprite(r3lastX, r3lastY, rocket3.frame[rocket3.curFrame]);
		PutSprite(lastX, lastY, stickMan.frame[stickMan.curFrame]);

		animateSprite(rocket);
		animateSprite(rocket2);
		animateSprite(rocket3);
		animateSprite(stickMan);

		Delay(10);
		WaitVSync;

		UndrawSprite(lastX, lastY, pic.pixeldata);
		UndrawSprite(rlastX, rlastY, pic.pixeldata);
		UndrawSprite(r2lastX, r2lastY, pic.pixeldata);
		UndrawSprite(r3lastX, r3lastY, pic.pixeldata);
	end;
end;

begin
	loadPic('background.pict', pic);
	loadPalette(pic);
	showPic(pic);

	open(infile, 'walking.sprt', ModeReadOnly);
	loadSpriteFrame(stickMan, 0, infile, 0);
	loadSpriteFrame(stickMan, 1, infile, 1);
	loadSpriteFrame(stickMan, 2, infile, 2);
	loadSpriteFrame(stickMan, 3, infile, 3);
	close(infile);

	open(infile, 'rocket.sprt', ModeReadOnly);
	loadSpriteFrame(rocket, 0, infile, 0);
	loadSpriteFrame(rocket, 1, infile, 1);
	loadSpriteFrame(rocket, 2, infile, 2);
	loadSpriteFrame(rocket, 3, infile, 3);
	close(infile);

	rocket2 := rocket;
	rocket3 := rocket;

	buf := readAudioFile('footsteps.tdrau');
	SampleQStart(buf, true, 16000);
	
	animLoop;

	SampleQStop;
	dispose(buf);
end.