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{
Ported to FPC by Nikolay Nikolov (nickysn@users.sourceforge.net)
}
{
Tunnel demo for OpenPTC 1.0 C++ API
Originally coded by Thomas Rizos (rizos@swipnet.se)
Adapted for OpenPTC by Glenn Fiedler (ptc@gaffer.org)
This source code is licensed under the GNU GPL
}
program Tunnel;
{$MODE objfpc}
uses
ptc, Math;
type
{ tunnel class }
TTunnel = class
public
constructor Create;
destructor Destroy; override;
procedure setup;
procedure draw(buffer: PUint32; t: Single);
private
{ tunnel data }
tunnel: PUint32;
texture: PUint8;
end;
constructor TTunnel.Create;
begin
{ allocate tables }
tunnel := GetMem(320*200*SizeOf(Uint32));
texture := GetMem(256*256*2*SizeOf(Uint8));
{ setup }
setup;
end;
destructor TTunnel.Destroy;
begin
{ free tables }
FreeMem(tunnel);
FreeMem(texture);
inherited Destroy;
end;
procedure TTunnel.setup;
var
index: Integer;
x, y: Integer;
angle, angle1, angle2, radius, u, v: Double;
begin
{ tunnel index }
index := 0;
{ generate tunnel table }
for y := 100 DownTo -99 do
for x := -160 to 159 do
begin
{ calculate angle from center }
angle := arctan2(y, x) * 256 / pi / 2;
{ calculate radius from center }
radius := sqrt(x * x + y * y);
{ clamp radius to minimum }
if radius < 1 then
radius := 1;
{ texture coordinates }
u := angle;
v := 6000 / radius;
{ calculate texture index for (u,v) }
tunnel[index] := (Trunc(v) and $FF) * 256 + (Trunc(u) and $FF);
Inc(index);
end;
{ generate blue plasma texture }
index := 0;
angle2 := pi * 2/256 * 230;
for y := 0 to 256 * 2 - 1 do
begin
angle1 := pi * 2/256 * 100;
for x := 0 to 256-1 do
begin
texture[index] := Trunc(sin(angle1)*80 + sin(angle2)*40 + 128);
angle1 := angle1 + pi*2/256*3;
Inc(index);
end;
angle2 := angle2 + pi * 2/256 *2;
end;
end;
procedure TTunnel.draw(buffer: PUint32; t: Single);
var
x, y: Integer;
scroll: Uint32;
i: Integer;
begin
{ tunnel control functions }
x := Trunc(sin(t) * 99.9);
y := Trunc(t * 200);
{ calculate tunnel scroll offset }
scroll := ((y and $FF) shl 8) + (x and $FF);
{ loop through each pixel }
for i := 0 to 64000-1 do
{ lookup tunnel texture }
buffer[i] := texture[tunnel[i] + scroll];
end;
var
format: IPTCFormat;
console: IPTCConsole;
surface: IPTCSurface;
TheTunnel: TTunnel = nil;
time, delta: Single;
buffer: PUint32;
begin
try
try
{ create format }
format := TPTCFormatFactory.CreateNew(32, $00FF0000, $0000FF00, $000000FF);
{ create console }
console := TPTCConsoleFactory.CreateNew;
{ open console }
console.open('Tunnel demo', 320, 200, format);
{ create surface }
surface := TPTCSurfaceFactory.CreateNew(320, 200, format);
{ create tunnel }
TheTunnel := TTunnel.Create;
{ time data }
time := 0;
delta := 0.03;
{ loop until a key is pressed }
while not console.KeyPressed do
begin
{ lock surface }
buffer := surface.lock;
try
{ draw tunnel }
TheTunnel.draw(buffer, time);
finally
{ unlock surface }
surface.unlock;
end;
{ copy to console }
surface.copy(console);
{ update console }
console.update;
{ update time }
time := time + delta;
end;
finally
TheTunnel.Free;
if Assigned(console) then
console.close;
end;
except
on error: TPTCError do
{ report error }
error.report;
end;
end.
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