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// -*- compile-command: "./test_single_testcase.sh TTestCubeMap" -*-
{
Copyright 2008-2022 Michalis Kamburelis.
This file is part of "Castle Game Engine".
"Castle Game Engine" is free software; see the file COPYING.txt,
included in this distribution, for details about the copyright.
"Castle Game Engine" is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
----------------------------------------------------------------------------
}
unit TestCastleCubeMaps;
interface
uses
Classes, SysUtils, Generics.Collections, CastleTester;
type
TTestCubeMap = class(TCastleTestCase)
published
procedure TestReverse;
procedure TestCubeMapSolidAngle;
end;
implementation
uses CastleVectors, CastleInternalCubeMaps, Math;
procedure TTestCubeMap.TestReverse;
var
Side, NewSide: TCubeMapSide;
Pixel, NewPixel: Cardinal;
Dir: TVector3;
begin
for Side := Low(Side) to High(Side) do
for Pixel := 0 to Sqr(CubeMapSize) - 1 do
begin
Dir := CubeMapDirection(Side, Pixel);
DirectionToCubeMap(Dir, NewSide, NewPixel);
AssertTrue(NewSide = Side);
AssertTrue(NewPixel = Pixel);
end;
end;
type
TTesterSingle = class
procedure DoTest(const TestCase: TCastleTestCase);
end;
TTesterDouble = class
procedure DoTest(const TestCase: TCastleTestCase);
end;
TTesterExtended = class
procedure DoTest(const TestCase: TCastleTestCase);
end;
procedure TTesterSingle.DoTest(const TestCase: TCastleTestCase);
var
Side: TCubeMapSide;
Pixel: Cardinal;
SphereArea, SphereArea2: Single;
begin
SphereArea := 0;
SphereArea2 := 0;
for Side := Low(Side) to High(Side) do
for Pixel := 0 to Sqr(CubeMapSize) - 1 do
begin
SphereArea := SphereArea + CubeMapSolidAngle(Side, Pixel);
SphereArea2 := SphereArea2 + (4 * Pi)/(6*Sqr(CubeMapSize));
end;
{ I use SphereArea2 only to test the accuracy of addition:
remember that even if CubeMapSolidAngle would be perfect,
adding "6*Sqr(CubeMapSize)" values together always has some precision
error accumulated.
Results comparing SphereArea2 with (4 * Pi) (accuracy of addition):
Single:
12.566516876220703
12.566370614359173
| - difference here
Double:
12.566370614359418
12.566370614359173
| - difference here
Extended:
12.566370614359173
12.566370614359173
| no visible difference of these digits.
Looked at 30 first decimal digits,
still no difference.
}
{
Writeln(Format('%g', [SphereArea]));
// Writeln(Format('%g', [SphereArea2]));
Writeln(Format('%g', [4 * Pi]));
}
{ CubeMapSolidAngle is a gross approximation now, so we allow quite large
error. }
TestCase.AssertSameValue(4 * Pi, SphereArea, 0.02);
end;
procedure TTesterDouble.DoTest(const TestCase: TCastleTestCase);
var
Side: TCubeMapSide;
Pixel: Cardinal;
SphereArea, SphereArea2: Double;
begin
SphereArea := 0;
SphereArea2 := 0;
for Side := Low(Side) to High(Side) do
for Pixel := 0 to Sqr(CubeMapSize) - 1 do
begin
SphereArea := SphereArea + CubeMapSolidAngle(Side, Pixel);
SphereArea2 := SphereArea2 + (4 * Pi)/(6*Sqr(CubeMapSize));
end;
{ I use SphereArea2 only to test the accuracy of addition:
remember that even if CubeMapSolidAngle would be perfect,
adding "6*Sqr(CubeMapSize)" values together always has some precision
error accumulated.
Results comparing SphereArea2 with (4 * Pi) (accuracy of addition):
Single:
12.566516876220703
12.566370614359173
| - difference here
Double:
12.566370614359418
12.566370614359173
| - difference here
Extended:
12.566370614359173
12.566370614359173
| no visible difference of these digits.
Looked at 30 first decimal digits,
still no difference.
}
{
Writeln(Format('%g', [SphereArea]));
// Writeln(Format('%g', [SphereArea2]));
Writeln(Format('%g', [4 * Pi]));
}
{ CubeMapSolidAngle is a gross approximation now, so we allow quite large
error. }
TestCase.AssertSameValue(4 * Pi, SphereArea, 0.02);
end;
procedure TTesterExtended.DoTest(const TestCase: TCastleTestCase);
var
Side: TCubeMapSide;
Pixel: Cardinal;
SphereArea, SphereArea2: Extended;
begin
SphereArea := 0;
SphereArea2 := 0;
for Side := Low(Side) to High(Side) do
for Pixel := 0 to Sqr(CubeMapSize) - 1 do
begin
SphereArea := SphereArea + CubeMapSolidAngle(Side, Pixel);
SphereArea2 := SphereArea2 + (4 * Pi)/(6*Sqr(CubeMapSize));
end;
{ I use SphereArea2 only to test the accuracy of addition:
remember that even if CubeMapSolidAngle would be perfect,
adding "6*Sqr(CubeMapSize)" values together always has some precision
error accumulated.
Results comparing SphereArea2 with (4 * Pi) (accuracy of addition):
Single:
12.566516876220703
12.566370614359173
| - difference here
Double:
12.566370614359418
12.566370614359173
| - difference here
Extended:
12.566370614359173
12.566370614359173
| no visible difference of these digits.
Looked at 30 first decimal digits,
still no difference.
}
{
Writeln(Format('%g', [SphereArea]));
// Writeln(Format('%g', [SphereArea2]));
Writeln(Format('%g', [4 * Pi]));
}
{ CubeMapSolidAngle is a gross approximation now, so we allow quite large
error. }
TestCase.AssertSameValue(4 * Pi, SphereArea, 0.02);
end;
procedure TTestCubeMap.TestCubeMapSolidAngle;
var
TS: TTesterSingle;
TD: TTesterDouble;
TE: TTesterExtended;
begin
TS := TTesterSingle.Create;
TS.DoTest(Self);
TS.Free;
TD := TTesterDouble.Create;
TD.DoTest(Self);
TD.Free;
TE := TTesterExtended.Create;
TE.DoTest(Self);
TE.Free;
end;
initialization
RegisterTest(TTestCubeMap);
end.
|
