private static string GetKeyDescription(int key)
{
const int startOfKeyObjects = 0x51;
if (key < 0 || key > 7)
{
throw new ArgumentOutOfRangeException(nameof(key));
}
var result = key.ToString();
int objectType = startOfKeyObjects + key;
var objectSprite = SpriteBuilder.ObjectSpriteLookup[objectType];
if (objectSprite != 0x4d)
{
result += " - does not exist";
return(result);
}
var colourScheme = SquarePalette.FromByte(SpriteBuilder.ObjectPaletteLookup[objectType]);
result += $" {colourScheme}";
return(result);
}
public void BuildBackgroundSprite(byte backgroundAndOrientation, SquarePalette palette)
{
byte background = (byte)(backgroundAndOrientation & 0x3f);
bool flipHorizontallyAndRightAlign = (backgroundAndOrientation & 0x80) != 0;
bool flipVerticallyAndBottomAlign = (backgroundAndOrientation & 0x40) != 0;
byte sprite = BackgroundSpriteLookup[background];
byte offsetAlongY = (byte)(BackgroundYOffsetLookup[background] & 0xf0);
var sourceRectangle = SpritePositions[sprite];
bool isSourceFlippedHorizontally = FlipSpriteHorizontally[sprite];
bool isSourceFlippedVertically = FlipSpriteVertically[sprite];
Func <int, int> toX;
if (!flipHorizontallyAndRightAlign && !isSourceFlippedHorizontally)
{
toX = x => x;
}
else if (!flipHorizontallyAndRightAlign) // && isSourceFlippedHorizontally
{
int right = sourceRectangle.Width - 1;
toX = x => right - x;
}
else if (!isSourceFlippedHorizontally) // && flipHorizontallyAndRightAlign
{
int width = SquareSize.Width - 1;
toX = x => width - x;
}
else // if flipHorizontallyAndRightAlign && isSourceFlippedHorizontally
{
var left = SquareSize.Width - sourceRectangle.Width;
toX = x => left + x;
}
if (flipVerticallyAndBottomAlign)
{
offsetAlongY += SpriteHeightLookup[sprite];
offsetAlongY |= 7;
offsetAlongY ^= 0xff;
}
offsetAlongY >>= 3;
Func <int, int> toY;
if (flipVerticallyAndBottomAlign ^ isSourceFlippedVertically)
{
int height = sourceRectangle.Height - 1;
toY = y => (height - y) + offsetAlongY;
}
else
{
toY = y => y + offsetAlongY;
}
for (int y = 0; y < sourceRectangle.Height; y++)
{
for (int x = 0; x < sourceRectangle.Width; x++)
{
int paletteIndex = GetPixelColour(x + sourceRectangle.X, y + sourceRectangle.Y);
Color pixelColour = palette[paletteIndex];
if (paletteIndex == 0)
{
Debug.Assert(pixelColour == Color.Black);
continue;
}
int x2 = toX(x);
int y2 = toY(y);
this.Sprite.SetPixel(x2, y2, pixelColour);
}
}
}
internal static PaletteData GetPalette(ref byte background, ref byte orientation, byte squareX, byte squareY)
{
if (background > 0x3f)
{
throw new ArgumentOutOfRangeException();
}
if ((orientation & 0x3f) != 0)
{
throw new ArgumentOutOfRangeException();
}
// ReSharper disable InlineOutVariableDeclaration
byte accumulator;
// ReSharper restore InlineOutVariableDeclaration
Flags flags = new Flags();
Load(out accumulator, BackgroundPaletteLookup[background], ref flags);
var backgroundPalette = accumulator;
if (!flags.Zero)
{
goto palette_not_zero;
}
// palette 0
Load(out accumulator, squareY, ref flags);
flags.Carry = true;
SubtractWithBorrow(ref accumulator, 0x54, ref flags);
LogicalShiftRight(ref accumulator, ref flags);
LogicalShiftRight(ref accumulator, ref flags);
LogicalShiftRight(ref accumulator, ref flags);
LogicalShiftRight(ref accumulator, ref flags);
byte index = accumulator;
Load(out accumulator, WallPaletteZeroLookup[index], ref flags);
palette_not_zero:
Compare(accumulator, 0x03, ref flags);
if (flags.Carry)
{
goto palette_not_one_or_two;
}
// palette 1 or 2
AddWithCarry(ref accumulator, 0xb1, ref flags);
BitTest(accumulator, squareY, ref flags);
if (!flags.Negative)
{
goto palette_not_six;
}
ArithmeticShiftLeft(ref accumulator, ref flags);
AddWithCarry(ref accumulator, 0x90, ref flags);
palette_not_one_or_two:
Compare(accumulator, 0x03, ref flags);
if (!flags.Zero)
{
goto palette_not_three;
}
// palette 3
Load(out accumulator, orientation, ref flags);
RotateLeft(ref accumulator, ref flags);
RotateLeft(ref accumulator, ref flags);
RotateLeft(ref accumulator, ref flags);
SubtractWithBorrow(ref accumulator, squareY, ref flags);
RotateRight(ref accumulator, ref flags);
flags.Carry = false;
AddWithCarry(ref accumulator, squareX, ref flags);
And(ref accumulator, 0x03, ref flags);
index = accumulator;
accumulator = WallPaletteThreeLookup[index];
palette_not_three:
Compare(accumulator, 0x04, ref flags);
if (!flags.Zero)
{
goto palette_not_four;
}
// palette 4
Load(out accumulator, squareY, ref flags);
RotateLeft(ref accumulator, ref flags);
RotateLeft(ref accumulator, ref flags);
RotateLeft(ref accumulator, ref flags);
RotateLeft(ref accumulator, ref flags);
And(ref accumulator, 0x7, ref flags);
index = accumulator;
accumulator = WallPaletteFourLookup[index];
palette_not_four:
Compare(accumulator, 0x05, ref flags);
if (!flags.Zero)
{
goto palette_not_five;
}
// palette 5
Load(out accumulator, squareY, ref flags);
RotateRight(ref accumulator, ref flags);
RotateRight(ref accumulator, ref flags);
Eor(ref accumulator, squareY, ref flags);
RotateRight(ref accumulator, ref flags);
if (flags.Carry)
{
background = 0x19;
}
RotateRight(ref accumulator, ref flags);
SubtractWithBorrow(ref accumulator, squareY, ref flags);
And(ref accumulator, 0x40, ref flags);
Eor(ref accumulator, orientation, ref flags);
BitTest(accumulator, orientation, ref flags);
orientation = accumulator;
Load(out accumulator, 0xB1, ref flags);
if (!flags.Overflow)
{
goto palette_not_six;
}
AddWithCarry(ref accumulator, 0x0a, ref flags);
palette_not_five:
Compare(accumulator, 0x06, ref flags);
if (!flags.Zero)
{
goto palette_not_six;
}
// palette 6
Load(out accumulator, 0x9c, ref flags);
BitTest(accumulator, orientation, ref flags);
if (!flags.Overflow)
{
goto palette_not_six;
}
Load(out accumulator, 0xcf, ref flags);
palette_not_six:
var displayedPalette = accumulator;
var result = new PaletteData {
BackgroundPalette = backgroundPalette, Palette = SquarePalette.FromByte(displayedPalette)
};
return(result);
}
public void BuildObjectFromDataSprite(byte data, byte orientation)
{
data = (byte)(data & 0x7f);
byte sprite = ObjectSpriteLookup[data];
byte objectPalette = ObjectPaletteLookup[data];
var palette = SquarePalette.FromByte(objectPalette);
var sourceRectangle = SpritePositions[sprite];
bool flipHorizontallyAndRightAlign = (orientation & 0x80) != 0;
bool flipVerticallyAndTopAlign = (orientation & 0x40) != 0;
bool isSourceFlippedHorizontally = FlipSpriteHorizontally[sprite];
bool isSourceFlippedVertically = FlipSpriteVertically[sprite];
Func <int, int> toX;
if (!flipHorizontallyAndRightAlign && !isSourceFlippedHorizontally)
{
toX = x => x;
}
else if (!flipHorizontallyAndRightAlign) // && isSourceFlippedHorizontally
{
int right = sourceRectangle.Width - 1;
toX = x => right - x;
}
else if (!isSourceFlippedHorizontally) // && flipHorizontallyAndRightAlign
{
int width = SquareSize.Width - 1;
toX = x => width - x;
}
else // if flipHorizontallyAndRightAlign && isSourceFlippedHorizontally
{
var left = SquareSize.Width - sourceRectangle.Width;
toX = x => left + x;
}
Func <int, int> toY;
if (!flipVerticallyAndTopAlign && !isSourceFlippedVertically) // so bottom aligned and no flip
{
int yOffset = SquareSize.Height - sourceRectangle.Height;
toY = y => y + yOffset;
}
else if (!isSourceFlippedVertically) // so top align with flip
{
var height = sourceRectangle.Height - 1;
toY = y => height - y;
}
else if (!flipVerticallyAndTopAlign) // so bottom align with flip
{
int bottom = sourceRectangle.Height - 1;
toY = y => bottom - y;
}
else // so top align with flip
{
toY = y => y;
}
for (int y = 0; y < sourceRectangle.Height; y++)
{
for (int x = 0; x < sourceRectangle.Width; x++)
{
int paletteIndex = GetPixelColour(x + sourceRectangle.X, y + sourceRectangle.Y);
Color pixelColour = palette[paletteIndex];
if (paletteIndex == 0)
{
Debug.Assert(pixelColour == Color.Black);
continue;
}
int x2 = toX(x);
int y2 = toY(y);
this.Sprite.SetPixel(x2, y2, pixelColour);
}
}
}
