/// <summary>
/// Converts this image to an RGBA image with the palette provided.
/// </summary>
/// <param name="palette">The palette to convert with.</param>
/// <returns>The RGBA image.</returns>
public RgbaImage ToColor(Palette palette)
{
PaletteLayer paletteLayer = palette.Default;
Color[] pixels = new Color[Area];
for (int i = 0; i < Area; i++)
{
// TODO: Could we extend the palette by 1 and set it to be transparent to avoid branching *every* pixel?
short index = Indices[i];
Color color = index == TransparentIndex ? RgbaImage.Transparent : paletteLayer[index];
pixels[i] = color;
}
RgbaImage image = RgbaImage.From(Width, Height, pixels).Value;
image.Namespace = Namespace;
image.Offset = Offset;
return(image);
}
/// <summary>
/// Takes the image given and draws it on top of the current image.
/// Does not draw a pixel if the alpha is not fully opaque (as in
/// alpha must be >= 1.0f).
/// </summary>
/// <param name="image">The image to draw on top.</param>
/// <param name="topLeft">The top left corner to start drawing the
/// image from.</param>
/// <returns>True on success, false if it could not be written due to
/// bounding issues (ex: image would write outside the bounds).
/// </returns>
public bool DrawOntoThis(RgbaImage image, Vec2I topLeft)
{
// We want to find the area we draw. This is effectively finding
// the rectangle overlap. If there is none, we exit early.
Vec2I drawStart = new Vec2I(Math.Max(0, topLeft.X), Math.Max(0, topLeft.Y));
Vec2I drawEnd = new Vec2I(Math.Min(topLeft.X + image.Width, Width), Math.Min(topLeft.Y + image.Height, Height));
Vec2I drawRange = drawEnd - drawStart;
if (drawRange.X <= 0 || drawRange.Y <= 0)
{
return(false);
}
// The starting coordinate from the source image is usually from
// the top left corner, but if the offset is negative then we are
// going to have to draw from the insides of the source image.
Vec2I srcStart = Vec2I.Zero;
if (topLeft.X < 0)
{
srcStart = srcStart.WithX(-topLeft.X);
}
if (topLeft.Y < 0)
{
srcStart = srcStart.WithY(-topLeft.Y);
}
// The destination coordinate is usually at the top left coordinate
// provided, but if the top left is negative then we will start our
// drawing at the zero index for that axis. If we have no drawing
// overlap we'd have exited early before reaching this, so starting
// at zero is okay.
Vec2I destStart = topLeft;
if (destStart.X < 0)
{
destStart = destStart.WithX(0);
}
if (destStart.Y < 0)
{
destStart = destStart.WithY(0);
}
// Now we have enough info to draw.
RgbaImage src = image;
RgbaImage dest = this;
int srcOffset = (srcStart.Y * src.Width) + srcStart.X;
int destOffset = (destStart.Y * dest.Width) + destStart.X;
try
{
for (int y = 0; y < drawRange.Y; y++)
{
int srcIndex = srcOffset;
int destIndex = destOffset;
for (int x = 0; x < drawRange.X; x++)
{
// For now, only draw the pixel if it is opaque. In the
// future we can do alpha blending.
Color srcColor = src.Pixels[srcIndex];
if (srcColor.a >= 1.0f)
{
dest.Pixels[destIndex] = srcColor;
}
srcIndex++;
destIndex++;
}
srcOffset += src.Width;
destOffset += dest.Width;
}
return(true);
}
catch
{
return(false);
}
}