//Draws a circle on the bitmap using Bresenham
public static PixelMatrix BresenhamCircle(PixelMatrix bitmap, int centerX, int centerY, int radius, Color color)
{
int d = (5 - radius * 4) / 4;
int x = 0;
int y = radius;
do
{
bitmap.SetPixel(centerX + x, centerY + y, color);
bitmap.SetPixel(centerX + x, centerY - y, color);
bitmap.SetPixel(centerX - x, centerY + y, color);
bitmap.SetPixel(centerX - x, centerY - y, color);
bitmap.SetPixel(centerX + y, centerY + x, color);
bitmap.SetPixel(centerX + y, centerY - x, color);
bitmap.SetPixel(centerX - y, centerY + x, color);
bitmap.SetPixel(centerX - y, centerY - x, color);
if (d < 0)
{
d += 2 * x + 1;
}
else
{
d += 2 * (x - y) + 1;
y--;
}
x++;
} while (x <= y);
return(bitmap);
}
//Draws a line on the bitmap using Bresenham
public static PixelMatrix BresenhamLine(PixelMatrix bitmap, int x0, int y0, int x1, int y1, Color color)
{
int dx = Mathf.Abs(x1 - x0), sx = x0 < x1 ? 1 : -1;
int dy = Mathf.Abs(y1 - y0), sy = y0 < y1 ? 1 : -1;
int err = (dx > dy ? dx : -dy) / 2, e2;
do
{
bitmap.SetPixel(x0, y0, color);
if (x0 == x1 && y0 == y1)
{
break;
}
e2 = err;
if (e2 > -dx)
{
err -= dy;
x0 += sx;
}
if (e2 < dy)
{
err += dx;
y0 += sy;
}
} while (true);
return(bitmap);
}
//Add a decal to an image
public static PixelMatrix Decal(PixelMatrix original, PixelMatrix decal, int x, int y)
{
//Offsets to apply
int widthOffset = -decal.width / 2 + x;
int heightOffset = -decal.height / 2 + y;
for (int i = 0; i < decal.width; i++)
{
//X offset
int finalX = i + widthOffset;
//Skip column if out of original
if (finalX < 0 || finalX > original.width - 1)
{
continue;
}
for (int j = 0; j < decal.height; j++)
{
//Get color
Color cl = decal.GetPixelSafe(i, j);
//Skip transparent pixels
//TODO Blend with transparency?
if (cl.a < 0.7)
{
continue;
}
//Y offset
int finalY = j + heightOffset;
//Apply color
original.SetPixel(finalX, finalY, cl);
}
}
return(original);
}