private static Bitmap GenerateBitmap16x16(ColorGradientEnum gradient)
{
int n = 16, m = 16;
Bitmap bitmap = new Bitmap(n, m, PixelFormat.Format32bppArgb);
float[,] values = new float[n, m];
for (int i = 0; i < n; i++)
{
for (int j = 0; j < m; j++)
{
values[i, j] = ((float)i + (float)j) / (float)(n * m);
}
}
GetMinMax(values, out float vMin, out float vMax);
Rectangle rectangle = new Rectangle(0, 0, n, m);
GradientBitmap.FromValues(bitmap, rectangle, (int i, int j) =>
{
float z = (values[i, j] - vMin) / (vMax - vMin);
return(ColorUtilities.GetColor(z, gradient, false));
});
return(bitmap);
}
public static void DrawLegend(
Bitmap bitmap,
float minValue, float maxValue, string format,
ColorGradientEnum colorGradient, bool inverseGradient,
params string[] lines)
{
if (float.IsNaN(minValue) || float.IsNaN(maxValue))
{
return;
}
const int a = 12; // distance from right legend to right bitmap
const int b = 12; // distance from bottom legend to bottom bitmap
const int l = 16; // height of a text line
const int h = 60; // height of the color gradient indicator
const int w = 64; // width
const int d = 2; // distance from y to text string
int n = lines != null ? lines.Length : 0;
float x1 = bitmap.Width - a, x0 = x1 - w, x2 = x0;
float y4 = bitmap.Height - b, y3 = y4 - l, y2 = y3 - h, y1 = y2 - l, y0 = y1 - n * l;
using (Graphics graphics = Graphics.FromImage(bitmap))
{
// background
using (SolidBrush backgroundBrush = new SolidBrush(Color.FromArgb(0xF0, 0xF0, 0xF0)))
{
graphics.FillRectangle(backgroundBrush, x0, y0, w, h + (2 + n) * l);
}
// color gradient
using (Pen gradientPen = new Pen(Color.Black, 1f))
{
for (int i = 0; i <= h; i++)
{
float z = maxValue > minValue ? (float)i / h : 0.5f;
gradientPen.Color = ColorUtilities.GetColor(z, colorGradient, inverseGradient);
float y = y2 + i;
graphics.DrawLine(gradientPen, x0, y, x1, y);
}
}
// text
using (Pen textPen = new Pen(Color.Black, 1f))
using (SolidBrush textBrush = new SolidBrush(Color.Black))
using (StringFormat stringFormat = new StringFormat
{
Alignment = StringAlignment.Near, LineAlignment = StringAlignment.Near
})
{
Font font = Control.DefaultFont;
textBrush.Color = Color.Black;
textPen.Color = Color.Black;
for (int i = 0; i < n; i++)
{
graphics.DrawString(lines[i], font, textBrush, x2, y0 + i * l + d, stringFormat);
graphics.DrawRectangle(textPen, x0, y0 + i * l, w, l);
}
graphics.DrawString(minValue.ToString(format), font, textBrush, x2, y1 + d, stringFormat);
graphics.DrawString(maxValue.ToString(format), font, textBrush, x2, y3 + d, stringFormat);
graphics.DrawRectangle(textPen, x0, y1, w, h + 2 * l);
}
}
}