SimplexNoise terrain in MonoGame - c#

I'm making a randomly generated tile game in MonoGame, and I'm trying to use Simplex Noise to generate the terrain. Problem is, I've never used Simplex Noise before, so as you can probably guess, my code doesn't work. It only creates grass tiles. Here's the code I've tried:
public void Generate() {
Tiles = new List<Tile>();
Seed = GenerateSeed();
for (int x = 0; x < Width; x++) {
for (int y = 0; y < Height; y++) {
float value = Noise.Generate((x / Width) * Seed, (y / Height) * Seed) / 10.0f;
if (value <= 0.1f) {
Tiles.Add(new Tile(Main.TileGrass, new Vector2((int)x * Tile.Size, (int)y * Tile.Size)));
}
else if (value > 0.1f && value <= 0.5f) {
Tiles.Add(new Tile(Main.TileSand, new Vector2((int)x * Tile.Size, (int)y * Tile.Size)));
}
else {
Tiles.Add(new Tile(Main.TileWater, new Vector2((int)x * Tile.Size, (int)y * Tile.Size)));
}
}
}
}
public int GenerateSeed() {
Random random = new Random();
int length = 8;
int result = 0;
for (int i = 0; i < length; i++) {
result += random.Next(0, 9);
}
return result;
}
I'm using this implementation to generate noise.

Check line 133 in the SimplexNoise you are using:
// The result is scaled to return values in the interval [-1,1].
After you divide it by 10, the result would be in range from -0.1 to +0.1
You need a range from 0 to 1, so instead of dividing by 10, you need to:
Add 1 (the range would be from 0 to 2).
Divide by 2 (the range would be from 0 to 1).
float value = (Noise.Generate((x / Width) * Seed, (y / Height) * Seed) + 1) / 2.0f;
Or change your if/else to work with -1 to +1 ranges.
if (value <= -0.8f)
{
Tiles.Add(new Tile(Main.TileGrass, new Vector2((int)x * Tile.Size, (int)y * Tile.Size)));
}
else if (value <= 0)
{
Tiles.Add(new Tile(Main.TileSand, new Vector2((int)x * Tile.Size, (int)y * Tile.Size)));
}
else
{
Tiles.Add(new Tile(Main.TileWater, new Vector2((int)x * Tile.Size, (int)y * Tile.Size)));
}

Related

Calculation island error with perlin noise

I'm developing a small project, which is a grid of 100 x 100 hexagons.
In the script below, I paint my hexagons with the perlin noise, but the format I want to island does not go away.
I'll leave my code and 2 examples as my map stays and how I wish it to stay.
My island
My Island
As i need
Im Need
int getColor(float x, float z)
{
xTO = (int)x / terrainWidth - 30;
zTO = (int)z / terrainHeight - 30;
float v = Mathf.PerlinNoise((xTO + x + seed) * freq, (zTO + z) * freq);
// v += 0.001f;
float form = formWorld(x, z);
if (v < 0.25f)
{
//water
return 0;
}
else if (v < 0.5f)
{
//sand
return 1;
}
else if (v < 0.75f)
{
//grass
return 2;
}
else
{
//Trees / Forest
MakeNewTree(new Vector3(xx, 0, z * 7.5f));
return 2;
}
}
If you want your image to look more like the second one, the best option is going to be adding a circular gradient which offsets your Perlin Noise.
The easiest way to do this is to measure the distance from the center and combine that with the perlin noise.
Here's some untested code.
int getColor(float x, float z)
{
xTO = (int)x / terrainWidth - 30;
zTO = (int)z / terrainHeight - 30;
float v = Mathf.PerlinNoise((xTO + x + seed) * freq, (zTO + z) * freq);
// v += 0.001f;
v -= CircleOffset(x,z)/2; //Change the two to make the island bigger.
float form = formWorld(x, z);
if (v < 0.25f)
{
//water
return 0;
}
else if (v < 0.5f)
{
//sand
return 1;
}
else if (v < 0.75f)
{
//grass
return 2;
}
else
{
//Trees / Forest
MakeNewTree(new Vector3(xx, 0, z * 7.5f));
return 2;
}
}
float CircleOffset(float x, float y)
{
Vector2 center = new Vector2(terrainWidth/2,terrainHeight/2);
float distance = Mathf.Sqrt((center.x - x)*(center.x - x) + (center.y - y) * (center.y - y));
return distance/terrainWidth;
}
Hope this helps!

Make circle in C# with only pen tool, without using ellipse method

The code i have made is hard coded and i want it to convert it into circle any snippet i can add or something
The code is in C sharp, The output is like the rectangle which i have to convert it into a circle
private void pictureBox1_Click(object sender, EventArgs e)
{
int length = 100;
int flag = 0;
int flag2 = 0;
int flag3 = 0;
Pen p = new Pen(Color.Red, 4);
Graphics g = pictureBox1.CreateGraphics();
Brush redBrush = new SolidBrush(Color.Red);
for (int i = 0; i < 20; i++)
{
if(i==0 || i<10)
{
g.DrawLine(p, 622 - 10 * i, 229+10*i, 623 - 10 * i, 229+10*i);
}
if(i==10)
{
flag = 1;
}
if(flag==1)
{
g.DrawLine(p, 622 - 10 * i, 419 - 10 * i, 623 - 10 * i, 419-10*i);
flag2 = 1;
}
if(flag2 == 1)
{
g.DrawLine(p, 622 - 10 * i, 29+10*i, 623 - 10 * i, 29+10*i);
flag3 = 1;
}
if (flag3 == 1)
{
g.DrawLine(p, 432 + 10 * i, 29+10*i, 433 + 10 * i, 29 + 10 *i);
}
}
There is a built-in function for this. Use g.DrawEllipse() instead.
You can do this
void DrawCircle(Graphics g, Pen p, Point centre, double radius=20, int sides = 360)
{
var angle = 2 * Math.PI / sides;
for (int i = 0; i < sides; i++)
{
Point from = new Point((int)(radius * Math.Sin(i * angle) + centre.X), (int)(radius * Math.Cos(i * angle) + centre.Y));
Point to = new Point((int)(radius * Math.Sin((i+1) * angle) + centre.X), (int)(radius * Math.Cos((i+1) * angle) + centre.Y));
g.DrawLine(p, from, to);
}
}
and to use
DrawCircle(g, p, new Point(100, 100), 50, 8); // 8 sides, an octagon
Increase the number of sides to make it more accurate.
Alternatively,
g.DrawEllipse(p, (float)(centre.X-radius), (float)(centre.Y-radius), (float)radius*2, (float)radius*2);

I converted a CSV file to shapefile, but can't create its projection

I tried to convert a csv file to shapefile with its projection. Conversion works but I can't create the .prj file.
The error says that
"there is no source code available for current location".
My code is as follows:
public Form1() {
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e) {
AxMap axMap1 = new AxMap();
Shapefile sf = new Shapefile();
bool result = sf.CreateNewWithShapeID("", ShpfileType.SHP_POLYGON);
if (!result) {
MessageBox.Show(sf.get_ErrorMsg(sf.LastErrorCode));
} else {
double xMin = 0.0;
double yMin = 0.0;
double xMax = 1000.0;
double yMax = 1000.0;
Random rnd = new Random(DateTime.Now.Millisecond);
int fldX = sf.EditAddField("x", FieldType.DOUBLE_FIELD, 9, 12);
int fldY = sf.EditAddField("y", FieldType.DOUBLE_FIELD, 9, 12);
int fldArea = sf.EditAddField("area", FieldType.DOUBLE_FIELD, 9, 12);
// In a loop we are creating 100 different points using the box established above.
for (int i = 0; i < 100; i++) {
if (i % 10 == 0) {
Shape shp1 = new Shape();
shp1.Create(ShpfileType.SHP_POLYGON);
sf.EditInsertShape(shp1, ref i);
} else {
double xCenter = xMin + (xMax - xMin) * rnd.NextDouble();
double yCenter = yMin + (yMax - yMin) * rnd.NextDouble();
// random radius from 10 to 100
double radius = 10 + rnd.NextDouble() * 90;
// polygons must be clockwise
Shape shp = new Shape();
shp.Create(ShpfileType.SHP_POLYGON);
for (int j = 0; j < 37; j++) {
Point pnt = new Point();
pnt.x = xCenter + radius * Math.Cos(j * Math.PI / 18);
pnt.y = yCenter - radius * Math.Sin(j * Math.PI / 18);
shp.InsertPoint(pnt, ref j);
}
sf.EditInsertShape(shp, ref i);
sf.EditCellValue(fldX, i, xCenter.ToString());
sf.EditCellValue(fldY, i, yCenter.ToString());
sf.EditCellValue(fldArea, i, Math.PI * radius * radius);
}
}
axMap1.CreateControl();
axMap1.AddLayer(sf, true);
axMap1.ZoomToLayer(0);
sf.Categories.Generate(fldArea, tkClassificationType.ctNaturalBreaks, 7);
ColorScheme scheme = new ColorScheme();
scheme.SetColors2(tkMapColor.Wheat, tkMapColor.Salmon); sf.Categories.ApplyColorScheme(tkColorSchemeType.ctSchemeGraduated, scheme);
axMap1.Redraw();
sf.SaveAs(#"D:\shp1\polygons.shp", null);
sf.Open("D:\\shp1\\polygons.shp");
sf.Projection = (DotSpatial.Projections.KnownCoordinateSystems.Projected.UtmWgs1984.WGS1984UTMZone32N).ToString();
sf.SaveAs(#"D:\shp1\polygons.prj");
}
}

How to rotate figure from points(Hilbert curve)?

I am working on Hilbert curve, and I cant rotate the whole figure, just lower rectangle(look at the screenshots, on third and next steps I have a problem)
first 3 steps
I have a Figure class. I use it to store every figure and build next firuge from previous one. Here is my code
public class Fragment
{
public static int PADDING = 50;
public static float sideLength;
private readonly Pen crimsonPen = new Pen(Color.Crimson);
public List<PointF> pointsF = new List<PointF>();
public PointF[] points;
public Fragment(int step, Graphics graphics)
{
sideLength = Form1.sideLenght;
points = new PointF[(int)Math.Pow(4, step + 1)];
if (step.Equals(0))
{
points[0] = new PointF(PADDING, PADDING + sideLength);
points[1] = new PointF(PADDING, PADDING);
points[2] = new PointF(PADDING + sideLength, PADDING);
points[3] = new PointF(PADDING + sideLength, PADDING + sideLength);
graphics.DrawLines(crimsonPen, new[] { points[0], points[1], points[2], points[3] });
}
else
{
var frag = Form1.fragments[step - 1];
for (var i = 0; i < step; i++)
{
PointF tmpPoint;
// left lower #1
for (int j = frag.points.Length - 1; j >= 0; j--)
{
points[frag.points.Length - 1 - j] = frag.points[j];
points[frag.points.Length - 1 - j].Y += sideLength * 2 * (i + 1);
}
//rotate left lower #1
for (int b = 0; b < Math.Pow(4, step) - 1; b++)
{
tmpPoint = points[0];
for (int j = 0; j < frag.points.Length; j++)
{
if (j.Equals(frag.points.Length - 1))
{
points[j] = tmpPoint;
}
else
{
points[j] = points[j + 1];
}
}
}
// left upper #2
for (int j = 0; j < frag.points.Length; j++)
{
points[j + frag.points.Length] = frag.points[j];
}
// right upper #3
for (int j = 0; j < frag.points.Length; j++)
{
points[j + 2 * frag.points.Length] = points[j + frag.points.Length];
points[j + 2 * frag.points.Length].X += sideLength * 2 * (i + 1);
}
//right lower #4
for (int j = frag.points.Length - 1; j >= 0; j--)
{
points[3 * frag.points.Length + j] = points[2 * frag.points.Length + frag.points.Length - j - 1];
points[3 * frag.points.Length + j].Y += sideLength * 2 * (i + 1);
}
tmpPoint = points[3 * frag.points.Length];
//rotate right lower #4
for (int j = 0; j < frag.points.Length; j++)
{
if (j.Equals(frag.points.Length - 1))
{
points[4 * (frag.points.Length) - 1] = tmpPoint;
}
else
{
points[3 * frag.points.Length + j] = points[3 * frag.points.Length + j + 1];
}
}
}
graphics.DrawLines(crimsonPen, points);
}
}
}
Here I use my recursive method to draw figures
private void drawButton_Click(object sender, EventArgs e)
{
canvas.Refresh();
count = 0;
if (Int32.TryParse(stepsTextBox.Text, out steps))
{
sideLenght = (float)((canvas.Width - 100) / (Math.Pow(2, steps) - 1));
fragments = new Fragment[steps];
drawCurve();
}
else
{
MessageBox.Show("Wow, incorrect input", "Try again");
}
}
private void drawCurve()
{
if (count < steps)
{
fragments[count] = new Fragment(count, graphics);
++count;
drawCurve();
}
}
I've tried to rotate points around figure center and use next code but the rotation is incorrect
public PointF rotatePoint(PointF pointToRotate)
{
pointToRotate.X = (float)(Math.Cos(180 * Math.PI / 180) * (pointToRotate.X - centerPoint.X) -
Math.Sin(180 * Math.PI / 180) * (pointToRotate.Y - centerPoint.Y) +
centerPoint.X);
pointToRotate.Y = (float)(Math.Sin(0 * Math.PI / 180) * (pointToRotate.X - centerPoint.X) +
Math.Cos(0 * Math.PI / 180) * (pointToRotate.Y - centerPoint.Y) +
centerPoint.Y);
return pointToRotate;
}
The problem is that you are using the X co-ordinate that you have already rotated when you calculate the rotated Y co-ordinate. Use a temp variable to avoid this:
public PointF rotatePoint(PointF pointToRotate)
{
float rotatedX = (float)(Math.Cos(180 * Math.PI / 180) * (pointToRotate.X - centerPoint.X) -
Math.Sin(180 * Math.PI / 180) * (pointToRotate.Y - centerPoint.Y) +
centerPoint.X);
pointToRotate.Y = (float)(Math.Sin(0 * Math.PI / 180) * (pointToRotate.X - centerPoint.X) +
Math.Cos(0 * Math.PI / 180) * (pointToRotate.Y - centerPoint.Y) +
centerPoint.Y);
pointToRotate.X = rotatedX;
return pointToRotate;
}

Optimizing a formula to create a triangle from arbitrary points

I think a little background will help before I get into my question. What I'm doing is creating my own small 2D physics library in xna, for fun nonetheless. This is also my first independent xna project, and my first time working with the 3D tools, so I may be doing things all wacky. Anyway, I'm currently making a triangle class in which the constructor takes three arbitrary points in the form of Vector2s. In the constructor I have to put these points in clockwise order (so they're not culled) and then find the texture coordinates they should correspond to (since I'm using VertexPositionTextures as my vertices). What I've got works, but it seems very long and complicated. I'm looking for any ways to shorten/simplify the code, which is this:
public PTriangle(Vector2 a, Vector2 b, Vector2 c)
: base()
{
//set up vertices
VertexPositionTexture[] vertices = new VertexPositionTexture[3];
//center vertices around origin
Vector2 center = new Vector2((a.X + b.X + c.X) / 3, (a.Y + b.Y + c.Y) / 3);
Vector2 newA = a - center;
Vector2 newB = b - center;
Vector2 newC = c - center;
//get angle of each vertex (clockwise from -x axis)
double angleA = MathHelper.Pi - Math.Atan((double)(newA.Y / newA.X));
double angleB = MathHelper.Pi - Math.Atan((double)(newB.Y / newB.X));
double angleC = MathHelper.Pi - Math.Atan((double)(newC.Y / newC.X));
if (newA.X < 0)
{
if (newA.Y < 0)
{
angleA += MathHelper.Pi;
}
else
{
angleA -= MathHelper.Pi;
}
}
if (newB.X < 0)
{
if (newB.Y < 0)
{
angleB += MathHelper.Pi;
}
else
{
angleB -= MathHelper.Pi;
}
}
if (newC.X < 0)
{
if (newC.Y < 0)
{
angleC += MathHelper.Pi;
}
else
{
angleC -= MathHelper.Pi;
}
}
//order vertices by angle
Vector2[] newVertices = new Vector2[3];
if (angleA < angleB && angleA < angleC)
{
newVertices[0] = newA;
if (angleB < angleC)
{
newVertices[1] = newB;
newVertices[2] = newC;
}
else
{
newVertices[1] = newC;
newVertices[2] = newB;
}
}
else if (angleB < angleA && angleB < angleC)
{
newVertices[0] = newB;
if (angleA < angleC)
{
newVertices[1] = newA;
newVertices[2] = newC;
}
else
{
newVertices[1] = newC;
newVertices[2] = newA;
}
}
else
{
newVertices[0] = newC;
if (angleA < angleB)
{
newVertices[1] = newA;
newVertices[2] = newB;
}
else
{
newVertices[1] = newB;
newVertices[2] = newA;
}
}
//set positions of vertices
vertices[0].Position = new Vector3(newVertices[0] + center, 0);
vertices[1].Position = new Vector3(newVertices[1] + center, 0);
vertices[2].Position = new Vector3(newVertices[2] + center, 0);
//get width and height of triangle
float minX = 0;
float minY = 0;
float maxX = 0;
float maxY = 0;
foreach (Vector2 vertex in newVertices)
{
if (vertex.X < minX)
{
minX = vertex.X;
}
else if (vertex.X > maxX)
{
maxX = vertex.X;
}
if (vertex.Y < minY)
{
minY = vertex.Y;
}
else if (vertex.Y > maxY)
{
maxY = vertex.Y;
}
}
float width = maxX - minX;
float height = maxY - minY;
//shift triangle so fits in quadrant IV, and set texture coordinates
for (int index = 0; index < newVertices.Length; ++index)
{
newVertices[index].X -= minX;
newVertices[index].Y -= minY;
vertices[index].TextureCoordinate = new Vector2(
newVertices[index].X / width,
1 - (newVertices[index].Y / height));
}
this.Vertices = vertices;
//set up indices
this.Indices = new short[] { 0, 1, 2 };
}
To put the 3 points in clockwise order, you can use counter-clockwise test (or left-turn test) to check the direction of the 3 points.
Pseudocode from Wikipedia
# Three points are a counter-clockwise turn if ccw > 0, clockwise if
# ccw < 0, and collinear if ccw = 0 because ccw is a determinant that
# gives the signed area of the triangle formed by p1, p2 and p3.
function ccw(p1, p2, p3):
return (p2.x - p1.x)*(p3.y - p1.y) - (p2.y - p1.y)*(p3.x - p1.x)
If the 3 points are counter-clockwise, you can just swap the last 2 points to make the 3 points clockwise order.

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