/// <summary>
/// Creates a new terrain
/// </summary>
/// <param name="size">The size of the terrain</param>
public Terrain(Vector2 size)
{
Position = Vector2.Zero;
this._size = size;
Vertices = new TerrainVertex[(int)(size.X * size.Y)];
//Generate vertices
for (int y = 0; y < size.Y; y++)
{
for (int x = 0; x < size.X; x++)
{
this[x, y] = GenerateVertex(x, y);
}
}
//Generate the indices
List <uint> indices = new List <uint>();
//Adds a single index to the list based on the position of the vertex
void AddIndex(int x, int y)
{
indices.Add((uint)(x + y * size.Y));
}
//Generate all the indices
for (int y = 0; y < size.Y - 1; y++)
{
for (int x = 0; x < size.X - 1; x++)
{
AddIndex(x, y);
AddIndex(x + 1, y + y % 2);
AddIndex(x, y + 1);
if (x != 0)
{
AddIndex(x, y);
AddIndex(x, y + 1);
AddIndex(x - 1, y + (y + 1) % 2);
}
}
}
Vao = new VertexArray();
VertexBuffer vbo = new VertexBuffer();
IndexBuffer ibo = new IndexBuffer();
BufferLayout layout = new BufferLayout();
//Initialize the buffer objects
Vao.Init();
vbo.Init(Vertices);
ibo.Init(indices.ToArray());
//Set up the layout of the data
layout.AddLayoutItem(VertexAttribPointerType.Float, 3);
layout.AddLayoutItem(VertexAttribPointerType.Float, 4);
//Add the buffers to the VAO
Vao.Vbo = vbo;
Vao.Ibo = ibo;
Vao.Layout = layout;
}
/// <summary>
/// Generate the terrain vertex information based on the position
/// </summary>
/// <param name="x">The x position of the vertex</param>
/// <param name="y">The y position of the vertex</param>
/// <returns>The information for the terrain vertex</returns>
public static TerrainVertex GetVertex(float x, float y)
{
//Create the vertex
TerrainVertex vertex = new TerrainVertex();
//Get the biome
float humidity, temperature;
void GetHumidityAndTemperature(float xOffset, float yOffset)
{
humidity = MathHelper.Clamp(_humidity.GetValueFractal(x + xOffset, y + yOffset) + 0.5f, 0f, 1f);
temperature = MathHelper.Clamp(_temperature.GetValueFractal(x + xOffset, y + yOffset) + 0.5f, 0f, 1f);
}
GetHumidityAndTemperature(0, 0);
Biome biome = ModLoader.GetBiome(humidity, temperature);
//Set the data for the vertex
float GetYPosition(Biome bio, float xOffset, float yOffset)
{
_height.SetFrequency(bio.Topology.Frequency);
return((_height.GetSimplexFractal(x + xOffset, y + yOffset) + 0.5f) * bio.Topology.Amplitude + bio.Topology.MinHeight);
}
vertex.Position = new Vector3(x, GetYPosition(biome, 0, 0), y);
vertex.Color = biome.Color;
//Check for biome blending
void BlendBiomes(float xOffset, float yOffset)
{
Vector2 checkOffset = new Vector2(xOffset, yOffset);
float thisY = 0;
//Step 1: Check when the border of the biomes are
while (xOffset != 0 || yOffset != 0)
{
//Get the humidity and temperature
GetHumidityAndTemperature(xOffset, yOffset);
//Check if it is within the original biome
if (biome.boundary.Contains(new Vector2(humidity, temperature)))
{
if (xOffset == checkOffset.X && yOffset == checkOffset.Y)
{
return;
}
break;
}
//Move one step closer to no offset
xOffset -= xOffset > 0 ? 1 : xOffset < 0 ? -1 : 0;
yOffset -= yOffset > 0 ? 1 : yOffset < 0 ? -1 : 0;
}
//(We need to put the x- and yOffset one back)
thisY = GetYPosition(biome, xOffset, yOffset);
xOffset += checkOffset.X > 0 ? 1 : checkOffset.X < 0 ? -1 : 0;
yOffset += checkOffset.Y > 0 ? 1 : checkOffset.Y < 0 ? -1 : 0;
//Step 2: Get the new biome
GetHumidityAndTemperature(xOffset, yOffset);
Biome b = ModLoader.GetBiome(humidity, temperature);
//Step 3: Calculate the blend proportion
float blendProportion = 1;
if (xOffset != checkOffset.X)
{
blendProportion = xOffset / checkOffset.X;
}
if (yOffset != checkOffset.Y)
{
blendProportion *= yOffset / checkOffset.Y;
}
//Step 4: Blend the biomes
float otherY = GetYPosition(b, xOffset, yOffset);
Vector3 position = vertex.Position;
position.Y = ((otherY - thisY) / 2 + thisY) * (1 - blendProportion) + position.Y * blendProportion;
vertex.Position = position;
}
BlendBiomes(10, 0);
BlendBiomes(-10, 0);
BlendBiomes(0, 10);
BlendBiomes(0, -10);
return(vertex);
}
