/// <summary>
/// Initializes the VBO but does not modify graphics state
/// </summary>
public void Prerender(Structure structure, BlockAtlas blockAtlas)
{
_vbi.Reset();
for (var pass = 0; pass <= 1; pass++)
{
for (var x = X * 16; x < X * 16 + 16; x++)
{
for (var y = 0; y < 256; y++)
{
for (var z = Z * 16; z < Z * 16 + 16; z++)
{
if (!structure.Contains(x, y, z))
{
continue;
}
var block = structure[x, y, z];
if (block == null)
{
continue;
}
var blockData = blockAtlas[block.Id];
if (blockData == null || blockData.Properties.Render == "none" || blockData.Textures.Count == 0)
{
continue;
}
ChunkRenderer.Render(structure, x, y, z, blockAtlas, _vbi, pass);
}
}
}
}
}
/// <summary>
/// Initializes the VBO but does not modify graphics state
/// </summary>
public void Prerender()
{
const int color = 0xFFFFFF;
const int occludedColor = 0xC0C0C0;
_vbi.Reset();
for (var x = X * 16; x < X * 16 + 16; x++)
{
for (var z = Z * 16; z < Z * 16 + 16; z++)
{
var nx = x - X * 16 + 1;
var nz = z - Z * 16 + 1;
// Heightmap value here
var valueHere = (float)_heightmap[nx, nz];
// Neighboring positions
var valuePosX = _heightmap[nx + 1, nz];
var valueNegX = _heightmap[nx - 1, nz];
var valuePosZ = _heightmap[nx, nz + 1];
var valueNegZ = _heightmap[nx, nz - 1];
var valuePosXPosZ = _heightmap[nx + 1, nz + 1];
var valueNegXPosZ = _heightmap[nx - 1, nz + 1];
var valuePosXNegZ = _heightmap[nx + 1, nz - 1];
var valueNegXNegZ = _heightmap[nx - 1, nz - 1];
// Comparisons used in cheap AO
var isPosXHigher = valuePosX > valueHere;
var isNegXHigher = valueNegX > valueHere;
var isPosZHigher = valuePosZ > valueHere;
var isNegZHigher = valueNegZ > valueHere;
var isPosXPosZHigher = valuePosXPosZ > valueHere;
var isNegXPosZHigher = valueNegXPosZ > valueHere;
var isPosXNegZHigher = valuePosXNegZ > valueHere;
var isNegXNegZHigher = valueNegXNegZ > valueHere;
// Always draw a top face for a block
_vbi.Append(
new Vertex(x, valueHere, z),
SmallVertex.UnitY,
isPosXHigher || isPosZHigher || isPosXPosZHigher ? occludedColor : color
);
_vbi.Append(
new Vertex(x - 1, valueHere, z),
SmallVertex.UnitY,
isNegXHigher || isPosZHigher || isNegXPosZHigher ? occludedColor : color
);
_vbi.Append(
new Vertex(x - 1, valueHere, z - 1),
SmallVertex.UnitY,
isNegXHigher || isNegZHigher || isNegXNegZHigher ? occludedColor : color
);
_vbi.Append(
new Vertex(x, valueHere, z - 1),
SmallVertex.UnitY,
isPosXHigher || isNegZHigher || isPosXNegZHigher ? occludedColor : color
);
// Try and draw the PosZ face
if (valuePosZ < valueHere)
{
_vbi.Append(
new Vertex(x, valueHere, z),
SmallVertex.UnitZ,
color
);
_vbi.Append(
new Vertex(x, valuePosZ, z),
SmallVertex.UnitZ,
occludedColor
);
_vbi.Append(
new Vertex(x - 1, valuePosZ, z),
SmallVertex.UnitZ,
occludedColor
);
_vbi.Append(
new Vertex(x - 1, valueHere, z),
SmallVertex.UnitZ,
color
);
}
// Try and draw the NegZ face
if (valueNegZ < valueHere)
{
_vbi.Append(
new Vertex(x, valueHere, z - 1),
SmallVertex.UnitNZ,
color
);
_vbi.Append(
new Vertex(x, valueNegZ, z - 1),
SmallVertex.UnitNZ,
occludedColor
);
_vbi.Append(
new Vertex(x - 1, valueNegZ, z - 1),
SmallVertex.UnitNZ,
occludedColor
);
_vbi.Append(
new Vertex(x - 1, valueHere, z - 1),
SmallVertex.UnitNZ,
color
);
}
// Try and draw the PosX face
if (valuePosX < valueHere)
{
_vbi.Append(
new Vertex(x, valueHere, z),
SmallVertex.UnitX,
color
);
_vbi.Append(
new Vertex(x, valuePosX, z),
SmallVertex.UnitX,
occludedColor
);
_vbi.Append(
new Vertex(x, valuePosX, z - 1),
SmallVertex.UnitX,
occludedColor
);
_vbi.Append(
new Vertex(x, valueHere, z - 1),
SmallVertex.UnitX,
color
);
}
// Try and draw the NegX face
if (valueNegX < valueHere)
{
_vbi.Append(
new Vertex(x - 1, valueHere, z),
SmallVertex.UnitNX,
color
);
_vbi.Append(
new Vertex(x - 1, valueNegX, z),
SmallVertex.UnitNX,
occludedColor
);
_vbi.Append(
new Vertex(x - 1, valueNegX, z - 1),
SmallVertex.UnitNX,
occludedColor
);
_vbi.Append(
new Vertex(x - 1, valueHere, z - 1),
SmallVertex.UnitNX,
color
);
}
}
}
}