/// <summary>
/// Used when the patch below is more detailed, and we are filling the bottom row
/// </summary>
/// <param name="pIndexBuilder"></param>
/// <param name="hSkip"></param>
/// <param name="hHalfSkip"></param>
/// <param name="bLeft"></param>
/// <param name="bRight"></param>
private void AddTrianglesBottomRow(IndexBuilder pIndexBuilder,
int nY, int hSkip, int hHalfSkip,
bool bLeft, bool bRight)
{
int nStartX = 0, nEndX = _patchSize - 1;
if (bLeft)
{
pIndexBuilder.AddIndex(0, nY + hSkip);
pIndexBuilder.AddIndex(0, nY + hHalfSkip);
pIndexBuilder.AddIndex(hHalfSkip, nY + hSkip);
pIndexBuilder.AddIndex(0, nY);
pIndexBuilder.AddIndex(hSkip, nY + hSkip);
pIndexBuilder.AddIndex(hSkip, nY);
nStartX = hSkip;
}
// if right patch is more detailed, don't fill the end block normally
if (bRight)
{
nEndX -= hSkip;
}
for (int x = nStartX; x < nEndX; x += hSkip)
{
pIndexBuilder.AddIndex(x, nY + hSkip);
pIndexBuilder.AddIndex(x, nY);
pIndexBuilder.AddIndex(x + hHalfSkip, nY + hSkip);
pIndexBuilder.AddIndex(x + hSkip, nY);
pIndexBuilder.AddIndex(x + hSkip, nY + hSkip);
if (x != _patchSize - 1 - hSkip)
{
pIndexBuilder.AddLastIndexAgain();
}
}
if (bRight)
{
int nRightX = _patchSize - 1 - hSkip;
pIndexBuilder.AddIndex(nRightX, nY + hSkip);
pIndexBuilder.AddIndex(nRightX, nY);
pIndexBuilder.AddIndex(nRightX + hHalfSkip, nY + hSkip);
pIndexBuilder.AddIndex(nRightX + hSkip, nY + hSkip);
pIndexBuilder.AddLastIndexAgain();
pIndexBuilder.AddIndex(nRightX, nY);
pIndexBuilder.AddIndex(nRightX + hSkip, nY + hHalfSkip);
pIndexBuilder.AddIndex(nRightX + hSkip, nY);
}
}
private IndexCollection[] BuildIndices(int numLevels, int level)
{
// calculate number of vertices
int nNumVerticesOneSide = GetPowerOfTwo((int)(numLevels - 1 - level)) + 1;
int nNumVertices = nNumVerticesOneSide * nNumVerticesOneSide;
// calculate number of primitives
int nNumRows = nNumVerticesOneSide - 1;
// for level 0, we only have set of indices because we never adapt to neighbours
int nTotalNeighbourCodes = (level == 0) ? 1 : TotalNeighbourCodes;
IndexCollection[] indices = new IndexCollection[nTotalNeighbourCodes];
int hSkip = GetPowerOfTwo(level);
int hHalfSkip = hSkip / 2;
for (int j = 0; j < nTotalNeighbourCodes; j++)
{
bool bLeft, bRight, bTop, bBottom;
GetNeighboursBoolean(j, out bLeft, out bRight, out bTop, out bBottom);
// generate indices
if (level == numLevels - 1)
{
indices[j] = AddHighestLevelTriangles(hSkip, hHalfSkip, j);
}
else
{
IndexBuilder pIndexBuilder = new IndexBuilder(this);
for (int y = 0; y < _patchSize - hSkip; y += hSkip)
{
AddTriangleRow(pIndexBuilder, y, hSkip, hHalfSkip, bLeft, bRight, bTop, bBottom);
}
indices[j] = pIndexBuilder.Indices;
}
}
return(indices);
}
private void AddTriangleRow(IndexBuilder pIndexBuilder,
int nY, int hSkip, int hHalfSkip,
bool bLeft, bool bRight, bool bTop, bool bBottom)
{
// special case for top row when patch above is more detailed
if (bTop && nY == 0)
{
AddTrianglesTopRow(pIndexBuilder, hSkip, hHalfSkip, bLeft, bRight);
return;
}
// if this is not the first row, add index for degenerate triangle
// coming from previous row (this is so that we can keep the triangle list going)
if (nY != 0)
{
pIndexBuilder.AddIndex(0, nY + hSkip);
}
// special case for bottom row when patch below is more detailed
if (bBottom && (nY == _patchSize - 1 - hSkip))
{
AddTrianglesBottomRow(pIndexBuilder, nY, hSkip, hHalfSkip, bLeft, bRight);
return;
}
int nStartX = 0, nEndX = _patchSize;
// special case if left patch (or left and top patch, or left and bottom patch) is more detailed
if (bLeft)
{
pIndexBuilder.AddIndex(0, nY + hSkip);
pIndexBuilder.AddIndex(0, nY + hHalfSkip);
pIndexBuilder.AddIndex(hSkip, nY + hSkip);
pIndexBuilder.AddIndex(0, nY);
pIndexBuilder.AddIndex(hSkip, nY);
pIndexBuilder.AddLastIndexAgain();
// shift starting x pos
nStartX = hSkip;
}
// if right patch is more detailed, don't fill the end block normally
if (bRight)
{
nEndX -= hSkip;
}
// standard row filler
for (int x = nStartX; x < nEndX; x += hSkip)
{
pIndexBuilder.AddIndex(x, nY + hSkip);
pIndexBuilder.AddIndex(x, nY);
}
// special case if right patch is more detailed
if (bRight)
{
int nRightX = _patchSize - 1 - hSkip;
pIndexBuilder.AddIndex(nRightX, nY + hSkip);
pIndexBuilder.AddLastIndexAgain();
pIndexBuilder.AddIndex(nRightX + hSkip, nY + hSkip);
pIndexBuilder.AddIndex(nRightX, nY);
pIndexBuilder.AddIndex(nRightX + hSkip, nY + hHalfSkip);
pIndexBuilder.AddIndex(nRightX + hSkip, nY);
}
// if this is not last row, add extra index for degenerate triangle
if (nY != _patchSize - 1 - hSkip)
{
pIndexBuilder.AddLastIndexAgain();
}
}
private IndexCollection[] BuildIndices(int numLevels, int level)
{
// calculate number of vertices
int nNumVerticesOneSide = GetPowerOfTwo((int) (numLevels - 1 - level)) + 1;
int nNumVertices = nNumVerticesOneSide * nNumVerticesOneSide;
// calculate number of primitives
int nNumRows = nNumVerticesOneSide - 1;
// for level 0, we only have set of indices because we never adapt to neighbours
int nTotalNeighbourCodes = (level == 0) ? 1 : TotalNeighbourCodes;
IndexCollection[] indices = new IndexCollection[nTotalNeighbourCodes];
int hSkip = GetPowerOfTwo(level);
int hHalfSkip = hSkip / 2;
for (int j = 0; j < nTotalNeighbourCodes; j++)
{
bool bLeft, bRight, bTop, bBottom;
GetNeighboursBoolean(j, out bLeft, out bRight, out bTop, out bBottom);
// generate indices
if (level == numLevels - 1)
{
indices[j] = AddHighestLevelTriangles(hSkip, hHalfSkip, j);
}
else
{
IndexBuilder pIndexBuilder = new IndexBuilder(this);
for (int y = 0; y < _patchSize - hSkip; y += hSkip)
AddTriangleRow(pIndexBuilder, y, hSkip, hHalfSkip, bLeft, bRight, bTop, bBottom);
indices[j] = pIndexBuilder.Indices;
}
}
return indices;
}
/// <summary>
/// Used when the patch above is more detailed, and we are filling the top row
/// </summary>
/// <param name="pIndexBuilder"></param>
/// <param name="hSkip"></param>
/// <param name="hHalfSkip"></param>
/// <param name="bLeft"></param>
/// <param name="bRight"></param>
private void AddTrianglesTopRow(IndexBuilder pIndexBuilder, int hSkip, int hHalfSkip,
bool bLeft, bool bRight)
{
int nStartX = 0, nEndX = _patchSize - 1;
if (bLeft)
{
pIndexBuilder.AddIndex(0, 0);
pIndexBuilder.AddIndex(hHalfSkip, 0);
pIndexBuilder.AddIndex(0, hHalfSkip);
pIndexBuilder.AddIndex(hSkip, 0);
pIndexBuilder.AddIndex(0, hSkip);
pIndexBuilder.AddIndex(hSkip, hSkip);
nStartX = hSkip;
}
// if right patch is more detailed, don't fill the end block normally
if (bRight)
{
nEndX -= hSkip;
}
for (int x = nStartX; x < nEndX; x += hSkip)
{
pIndexBuilder.AddIndex(x, 0);
pIndexBuilder.AddIndex(x + hHalfSkip, 0);
pIndexBuilder.AddIndex(x, hSkip);
pIndexBuilder.AddIndex(x + hSkip, 0);
pIndexBuilder.AddIndex(x + hSkip, hSkip);
if (x != _patchSize - 1)
{
pIndexBuilder.AddLastIndexAgain();
}
if (x == _patchSize - hSkip - 1)
{
pIndexBuilder.AddLastIndexAgain();
}
}
if (bRight)
{
int nRightX = _patchSize - 1 - hSkip;
pIndexBuilder.AddIndex(nRightX, 0);
pIndexBuilder.AddLastIndexAgain();
pIndexBuilder.AddIndex(nRightX, hSkip);
pIndexBuilder.AddIndex(nRightX + hHalfSkip, 0);
pIndexBuilder.AddIndex(nRightX + hSkip, 0);
pIndexBuilder.AddLastIndexAgain();
pIndexBuilder.AddIndex(nRightX, hSkip);
pIndexBuilder.AddIndex(nRightX + hSkip, hHalfSkip);
pIndexBuilder.AddIndex(nRightX + hSkip, hSkip);
}
// don't need to add degenerate triangle due to weird indexing
}
/// <summary>
/// Used when the patch below is more detailed, and we are filling the bottom row
/// </summary>
/// <param name="pIndexBuilder"></param>
/// <param name="hSkip"></param>
/// <param name="hHalfSkip"></param>
/// <param name="bLeft"></param>
/// <param name="bRight"></param>
private void AddTrianglesBottomRow(IndexBuilder pIndexBuilder,
int nY, int hSkip, int hHalfSkip,
bool bLeft, bool bRight)
{
int nStartX = 0, nEndX = _patchSize - 1;
if (bLeft)
{
pIndexBuilder.AddIndex(0, nY + hSkip);
pIndexBuilder.AddIndex(0, nY + hHalfSkip);
pIndexBuilder.AddIndex(hHalfSkip, nY + hSkip);
pIndexBuilder.AddIndex(0, nY);
pIndexBuilder.AddIndex(hSkip, nY + hSkip);
pIndexBuilder.AddIndex(hSkip, nY);
nStartX = hSkip;
}
// if right patch is more detailed, don't fill the end block normally
if (bRight)
{
nEndX -= hSkip;
}
for (int x = nStartX; x < nEndX; x += hSkip)
{
pIndexBuilder.AddIndex(x, nY + hSkip);
pIndexBuilder.AddIndex(x, nY);
pIndexBuilder.AddIndex(x + hHalfSkip, nY + hSkip);
pIndexBuilder.AddIndex(x + hSkip, nY);
pIndexBuilder.AddIndex(x + hSkip, nY + hSkip);
if (x != _patchSize - 1 - hSkip)
{
pIndexBuilder.AddLastIndexAgain();
}
}
if (bRight)
{
int nRightX = _patchSize - 1 - hSkip;
pIndexBuilder.AddIndex(nRightX, nY + hSkip);
pIndexBuilder.AddIndex(nRightX, nY);
pIndexBuilder.AddIndex(nRightX + hHalfSkip, nY + hSkip);
pIndexBuilder.AddIndex(nRightX + hSkip, nY + hSkip);
pIndexBuilder.AddLastIndexAgain();
pIndexBuilder.AddIndex(nRightX, nY);
pIndexBuilder.AddIndex(nRightX + hSkip, nY + hHalfSkip);
pIndexBuilder.AddIndex(nRightX + hSkip, nY);
}
}
private void AddTriangleRow(IndexBuilder pIndexBuilder,
int nY, int hSkip, int hHalfSkip,
bool bLeft, bool bRight, bool bTop, bool bBottom)
{
// special case for top row when patch above is more detailed
if (bTop && nY == 0)
{
AddTrianglesTopRow(pIndexBuilder, hSkip, hHalfSkip, bLeft, bRight);
return;
}
// if this is not the first row, add index for degenerate triangle
// coming from previous row (this is so that we can keep the triangle list going)
if (nY != 0)
{
pIndexBuilder.AddIndex(0, nY + hSkip);
}
// special case for bottom row when patch below is more detailed
if (bBottom && (nY == _patchSize - 1 - hSkip))
{
AddTrianglesBottomRow(pIndexBuilder, nY, hSkip, hHalfSkip, bLeft, bRight);
return;
}
int nStartX = 0, nEndX = _patchSize;
// special case if left patch (or left and top patch, or left and bottom patch) is more detailed
if (bLeft)
{
pIndexBuilder.AddIndex(0, nY + hSkip);
pIndexBuilder.AddIndex(0, nY + hHalfSkip);
pIndexBuilder.AddIndex(hSkip, nY + hSkip);
pIndexBuilder.AddIndex(0, nY);
pIndexBuilder.AddIndex(hSkip, nY);
pIndexBuilder.AddLastIndexAgain();
// shift starting x pos
nStartX = hSkip;
}
// if right patch is more detailed, don't fill the end block normally
if (bRight)
{
nEndX -= hSkip;
}
// standard row filler
for (int x = nStartX; x < nEndX; x += hSkip)
{
pIndexBuilder.AddIndex(x, nY + hSkip);
pIndexBuilder.AddIndex(x, nY);
}
// special case if right patch is more detailed
if (bRight)
{
int nRightX = _patchSize - 1 - hSkip;
pIndexBuilder.AddIndex(nRightX, nY + hSkip);
pIndexBuilder.AddLastIndexAgain();
pIndexBuilder.AddIndex(nRightX + hSkip, nY + hSkip);
pIndexBuilder.AddIndex(nRightX, nY);
pIndexBuilder.AddIndex(nRightX + hSkip, nY + hHalfSkip);
pIndexBuilder.AddIndex(nRightX + hSkip, nY);
}
// if this is not last row, add extra index for degenerate triangle
if (nY != _patchSize - 1 - hSkip)
{
pIndexBuilder.AddLastIndexAgain();
}
}