int GeoPatchContext::getIndices(std::vector<unsigned short> &pl, const unsigned int edge_hi_flags)
{
// calculate how many tri's there are
int tri_count = (VBO_COUNT_MID_IDX() / 3);
for( int i=0; i<4; ++i ) {
if( edge_hi_flags & (1 << i) ) {
tri_count += (VBO_COUNT_HI_EDGE() / 3);
} else {
tri_count += (VBO_COUNT_LO_EDGE() / 3);
}
}
// pre-allocate enough space
pl.reserve(tri_count);
// add all of the middle indices
for(int i=0; i<VBO_COUNT_MID_IDX(); ++i) {
pl.push_back(midIndices[i]);
}
// selectively add the HI or LO detail indices
for (int i=0; i<4; i++) {
if( edge_hi_flags & (1 << i) ) {
for(int j=0; j<VBO_COUNT_HI_EDGE(); ++j) {
pl.push_back(hiEdgeIndices[i][j]);
}
} else {
for(int j=0; j<VBO_COUNT_LO_EDGE(); ++j) {
pl.push_back(loEdgeIndices[i][j]);
}
}
}
return tri_count;
}
//static
void GeoPatchContext::GenerateIndices()
{
if (prevEdgeLen == edgeLen)
return;
//
Uint32 *idx;
std::vector<Uint32> pl_short;
int tri_count = 0;
{
// calculate how many tri's there are
tri_count = (VBO_COUNT_MID_IDX() / 3);
for (int i = 0; i<4; ++i) {
tri_count += (VBO_COUNT_HI_EDGE() / 3);
}
// pre-allocate enough space
pl_short.reserve(tri_count);
// add all of the middle indices
for (int i = 0; i<VBO_COUNT_MID_IDX(); ++i) {
pl_short.push_back(0);
}
// add the HI detail indices
for (int i = 0; i<4; i++) {
for (int j = 0; j<VBO_COUNT_HI_EDGE(); ++j) {
pl_short.push_back(0);
}
}
}
// want vtx indices for tris
idx = &pl_short[0];
for (int x = 0; x<edgeLen - 1; x++) {
for (int y = 0; y<edgeLen - 1; y++) {
// 1st tri
idx[0] = x + edgeLen*y;
idx[1] = x + 1 + edgeLen*y;
idx[2] = x + edgeLen*(y + 1);
idx += 3;
// 2nd tri
idx[0] = x + 1 + edgeLen*y;
idx[1] = x + 1 + edgeLen*(y + 1);
idx[2] = x + edgeLen*(y + 1);
idx += 3;
}
}
// populate the N indices lists from the arrays built during InitTerrainIndices()
// iterate over each index list and optimize it
{
VertexCacheOptimizerUInt vco;
VertexCacheOptimizerUInt::Result res = vco.Optimize(&pl_short[0], tri_count);
assert(0 == res);
//create buffer & copy
indices.Reset(Pi::renderer->CreateIndexBuffer(pl_short.size(), Graphics::BUFFER_USAGE_STATIC));
Uint32* idxPtr = indices->Map(Graphics::BUFFER_MAP_WRITE);
for (Uint32 j = 0; j < pl_short.size(); j++) {
idxPtr[j] = pl_short[j];
}
indices->Unmap();
}
prevEdgeLen = edgeLen;
}
void GeoPatchContext::Init() {
frac = 1.0 / double(edgeLen-1);
vbotemp = new VBOVertex[NUMVERTICES()];
unsigned short *idx;
midIndices.reset(new unsigned short[VBO_COUNT_MID_IDX()]);
for (int i=0; i<4; i++) {
loEdgeIndices[i].reset(new unsigned short[VBO_COUNT_LO_EDGE()]);
hiEdgeIndices[i].reset(new unsigned short[VBO_COUNT_HI_EDGE()]);
}
/* also want vtx indices for tris not touching edge of patch */
idx = midIndices.get();
for (int x=1; x<edgeLen-2; x++) {
for (int y=1; y<edgeLen-2; y++) {
idx[0] = x + edgeLen*y;
idx[1] = x+1 + edgeLen*y;
idx[2] = x + edgeLen*(y+1);
idx+=3;
idx[0] = x+1 + edgeLen*y;
idx[1] = x+1 + edgeLen*(y+1);
idx[2] = x + edgeLen*(y+1);
idx+=3;
}
}
{
for (int x=1; x<edgeLen-3; x+=2) {
// razor teeth near edge 0
idx[0] = x + edgeLen;
idx[1] = x+1;
idx[2] = x+1 + edgeLen;
idx+=3;
idx[0] = x+1;
idx[1] = x+2 + edgeLen;
idx[2] = x+1 + edgeLen;
idx+=3;
}
for (int x=1; x<edgeLen-3; x+=2) {
// near edge 2
idx[0] = x + edgeLen*(edgeLen-2);
idx[1] = x+1 + edgeLen*(edgeLen-2);
idx[2] = x+1 + edgeLen*(edgeLen-1);
idx+=3;
idx[0] = x+1 + edgeLen*(edgeLen-2);
idx[1] = x+2 + edgeLen*(edgeLen-2);
idx[2] = x+1 + edgeLen*(edgeLen-1);
idx+=3;
}
for (int y=1; y<edgeLen-3; y+=2) {
// near edge 1
idx[0] = edgeLen-2 + y*edgeLen;
idx[1] = edgeLen-1 + (y+1)*edgeLen;
idx[2] = edgeLen-2 + (y+1)*edgeLen;
idx+=3;
idx[0] = edgeLen-2 + (y+1)*edgeLen;
idx[1] = edgeLen-1 + (y+1)*edgeLen;
idx[2] = edgeLen-2 + (y+2)*edgeLen;
idx+=3;
}
for (int y=1; y<edgeLen-3; y+=2) {
// near edge 3
idx[0] = 1 + y*edgeLen;
idx[1] = 1 + (y+1)*edgeLen;
idx[2] = (y+1)*edgeLen;
idx+=3;
idx[0] = 1 + (y+1)*edgeLen;
idx[1] = 1 + (y+2)*edgeLen;
idx[2] = (y+1)*edgeLen;
idx+=3;
}
}
// full detail edge triangles
{
idx = hiEdgeIndices[0].get();
for (int x=0; x<edgeLen-1; x+=2) {
idx[0] = x; idx[1] = x+1; idx[2] = x+1 + edgeLen;
idx+=3;
idx[0] = x+1; idx[1] = x+2; idx[2] = x+1 + edgeLen;
idx+=3;
}
idx = hiEdgeIndices[1].get();
for (int y=0; y<edgeLen-1; y+=2) {
idx[0] = edgeLen-1 + y*edgeLen;
idx[1] = edgeLen-1 + (y+1)*edgeLen;
idx[2] = edgeLen-2 + (y+1)*edgeLen;
idx+=3;
idx[0] = edgeLen-1 + (y+1)*edgeLen;
idx[1] = edgeLen-1 + (y+2)*edgeLen;
idx[2] = edgeLen-2 + (y+1)*edgeLen;
idx+=3;
}
idx = hiEdgeIndices[2].get();
for (int x=0; x<edgeLen-1; x+=2) {
idx[0] = x + (edgeLen-1)*edgeLen;
idx[1] = x+1 + (edgeLen-2)*edgeLen;
idx[2] = x+1 + (edgeLen-1)*edgeLen;
idx+=3;
idx[0] = x+1 + (edgeLen-2)*edgeLen;
idx[1] = x+2 + (edgeLen-1)*edgeLen;
idx[2] = x+1 + (edgeLen-1)*edgeLen;
idx+=3;
}
idx = hiEdgeIndices[3].get();
for (int y=0; y<edgeLen-1; y+=2) {
idx[0] = y*edgeLen;
idx[1] = 1 + (y+1)*edgeLen;
idx[2] = (y+1)*edgeLen;
idx+=3;
idx[0] = (y+1)*edgeLen;
idx[1] = 1 + (y+1)*edgeLen;
idx[2] = (y+2)*edgeLen;
idx+=3;
}
}
// these edge indices are for patches with no
// neighbour of equal or greater detail -- they reduce
// their edge complexity by 1 division
{
idx = loEdgeIndices[0].get();
for (int x=0; x<edgeLen-2; x+=2) {
idx[0] = x;
idx[1] = x+2;
idx[2] = x+1+edgeLen;
idx += 3;
}
idx = loEdgeIndices[1].get();
for (int y=0; y<edgeLen-2; y+=2) {
idx[0] = (edgeLen-1) + y*edgeLen;
idx[1] = (edgeLen-1) + (y+2)*edgeLen;
idx[2] = (edgeLen-2) + (y+1)*edgeLen;
idx += 3;
}
idx = loEdgeIndices[2].get();
for (int x=0; x<edgeLen-2; x+=2) {
idx[0] = x+edgeLen*(edgeLen-1);
idx[2] = x+2+edgeLen*(edgeLen-1);
idx[1] = x+1+edgeLen*(edgeLen-2);
idx += 3;
}
idx = loEdgeIndices[3].get();
for (int y=0; y<edgeLen-2; y+=2) {
idx[0] = y*edgeLen;
idx[2] = (y+2)*edgeLen;
idx[1] = 1 + (y+1)*edgeLen;
idx += 3;
}
}
// these will hold the optimised indices
std::vector<unsigned short> pl_short[NUM_INDEX_LISTS];
// populate the N indices lists from the arrays built during InitTerrainIndices()
for( int i=0; i<NUM_INDEX_LISTS; ++i ) {
const unsigned int edge_hi_flags = i;
indices_tri_counts[i] = getIndices(pl_short[i], edge_hi_flags);
}
// iterate over each index list and optimize it
for( int i=0; i<NUM_INDEX_LISTS; ++i ) {
int tri_count = indices_tri_counts[i];
VertexCacheOptimizerUShort vco;
VertexCacheOptimizerUShort::Result res = vco.Optimize(&pl_short[i][0], tri_count);
assert(0 == res);
}
// everything should be hunky-dory for setting up as OpenGL index buffers now.
for( int i=0; i<NUM_INDEX_LISTS; ++i ) {
glGenBuffersARB(1, &indices_list[i]);
glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER, indices_list[i]);
glBufferDataARB(GL_ELEMENT_ARRAY_BUFFER, sizeof(unsigned short)*indices_tri_counts[i]*3, &(pl_short[i][0]), GL_STATIC_DRAW);
glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER, 0);
}
// default it to the last entry which uses the hi-res borders
indices_vbo = indices_list[NUM_INDEX_LISTS-1];
indices_tri_count = indices_tri_counts[NUM_INDEX_LISTS-1];
if (midIndices) {
midIndices.reset();
for (int i=0; i<4; i++) {
loEdgeIndices[i].reset();
hiEdgeIndices[i].reset();
}
}
}