bool CRenderer::Initialize( spCDisplayOutput _spDisplay )
{
m_spDisplay = _spDisplay;
// Default(disabled) blendmode.
AddBlend( "none", eOne, eZero, eAdd );
// Alphablend.
AddBlend( "alphablend", eSrc_Alpha, eOne_Minus_Src_Alpha, eAdd );
return true;
}
void CPatchRData::BuildBlends()
{
PROFILE3("build blends");
m_BlendSplats.clear();
std::vector<SBlendVertex> blendVertices;
std::vector<u16> blendIndices;
CTerrain* terrain = m_Patch->m_Parent;
std::vector<STileBlendStack> blendStacks;
blendStacks.reserve(PATCH_SIZE*PATCH_SIZE);
// For each tile in patch ..
for (ssize_t j = 0; j < PATCH_SIZE; ++j)
{
for (ssize_t i = 0; i < PATCH_SIZE; ++i)
{
ssize_t gx = m_Patch->m_X * PATCH_SIZE + i;
ssize_t gz = m_Patch->m_Z * PATCH_SIZE + j;
std::vector<STileBlend> blends;
blends.reserve(9);
// Compute a blend for every tile in the 3x3 square around this tile
for (size_t n = 0; n < 9; ++n)
{
ssize_t ox = gx + BlendOffsets[n][1];
ssize_t oz = gz + BlendOffsets[n][0];
CMiniPatch* nmp = terrain->GetTile(ox, oz);
if (!nmp)
continue;
STileBlend blend;
blend.m_Texture = nmp->GetTextureEntry();
blend.m_Priority = nmp->GetPriority();
blend.m_TileMask = 1 << n;
blends.push_back(blend);
}
// Sort the blends, highest priority first
std::sort(blends.begin(), blends.end(), STileBlend::DecreasingPriority());
STileBlendStack blendStack;
blendStack.i = i;
blendStack.j = j;
// Put the blends into the tile's stack, merging any adjacent blends with the same texture
for (size_t k = 0; k < blends.size(); ++k)
{
if (!blendStack.blends.empty() && blendStack.blends.back().m_Texture == blends[k].m_Texture)
blendStack.blends.back().m_TileMask |= blends[k].m_TileMask;
else
blendStack.blends.push_back(blends[k]);
}
// Remove blends that are after (i.e. lower priority than) the current tile
// (including the current tile), since we don't want to render them on top of
// the tile's base texture
blendStack.blends.erase(
std::find_if(blendStack.blends.begin(), blendStack.blends.end(), STileBlend::CurrentTile()),
blendStack.blends.end());
blendStacks.push_back(blendStack);
}
}
// Given the blend stack per tile, we want to batch together as many blends as possible.
// Group them into a series of layers (each of which has a single texture):
// (This is effectively a topological sort / linearisation of the partial order induced
// by the per-tile stacks, preferring to make tiles with equal textures adjacent.)
std::vector<SBlendLayer> blendLayers;
while (true)
{
if (!blendLayers.empty())
{
// Try to grab as many tiles as possible that match our current layer,
// from off the blend stacks of all the tiles
CTerrainTextureEntry* tex = blendLayers.back().m_Texture;
for (size_t k = 0; k < blendStacks.size(); ++k)
{
if (!blendStacks[k].blends.empty() && blendStacks[k].blends.back().m_Texture == tex)
{
SBlendLayer::Tile t = { blendStacks[k].i, blendStacks[k].j, blendStacks[k].blends.back().m_TileMask };
blendLayers.back().m_Tiles.push_back(t);
blendStacks[k].blends.pop_back();
}
// (We've already merged adjacent entries of the same texture in each stack,
// so we don't need to bother looping to check the next entry in this stack again)
}
}
// We've grabbed as many tiles as possible; now we need to start a new layer.
// The new layer's texture could come from the back of any non-empty stack;
// choose the longest stack as a heuristic to reduce the number of layers
CTerrainTextureEntry* bestTex = NULL;
size_t bestStackSize = 0;
for (size_t k = 0; k < blendStacks.size(); ++k)
{
if (blendStacks[k].blends.size() > bestStackSize)
{
bestStackSize = blendStacks[k].blends.size();
bestTex = blendStacks[k].blends.back().m_Texture;
}
}
// If all our stacks were empty, we're done
if (bestStackSize == 0)
break;
// Otherwise add the new layer, then loop back and start filling it in
SBlendLayer layer;
layer.m_Texture = bestTex;
blendLayers.push_back(layer);
}
// Now build outgoing splats
m_BlendSplats.resize(blendLayers.size());
for (size_t k = 0; k < blendLayers.size(); ++k)
{
SSplat& splat = m_BlendSplats[k];
splat.m_IndexStart = blendIndices.size();
splat.m_Texture = blendLayers[k].m_Texture;
for (size_t t = 0; t < blendLayers[k].m_Tiles.size(); ++t)
{
SBlendLayer::Tile& tile = blendLayers[k].m_Tiles[t];
AddBlend(blendVertices, blendIndices, tile.i, tile.j, tile.shape, splat.m_Texture);
}
splat.m_IndexCount = blendIndices.size() - splat.m_IndexStart;
}
// Release existing vertex buffer chunks
if (m_VBBlends)
{
g_VBMan.Release(m_VBBlends);
m_VBBlends = 0;
}
if (m_VBBlendIndices)
{
g_VBMan.Release(m_VBBlendIndices);
m_VBBlendIndices = 0;
}
if (blendVertices.size())
{
// Construct vertex buffer
m_VBBlends = g_VBMan.Allocate(sizeof(SBlendVertex), blendVertices.size(), GL_STATIC_DRAW, GL_ARRAY_BUFFER);
m_VBBlends->m_Owner->UpdateChunkVertices(m_VBBlends, &blendVertices[0]);
// Update the indices to include the base offset of the vertex data
for (size_t k = 0; k < blendIndices.size(); ++k)
blendIndices[k] += m_VBBlends->m_Index;
m_VBBlendIndices = g_VBMan.Allocate(sizeof(u16), blendIndices.size(), GL_STATIC_DRAW, GL_ELEMENT_ARRAY_BUFFER);
m_VBBlendIndices->m_Owner->UpdateChunkVertices(m_VBBlendIndices, &blendIndices[0]);
}
}
