From 261da8dd0ac6ddb64aa4154a863c950087a1e05a Mon Sep 17 00:00:00 2001 From: scrawl Date: Tue, 13 Jan 2015 01:47:42 +0100 Subject: [PATCH] Terrain: use 32-bit indices if necessary --- components/terrain/buffercache.cpp | 305 +++++++++++++++-------------- 1 file changed, 161 insertions(+), 144 deletions(-) diff --git a/components/terrain/buffercache.cpp b/components/terrain/buffercache.cpp index c26e475535..3d0b359104 100644 --- a/components/terrain/buffercache.cpp +++ b/components/terrain/buffercache.cpp @@ -4,6 +4,162 @@ #include "defs.hpp" +namespace +{ + +template +Ogre::HardwareIndexBufferSharedPtr createIndexBuffer(unsigned int flags, unsigned int verts, Ogre::HardwareIndexBuffer::IndexType type) +{ + // LOD level n means every 2^n-th vertex is kept + size_t lodLevel = (flags >> (4*4)); + + size_t lodDeltas[4]; + for (int i=0; i<4; ++i) + lodDeltas[i] = (flags >> (4*i)) & (0xf); + + bool anyDeltas = (lodDeltas[Terrain::North] || lodDeltas[Terrain::South] || lodDeltas[Terrain::West] || lodDeltas[Terrain::East]); + + size_t increment = 1 << lodLevel; + assert(increment < verts); + std::vector indices; + indices.reserve((verts-1)*(verts-1)*2*3 / increment); + + size_t rowStart = 0, colStart = 0, rowEnd = verts-1, colEnd = verts-1; + // If any edge needs stitching we'll skip all edges at this point, + // mainly because stitching one edge would have an effect on corners and on the adjacent edges + if (anyDeltas) + { + colStart += increment; + colEnd -= increment; + rowEnd -= increment; + rowStart += increment; + } + for (size_t row = rowStart; row < rowEnd; row += increment) + { + for (size_t col = colStart; col < colEnd; col += increment) + { + indices.push_back(verts*col+row); + indices.push_back(verts*(col+increment)+row+increment); + indices.push_back(verts*col+row+increment); + + indices.push_back(verts*col+row); + indices.push_back(verts*(col+increment)+row); + indices.push_back(verts*(col+increment)+row+increment); + } + } + + size_t innerStep = increment; + if (anyDeltas) + { + // Now configure LOD transitions at the edges - this is pretty tedious, + // and some very long and boring code, but it works great + + // South + size_t row = 0; + size_t outerStep = 1 << (lodDeltas[Terrain::South] + lodLevel); + for (size_t col = 0; col < verts-1; col += outerStep) + { + indices.push_back(verts*col+row); + indices.push_back(verts*(col+outerStep)+row); + // Make sure not to touch the right edge + if (col+outerStep == verts-1) + indices.push_back(verts*(col+outerStep-innerStep)+row+innerStep); + else + indices.push_back(verts*(col+outerStep)+row+innerStep); + + for (size_t i = 0; i < outerStep; i += innerStep) + { + // Make sure not to touch the left or right edges + if (col+i == 0 || col+i == verts-1-innerStep) + continue; + indices.push_back(verts*(col)+row); + indices.push_back(verts*(col+i+innerStep)+row+innerStep); + indices.push_back(verts*(col+i)+row+innerStep); + } + } + + // North + row = verts-1; + outerStep = size_t(1) << (lodDeltas[Terrain::North] + lodLevel); + for (size_t col = 0; col < verts-1; col += outerStep) + { + indices.push_back(verts*(col+outerStep)+row); + indices.push_back(verts*col+row); + // Make sure not to touch the left edge + if (col == 0) + indices.push_back(verts*(col+innerStep)+row-innerStep); + else + indices.push_back(verts*col+row-innerStep); + + for (size_t i = 0; i < outerStep; i += innerStep) + { + // Make sure not to touch the left or right edges + if (col+i == 0 || col+i == verts-1-innerStep) + continue; + indices.push_back(verts*(col+i)+row-innerStep); + indices.push_back(verts*(col+i+innerStep)+row-innerStep); + indices.push_back(verts*(col+outerStep)+row); + } + } + + // West + size_t col = 0; + outerStep = size_t(1) << (lodDeltas[Terrain::West] + lodLevel); + for (size_t row = 0; row < verts-1; row += outerStep) + { + indices.push_back(verts*col+row+outerStep); + indices.push_back(verts*col+row); + // Make sure not to touch the top edge + if (row+outerStep == verts-1) + indices.push_back(verts*(col+innerStep)+row+outerStep-innerStep); + else + indices.push_back(verts*(col+innerStep)+row+outerStep); + + for (size_t i = 0; i < outerStep; i += innerStep) + { + // Make sure not to touch the top or bottom edges + if (row+i == 0 || row+i == verts-1-innerStep) + continue; + indices.push_back(verts*col+row); + indices.push_back(verts*(col+innerStep)+row+i); + indices.push_back(verts*(col+innerStep)+row+i+innerStep); + } + } + + // East + col = verts-1; + outerStep = size_t(1) << (lodDeltas[Terrain::East] + lodLevel); + for (size_t row = 0; row < verts-1; row += outerStep) + { + indices.push_back(verts*col+row); + indices.push_back(verts*col+row+outerStep); + // Make sure not to touch the bottom edge + if (row == 0) + indices.push_back(verts*(col-innerStep)+row+innerStep); + else + indices.push_back(verts*(col-innerStep)+row); + + for (size_t i = 0; i < outerStep; i += innerStep) + { + // Make sure not to touch the top or bottom edges + if (row+i == 0 || row+i == verts-1-innerStep) + continue; + indices.push_back(verts*col+row+outerStep); + indices.push_back(verts*(col-innerStep)+row+i+innerStep); + indices.push_back(verts*(col-innerStep)+row+i); + } + } + } + + Ogre::HardwareBufferManager* mgr = Ogre::HardwareBufferManager::getSingletonPtr(); + Ogre::HardwareIndexBufferSharedPtr buffer = mgr->createIndexBuffer(type, + indices.size(), Ogre::HardwareBuffer::HBU_STATIC); + buffer->writeData(0, buffer->getSizeInBytes(), &indices[0], true); + return buffer; +} + +} + namespace Terrain { @@ -48,151 +204,12 @@ namespace Terrain return mIndexBufferMap[flags]; } - // LOD level n means every 2^n-th vertex is kept - size_t lodLevel = (flags >> (4*4)); + Ogre::HardwareIndexBufferSharedPtr buffer; + if (verts*verts > (0xffffu)) + buffer = createIndexBuffer(flags, verts, Ogre::HardwareIndexBuffer::IT_32BIT); + else + buffer = createIndexBuffer(flags, verts, Ogre::HardwareIndexBuffer::IT_16BIT); - size_t lodDeltas[4]; - for (int i=0; i<4; ++i) - lodDeltas[i] = (flags >> (4*i)) & (0xf); - - bool anyDeltas = (lodDeltas[North] || lodDeltas[South] || lodDeltas[West] || lodDeltas[East]); - - size_t increment = 1 << lodLevel; - assert(increment < verts); - std::vector indices; - indices.reserve((verts-1)*(verts-1)*2*3 / increment); - - size_t rowStart = 0, colStart = 0, rowEnd = verts-1, colEnd = verts-1; - // If any edge needs stitching we'll skip all edges at this point, - // mainly because stitching one edge would have an effect on corners and on the adjacent edges - if (anyDeltas) - { - colStart += increment; - colEnd -= increment; - rowEnd -= increment; - rowStart += increment; - } - for (size_t row = rowStart; row < rowEnd; row += increment) - { - for (size_t col = colStart; col < colEnd; col += increment) - { - indices.push_back(verts*col+row); - indices.push_back(verts*(col+increment)+row+increment); - indices.push_back(verts*col+row+increment); - - indices.push_back(verts*col+row); - indices.push_back(verts*(col+increment)+row); - indices.push_back(verts*(col+increment)+row+increment); - } - } - - size_t innerStep = increment; - if (anyDeltas) - { - // Now configure LOD transitions at the edges - this is pretty tedious, - // and some very long and boring code, but it works great - - // South - size_t row = 0; - size_t outerStep = 1 << (lodDeltas[South] + lodLevel); - for (size_t col = 0; col < verts-1; col += outerStep) - { - indices.push_back(verts*col+row); - indices.push_back(verts*(col+outerStep)+row); - // Make sure not to touch the right edge - if (col+outerStep == verts-1) - indices.push_back(verts*(col+outerStep-innerStep)+row+innerStep); - else - indices.push_back(verts*(col+outerStep)+row+innerStep); - - for (size_t i = 0; i < outerStep; i += innerStep) - { - // Make sure not to touch the left or right edges - if (col+i == 0 || col+i == verts-1-innerStep) - continue; - indices.push_back(verts*(col)+row); - indices.push_back(verts*(col+i+innerStep)+row+innerStep); - indices.push_back(verts*(col+i)+row+innerStep); - } - } - - // North - row = verts-1; - outerStep = size_t(1) << (lodDeltas[North] + lodLevel); - for (size_t col = 0; col < verts-1; col += outerStep) - { - indices.push_back(verts*(col+outerStep)+row); - indices.push_back(verts*col+row); - // Make sure not to touch the left edge - if (col == 0) - indices.push_back(verts*(col+innerStep)+row-innerStep); - else - indices.push_back(verts*col+row-innerStep); - - for (size_t i = 0; i < outerStep; i += innerStep) - { - // Make sure not to touch the left or right edges - if (col+i == 0 || col+i == verts-1-innerStep) - continue; - indices.push_back(verts*(col+i)+row-innerStep); - indices.push_back(verts*(col+i+innerStep)+row-innerStep); - indices.push_back(verts*(col+outerStep)+row); - } - } - - // West - size_t col = 0; - outerStep = size_t(1) << (lodDeltas[West] + lodLevel); - for (size_t row = 0; row < verts-1; row += outerStep) - { - indices.push_back(verts*col+row+outerStep); - indices.push_back(verts*col+row); - // Make sure not to touch the top edge - if (row+outerStep == verts-1) - indices.push_back(verts*(col+innerStep)+row+outerStep-innerStep); - else - indices.push_back(verts*(col+innerStep)+row+outerStep); - - for (size_t i = 0; i < outerStep; i += innerStep) - { - // Make sure not to touch the top or bottom edges - if (row+i == 0 || row+i == verts-1-innerStep) - continue; - indices.push_back(verts*col+row); - indices.push_back(verts*(col+innerStep)+row+i); - indices.push_back(verts*(col+innerStep)+row+i+innerStep); - } - } - - // East - col = verts-1; - outerStep = size_t(1) << (lodDeltas[East] + lodLevel); - for (size_t row = 0; row < verts-1; row += outerStep) - { - indices.push_back(verts*col+row); - indices.push_back(verts*col+row+outerStep); - // Make sure not to touch the bottom edge - if (row == 0) - indices.push_back(verts*(col-innerStep)+row+innerStep); - else - indices.push_back(verts*(col-innerStep)+row); - - for (size_t i = 0; i < outerStep; i += innerStep) - { - // Make sure not to touch the top or bottom edges - if (row+i == 0 || row+i == verts-1-innerStep) - continue; - indices.push_back(verts*col+row+outerStep); - indices.push_back(verts*(col-innerStep)+row+i+innerStep); - indices.push_back(verts*(col-innerStep)+row+i); - } - } - } - - Ogre::HardwareBufferManager* mgr = Ogre::HardwareBufferManager::getSingletonPtr(); - Ogre::HardwareIndexBufferSharedPtr buffer = mgr->createIndexBuffer(Ogre::HardwareIndexBuffer::IT_16BIT, - indices.size(), Ogre::HardwareBuffer::HBU_STATIC); - buffer->writeData(0, buffer->getSizeInBytes(), &indices[0], true); mIndexBufferMap[flags] = buffer; return buffer; }