/*
* Copyright (c) 2015 scrawl <scrawl@baseoftrash.de>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "buffercache.hpp"
#include <OgreHardwareBufferManager.h>
#include "defs.hpp"
namespace
{
template <typename IndexType>
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<IndexType> 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)
{
// diamond pattern
if ((row + col%2) % 2 == 1)
{
indices.push_back(verts*(col+increment)+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)+row+increment);
}
else
{
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
{
Ogre::HardwareVertexBufferSharedPtr BufferCache::getUVBuffer()
{
if (mUvBufferMap.find(mNumVerts) != mUvBufferMap.end())
{
return mUvBufferMap[mNumVerts];
}
int vertexCount = mNumVerts * mNumVerts;
std::vector<float> uvs;
uvs.reserve(vertexCount*2);
for (unsigned int col = 0; col < mNumVerts; ++col)
{
for (unsigned int row = 0; row < mNumVerts; ++row)
{
uvs.push_back(col / static_cast<float>(mNumVerts-1)); // U
uvs.push_back(row / static_cast<float>(mNumVerts-1)); // V
}
}
Ogre::HardwareBufferManager* mgr = Ogre::HardwareBufferManager::getSingletonPtr();
Ogre::HardwareVertexBufferSharedPtr buffer = mgr->createVertexBuffer(
Ogre::VertexElement::getTypeSize(Ogre::VET_FLOAT2),
vertexCount, Ogre::HardwareBuffer::HBU_STATIC);
buffer->writeData(0, buffer->getSizeInBytes(), &uvs[0], true);
mUvBufferMap[mNumVerts] = buffer;
return buffer;
}
Ogre::HardwareIndexBufferSharedPtr BufferCache::getIndexBuffer(unsigned int flags)
{
unsigned int verts = mNumVerts;
if (mIndexBufferMap.find(flags) != mIndexBufferMap.end())
{
return mIndexBufferMap[flags];
}
Ogre::HardwareIndexBufferSharedPtr buffer;
if (verts*verts > (0xffffu))
buffer = createIndexBuffer<unsigned int>(flags, verts, Ogre::HardwareIndexBuffer::IT_32BIT);
else
buffer = createIndexBuffer<unsigned short>(flags, verts, Ogre::HardwareIndexBuffer::IT_16BIT);
mIndexBufferMap[flags] = buffer;
return buffer;
}
}