void run()
{
if(!initialize())
shutdown("Failed to initialize");
if(!loadContent())
shutdown("Failed to load resources");
Mesh cubeMesh = Mesh::genUnitColoredCube();
MeshBuffer cubeBuffer(cubeMesh);
Model cube(cubeBuffer);
Mesh waterMesh = Mesh::genUnitColoredPlane(Color(0.57f, 0.63f, 0.98f));
MeshBuffer waterBuffer(waterMesh);
Model water(waterBuffer);
BufferObject quadVbo;
float quadVertices[] = {
-1.0f, -1.0f, 0.0f, 0.0f,
+1.0f, -1.0f, 1.0f, 0.0f,
+1.0f, +1.0f, 1.0f, 1.0f,
+1.0f, +1.0f, 1.0f, 1.0f,
-1.0f, +1.0f, 0.0f, 1.0f,
-1.0f, -1.0f, 0.0f, 0.0f
};
quadVbo.create(GL_ARRAY_BUFFER, GL_STATIC_DRAW, sizeof(quadVertices), quadVertices);
Mesh gridMesh;
for(int i = 0; i <= 8; ++i)
{
float f = (i / 8.0) * 2.0f - 1.0f;
int j = gridMesh.getPositionCount();
gridMesh.addPosition(f * 3.0f, 0.0f, -3.0f);
gridMesh.addPosition(f * 3.0f, 0.0f, +3.0f);
gridMesh.addPosition(-3.0f, 0.0f, f * 3.0f);
gridMesh.addPosition(+3.0f, 0.0f, f * 3.0f);
gridMesh.addColor(Colors::White);
gridMesh.addColor(Colors::White);
gridMesh.addColor(Colors::White);
gridMesh.addColor(Colors::White);
gridMesh.addIndex(j + 0); gridMesh.addIndex(j + 1);
gridMesh.addIndex(j + 2); gridMesh.addIndex(j + 3);
}
MeshBuffer gridBuffer(gridMesh);
Model grid(gridBuffer);
VertexArray vao;
vao.create();
vao.bind();
mat4 perspectiveMatrix = glm::perspective(45.0f, windowWidth / float(windowHeight), 0.05f, 50.0f);
// The geometry to be refracted and reflected are stored in these
// In addition to RGB values, the world-space height is stored in the alpha-channel
// of the refraction texture.
// Fresnel equations is used to blend between the two textures
RenderTexture refractionRT(windowWidth, windowHeight);
RenderTexture reflectionRT(windowWidth, windowHeight);
renderer.setClearColor(0.55f, 0.45f, 0.45f, 1.0f);
renderer.setClearDepth(1.0);
Timer timer;
timer.start();
double renderTime = 0.0;
while(context.isOpen())
{
timer.step();
double time = timer.getElapsedTime();
update(time, timer.getDelta());
double renderStart = timer.getElapsedTime();
MatrixStack viewMatrix;
viewMatrix.push();
viewMatrix.translate(0.0f, 0.0f, -3.0f);
viewMatrix.rotateX(xAxisRotation);
viewMatrix.rotateY(yAxisRotation);
renderer.setCullState(CullStates::CullNone);
renderer.setDepthTestState(DepthTestStates::LessThanOrEqual);
colorShader.begin();
colorShader.setUniform("projection", perspectiveMatrix);
cube.pushTransform();
cube.translate(0.0f, 0.0f, 0.0f);
cube.scale(0.5f);
// Render the geometry to be refracted, store result in rt
refractionRT.begin();
renderer.clearColorAndDepth();
colorShader.setUniform("view", viewMatrix.top());
cube.draw(GL_TRIANGLES);
grid.draw(GL_LINES);
refractionRT.end();
// Render the geometry to be reflected, store result in rt
reflectionRT.begin();
renderer.clearColorAndDepth();
viewMatrix.push();
viewMatrix.scale(1.0f, -1.0f, 1.0f); // Reflect about xz-plane
colorShader.setUniform("view", viewMatrix.top());
cube.draw(GL_TRIANGLES);
viewMatrix.pop();
reflectionRT.end();
colorShader.end();
cube.popTransform();
// Render the water with the previous reflection/refraction texture
waterShader.begin();
waterShader.setUniform("time", time);
glActiveTexture(GL_TEXTURE0 + 0);
refractionRT.bindTexture();
glActiveTexture(GL_TEXTURE0 + 1);
reflectionRT.bindTexture();
glActiveTexture(GL_TEXTURE0 + 2);
waterNormals.bind();
//waterShader.setUniform("view", viewMatrix.top());
waterShader.setUniform("refraction_tex", 0);
waterShader.setUniform("reflection_tex", 1);
waterShader.setUniform("water_normals_tex", 2);
//waterShader.setUniform("light0_pos", vec3(0.0f, 1.0f, 0.0f));
//waterShader.setUniform("light0_col", vec3(1.0f, 0.8f, 0.5f));
//waterShader.setUniform("ambient", vec3(67.0f/255.0f, 66.0f/255.0f, 63.0f/255.0f));
quadVbo.bind();
waterShader.setAttributefv("position", 2, 4, 0);
waterShader.setAttributefv("texel", 2, 4, 2);
glDrawArrays(GL_TRIANGLES, 0, 6);
quadVbo.unbind();
reflectionRT.unbindTexture();
refractionRT.unbindTexture();
waterNormals.unbind();
waterShader.end();
glActiveTexture(GL_TEXTURE0 + 0);
// Render unmirrored scene
//colorShader.begin();
//renderer.clearColorAndDepth();
//renderer.setCullState(CullStates::CullNone);
//renderer.setBlendState(BlendStates::AlphaBlend);
//renderer.setDepthTestState(DepthTestStates::LessThanOrEqual);
//colorShader.setUniform("projection", perspectiveMatrix);
//colorShader.setUniform("view", viewMatrix.top());
//cube.pushTransform();
//cube.translate(0.0f, 0.4f, 0.0f);
//cube.scale(0.5f);
//cube.draw(GL_TRIANGLES);
/*grid.pushTransform();
grid.translate(0.0f, -0.5f, 0.0f);
grid.draw(GL_LINES);
grid.popTransform();*/
// Draw mirrored scene to a rendertarget
/*rt.begin();
renderer.clearColorAndDepth();
viewMatrix.push();
viewMatrix.scale(1.0f, -1.0f, 1.0f);
colorShader.setUniform("view", viewMatrix.top());
cube.draw(GL_TRIANGLES);
cube.popTransform();
viewMatrix.pop();
rt.end();*/
// Enable stencil testing and mask out a section containing the water mesh
//glEnable(GL_STENCIL_TEST);
//glStencilFunc(GL_ALWAYS, 1, 0xFF); // Set any stencil to 1
//glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
//glStencilMask(0xFF); // Write to stencil buffer
//glDepthMask(GL_FALSE); // Don't write to depth buffer
//glClear(GL_STENCIL_BUFFER_BIT); // Clear stencil buffer (0 by default)
//// Draw water mesh
//water.pushTransform();
//water.scale(3.0f);
//water.draw(GL_TRIANGLES);
//water.popTransform();
//colorShader.end();
//// Draw previous rendertarget as a quad masked into the water plane
//glStencilFunc(GL_EQUAL, 1, 0xFF); // Pass test if stencil value is 1
//glStencilMask(0x00); // Don't write anything to stencil buffer
//glDepthMask(GL_TRUE);
//glDisable(GL_STENCIL_TEST);
viewMatrix.pop();
context.display();
renderTime = timer.getElapsedTime() - renderStart;
if(renderTime < 0.013)
context.sleep(0.013 - renderTime);
if(checkGLErrors(std::cerr))
{
std::cin.get();
context.close();
}
}
waterNormals.dispose();
colorShader.dispose();
waterShader.dispose();
vao.dispose();
context.dispose();
}
std::vector<Grid_t> DiffusionGrid(const unsigned gridDim, const float d,
const float dt,
std::vector<float> const &_timesToRecord) {
std::vector<float> timesToRecord(_timesToRecord);
const int nSnapshots = timesToRecord.size();
// Construct cartesian grid
int nHorizontal, nVertical;
const int nRanks = mpi::size();
nHorizontal = nVertical = std::sqrt(nRanks);
while (true) {
int nCells = nHorizontal*nVertical;
if (nCells == nRanks) {
break;
}
if (nCells < nRanks) {
++nVertical;
} else {
--nHorizontal;
}
}
mpi::CartesianGrid<2> mpiGrid({{nVertical, nHorizontal}}, false);
// Determine local grid
const int rowBegin = gridDim * mpiGrid.row() / mpiGrid.rowMax();
const int rowEnd = gridDim * (mpiGrid.row() + 1) / mpiGrid.rowMax();
const int nRows = rowEnd - rowBegin;
const int colBegin = gridDim * mpiGrid.col() / mpiGrid.colMax();
const int colEnd = gridDim * (mpiGrid.col() + 1) / mpiGrid.colMax();
const int nCols = colEnd - colBegin;
Grid_t grid(nRows + 2, Row_t(nCols + 2)); // Added padding
// Initialize local grid values
const int fillStart = gridDim / 4;
const int fillEnd = gridDim - fillStart;
const int minRow = fillStart - rowBegin;
const int maxRow = fillEnd - rowBegin;
const int minCol = fillStart - colBegin;
const int maxCol = fillEnd - colBegin;
const int iMax = nRows + 1;
const int jMax = nCols + 1;
for (int i = -1; i < iMax; ++i) {
const bool inRow = i > minRow && i < maxRow;
for (int j = -1; j < jMax; ++j) {
grid[i + 1][j + 1] = inRow && j > minCol && j < maxCol;
}
}
Grid_t gridBuffer(grid); // Copy into gridBuffer
// Run diffusion
std::sort(timesToRecord.begin(), timesToRecord.end());
std::vector<Grid_t> localSnapshots(nSnapshots);
auto outputItr = localSnapshots.begin();
auto timeItr = timesToRecord.cbegin();
const auto timeItrEnd = timesToRecord.cend();
const float ds = 2. / gridDim;
const float factor = d * dt / (ds * ds);
const int iMaxInner = iMax - 1;
const int jMaxInner = jMax - 1;
float t = 0;
auto diffuse = [&grid, &factor](const int i, const int j) {
return grid[i][j] +
factor * (grid[i - 1][j] + grid[i][j - 1] - 4 * grid[i][j] +
grid[i][j + 1] + grid[i + 1][j]);
};
const std::array<std::pair<int, bool>, 4> neighbors = {
{mpiGrid.up(), mpiGrid.down(), mpiGrid.left(), mpiGrid.right()}};
std::vector<float> bufferSendLeft(nRows+2);
std::vector<float> bufferSendRight(nRows+2);
std::vector<float> bufferReceiveLeft(nRows+2);
std::vector<float> bufferReceiveRight(nRows+2);
for (;;t += dt) {
if (t >= *timeItr) {
// Collect snapshot
*outputItr++ = grid;
if (++timeItr == timeItrEnd) {
break;
}
}
// Handle edges
std::vector<MPI_Request> colReceive;
std::vector<MPI_Request> requests;
// Horizontal edges
for (int i = 1; i < iMax; ++i) {
bufferSendLeft[i] = diffuse(i, 1);
bufferSendRight[i] = diffuse(i, nCols);
}
if (neighbors[2].second) {
requests.emplace_back(mpi::SendAsync(bufferSendLeft.begin(),
bufferSendLeft.end(),
neighbors[2].first));
colReceive.emplace_back(mpi::ReceiveAsync(bufferReceiveLeft.begin(),
bufferReceiveLeft.end(),
neighbors[2].first));
}
if (neighbors[3].second) {
requests.emplace_back(mpi::SendAsync(bufferSendRight.begin(),
bufferSendRight.end(),
neighbors[3].first));
colReceive.emplace_back(mpi::ReceiveAsync(bufferReceiveRight.begin(),
bufferReceiveRight.end(),
neighbors[3].first));
}
// Top edge
for (int j = 1; j < jMax; ++j) {
gridBuffer[1][j] = diffuse(1, j);
}
if (neighbors[0].second) {
requests.emplace_back(mpi::SendAsync(
gridBuffer[1].begin(), gridBuffer[1].end(), neighbors[0].first));
requests.emplace_back(mpi::ReceiveAsync(
gridBuffer[0].begin(), gridBuffer[0].end(), neighbors[0].first));
}
// Bottom edge
for (int j = 1; j < jMax; ++j) {
gridBuffer[nRows][j] = diffuse(nRows, j);
}
if (neighbors[1].second) {
requests.emplace_back(mpi::SendAsync(gridBuffer[nRows].begin(),
gridBuffer[nRows].end(),
neighbors[1].first));
requests.emplace_back(mpi::ReceiveAsync(gridBuffer[nRows + 1].begin(),
gridBuffer[nRows + 1].end(),
neighbors[1].first));
}
// Retrieve the cols so they can be copied to the grid while computing the
// bulk
mpi::WaitAll(colReceive);
// Compute the bulk
for (int i = 2; i < iMaxInner; ++i) {
gridBuffer[i][0] = bufferReceiveLeft[i];
gridBuffer[i][1] = bufferSendLeft[i];
for (int j = 2; j < jMaxInner; ++j) {
gridBuffer[i][j] = diffuse(i, j);
}
gridBuffer[i][nCols] = bufferSendRight[i];
gridBuffer[i][nCols + 1] = bufferReceiveRight[i];
}
// Wait for all remaining sends and receives to finish
mpi::WaitAll(requests);
gridBuffer.swap(grid);
} // End main loop
// Gather results
const MPI_Comm rowComm = mpiGrid.Partition<0>();
const MPI_Comm colComm = mpiGrid.Partition<1>();
const int rank = mpi::rank();
const int colRank = mpi::rank(colComm);
const int rowRank = mpi::rank(rowComm);
std::vector<Grid_t> totalSnapshots;
if (rank == 0) {
totalSnapshots =
std::vector<Grid_t>(nSnapshots, Grid_t(gridDim, Row_t(gridDim)));
}
std::vector<Grid_t> rowSnapshots;
if (colRank == 0) {
rowSnapshots =
std::vector<Grid_t>(nSnapshots, Grid_t(nRows, Row_t(gridDim)));
}
std::vector<MPI_Request> requests;
std::vector<int> colSizes;
std::vector<int> colOffsets;
// Generate gather parameters
if (colRank == 0) {
colOffsets.emplace_back(0);
for (int i = 0; i < nHorizontal; ++i) {
colSizes.emplace_back(gridDim * (i + 1) / mpiGrid.colMax() -
gridDim * i / mpiGrid.colMax());
if (i > 0) {
colOffsets.emplace_back(colOffsets[i - 1] + colSizes[i] - 1);
}
}
}
for (int s = 0; s < nSnapshots; ++s) {
// Gather grid rows across columns in each row of MPI ranks
for (int i = 0; i < nRows; ++i) {
typename Row_t::iterator target;
if (colRank == 0) {
target = rowSnapshots[s][i].begin();
}
mpi::Gather(localSnapshots[s][i + 1].begin() + 1,
localSnapshots[s][i + 1].end() - 1, target, colSizes,
colOffsets, 0, colComm);
}
// Gather all rows in root rank
if (colRank == 0) {
if (rowRank != 0) {
for (int i = 0; i < nRows; ++i) {
mpi::Send(rowSnapshots[s][i].begin(), rowSnapshots[s][i].end(), 0,
0, rowComm);
}
} else {
int globalRow = 0;
for (int i = 0; i < nRows; ++i) {
totalSnapshots[s][globalRow] = std::move(rowSnapshots[s][i]);
++globalRow;
}
for (int r = 1, rMax = mpiGrid.rowMax(); r < rMax; ++r) {
const int currRowBegin = gridDim*r/nVertical;
const int currRowEnd = gridDim*(r+1)/nVertical;
const int currNRows = currRowEnd - currRowBegin;
for (int i = 0; i < currNRows; ++i) {
requests.emplace_back(mpi::ReceiveAsync(
totalSnapshots[s][globalRow].begin(),
totalSnapshots[s][globalRow].end(), r, 0, rowComm));
++globalRow;
}
}
}
}
}
mpi::WaitAll(requests);
return totalSnapshots;
}