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// -----------------------------------------------------------------------------
//
// Gmsh C++ tutorial 8
//
// Post-processing and animations
//
// -----------------------------------------------------------------------------
#include <set>
#include <gmsh.h>
// In addition to creating geometries and meshes, the C++ API can also be used
// to manipulate post-processing datasets (called "views" in Gmsh).
int main(int argc, char **argv)
{
gmsh::initialize();
gmsh::model::add("t8");
// We first create a simple geometry
double lc = 1e-2;
gmsh::model::geo::addPoint(0, 0, 0, lc, 1);
gmsh::model::geo::addPoint(.1, 0, 0, lc, 2);
gmsh::model::geo::addPoint(.1, .3, 0, lc, 3);
gmsh::model::geo::addPoint(0, .3, 0, lc, 4);
gmsh::model::geo::addLine(1, 2, 1);
gmsh::model::geo::addLine(3, 2, 2);
gmsh::model::geo::addLine(3, 4, 3);
gmsh::model::geo::addLine(4, 1, 4);
gmsh::model::geo::addCurveLoop({4, 1, -2, 3}, 1);
gmsh::model::geo::addPlaneSurface({1}, 1);
gmsh::model::geo::synchronize();
// We merge some post-processing views to work on
try {
gmsh::merge("../view1.pos");
gmsh::merge("../view1.pos");
gmsh::merge("../view4.pos"); // contains 2 views inside
} catch(...) {
gmsh::logger::write("Could not load post-processing views: bye!");
gmsh::finalize();
return 0;
}
// Gmsh can read post-processing views in various formats. Here the
// `view1.pos' and `view4.pos' files are in the Gmsh "parsed" format, which is
// interpreted by the GEO script parser. The parsed format should only be used
// for relatively small datasets of course: for larger datasets using e.g. MSH
// files is much more efficient. Post-processing views can also be created
// directly from the C++ API.
// We then set some general options:
gmsh::option::setNumber("General.Trackball", 0);
gmsh::option::setNumber("General.RotationX", 0);
gmsh::option::setNumber("General.RotationY", 0);
gmsh::option::setNumber("General.RotationZ", 0);
int white[3] = {255, 255, 255};
int black[3] = {0, 0, 0};
gmsh::option::setColor("General.Background", white[0], white[1], white[2]);
gmsh::option::setColor("General.Foreground", black[0], black[1], black[2]);
gmsh::option::setColor("General.Text", black[0], black[1], black[2]);
gmsh::option::setNumber("General.Orthographic", 0);
gmsh::option::setNumber("General.Axes", 0);
gmsh::option::setNumber("General.SmallAxes", 0);
// Show the GUI:
std::set<std::string> args(argv, argv + argc);
if(!args.count("-nopopup")) gmsh::fltk::initialize();
// We also set some options for each post-processing view:
// If we were to follow the geo example blindly, we would read the number of
// views from the relevant option value, and use the gmsh::option::setNumber()
// and gmsh::option::setString() functions. A nicer way is to use
// gmsh::view::getTags() and to use the gmsh::view::option::setNumber() and
// gmsh::view::option::setString() functions.
std::vector<int> v;
gmsh::view::getTags(v);
if(v.size() != 4) {
gmsh::logger::write("Wrong number of views!", "error");
gmsh::finalize();
return 1;
}
gmsh::view::option::setNumber(v[0], "IntervalsType", 2);
gmsh::view::option::setNumber(v[0], "OffsetZ", 0.05);
gmsh::view::option::setNumber(v[0], "RaiseZ", 0);
gmsh::view::option::setNumber(v[0], "Light", 1);
gmsh::view::option::setNumber(v[0], "ShowScale", 0);
gmsh::view::option::setNumber(v[0], "SmoothNormals", 1);
gmsh::view::option::setNumber(v[1], "IntervalsType", 1);
// Note that we can't yet set the ColorTable through the API
gmsh::view::option::setNumber(v[1], "NbIso", 10);
gmsh::view::option::setNumber(v[1], "ShowScale", 0);
gmsh::view::option::setString(v[2], "Name", "Test...");
gmsh::view::option::setNumber(v[2], "Axes", 1);
gmsh::view::option::setNumber(v[2], "IntervalsType", 2);
gmsh::view::option::setNumber(v[2], "Type", 2);
gmsh::view::option::setNumber(v[2], "AutoPosition", 0);
gmsh::view::option::setNumber(v[2], "PositionX", 85);
gmsh::view::option::setNumber(v[2], "PositionY", 50);
gmsh::view::option::setNumber(v[2], "Width", 200);
gmsh::view::option::setNumber(v[2], "Height", 130);
gmsh::view::option::setNumber(v[3], "Visible", 0);
// You can save an MPEG movie directly by selecting `File->Export' in the
// GUI. Several predefined animations are setup, for looping on all the time
// steps in views, or for looping between views.
// But the API can be used to build much more complex animations, by changing
// options at run-time and re-rendering the graphics. Each frame can then be
// saved to disk as an image, and multiple frames can be encoded to form a
// movie. Below is an example of such a custom animation.
int t = 0; // Initial step
for(int num = 1; num <= 3; num++) {
double nbt;
gmsh::view::option::getNumber(v[0], "NbTimeStep", nbt);
t = (t < nbt - 1) ? t + 1 : 0;
// Set time step
for(auto vv : v) gmsh::view::option::setNumber(vv, "TimeStep", t);
double max;
gmsh::view::option::getNumber(v[0], "Max", max);
gmsh::view::option::setNumber(v[0], "RaiseZ", 0.01 / max * t);
if(num == 3) {
// Resize the graphics when num == 3, to create 640x480 frames
double mw;
gmsh::option::getNumber("General.MenuWidth", mw);
gmsh::option::setNumber("General.GraphicsWidth", mw + 640);
gmsh::option::setNumber("General.GraphicsHeight", 480);
}
int frames = 50;
for(int num2 = 1; num2 <= frames; num2++) {
// Incrementally rotate the scene
double rotx;
gmsh::option::getNumber("General.RotationX", rotx);
gmsh::option::setNumber("General.RotationX", rotx + 10);
gmsh::option::setNumber("General.RotationY", (rotx + 10) / 3.);
double rotz;
gmsh::option::getNumber("General.RotationZ", rotz);
gmsh::option::setNumber("General.RotationZ", rotz + 0.1);
// Draw the scene
gmsh::graphics::draw();
if(num == 3) {
// Uncomment the following lines to save each frame to an image file
// gmsh::write("t8-" + std::to_string(num2) + ".gif");
// gmsh::write("t8-" + std::to_string(num2) + ".ppm");
// gmsh::write("t8-" + std::to_string(num2) + ".jpg");
}
}
if(num == 3) {
// Here we could make a system call to generate a movie...
}
}
if(!args.count("-nopopup")) gmsh::fltk::run();
gmsh::finalize();
return 0;
}
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