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#include <memory>
#include <algorithm>
#include <iostream>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include "glfw/guard.h"
#include "glfw/window.h"
#include "buffer/vertex/fluid_cell_buffer.h"
#include "buffer/vertex/lattice_cell_buffer.h"
#include "shader/wrap/graphic_shader.h"
#include "shader/wrap/compute_shader.h"
#include "shader/code/geometry.glsl"
#include "shader/code/vertex.glsl"
#include "shader/code/fragment.glsl"
#include "shader/code/interact.glsl"
#include "shader/code/collide.glsl"
#include "shader/code/stream.glsl"
#include "timer.h"
constexpr GLuint nX = 256;
constexpr GLuint nY = 128;
constexpr int lups = 50; // max lattice updates per second
float getWorldHeight(int window_width, int window_height, float world_width) {
return world_width / window_width * window_height;
}
glm::mat4 getMVP(float world_width, float world_height) {
const glm::mat4 projection = glm::ortho(
-(world_width/2), world_width/2,
-(world_height/2), world_height/2,
0.1f, 100.0f
);
const glm::mat4 view = glm::lookAt(
glm::vec3(0,0,1),
glm::vec3(0,0,0),
glm::vec3(0,1,0)
);
return projection * view;
}
int setupGeometry(int x, int y) {
if ( x == 0 || y == 0 || x == nX-1 || y == nY-1 ) {
return 0; // disable end of world
}
if ( (x == 1 || x == nX-2) && (y > 0 && y < nY-1) ) {
if ( x == 1 && y > nY/4 && y < 3*nY/4 ) {
return 5; // inflow
}
if ( x == nX-2 && y > nY/4 && y < 3*nY/4 ) {
return 6; // outflow
}
return 2; // bounce back outer walls
}
if ( (y == 1 || y == nY-2) && (x > 0 && x < nX-1) ) {
return 2; // bounce back outer walls
}
return 1; // everything else shall be bulk fluid
}
int renderWindow() {
Window window("compustream");
if ( !window.isGood() ) {
std::cerr << "Failed to open GLFW window." << std::endl;
return -1;
}
float world_width = 1*nX;
float world_height = getWorldHeight(window.getWidth(), window.getHeight(), world_width);
glm::mat4 MVP = getMVP(world_width, world_height);
std::unique_ptr<GraphicShader> scene_shader;
std::unique_ptr<LatticeCellBuffer> lattice_a;
std::unique_ptr<LatticeCellBuffer> lattice_b;
std::unique_ptr<FluidCellBuffer> fluid;
std::unique_ptr<ComputeShader> interact_shader;
std::unique_ptr<ComputeShader> collide_shader;
std::unique_ptr<ComputeShader> stream_shader;
window.init([&]() {
scene_shader = std::make_unique<GraphicShader>(
VERTEX_SHADER_CODE, GEOMETRY_SHADER_CODE, FRAGMENT_SHADER_CODE);
lattice_a = std::make_unique<LatticeCellBuffer>(nX, nY);
lattice_b = std::make_unique<LatticeCellBuffer>(nX, nY);
fluid = std::make_unique< FluidCellBuffer>(nX, nY, setupGeometry);
interact_shader = std::make_unique<ComputeShader>(INTERACT_SHADER_CODE);
collide_shader = std::make_unique<ComputeShader>(COLLIDE_SHADER_CODE);
stream_shader = std::make_unique<ComputeShader>(STREAM_SHADER_CODE);
});
if ( !interact_shader->isGood() || !collide_shader->isGood() || !stream_shader->isGood() ) {
std::cerr << "Compute shader error." << std::endl;
return -1;
}
auto last_frame = timer::now();
bool update_lattice = true;
bool tick = true;
auto pause_key = window.getKeyWatcher(GLFW_KEY_SPACE);
int prevMouseState = 0;
float prevLatticeMouseX;
float prevLatticeMouseY;
int currMouseState = 0;
float currLatticeMouseX;
float currLatticeMouseY;
auto tick_buffers = { lattice_a->getBuffer(), lattice_b->getBuffer(), fluid->getBuffer() };
auto tock_buffers = { lattice_b->getBuffer(), lattice_a->getBuffer(), fluid->getBuffer() };
window.render([&](bool window_size_changed) {
if ( pause_key.wasClicked() ) {
update_lattice = !update_lattice;
}
if ( window_size_changed ) {
world_height = getWorldHeight(window.getWidth(), window.getHeight(), world_width);
MVP = getMVP(world_width, world_height);
}
if ( update_lattice ) {
if ( timer::millisecondsSince(last_frame) >= 1000/lups ) {
if ( tick ) {
collide_shader->workOn(tick_buffers);
stream_shader->workOn(tick_buffers);
interact_shader->workOn(tick_buffers);
tick = false;
} else {
collide_shader->workOn(tock_buffers);
stream_shader->workOn(tock_buffers);
interact_shader->workOn(tock_buffers);
tick = true;
}
/// Update mouse projection
{
const auto m = window.getMouse();
prevMouseState = currMouseState;
prevLatticeMouseX = currLatticeMouseX;
prevLatticeMouseY = currLatticeMouseY;
currMouseState = std::get<0>(m);
currLatticeMouseX = float(std::get<1>(m)) / window.getWidth() * world_width + nX/2;
currLatticeMouseY = float(std::get<2>(m)) / window.getHeight() * world_height + nY/2;
}
/// Handle mouse-based interaction
if ( currMouseState != 0 || prevMouseState != 0 ) {
auto guard = interact_shader->use();
interact_shader->setUniform("influxRequested", currMouseState == 1);
interact_shader->setUniform("wallRequested", currMouseState == 2);
interact_shader->setUniform("startOfLine", prevLatticeMouseX, prevLatticeMouseY);
interact_shader->setUniform("endOfLine", currLatticeMouseX, currLatticeMouseY);
interact_shader->dispatch(nX, nY);
}
/// Perform collide & stream steps
{
auto guard = collide_shader->use();
collide_shader->dispatch(nX, nY);
}
{
auto guard = stream_shader->use();
stream_shader->dispatch(nX, nY);
}
last_frame = timer::now();
}
}
{
auto guard = scene_shader->use();
scene_shader->setUniform("MVP", MVP);
scene_shader->setUniform("nX", nX);
scene_shader->setUniform("nY", nY);
glClear(GL_COLOR_BUFFER_BIT);
fluid->draw();
}
});
return 0;
}
int main(int argc, char* argv[]) {
GlfwGuard glfw;
if( !glfw.isGood() ) {
std::cerr << "Failed to initialize GLFW." << std::endl;
return -1;
}
return renderWindow();
}
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