asciiFluidSimulation.js

// Generated by CoffeeScript 1.10.0
var CONSOLE_HEIGHT, CONSOLE_WIDTH, Particle, calculateDensities, calculateForces, gravity, loadExample, particles, pressure, simulationNextStep, totalOfParticles, viscosity;

CONSOLE_WIDTH = 80;

CONSOLE_HEIGHT = 24;

particles = [];

totalOfParticles = 0;

gravity = 1;

pressure = 4;

viscosity = 7;

Particle = (function() {
  function Particle() {}

  Particle.prototype.density = 0.0;

  Particle.prototype.xForce = 0.0;

  Particle.prototype.xVelocity = 0.0;

  Particle.prototype.yForce = 0.0;

  Particle.prototype.yVelocity = 0.0;

  Particle.prototype.wallflag = 0;

  Particle.prototype.dead = false;

  Particle.prototype.xPos = 0.0;

  Particle.prototype.yPos = 0.0;

  return Particle;

})();

loadExample = function(selectedExample) {
  var i, len, particlesCounter, ref, results, x, xSandboxAreaScan, ySandboxAreaScan;
  if (selectedExample == null) {
    selectedExample = document.getElementById("exampleSelection");
    selectedExample = selectedExample.options[selectedExample.selectedIndex].value;
  }
  particles = [];
  totalOfParticles = 0;
  xSandboxAreaScan = 0;
  ySandboxAreaScan = 0;
  particlesCounter = 0;
  ref = examples[selectedExample].data;
  results = [];
  for (i = 0, len = ref.length; i < len; i++) {
    x = ref[i];
    if (x === '\n') {
      ySandboxAreaScan += 2;
      xSandboxAreaScan = -1;
    } else if (x !== ' ') {
      particles.push(new Particle());
      particles.push(new Particle());
      if (x === "#") {
        particles[particlesCounter].wallflag = particles[particlesCounter + 1].wallflag = 1;
      }
      particles[particlesCounter].xPos = xSandboxAreaScan;
      particles[particlesCounter].yPos = ySandboxAreaScan;
      particles[particlesCounter + 1].xPos = xSandboxAreaScan;
      particles[particlesCounter + 1].yPos = ySandboxAreaScan + 1;
      particlesCounter += 2;
      totalOfParticles = particlesCounter;
    }
    results.push(xSandboxAreaScan += 1);
  }
  return results;
};

calculateDensities = function(particles, totalOfParticles) {
  var i, j, particlesCursor, particlesCursor2, particlesDistance, particlesInteraction, ref, ref1, xParticleDistance, yParticleDistance;
  particlesCursor = 0;
  particlesCursor2 = 0;
  for (particlesCursor = i = 0, ref = totalOfParticles; 0 <= ref ? i < ref : i > ref; particlesCursor = 0 <= ref ? ++i : --i) {
    if (particles[particlesCursor].dead) {
      continue;
    }
    particles[particlesCursor].density = particles[particlesCursor].wallflag * 9;
    for (particlesCursor2 = j = 0, ref1 = totalOfParticles; 0 <= ref1 ? j < ref1 : j > ref1; particlesCursor2 = 0 <= ref1 ? ++j : --j) {
      if (particles[particlesCursor2].dead) {
        continue;
      }
      xParticleDistance = particles[particlesCursor].xPos - particles[particlesCursor2].xPos;
      yParticleDistance = particles[particlesCursor].yPos - particles[particlesCursor2].yPos;
      particlesDistance = Math.sqrt(xParticleDistance * xParticleDistance + yParticleDistance * yParticleDistance);
      particlesInteraction = particlesDistance / 2.0 - 1.0;
      if (Math.floor(1.0 - particlesInteraction) > 0) {
        particles[particlesCursor].density += particlesInteraction * particlesInteraction;
      }
    }
  }
};

calculateForces = function(particles, totalOfParticles) {
  var i, j, particlesCursor, particlesCursor2, particlesDistance, particlesInteraction, ref, ref1, xParticleDistance, yParticleDistance;
  particlesCursor = 0;
  particlesCursor2 = 0;
  for (particlesCursor = i = 0, ref = totalOfParticles; 0 <= ref ? i < ref : i > ref; particlesCursor = 0 <= ref ? ++i : --i) {
    if (particles[particlesCursor].wallflag === 1 || particles[particlesCursor].dead) {
      continue;
    }
    particles[particlesCursor].yForce = gravity;
    particles[particlesCursor].xForce = 0;
    for (particlesCursor2 = j = 0, ref1 = totalOfParticles; 0 <= ref1 ? j < ref1 : j > ref1; particlesCursor2 = 0 <= ref1 ? ++j : --j) {
      if (particles[particlesCursor2].dead) {
        continue;
      }
      xParticleDistance = particles[particlesCursor].xPos - particles[particlesCursor2].xPos;
      yParticleDistance = particles[particlesCursor].yPos - particles[particlesCursor2].yPos;
      particlesDistance = Math.sqrt(xParticleDistance * xParticleDistance + yParticleDistance * yParticleDistance);
      particlesInteraction = particlesDistance / 2.0 - 1.0;
      if (Math.floor(1.0 - particlesInteraction) > 0) {
        particles[particlesCursor].xForce += particlesInteraction * (xParticleDistance * (3 - particles[particlesCursor].density - particles[particlesCursor2].density) * pressure + particles[particlesCursor].xVelocity * viscosity - particles[particlesCursor2].xVelocity * viscosity) / particles[particlesCursor].density;
        particles[particlesCursor].yForce += particlesInteraction * (yParticleDistance * (3 - particles[particlesCursor].density - particles[particlesCursor2].density) * pressure + particles[particlesCursor].yVelocity * viscosity - particles[particlesCursor2].yVelocity * viscosity) / particles[particlesCursor].density;
      }
    }
  }
};

simulationNextStep = function() {
  var i, j, k, particlesCursor, ref, ref1, ref2, screenBuffer, screenBufferIndex, screenBufferString, x, y;
  calculateDensities(particles, totalOfParticles);
  calculateForces(particles, totalOfParticles);
  screenBuffer = [];
  screenBufferIndex = 0;
  for (screenBufferIndex = i = 0, ref = CONSOLE_WIDTH * CONSOLE_HEIGHT; 0 <= ref ? i < ref : i > ref; screenBufferIndex = 0 <= ref ? ++i : --i) {
    screenBuffer[screenBufferIndex] = 0;
  }
  for (particlesCursor = j = 0, ref1 = totalOfParticles; 0 <= ref1 ? j < ref1 : j > ref1; particlesCursor = 0 <= ref1 ? ++j : --j) {
    if (particles[particlesCursor].wallflag === 0) {
      if (Math.sqrt(particles[particlesCursor].xForce * particles[particlesCursor].xForce + particles[particlesCursor].yForce * particles[particlesCursor].yForce) < 4.2) {
        particles[particlesCursor].xVelocity += particles[particlesCursor].xForce / 10;
        particles[particlesCursor].yVelocity += particles[particlesCursor].yForce / 10;
      } else {
        particles[particlesCursor].xVelocity += particles[particlesCursor].xForce / 11;
        particles[particlesCursor].yVelocity += particles[particlesCursor].yForce / 11;
      }
      particles[particlesCursor].xPos += particles[particlesCursor].xVelocity;
      particles[particlesCursor].yPos += particles[particlesCursor].yVelocity;
    }
    x = Math.round(particles[particlesCursor].xPos);
    y = Math.round(particles[particlesCursor].yPos / 2);
    screenBufferIndex = Math.round(x + CONSOLE_WIDTH * y);
    if (y >= 0 && y < CONSOLE_HEIGHT - 1 && x >= 0 && x < CONSOLE_WIDTH - 1) {
      screenBuffer[screenBufferIndex] |= 8;
      screenBuffer[screenBufferIndex + 1] |= 4;
      screenBuffer[screenBufferIndex + CONSOLE_WIDTH] |= 2;
      screenBuffer[screenBufferIndex + CONSOLE_WIDTH + 1] |= 1;
    } else {
      particles[particlesCursor].dead = true;
    }
  }
  screenBufferString = '';
  for (screenBufferIndex = k = 0, ref2 = CONSOLE_WIDTH * CONSOLE_HEIGHT; 0 <= ref2 ? k < ref2 : k > ref2; screenBufferIndex = 0 <= ref2 ? ++k : --k) {
    if (screenBufferIndex % CONSOLE_WIDTH === CONSOLE_WIDTH - 1) {
      screenBufferString += '<br>';
    } else {
      screenBufferString += " '`-.|//,\\|\\_\\/#"[screenBuffer[screenBufferIndex]];
    }
  }
  document.getElementById("simulationOutput").innerHTML = screenBufferString.replace(/ /g, "&nbsp;");
  return window.requestAnimationFrame(simulationNextStep);
};

//# sourceMappingURL=asciiFluidSimulation.js.map