​

let sun;

let mapPos;

​

let heightMap;

​

let shadowShader;

let heightmapShader;

​

let voronoiTex;

​

let sunSetCol;

let midDayCol;

​

function preload() {

  shadowShader = loadShader("/shaders/shader.vert", "/shaders/shadow.frag");

  heightmapShader = loadShader("/shaders/shader.vert", "/shaders/heightmap.frag");

  voronoiTex = loadImage("voronoi.jpeg");

}

​

​

function setup() {

  createCanvas(800, 800, WEBGL);

  sunSetCol = createVector(0.5, 0.1, 0.1);

  midDayCol = createVector(1, 1, 0.9);

  heightMap = createGraphics(width, height, WEBGL);

  sun = createVector(0, 0.5, 1); // sun at 1 unit high

  mapPos = createVector(0, -0.1);

  heightMap.shader(heightmapShader);

  shader(shadowShader);

  generateHeightMap();

}

​

function draw() {

  sun.x = mouseX/width;

  sun.y = mouseY/height;

//   const secondsPerDay = 4;

//   const t = millis()/(secondsPerDay * 1000);

//   sun.x = cos(t * PI);

//   sun.z = sin(t * PI);

  const distSq = pow(sun.x - 0.5, 2) + pow(sun.y - 0.5, 2);

  const sunD = sqrt(distSq);

  // Make the sun lower in the sky when it's further from the centre

  sun.z = constrain(sqrt(1 - sunD * sunD), 0, 1);

  const amb = 1 - distSq;

  const col = p5.Vector.lerp(sunSetCol, midDayCol, 1 - distSq);

​

  shadowShader.setUniform("voronoiTex", voronoiTex);

  shadowShader.setUniform("heightMod", 1);//(sin(millis()/1000) + 1)/2);

  shadowShader.setUniform("millis", millis());

  shadowShader.setUniform("heightMap", heightMap);

  shadowShader.setUniform("sunPos", [sun.x, sun.y, sun.z]);

  shadowShader.setUniform("pix", [1/width, 1/height, 0]);

  shadowShader.setUniform("waterLevel", waterLevel);

  shadowShader.setUniform("ambientStrength", amb * 0.1);

  shadowShader.setUniform("ambientColour", [col.x, col.y, col.z]);

  shadowShader.setUniform("lightColour", [col.x, col.y, col.z]);

  shadowShader.setUniform("res", [width/height, 1]);

  clear();

  rect(0, 0, width, height);

}

​

function generateHeightMap() {

  heightmapShader.setUniform("mapPos", [mapPos.x, mapPos.y]);

  heightmapShader.setUniform("res", [width/height, 1]);

  heightMap.clear();

  heightMap.rect(0, 0, width, height);

}