cg1_tut_mdi/src/script.js

287 lines
6.9 KiB
JavaScript

"use strict";
let cv, gl;
let program;
let cubeVertices;
let cubeVertexBuffer;
let lineCubeVertices;
let lineCubeVertexBuffer;
let originVertices;
let originVertexBuffer;
let floorVertices;
let floorVertexBuffer;
let lastFrame = Date.now();
async function init() {
cv = document.getElementById("cv");
gl = cv.getContext("webgl");
if (!gl) {
window.alert("WebGL not supported");
}
console.log("compiling shaders...");
program = await buildShaderProgram(gl, "shaders/vertex.glsl", "shaders/fragment.glsl");
console.log("creating vertex buffer");
cubeVertices = [
// Back face (red)
-1, -1, -1, 1, 0.5, 0.5,
-1, 1, -1, 1, 0.5, 0.5,
1, 1, -1, 1, 0.5, 0.5,
-1, -1, -1, 1, 0.5, 0.5,
1, 1, -1, 1, 0.5, 0.5,
1, -1, -1, 1, 0.5, 0.5,
// Front face (green)
-1, -1, 1, 0.5, 1, 0.5,
1, -1, 1, 0.5, 1, 0.5,
1, 1, 1, 0.5, 1, 0.5,
-1, -1, 1, 0.5, 1, 0.5,
1, 1, 1, 0.5, 1, 0.5,
-1, 1, 1, 0.5, 1, 0.5,
// Left face (blue)
-1, 1, -1, 0.5, 0.5, 1,
-1, -1, -1, 0.5, 0.5, 1,
-1, 1, 1, 0.5, 0.5, 1,
-1, 1, 1, 0.5, 0.5, 1,
-1, -1, -1, 0.5, 0.5, 1,
-1, -1, 1, 0.5, 0.5, 1,
// Right face (yellow)
1, -1, -1, 1, 1, 0.5,
1, 1, -1, 1, 1, 0.5,
1, 1, 1, 1, 1, 0.5,
1, -1, -1, 1, 1, 0.5,
1, 1, 1, 1, 1, 0.5,
1, -1, 1, 1, 1, 0.5,
// Top face (magenta)
-1, 1, -1, 1, 0.5, 1,
-1, 1, 1, 1, 0.5, 1,
1, 1, 1, 1, 0.5, 1,
-1, 1, -1, 1, 0.5, 1,
1, 1, 1, 1, 0.5, 1,
1, 1, -1, 1, 0.5, 1,
// Bottom face (cyan)
-1, -1, 1, 0.5, 1, 1,
-1, -1, -1, 0.5, 1, 1,
1, -1, 1, 0.5, 1, 1,
1, -1, 1, 0.5, 1, 1,
-1, -1, -1, 0.5, 1, 1,
1, -1, -1, 0.5, 1, 1
];
lineCubeVertices = [
1, 1, 1, 1, 0, 0,
1, 1, -1, 1, 0, 0,
1, 1, 1, 1, 0, 0,
1, -1, 1, 1, 0, 0,
1, 1, 1, 1, 0, 0,
-1, 1, 1, 1, 0, 0,
1, 1, -1, 1, 0, 0,
1, -1, -1, 1, 0, 0,
1, 1, -1, 1, 0, 0,
-1, 1, -1, 1, 0, 0,
1, -1, 1, 1, 0, 0,
1, -1, -1, 1, 0, 0,
1, -1, 1, 1, 0, 0,
-1, -1, 1, 1, 0, 0,
-1, 1, 1, 1, 0, 0,
-1, 1, -1, 1, 0, 0,
-1, 1, 1, 1, 0, 0,
-1, -1, 1, 1, 0, 0,
1, -1, -1, 1, 0, 0,
-1, -1, -1, 1, 0, 0,
-1, -1, 1, 1, 0, 0,
-1, -1, -1, 1, 0, 0,
-1, 1, -1, 1, 0, 0,
-1, -1, -1, 1, 0, 0,
];
originVertices = [
0, 0, 0, 1, 0, 0,
1, 0, 0, 1, 0, 0,
0, 0, 0, 0, 1, 0,
0, 1, 0, 0, 1, 0,
0, 0, 0, 0, 0, 1,
0, 0, 1, 0, 0, 1,
];
floorVertices = [
1, 0, 1, 0, 0, 0,
-1, 0, -1, 0, 0, 0,
-1, 0, 1, 0, 0, 0,
-1, 0, -1, 0, 0, 0,
1, 0, 1, 0, 0, 0,
1, 0, -1, 0, 0, 0,
];
cubeVertexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(cubeVertices), gl.STATIC_DRAW);
lineCubeVertexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, lineCubeVertexBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(lineCubeVertices), gl.STATIC_DRAW);
originVertexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, originVertexBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(originVertices), gl.STATIC_DRAW);
floorVertexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, floorVertexBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(floorVertices), gl.STATIC_DRAW);
// unbind buffer
gl.bindBuffer(gl.ARRAY_BUFFER, null);
// set clear colour
gl.clearColor(...hexToRgb("181825"), 1.0);
gl.enable(gl.CULL_FACE);
// start drawing
requestAnimationFrame(draw);
}
function setAttribPointers() {
let positionAttribLocation = gl.getAttribLocation(program, "vertPosition");
let colorAttribLocation = gl.getAttribLocation(program, "vertColor");
gl.vertexAttribPointer(positionAttribLocation, 3, gl.FLOAT, gl.FALSE, 6 * Float32Array.BYTES_PER_ELEMENT, 0);
gl.vertexAttribPointer(colorAttribLocation, 3, gl.FLOAT, gl.FALSE, 6 * Float32Array.BYTES_PER_ELEMENT, 3 * Float32Array.BYTES_PER_ELEMENT);
gl.enableVertexAttribArray(positionAttribLocation);
gl.enableVertexAttribArray(colorAttribLocation);
}
let frameCount = 0;
let lastStatUpdate = Date.now();
function updateStats(deltaTime) {
frameCount++;
let now = Date.now();
let timeSinceLastUpdate = (now - lastStatUpdate) / 1000;
if (timeSinceLastUpdate < 0.5) return;
lastStatUpdate = now;
let fpsDisplay = document.getElementById("fps");
fpsDisplay.innerText = Math.round(frameCount / timeSinceLastUpdate)
let msDisplay = document.getElementById("ms");
msDisplay.innerText = deltaTime * 1000 + "ms";
frameCount = 0;
}
let hue = 0;
async function draw() {
let now = Date.now();
let deltaTime = (now - lastFrame) / 1000;
hue += deltaTime / 5;
if (hue > 1) hue = 0;
updateStats(deltaTime);
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
gl.useProgram(program);
let modelViewLocation = gl.getUniformLocation(program, "modelViewMatrix");
let projectionLocation = gl.getUniformLocation(program, "projectionMatrix");
let projectionMatrix = [];
mat4BuildPerspective(projectionMatrix, 90.0 / 180.0 * Math.PI, cv.width / cv.height, 0.1, 20);
gl.uniformMatrix4fv(projectionLocation, gl.FALSE, new Float32Array(projectionMatrix));
let viewMatrix = [];
let cameraPosition = [2, 2, 2];
let cameraLookAt = [0, 0, -1];
let cameraUp = [0, 1, 0];
mat4BuildLookAt(viewMatrix, cameraPosition, cameraLookAt, cameraUp);
let modelMatrix = [];
mat4Identity(modelMatrix);
mat4RotateX(modelMatrix, modelMatrix, hue * 2 * Math.PI);
mat4RotateY(modelMatrix, modelMatrix, hue * 2 * Math.PI);
let modelViewMatrix = [];
mat4Multiply(modelViewMatrix, viewMatrix, modelMatrix);
gl.uniformMatrix4fv(modelViewLocation, gl.FALSE, new Float32Array(modelViewMatrix));
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexBuffer);
setAttribPointers();
gl.drawArrays(gl.TRIANGLES, 0, cubeVertices.length / 6);
gl.lineWidth(3);
gl.bindBuffer(gl.ARRAY_BUFFER, lineCubeVertexBuffer);
setAttribPointers();
gl.drawArrays(gl.LINES, 0, lineCubeVertices.length / 6);
gl.uniformMatrix4fv(modelViewLocation, gl.FALSE, new Float32Array(viewMatrix));
gl.bindBuffer(gl.ARRAY_BUFFER, originVertexBuffer);
setAttribPointers();
gl.drawArrays(gl.LINES, 0, originVertices.length / 6);
lastFrame = now;
requestAnimationFrame(draw);
}
function hexToRgb(hex) {
let r = parseInt(hex.substring(0, 2), 16) / 255;
let g = parseInt(hex.substring(2, 4), 16) / 255;
let b = parseInt(hex.substring(4, 6), 16) / 255;
return [r, g, b];
}
function hslToRgb(h, s, l) {
let r, g, b;
if (s == 0) {
r = g = b = l;
} else {
let hue2rgb = function hue2rgb(p, q, t) {
if (t < 0) t += 1;
if (t > 1) t -= 1;
if (t < 1 / 6) return p + (q - p) * 6 * t;
if (t < 1 / 2) return q;
if (t < 2 / 3) return p + (q - p) * (2 / 3 - t) * 6;
return p;
}
let q = l < 0.5 ? l * (1 + s) : l + s - l * s;
let p = 2 * l - q;
r = hue2rgb(p, q, h + 1 / 3);
g = hue2rgb(p, q, h);
b = hue2rgb(p, q, h - 1 / 3);
}
return [r, g, b];
}
window.addEventListener("DOMContentLoaded", init);