canvas+webgl实现鼠标交互变形动画效果代码
代码语言:html
所属分类:动画
代码描述:canvas+webgl实现鼠标交互变形动画效果代码
代码标签: canvas webgl 鼠标 交互 变形 动画
下面为部分代码预览,完整代码请点击下载或在bfwstudio webide中打开
<!DOCTYPE html> <html lang="en" > <head> <meta charset="UTF-8"> <style> body { background-color: #000; margin: 0; overflow: hidden; background-repeat: no-repeat; } canvas { position: absolute; } </style> </head> <body> <script > "use strict"; let canv, gl; let maxx, maxy; let midx, midy; let widthHandle, heightHandle; let c0Handle; let mousePos = {}; let algo, algoHandle; let orb, orbHandle; let auto = false, autoLevel = 0; // 0: mouse driven, 1 : automatic motion let timeLastMove; let reqCoords; let animState = 0; const mrandom = Math.random; const mfloor = Math.floor; const mround = Math.round; const mceil = Math.ceil; const mabs = Math.abs; const mmin = Math.min; const mmax = Math.max; const mPI = Math.PI; const mPIS2 = Math.PI / 2; const m2PI = Math.PI * 2; const msin = Math.sin; const mcos = Math.cos; const matan2 = Math.atan2; const mhypot = Math.hypot; const msqrt = Math.sqrt; //----------------------------------------------------------------------------- // miscellaneous functions //----------------------------------------------------------------------------- function alea(min, max) { // random number [min..max[ . If no max is provided, [0..min[ if (typeof max == "undefined") return min * mrandom(); return min + (max - min) * mrandom(); } // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - function intAlea(min, max) { // random integer number [min..max[ . If no max is provided, [0..min[ if (typeof max == "undefined") { max = min; min = 0; } return mfloor(min + (max - min) * mrandom()); } // intAlea // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - function lerp(p0, p1, alpha) { return { x: (1 - alpha) * p0.x + alpha * p1.x, y: (1 - alpha) * p0.y + alpha * p1.y }; } // function lerp //----------------------------------------------------------------------------- //----------------------------------------------------------------------------- //************** Shader sources ************** const R = 0.2; const A = -3.0; // < 0; heart tip is at (0, A *R); // values used by shader but easier to calculate in JS // junction point between circle and straight line const X0 = 2 * A * A / (A * A + 1) * R; const Y0 = X0 / A; const PA = 2 * A / (A * A - 1); // slope of perp. to straight line const PB = -1 / PA; // slope of straight Line const LNG = mhypot(X0, A * R - Y0); // length of straight line let vertexSource = ` attribute vec2 position; void main() { gl_Position = vec4(position, 0.0, 1.0); } `; let fragmentSource = ` precision mediump float; #define ITER_MAX 100 uniform float width; uniform float height; uniform vec2 c0; // constant in Julia iterative formula uniform int algo; uniform vec2 orb; vec2 iResolution; vec2 z; void main(){ iResolution = vec2(width, height); float dist, thismin; float zoom = 1.0; // defines width of displayed area in the complex plane float factor = 4.0; // this factor changes the thickness of displayed patterns if (algo == 1) { /* it would be smarter to use uniforms for zoom and factor, and set their values in JS. */ zoom = 1.5; factor = 5.0; } else if (algo == 2) { factor = 12.0; } dist = 10000.; z = (gl_FragCoord.xy - 0.5 * iResolution.xy ) / min(width, height) * 2.0 * zoom ; int k = 0; for (int kk = 0; kk < ITER_MAX; ++kk) { z = vec2 (z.x * z.x - z.y * z.y, 2.0 * z.x * z.y) + c0; // Julia formula, normal // here comes the orbit trap algorithm, as descriped in Wikipedia : https://en.wikipedia.org/wiki/Orbit_trap // algo #0 uses point orb as a trap; algo #1 uses x and y axes if (algo == 0) { thismin = length(z - orb); } else if (algo == 1) { thismin = min(abs(z.x), abs(z.y)); } else { float rx = abs(z.x); if ((z.y > 0.0) || (z.y > (rx - ${R}) * ${PA})) { thismin = abs(length(vec2(rx, z.y)-vec2(${R}, 0))-${R}); } else { if (z.y < ${A * R} + rx * ${PA}) { // beyond heart tip thismin = length(z - vec2(0, ${A * R})); } else { thismin = abs(${X0} * (z.y - ${Y0}) - ${ Y0 - A * R }*(rx - ${X0})) / ${LNG}; thismin = min(thismin, length(z)); } } } if (thismin < dist) { dist = thismin; k = kk - (kk / 6) * 6; } }; vec3 s; if (k == 0) s = vec3(1.0, 0.0, 0.0); else if (k == 1) s = vec3(1.0, 1.0, 0.0); else if (k == 2) s = vec3(0.0, 1.0, 0.0); else if (k == 3) s = vec3(0.0, 1.0, 1.0); else if (k == 4) s = vec3(0.0, 0.0, 1.0); else s = vec3(1.0, 0.0, 1.0); float lum = (1.0-clamp(dist * factor , 0.0, 1.0)); lum = sqrt(lum); gl_FragColor = vec4(s*lum, 1.0); } `; //************** Utility functions ************** //Compile shader and combine with source function compileShader(shaderSource, shaderType) { let shader = gl.createShader(shaderType); gl.shaderSource(shader, shaderSource); gl.compileShader(shader); if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) { throw "Shader compile failed with: " + gl.getShaderInfoLog(shader); } return shader; } //From https://codepen.io/jlfwong/pen/GqmroZ //Utility to complain loudly if we fail to find the attribute/uniform function getAttribLocation(program, name) { let attributeLocation = gl.getAttribLocation(program, name); if (attributeLocation === -1) { throw "Cannot find attribute " + name + "."; } return attributeLocation; } function getUniformLocation(program, name) { let attributeLocation = gl.getUniformLocation(program, name); if (attributeLocation === null) { throw "Cannot find uniform " + name + "."; } return attributeLocation; } //--------------------------------------------------------- function initShadersStuff() { //************** Create shaders ************** //Create vertex and fragment shaders let vertexShader = compileShader(vertexSource, gl.VERTEX_SHADER); let fragmentShader = compileShader(fragmentSource, gl.FRAGMENT_SHADER); //Create shader programs let program = gl.createProgram(); gl.attachShader(program, vertexShader); gl.attachShader(program, fragmentShader); gl.linkProgram(program); gl.useProgram(program); //Set up rectangle covering entire canvas let vertexData = new Float32Array([ -1.0, 1.0, // top left -1.0, -1.0, // bottom left 1.0, 1.0, // top right 1.0, -1.0 // bottom right ]); // Create vertex buffer let vertexDataBuffer = gl.createBuffer(); gl.bindBuffer(gl.ARRAY_BUFFER, vertexDataBuffer); gl.bufferData(gl.ARRAY_BUFFER, vertexData, gl.STATIC_DRAW); // Layout of our data in the vertex buffer let positionHandle = getAttribLocation(program, "position"); gl.enableVertexAttribArray(positionHandle); gl.vertexAttribPointer( positionHandle, 2, // position is a vec2 (2 values per component) gl.FLOAT, // each component is a float false, // don't normalize values 2 * 4, // two 4 byte float components per vertex (32 bit float is 4 bytes) 0 // how many bytes inside the buffer to start from ); //Get uniform handles widthHandle = getUniformLocation(program, "width"); heightHandle = getUniformLocation(program, "height"); c0Handle = getUniformLocation(program, "c0"); algoHandle = getUniformLocation(program, "algo"); orbHandle = getUniformLocation(program, "orb"); } //--------------------------------------------------------- class Mover { constructor(poi) { this.poi = poi; this.tPrev = performance.now(); // time of previous move this.tRel = 0; // relative time, inside current step this.step = 0; this.lastP = poi.at(-1).p; // mimic we are starting from end of last movement this.speed = 1.0; } move() { /* returns current position of mover */ let dt = performance.now() - this.tPrev; this.tPrev += dt; dt *= this.speed; this.tRel += dt; // time is running... while (this.tRel > this.poi[this.step].duration) { this.tRel -= this.poi[this.step].duration; this.lastP = this.poi[this.step].p; ++this.step; if (this.step >= this.poi.length) this.step = 0; } return lerp( this.lastP, this.poi[this.step].p, this.tRel / this.poi[this.step].duration); } // move } // class Mover const durl = 3000; const durs = 1000; const durss = 500; const POI0 = [ // for algorithm #0 { p: { x: -0.092357, y: -0.929936 }, duration: durl }, { p: { x: -0.070064, y: -0.671974 }, duration: durs }, { p: { x: -0.07962, y: -0.678344 }, duration: durs }, { p: { x: -0.07962, y: -0.6656 }, duration: durs }, { p: { x: -0.13057, y: -0.678344 }, duration: durl }, { p: { x: -0.1465, y: -0.65637 }, duration: durs }, { p: { x: -0.1793, y: -0.66669 }, duration: durs }, { p: { x: -0.22293, y: -0.665605 }, duration: durs }, { p: { x: -0.226115, y: -0.640127 }, duration: durs }, { p: { x: -0.267516, y: -0.579618 }, duration: durs }, { p: { x: -0.273885, y: -0.496815 }, duration: durs }, { p: { x: 0.261146, y: -0.492675 }, duration: durl }, { p: { x: 0.267516, y: -0.519108 }, duration: durs }, { p: { .........完整代码请登录后点击上方下载按钮下载查看
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