HTML 樱花飘落界面效果 | 金条k的博客

LOADING

加载过慢请开启缓存 浏览器默认开启

若长时间无反应 可刷新后再尝试

HTML 樱花飘落界面效果

2023/8/9 转载 html

效果图

1

使用方法与源码

首先创建一个html格式的文件,然后填入源码:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>樱花飘落</title>
        <style>
            body {
                padding:0;
                margin:0;
                overflow:hidden;
                height: 600px;
            }
            canvas {
                padding:0;
                margin:0;
            }
            div.btnbg {
                position:fixed;
                left:0;
                top:0;
            }
        </style>
    </head>
    <body>
        <canvas id="sakura"></canvas>
        <div class="btnbg"></div>
        <div style="position: absolute;top:30%;left: 18%;z-index: 1;width: 430px;height: 400px;font-size: 30px;color: #ff826c;">
            <div style="margin-left: 10px;margin-bottom: 20px;">FOR YOU:</div>
            <div style="margin-left: 68px;margin-bottom: 20px;">以梦为马 不负韶华</div>   
            <div style="margin-left: 180px;font-size: 24px;">LOVE  U FROEVER</div>		
        </div>
        <!-- sakura shader -->
        <script id="sakura_point_vsh" type="x-shader/x_vertex">
        uniform mat4 uProjection;
        uniform mat4 uModelview;
        uniform vec3 uResolution;
        uniform vec3 uOffset;
        uniform vec3 uDOF;  //x:focus distance, y:focus radius, z:max radius
        uniform vec3 uFade; //x:start distance, y:half distance, z:near fade start
        
        attribute vec3 aPosition;
        attribute vec3 aEuler;
        attribute vec2 aMisc; //x:size, y:fade
        
        varying vec3 pposition;
        varying float psize;
        varying float palpha;
        varying float pdist;
        
        //varying mat3 rotMat;
        varying vec3 normX;
        varying vec3 normY;
        varying vec3 normZ;
        varying vec3 normal;
        
        varying float diffuse;
        varying float specular;
        varying float rstop;
        varying float distancefade;
        
        void main(void) {
            // Projection is based on vertical angle
            vec4 pos = uModelview * vec4(aPosition + uOffset, 1.0);
            gl_Position = uProjection * pos;
            gl_PointSize = aMisc.x * uProjection[1][1] / -pos.z * uResolution.y * 0.5;
            
            pposition = pos.xyz;
            psize = aMisc.x;
            pdist = length(pos.xyz);
            palpha = smoothstep(0.0, 1.0, (pdist - 0.1) / uFade.z);
            
            vec3 elrsn = sin(aEuler);
            vec3 elrcs = cos(aEuler);
            mat3 rotx = mat3(
                1.0, 0.0, 0.0,
                0.0, elrcs.x, elrsn.x,
                0.0, -elrsn.x, elrcs.x
            );
            mat3 roty = mat3(
                elrcs.y, 0.0, -elrsn.y,
                0.0, 1.0, 0.0,
                elrsn.y, 0.0, elrcs.y
            );
            mat3 rotz = mat3(
                elrcs.z, elrsn.z, 0.0, 
                -elrsn.z, elrcs.z, 0.0,
                0.0, 0.0, 1.0
            );
            mat3 rotmat = rotx * roty * rotz;
            normal = rotmat[2];
            
            mat3 trrotm = mat3(
                rotmat[0][0], rotmat[1][0], rotmat[2][0],
                rotmat[0][1], rotmat[1][1], rotmat[2][1],
                rotmat[0][2], rotmat[1][2], rotmat[2][2]
            );
           
            normX = trrotm[0];
            normY = trrotm[1];
            normZ = trrotm[2];
            
            const vec3 lit = vec3(0.6917144638660746, 0.6917144638660746, -0.20751433915982237);
            
            float tmpdfs = dot(lit, normal);
            if(tmpdfs < 0.0) {
                normal = -normal;
                tmpdfs = dot(lit, normal);
            }
            diffuse = 0.4 + tmpdfs;
            
            vec3 eyev = normalize(-pos.xyz);
            if(dot(eyev, normal) > 0.0) {
                vec3 hv = normalize(eyev + lit);
                specular = pow(max(dot(hv, normal), 0.0), 20.0);
            }
            else {
                specular = 0.0;
            }
            
            rstop = clamp((abs(pdist - uDOF.x) - uDOF.y) / uDOF.z, 0.0, 1.0);
            rstop = pow(rstop, 0.5);
            //-0.69315 = ln(0.5)
            distancefade = min(1.0, exp((uFade.x - pdist) * 0.69315 / uFade.y));
        }
        </script>
        <script id="sakura_point_fsh" type="x-shader/x_fragment">
        #ifdef GL_ES
        //precision mediump float;
        precision highp float;
        #endif
        
        uniform vec3 uDOF;  //x:focus distance, y:focus radius, z:max radius
        uniform vec3 uFade; //x:start distance, y:half distance, z:near fade start
        
        const vec3 fadeCol = vec3(0.08, 0.03, 0.06);
        
        varying vec3 pposition;
        varying float psize;
        varying float palpha;
        varying float pdist;
        
        //varying mat3 rotMat;
        varying vec3 normX;
        varying vec3 normY;
        varying vec3 normZ;
        varying vec3 normal;
        
        varying float diffuse;
        varying float specular;
        varying float rstop;
        varying float distancefade;
        
        float ellipse(vec2 p, vec2 o, vec2 r) {
            vec2 lp = (p - o) / r;
            return length(lp) - 1.0;
        }
        
        void main(void) {
            vec3 p = vec3(gl_PointCoord - vec2(0.5, 0.5), 0.0) * 2.0;
            vec3 d = vec3(0.0, 0.0, -1.0);
            float nd = normZ.z; //dot(-normZ, d);
            if(abs(nd) < 0.0001) discard;
            
            float np = dot(normZ, p);
            vec3 tp = p + d * np / nd;
            vec2 coord = vec2(dot(normX, tp), dot(normY, tp));
            
            //angle = 15 degree
            const float flwrsn = 0.258819045102521;
            const float flwrcs = 0.965925826289068;
            mat2 flwrm = mat2(flwrcs, -flwrsn, flwrsn, flwrcs);
            vec2 flwrp = vec2(abs(coord.x), coord.y) * flwrm;
            
            float r;
            if(flwrp.x < 0.0) {
                r = ellipse(flwrp, vec2(0.065, 0.024) * 0.5, vec2(0.36, 0.96) * 0.5);
            }
            else {
                r = ellipse(flwrp, vec2(0.065, 0.024) * 0.5, vec2(0.58, 0.96) * 0.5);
            }
            
            if(r > rstop) discard;
            
            vec3 col = mix(vec3(1.0, 0.8, 0.75), vec3(1.0, 0.9, 0.87), r);
            float grady = mix(0.0, 1.0, pow(coord.y * 0.5 + 0.5, 0.35));
            col *= vec3(1.0, grady, grady);
            col *= mix(0.8, 1.0, pow(abs(coord.x), 0.3));
            col = col * diffuse + specular;
            
            col = mix(fadeCol, col, distancefade);
            
            float alpha = (rstop > 0.001)? (0.5 - r / (rstop * 2.0)) : 1.0;
            alpha = smoothstep(0.0, 1.0, alpha) * palpha;
            
            gl_FragColor = vec4(col * 0.5, alpha);
        }
        </script>
        <!-- effects -->
        <script id="fx_common_vsh" type="x-shader/x_vertex">
        uniform vec3 uResolution;
        attribute vec2 aPosition;
        
        varying vec2 texCoord;
        varying vec2 screenCoord;
        
        void main(void) {
            gl_Position = vec4(aPosition, 0.0, 1.0);
            texCoord = aPosition.xy * 0.5 + vec2(0.5, 0.5);
            screenCoord = aPosition.xy * vec2(uResolution.z, 1.0);
        }
        </script>
        <script id="bg_fsh" type="x-shader/x_fragment">
        #ifdef GL_ES
        //precision mediump float;
        precision highp float;
        #endif
        
        uniform vec2 uTimes;
        
        varying vec2 texCoord;
        varying vec2 screenCoord;
        
        void main(void) {
            vec3 col;
            float c;
            vec2 tmpv = texCoord * vec2(0.8, 1.0) - vec2(0.95, 1.0);
            c = exp(-pow(length(tmpv) * 1.8, 2.0));
            col = mix(vec3(0.02, 0.0, 0.03), vec3(0.96, 0.98, 1.0) * 1.5, c);
            gl_FragColor = vec4(col * 0.5, 1.0);
        }
        </script>
        <script id="fx_brightbuf_fsh" type="x-shader/x_fragment">
        #ifdef GL_ES
        //precision mediump float;
        precision highp float;
        #endif
        uniform sampler2D uSrc;
        uniform vec2 uDelta;
        
        varying vec2 texCoord;
        varying vec2 screenCoord;
        
        void main(void) {
            vec4 col = texture2D(uSrc, texCoord);
            gl_FragColor = vec4(col.rgb * 2.0 - vec3(0.5), 1.0);
        }
        </script>
        <script id="fx_dirblur_r4_fsh" type="x-shader/x_fragment">
        #ifdef GL_ES
        //precision mediump float;
        precision highp float;
        #endif
        uniform sampler2D uSrc;
        uniform vec2 uDelta;
        uniform vec4 uBlurDir; //dir(x, y), stride(z, w)
        
        varying vec2 texCoord;
        varying vec2 screenCoord;
        
        void main(void) {
            vec4 col = texture2D(uSrc, texCoord);
            col = col + texture2D(uSrc, texCoord + uBlurDir.xy * uDelta);
            col = col + texture2D(uSrc, texCoord - uBlurDir.xy * uDelta);
            col = col + texture2D(uSrc, texCoord + (uBlurDir.xy + uBlurDir.zw) * uDelta);
            col = col + texture2D(uSrc, texCoord - (uBlurDir.xy + uBlurDir.zw) * uDelta);
            gl_FragColor = col / 5.0;
        }
        </script>
        <!-- effect fragment shader template -->
        <script id="fx_common_fsh" type="x-shader/x_fragment">
        #ifdef GL_ES
        //precision mediump float;
        precision highp float;
        #endif
        uniform sampler2D uSrc;
        uniform vec2 uDelta;
        
        varying vec2 texCoord;
        varying vec2 screenCoord;
        
        void main(void) {
            gl_FragColor = texture2D(uSrc, texCoord);
        }
        </script>
        <!-- post processing -->
        <script id="pp_final_vsh" type="x-shader/x_vertex">
        uniform vec3 uResolution;
        attribute vec2 aPosition;
        varying vec2 texCoord;
        varying vec2 screenCoord;
        void main(void) {
            gl_Position = vec4(aPosition, 0.0, 1.0);
            texCoord = aPosition.xy * 0.5 + vec2(0.5, 0.5);
            screenCoord = aPosition.xy * vec2(uResolution.z, 1.0);
        }
        </script>
        <script id="pp_final_fsh" type="x-shader/x_fragment">
        #ifdef GL_ES
        //precision mediump float;
        precision highp float;
        #endif
        uniform sampler2D uSrc;
        uniform sampler2D uBloom;
        uniform vec2 uDelta;
        varying vec2 texCoord;
        varying vec2 screenCoord;
        void main(void) {
            vec4 srccol = texture2D(uSrc, texCoord) * 2.0;
            vec4 bloomcol = texture2D(uBloom, texCoord);
            vec4 col;
            col = srccol + bloomcol * (vec4(1.0) + srccol);
            col *= smoothstep(1.0, 0.0, pow(length((texCoord - vec2(0.5)) * 2.0), 1.2) * 0.5);
            col = pow(col, vec4(0.45454545454545)); //(1.0 / 2.2)
            
            gl_FragColor = vec4(col.rgb, 1.0);
            gl_FragColor.a = 1.0;
        }
        </script>
        <script>
          // Utilities
        var Vector3 = {};
        var Matrix44 = {};
        Vector3.create = function(x, y, z) {
            return {'x':x, 'y':y, 'z':z};
        };
        Vector3.dot = function (v0, v1) {
            return v0.x * v1.x + v0.y * v1.y + v0.z * v1.z;
        };
        Vector3.cross = function (v, v0, v1) {
            v.x = v0.y * v1.z - v0.z * v1.y;
            v.y = v0.z * v1.x - v0.x * v1.z;
            v.z = v0.x * v1.y - v0.y * v1.x;
        };
        Vector3.normalize = function (v) {
            var l = v.x * v.x + v.y * v.y + v.z * v.z;
            if(l > 0.00001) {
                l = 1.0 / Math.sqrt(l);
                v.x *= l;
                v.y *= l;
                v.z *= l;
            }
        };
        Vector3.arrayForm = function(v) {
            if(v.array) {
                v.array[0] = v.x;
                v.array[1] = v.y;
                v.array[2] = v.z;
            }
            else {
                v.array = new Float32Array([v.x, v.y, v.z]);
            }
            return v.array;
        };
        Matrix44.createIdentity = function () {
            return new Float32Array([1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0]);
        };
        Matrix44.loadProjection = function (m, aspect, vdeg, near, far) {
            var h = near * Math.tan(vdeg * Math.PI / 180.0 * 0.5) * 2.0;
            var w = h * aspect;
            
            m[0] = 2.0 * near / w;
            m[1] = 0.0;
            m[2] = 0.0;
            m[3] = 0.0;
            
            m[4] = 0.0;
            m[5] = 2.0 * near / h;
            m[6] = 0.0;
            m[7] = 0.0;
            
            m[8] = 0.0;
            m[9] = 0.0;
            m[10] = -(far + near) / (far - near);
            m[11] = -1.0;
            
            m[12] = 0.0;
            m[13] = 0.0;
            m[14] = -2.0 * far * near / (far - near);
            m[15] = 0.0;
        };
        Matrix44.loadLookAt = function (m, vpos, vlook, vup) {
            var frontv = Vector3.create(vpos.x - vlook.x, vpos.y - vlook.y, vpos.z - vlook.z);
            Vector3.normalize(frontv);
            var sidev = Vector3.create(1.0, 0.0, 0.0);
            Vector3.cross(sidev, vup, frontv);
            Vector3.normalize(sidev);
            var topv = Vector3.create(1.0, 0.0, 0.0);
            Vector3.cross(topv, frontv, sidev);
            Vector3.normalize(topv);
            
            m[0] = sidev.x;
            m[1] = topv.x;
            m[2] = frontv.x;
            m[3] = 0.0;
            
            m[4] = sidev.y;
            m[5] = topv.y;
            m[6] = frontv.y;
            m[7] = 0.0;
            
            m[8] = sidev.z;
            m[9] = topv.z;
            m[10] = frontv.z;
            m[11] = 0.0;
            
            m[12] = -(vpos.x * m[0] + vpos.y * m[4] + vpos.z * m[8]);
            m[13] = -(vpos.x * m[1] + vpos.y * m[5] + vpos.z * m[9]);
            m[14] = -(vpos.x * m[2] + vpos.y * m[6] + vpos.z * m[10]);
            m[15] = 1.0;
        };
        //
        var timeInfo = {
            'start':0, 'prev':0, // Date
            'delta':0, 'elapsed':0 // Number(sec)
        };
        
        //
        var gl;
        var renderSpec = {
            'width':0,
            'height':0,
            'aspect':1,
            'array':new Float32Array(3),
            'halfWidth':0,
            'halfHeight':0,
            'halfArray':new Float32Array(3)
            // and some render targets. see setViewport()
        };
        renderSpec.setSize = function(w, h) {
            renderSpec.width = w;
            renderSpec.height = h;
            renderSpec.aspect = renderSpec.width / renderSpec.height;
            renderSpec.array[0] = renderSpec.width;
            renderSpec.array[1] = renderSpec.height;
            renderSpec.array[2] = renderSpec.aspect;
            
            renderSpec.halfWidth = Math.floor(w / 2);
            renderSpec.halfHeight = Math.floor(h / 2);
            renderSpec.halfArray[0] = renderSpec.halfWidth;
            renderSpec.halfArray[1] = renderSpec.halfHeight;
            renderSpec.halfArray[2] = renderSpec.halfWidth / renderSpec.halfHeight;
        };
        
        function deleteRenderTarget(rt) {
            gl.deleteFramebuffer(rt.frameBuffer);
            gl.deleteRenderbuffer(rt.renderBuffer);
            gl.deleteTexture(rt.texture);
        }
        
        function createRenderTarget(w, h) {
            var ret = {
                'width':w,
                'height':h,
                'sizeArray':new Float32Array([w, h, w / h]),
                'dtxArray':new Float32Array([1.0 / w, 1.0 / h])
            };
            ret.frameBuffer = gl.createFramebuffer();
            ret.renderBuffer = gl.createRenderbuffer();
            ret.texture = gl.createTexture();
            
            gl.bindTexture(gl.TEXTURE_2D, ret.texture);
            gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, w, h, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
            
            gl.bindFramebuffer(gl.FRAMEBUFFER, ret.frameBuffer);
            gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, ret.texture, 0);
            
            gl.bindRenderbuffer(gl.RENDERBUFFER, ret.renderBuffer);
            gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, w, h);
            gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, ret.renderBuffer);
            
            gl.bindTexture(gl.TEXTURE_2D, null);
            gl.bindRenderbuffer(gl.RENDERBUFFER, null);
            gl.bindFramebuffer(gl.FRAMEBUFFER, null);
            
            return ret;
        }
        
        function compileShader(shtype, shsrc) {
            var retsh = gl.createShader(shtype);
            
            gl.shaderSource(retsh, shsrc);
            gl.compileShader(retsh);
            
            if(!gl.getShaderParameter(retsh, gl.COMPILE_STATUS)) {
                var errlog = gl.getShaderInfoLog(retsh);
                gl.deleteShader(retsh);
                console.error(errlog);
                return null;
            }
            return retsh;
        }
        function createShader(vtxsrc, frgsrc, uniformlist, attrlist) {
            var vsh = compileShader(gl.VERTEX_SHADER, vtxsrc);
            var fsh = compileShader(gl.FRAGMENT_SHADER, frgsrc);
            
            if(vsh == null || fsh == null) {
                return null;
            }
            
            var prog = gl.createProgram();
            gl.attachShader(prog, vsh);
            gl.attachShader(prog, fsh);
            
            gl.deleteShader(vsh);
            gl.deleteShader(fsh);
            
            gl.linkProgram(prog);
            if (!gl.getProgramParameter(prog, gl.LINK_STATUS)) {
                var errlog = gl.getProgramInfoLog(prog);
                console.error(errlog);
                return null;
            }
            
            if(uniformlist) {
                prog.uniforms = {};
                for(var i = 0; i < uniformlist.length; i++) {
                    prog.uniforms[uniformlist[i]] = gl.getUniformLocation(prog, uniformlist[i]);
                }
            }
            
            if(attrlist) {
                prog.attributes = {};
                for(var i = 0; i < attrlist.length; i++) {
                    var attr = attrlist[i];
                    prog.attributes[attr] = gl.getAttribLocation(prog, attr);
                }
            }
            
            return prog;
        }
        
        function useShader(prog) {
            gl.useProgram(prog);
            for(var attr in prog.attributes) {
                gl.enableVertexAttribArray(prog.attributes[attr]);;
            }
        }
        
        function unuseShader(prog) {
            for(var attr in prog.attributes) {
                gl.disableVertexAttribArray(prog.attributes[attr]);;
            }
            gl.useProgram(null);
        }
        
        var projection = {
            'angle':60,
            'nearfar':new Float32Array([0.1, 100.0]),
            'matrix':Matrix44.createIdentity()
        };
        var camera = {
            'position':Vector3.create(0, 0, 100),
            'lookat':Vector3.create(0, 0, 0),
            'up':Vector3.create(0, 1, 0),
            'dof':Vector3.create(10.0, 4.0, 8.0),
            'matrix':Matrix44.createIdentity()
        };
        
        var pointFlower = {};
        var meshFlower = {};
        var sceneStandBy = false;
        
        var BlossomParticle = function () {
            this.velocity = new Array(3);
            this.rotation = new Array(3);
            this.position = new Array(3);
            this.euler = new Array(3);
            this.size = 1.0;
            this.alpha = 1.0;
            this.zkey = 0.0;
        };
        
        BlossomParticle.prototype.setVelocity = function (vx, vy, vz) {
            this.velocity[0] = vx;
            this.velocity[1] = vy;
            this.velocity[2] = vz;
        };
        
        BlossomParticle.prototype.setRotation = function (rx, ry, rz) {
            this.rotation[0] = rx;
            this.rotation[1] = ry;
            this.rotation[2] = rz;
        };
        
        BlossomParticle.prototype.setPosition = function (nx, ny, nz) {
            this.position[0] = nx;
            this.position[1] = ny;
            this.position[2] = nz;
        };
        
        BlossomParticle.prototype.setEulerAngles = function (rx, ry, rz) {
            this.euler[0] = rx;
            this.euler[1] = ry;
            this.euler[2] = rz;
        };
        
        BlossomParticle.prototype.setSize = function (s) {
            this.size = s;
        };
        
        BlossomParticle.prototype.update = function (dt, et) {
            this.position[0] += this.velocity[0] * dt;
            this.position[1] += this.velocity[1] * dt;
            this.position[2] += this.velocity[2] * dt;
            
            this.euler[0] += this.rotation[0] * dt;
            this.euler[1] += this.rotation[1] * dt;
            this.euler[2] += this.rotation[2] * dt;
        };
        
        function createPointFlowers() {
            // get point sizes
            var prm = gl.getParameter(gl.ALIASED_POINT_SIZE_RANGE);
            renderSpec.pointSize = {'min':prm[0], 'max':prm[1]};
            
            var vtxsrc = document.getElementById("sakura_point_vsh").textContent;
            var frgsrc = document.getElementById("sakura_point_fsh").textContent;
            
            pointFlower.program = createShader(
                vtxsrc, frgsrc,
                ['uProjection', 'uModelview', 'uResolution', 'uOffset', 'uDOF', 'uFade'],
                ['aPosition', 'aEuler', 'aMisc']
            );
            
            useShader(pointFlower.program);
            pointFlower.offset = new Float32Array([0.0, 0.0, 0.0]);
            pointFlower.fader = Vector3.create(0.0, 10.0, 0.0);
            
            // paramerters: velocity[3], rotate[3]
            pointFlower.numFlowers = 1600;
            pointFlower.particles = new Array(pointFlower.numFlowers);
            // vertex attributes {position[3], euler_xyz[3], size[1]}
            pointFlower.dataArray = new Float32Array(pointFlower.numFlowers * (3 + 3 + 2));
            pointFlower.positionArrayOffset = 0;
            pointFlower.eulerArrayOffset = pointFlower.numFlowers * 3;
            pointFlower.miscArrayOffset = pointFlower.numFlowers * 6;
            
            pointFlower.buffer = gl.createBuffer();
            gl.bindBuffer(gl.ARRAY_BUFFER, pointFlower.buffer);
            gl.bufferData(gl.ARRAY_BUFFER, pointFlower.dataArray, gl.DYNAMIC_DRAW);
            gl.bindBuffer(gl.ARRAY_BUFFER, null);
            
            unuseShader(pointFlower.program);
            
            for(var i = 0; i < pointFlower.numFlowers; i++) {
                pointFlower.particles[i] = new BlossomParticle();
            }
        }
        
        function initPointFlowers() {
            //area
            pointFlower.area = Vector3.create(20.0, 20.0, 20.0);
            pointFlower.area.x = pointFlower.area.y * renderSpec.aspect;
            
            pointFlower.fader.x = 10.0; //env fade start
            pointFlower.fader.y = pointFlower.area.z; //env fade half
            pointFlower.fader.z = 0.1;  //near fade start
            
            //particles
            var PI2 = Math.PI * 2.0;
            var tmpv3 = Vector3.create(0, 0, 0);
            var tmpv = 0;
            var symmetryrand = function() {return (Math.random() * 2.0 - 1.0);};
            for(var i = 0; i < pointFlower.numFlowers; i++) {
                var tmpprtcl = pointFlower.particles[i];
                
                //velocity
                tmpv3.x = symmetryrand() * 0.3 + 0.8;
                tmpv3.y = symmetryrand() * 0.2 - 1.0;
                tmpv3.z = symmetryrand() * 0.3 + 0.5;
                Vector3.normalize(tmpv3);
                tmpv = 2.0 + Math.random() * 1.0;
                tmpprtcl.setVelocity(tmpv3.x * tmpv, tmpv3.y * tmpv, tmpv3.z * tmpv);
                
                //rotation
                tmpprtcl.setRotation(
                    symmetryrand() * PI2 * 0.5,
                    symmetryrand() * PI2 * 0.5,
                    symmetryrand() * PI2 * 0.5
                );
                
                //position
                tmpprtcl.setPosition(
                    symmetryrand() * pointFlower.area.x,
                    symmetryrand() * pointFlower.area.y,
                    symmetryrand() * pointFlower.area.z
                );
                
                //euler
                tmpprtcl.setEulerAngles(
                    Math.random() * Math.PI * 2.0,
                    Math.random() * Math.PI * 2.0,
                    Math.random() * Math.PI * 2.0
                );
                
                //size
                tmpprtcl.setSize(0.9 + Math.random() * 0.1);
            }
        }
        
        function renderPointFlowers() {
            //update
            var PI2 = Math.PI * 2.0;
            var limit = [pointFlower.area.x, pointFlower.area.y, pointFlower.area.z];
            var repeatPos = function (prt, cmp, limit) {
                if(Math.abs(prt.position[cmp]) - prt.size * 0.5 > limit) {
                    //out of area
                    if(prt.position[cmp] > 0) {
                        prt.position[cmp] -= limit * 2.0;
                    }
                    else {
                        prt.position[cmp] += limit * 2.0;
                    }
                }
            };
            var repeatEuler = function (prt, cmp) {
                prt.euler[cmp] = prt.euler[cmp] % PI2;
                if(prt.euler[cmp] < 0.0) {
                    prt.euler[cmp] += PI2;
                }
            };
            
            for(var i = 0; i < pointFlower.numFlowers; i++) {
                var prtcl = pointFlower.particles[i];
                prtcl.update(timeInfo.delta, timeInfo.elapsed);
                repeatPos(prtcl, 0, pointFlower.area.x);
                repeatPos(prtcl, 1, pointFlower.area.y);
                repeatPos(prtcl, 2, pointFlower.area.z);
                repeatEuler(prtcl, 0);
                repeatEuler(prtcl, 1);
                repeatEuler(prtcl, 2);
                
                prtcl.alpha = 1.0;//(pointFlower.area.z - prtcl.position[2]) * 0.5;
                
                prtcl.zkey = (camera.matrix[2] * prtcl.position[0]
                            + camera.matrix[6] * prtcl.position[1]
                            + camera.matrix[10] * prtcl.position[2]
                            + camera.matrix[14]);
            }
            
            // sort
            pointFlower.particles.sort(function(p0, p1){return p0.zkey - p1.zkey;});
            
            // update data
            var ipos = pointFlower.positionArrayOffset;
            var ieuler = pointFlower.eulerArrayOffset;
            var imisc = pointFlower.miscArrayOffset;
            for(var i = 0; i < pointFlower.numFlowers; i++) {
                var prtcl = pointFlower.particles[i];
                pointFlower.dataArray[ipos] = prtcl.position[0];
                pointFlower.dataArray[ipos + 1] = prtcl.position[1];
                pointFlower.dataArray[ipos + 2] = prtcl.position[2];
                ipos += 3;
                pointFlower.dataArray[ieuler] = prtcl.euler[0];
                pointFlower.dataArray[ieuler + 1] = prtcl.euler[1];
                pointFlower.dataArray[ieuler + 2] = prtcl.euler[2];
                ieuler += 3;
                pointFlower.dataArray[imisc] = prtcl.size;
                pointFlower.dataArray[imisc + 1] = prtcl.alpha;
                imisc += 2;
            }
            
            //draw
            gl.enable(gl.BLEND);
            //gl.disable(gl.DEPTH_TEST);
            gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);
            
            var prog = pointFlower.program;
            useShader(prog);
            
            gl.uniformMatrix4fv(prog.uniforms.uProjection, false, projection.matrix);
            gl.uniformMatrix4fv(prog.uniforms.uModelview, false, camera.matrix);
            gl.uniform3fv(prog.uniforms.uResolution, renderSpec.array);
            gl.uniform3fv(prog.uniforms.uDOF, Vector3.arrayForm(camera.dof));
            gl.uniform3fv(prog.uniforms.uFade, Vector3.arrayForm(pointFlower.fader));
            
            gl.bindBuffer(gl.ARRAY_BUFFER, pointFlower.buffer);
            gl.bufferData(gl.ARRAY_BUFFER, pointFlower.dataArray, gl.DYNAMIC_DRAW);
            
            gl.vertexAttribPointer(prog.attributes.aPosition, 3, gl.FLOAT, false, 0, pointFlower.positionArrayOffset * Float32Array.BYTES_PER_ELEMENT);
            gl.vertexAttribPointer(prog.attributes.aEuler, 3, gl.FLOAT, false, 0, pointFlower.eulerArrayOffset * Float32Array.BYTES_PER_ELEMENT);
            gl.vertexAttribPointer(prog.attributes.aMisc, 2, gl.FLOAT, false, 0, pointFlower.miscArrayOffset * Float32Array.BYTES_PER_ELEMENT);
            
            // doubler
            for(var i = 1; i < 2; i++) {
                var zpos = i * -2.0;
                pointFlower.offset[0] = pointFlower.area.x * -1.0;
                pointFlower.offset[1] = pointFlower.area.y * -1.0;
                pointFlower.offset[2] = pointFlower.area.z * zpos;
                gl.uniform3fv(prog.uniforms.uOffset, pointFlower.offset);
                gl.drawArrays(gl.POINT, 0, pointFlower.numFlowers);
                
                pointFlower.offset[0] = pointFlower.area.x * -1.0;
                pointFlower.offset[1] = pointFlower.area.y *  1.0;
                pointFlower.offset[2] = pointFlower.area.z * zpos;
                gl.uniform3fv(prog.uniforms.uOffset, pointFlower.offset);
                gl.drawArrays(gl.POINT, 0, pointFlower.numFlowers);
                
                pointFlower.offset[0] = pointFlower.area.x *  1.0;
                pointFlower.offset[1] = pointFlower.area.y * -1.0;
                pointFlower.offset[2] = pointFlower.area.z * zpos;
                gl.uniform3fv(prog.uniforms.uOffset, pointFlower.offset);
                gl.drawArrays(gl.POINT, 0, pointFlower.numFlowers);
                
                pointFlower.offset[0] = pointFlower.area.x *  1.0;
                pointFlower.offset[1] = pointFlower.area.y *  1.0;
                pointFlower.offset[2] = pointFlower.area.z * zpos;
                gl.uniform3fv(prog.uniforms.uOffset, pointFlower.offset);
                gl.drawArrays(gl.POINT, 0, pointFlower.numFlowers);
            }
           //main
            pointFlower.offset[0] = 0.0;
            pointFlower.offset[1] = 0.0;
            pointFlower.offset[2] = 0.0;
            gl.uniform3fv(prog.uniforms.uOffset, pointFlower.offset);
            gl.drawArrays(gl.POINT, 0, pointFlower.numFlowers);
            
            gl.bindBuffer(gl.ARRAY_BUFFER, null);
            unuseShader(prog);
            
            gl.enable(gl.DEPTH_TEST);
            gl.disable(gl.BLEND);
        }
        
        // effects
        //common util
        function createEffectProgram(vtxsrc, frgsrc, exunifs, exattrs) {
            var ret = {};
            var unifs = ['uResolution', 'uSrc', 'uDelta'];
            if(exunifs) {
                unifs = unifs.concat(exunifs);
            }
            var attrs = ['aPosition'];
            if(exattrs) {
                attrs = attrs.concat(exattrs);
            }
            
            ret.program = createShader(vtxsrc, frgsrc, unifs, attrs);
            useShader(ret.program);
            
            ret.dataArray = new Float32Array([
                -1.0, -1.0,
                 1.0, -1.0,
                -1.0,  1.0,
                 1.0,  1.0
            ]);
            ret.buffer = gl.createBuffer();
            gl.bindBuffer(gl.ARRAY_BUFFER, ret.buffer);
            gl.bufferData(gl.ARRAY_BUFFER, ret.dataArray, gl.STATIC_DRAW);
            
            gl.bindBuffer(gl.ARRAY_BUFFER, null);
            unuseShader(ret.program);
            
            return ret;
        }
        
        // basic usage
        // useEffect(prog, srctex({'texture':texid, 'dtxArray':(f32)[dtx, dty]})); //basic initialize
        // gl.uniform**(...); //additional uniforms
        // drawEffect()
        // unuseEffect(prog)
        // TEXTURE0 makes src
        function useEffect(fxobj, srctex) {
            var prog = fxobj.program;
            useShader(prog);
            gl.uniform3fv(prog.uniforms.uResolution, renderSpec.array);
            
            if(srctex != null) {
                gl.uniform2fv(prog.uniforms.uDelta, srctex.dtxArray);
                gl.uniform1i(prog.uniforms.uSrc, 0);
                
                gl.activeTexture(gl.TEXTURE0);
                gl.bindTexture(gl.TEXTURE_2D, srctex.texture);
            }
        }
        function drawEffect(fxobj) {
            gl.bindBuffer(gl.ARRAY_BUFFER, fxobj.buffer);
            gl.vertexAttribPointer(fxobj.program.attributes.aPosition, 2, gl.FLOAT, false, 0, 0);
            gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);
        }
        function unuseEffect(fxobj) {
            unuseShader(fxobj.program);
        }
        
        var effectLib = {};
        function createEffectLib() {
            
            var vtxsrc, frgsrc;
            //common
            var cmnvtxsrc = document.getElementById("fx_common_vsh").textContent;
            
            //background
            frgsrc = document.getElementById("bg_fsh").textContent;
            effectLib.sceneBg = createEffectProgram(cmnvtxsrc, frgsrc, ['uTimes'], null);
            
            // make brightpixels buffer
            frgsrc = document.getElementById("fx_brightbuf_fsh").textContent;
            effectLib.mkBrightBuf = createEffectProgram(cmnvtxsrc, frgsrc, null, null);
            
            // direction blur
            frgsrc = document.getElementById("fx_dirblur_r4_fsh").textContent;
            effectLib.dirBlur = createEffectProgram(cmnvtxsrc, frgsrc, ['uBlurDir'], null);
            
            //final composite
            vtxsrc = document.getElementById("pp_final_vsh").textContent;
            frgsrc = document.getElementById("pp_final_fsh").textContent;
            effectLib.finalComp = createEffectProgram(vtxsrc, frgsrc, ['uBloom'], null);
        }
        
        // background
        function createBackground() {
            //console.log("create background");
        }
        function initBackground() {
            //console.log("init background");
        }
        function renderBackground() {
            gl.disable(gl.DEPTH_TEST);
            
            useEffect(effectLib.sceneBg, null);
            gl.uniform2f(effectLib.sceneBg.program.uniforms.uTimes, timeInfo.elapsed, timeInfo.delta);
            drawEffect(effectLib.sceneBg);
            unuseEffect(effectLib.sceneBg);
            
            gl.enable(gl.DEPTH_TEST);
        }
        
        // post process
        var postProcess = {};
        function createPostProcess() {
            //console.log("create post process");
        }
        function initPostProcess() {
            //console.log("init post process");
        }
        
        function renderPostProcess() {
            gl.enable(gl.TEXTURE_2D);
            gl.disable(gl.DEPTH_TEST);
            var bindRT = function (rt, isclear) {
                gl.bindFramebuffer(gl.FRAMEBUFFER, rt.frameBuffer);
                gl.viewport(0, 0, rt.width, rt.height);
                if(isclear) {
                    gl.clearColor(0, 0, 0, 0);
                    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
                }
            };
            
            //make bright buff
            bindRT(renderSpec.wHalfRT0, true);
            useEffect(effectLib.mkBrightBuf, renderSpec.mainRT);
            drawEffect(effectLib.mkBrightBuf);
            unuseEffect(effectLib.mkBrightBuf);
            
            // make bloom
            for(var i = 0; i < 2; i++) {
                var p = 1.5 + 1 * i;
                var s = 2.0 + 1 * i;
                bindRT(renderSpec.wHalfRT1, true);
                useEffect(effectLib.dirBlur, renderSpec.wHalfRT0);
                gl.uniform4f(effectLib.dirBlur.program.uniforms.uBlurDir, p, 0.0, s, 0.0);
                drawEffect(effectLib.dirBlur);
                unuseEffect(effectLib.dirBlur);
                
                bindRT(renderSpec.wHalfRT0, true);
                useEffect(effectLib.dirBlur, renderSpec.wHalfRT1);
                gl.uniform4f(effectLib.dirBlur.program.uniforms.uBlurDir, 0.0, p, 0.0, s);
                drawEffect(effectLib.dirBlur);
                unuseEffect(effectLib.dirBlur);
            }
            
            //display
            gl.bindFramebuffer(gl.FRAMEBUFFER, null);
            gl.viewport(0, 0, renderSpec.width, renderSpec.height);
            gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
            
            useEffect(effectLib.finalComp, renderSpec.mainRT);
            gl.uniform1i(effectLib.finalComp.program.uniforms.uBloom, 1);
            gl.activeTexture(gl.TEXTURE1);
            gl.bindTexture(gl.TEXTURE_2D, renderSpec.wHalfRT0.texture);
            drawEffect(effectLib.finalComp);
            unuseEffect(effectLib.finalComp);
            
            gl.enable(gl.DEPTH_TEST);
        }
        
        
        var SceneEnv = {};
        function createScene() {
            createEffectLib();
            createBackground();
            createPointFlowers();
            createPostProcess();
            sceneStandBy = true;
        }
        
        function initScene() {
            initBackground();
            initPointFlowers();
            initPostProcess();
            
            //camera.position.z = 17.320508;
            camera.position.z = pointFlower.area.z + projection.nearfar[0];
            projection.angle = Math.atan2(pointFlower.area.y, camera.position.z + pointFlower.area.z) * 180.0 / Math.PI * 2.0;
            Matrix44.loadProjection(projection.matrix, renderSpec.aspect, projection.angle, projection.nearfar[0], projection.nearfar[1]);
        }
        
        function renderScene() {
            //draw
            Matrix44.loadLookAt(camera.matrix, camera.position, camera.lookat, camera.up);
            
            gl.enable(gl.DEPTH_TEST);
            
            //gl.bindFramebuffer(gl.FRAMEBUFFER, null);
            gl.bindFramebuffer(gl.FRAMEBUFFER, renderSpec.mainRT.frameBuffer);
            gl.viewport(0, 0, renderSpec.mainRT.width, renderSpec.mainRT.height);
            gl.clearColor(0.005, 0, 0.05, 0);
            gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
            
            renderBackground();
            renderPointFlowers();
            renderPostProcess();
        }
        
        
        function onResize(e) {
            makeCanvasFullScreen(document.getElementById("sakura"));
            setViewports();
            if(sceneStandBy) {
                initScene();
            }
        }
        
        function setViewports() {
            renderSpec.setSize(gl.canvas.width, gl.canvas.height);
            
            gl.clearColor(0.2, 0.2, 0.5, 1.0);
            gl.viewport(0, 0, renderSpec.width, renderSpec.height);
            
            var rtfunc = function (rtname, rtw, rth) {
                var rt = renderSpec[rtname];
                if(rt) deleteRenderTarget(rt);
                renderSpec[rtname] = createRenderTarget(rtw, rth);
            };
            rtfunc('mainRT', renderSpec.width, renderSpec.height);
            rtfunc('wFullRT0', renderSpec.width, renderSpec.height);
            rtfunc('wFullRT1', renderSpec.width, renderSpec.height);
            rtfunc('wHalfRT0', renderSpec.halfWidth, renderSpec.halfHeight);
            rtfunc('wHalfRT1', renderSpec.halfWidth, renderSpec.halfHeight);
        }
        
        function render() {
            renderScene();
        }
        
        var animating = true;
        function toggleAnimation(elm) {
            animating ^= true;
            if(animating) animate();
            if(elm) {
                elm.innerHTML = animating? "Stop":"Start";
            }
        }
        
        function stepAnimation() {
            if(!animating) animate();
        }
        
        function animate() {
            var curdate = new Date();
            timeInfo.elapsed = (curdate - timeInfo.start) / 1000.0;
            timeInfo.delta = (curdate - timeInfo.prev) / 1000.0;
            timeInfo.prev = curdate;
            
            if(animating) requestAnimationFrame(animate);
            render();
        }
        
        function makeCanvasFullScreen(canvas) {
            var b = document.body;
            var d = document.documentElement;
            fullw = Math.max(b.clientWidth , b.scrollWidth, d.scrollWidth, d.clientWidth);
            fullh = Math.max(b.clientHeight , b.scrollHeight, d.scrollHeight, d.clientHeight);
            canvas.width = fullw;
            canvas.height = fullh;
        }
        
        window.addEventListener('load', function(e) {
            var canvas = document.getElementById("sakura");
            try {
                makeCanvasFullScreen(canvas);
                gl = canvas.getContext('experimental-webgl');
            } catch(e) {
                alert("WebGL not supported." + e);
                console.error(e);
                return;
            }
            
            window.addEventListener('resize', onResize);
            
            setViewports();
            createScene();
            initScene();
            
            timeInfo.start = new Date();
            timeInfo.prev = timeInfo.start;
            animate();
        });
        
        //set window.requestAnimationFrame
        (function (w, r) {
            w['r'+r] = w['r'+r] || w['webkitR'+r] || w['mozR'+r] || w['msR'+r] || w['oR'+r] || function(c){ w.setTimeout(c, 1000 / 60); };
        })(window, 'equestAnimationFrame');
          </script>
        
        
    </body>
    
</html>

然后使用浏览器打开看效果

原文链接:

https://blog.csdn.net/weixin_52014130/article/details/125103207