1.效果图

2.代码如下:

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!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>
	
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