有趣的代码之樱花雨(html版)

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唯美樱花雨的动态效果展示

<!DOCTYPE HTML PUBLIC "-/W3C/DTD HTML 4.0 Transitional/EN">  
<HTML>  
<HEAD>  
<TITLE> 樱花雨 </TITLE>  
<META NAME="Generator" CONTENT="EditPlus">  
<META NAME="Author" CONTENT="">  
<META NAME="Keywords" CONTENT="">  
<META NAME="Description" CONTENT="">  
<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>  
  
<!-- 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 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) {  
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);  
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 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 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));  
  
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 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 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 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 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 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>  
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)  
};  
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() {  
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);  
  
pointFlower.numFlowers = 1600;  
pointFlower.particles = new Array(pointFlower.numFlowers);  
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() {  
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  
  
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];  
  
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);  
  
tmpprtcl.setRotation(  
symmetryrand() * PI2 * 0.5,  
symmetryrand() * PI2 * 0.5,  
symmetryrand() * PI2 * 0.5  
);  
  
tmpprtcl.setPosition(  
symmetryrand() * pointFlower.area.x,  
symmetryrand() * pointFlower.area.y,  
symmetryrand() * pointFlower.area.z  
);  
  
tmpprtcl.setEulerAngles(  
Math.random() * Math.PI * 2.0,  
Math.random() * Math.PI * 2.0,  
Math.random() * Math.PI * 2.0  
);  
  
tmpprtcl.setSize(0.9 + Math.random() * 0.1);  
}  
}  
  
function renderPointFlowers() {  
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) {  
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]);  
}  
  
pointFlower.particles.sort(function(p0, p1){return p0.zkey - p1.zkey;});  
  
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;  
}  
  
gl.enable(gl.BLEND);  
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);  
  
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);  
}  
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);  
}  
  
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;  
}  
  
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;  
var cmnvtxsrc = document.getElementById("fx_common_vsh").textContent;  
frgsrc = document.getElementById("bg_fsh").textContent;  
effectLib.sceneBg = createEffectProgram(cmnvtxsrc, frgsrc, ['uTimes'], null);  
  
frgsrc = document.getElementById("fx_brightbuf_fsh").textContent;  
effectLib.mkBrightBuf = createEffectProgram(cmnvtxsrc, frgsrc, null, null);  
  
frgsrc = document.getElementById("fx_dirblur_r4_fsh").textContent;  
effectLib.dirBlur = createEffectProgram(cmnvtxsrc, frgsrc, ['uBlurDir'], null);  
  
vtxsrc = document.getElementById("pp_final_vsh").textContent;  
frgsrc = document.getElementById("pp_final_fsh").textContent;  
effectLib.finalComp = createEffectProgram(vtxsrc, frgsrc, ['uBloom'], null);  
}  
  
  
function createBackground() {  
  
}  
function initBackground() {  
  
}  
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);  
}  
  
  
var postProcess = {};  
function createPostProcess() {  
}  
function initPostProcess() {  
}  
  
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);  
}  
};  
  
bindRT(renderSpec.wHalfRT0, true);  
useEffect(effectLib.mkBrightBuf, renderSpec.mainRT);  
drawEffect(effectLib.mkBrightBuf);  
unuseEffect(effectLib.mkBrightBuf);  
  
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);  
}  
  
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 = 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() {  
  
Matrix44.loadLookAt(camera.matrix, camera.position, camera.lookat, camera.up);  
  
gl.enable(gl.DEPTH_TEST);  
  
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();  
});  
  
(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>

动态效果如下:

image.png

结语

本文只是略作修改,不是原创,直接复制到记事本然后将文件后缀改为 .html就行了。