这篇文章主要为大家展示了“HTML如何实现动态散花背景”，内容简而易懂，条理清晰，希望能够帮助大家解决疑惑，下面让小编带领大家一起研究并学习一下“HTML如何实现动态散花背景”这篇文章吧。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>动态散花背景</title>
<meta name="description" content="Change OR Die" />
</head>
<body>
<style type="text/css">
*{margin:0;padding:0;list-style-type:none;}
a,img{border:0;}
body{font:12px/180% Arial, Helvetica, sans-serif, "新宋体";}
</style>
<canvas id="sakura"></canvas>
<!-- 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 src="js/index.js"></script>
<div style="text-align:center;">
<p></p>
</div>
</body>
</html>以上是“HTML如何实现动态散花背景”这篇文章的所有内容，感谢各位的阅读！相信大家都有了一定的了解，希望分享的内容对大家有所帮助，如果还想学习更多知识，欢迎关注编程网行业资讯频道！
