文章目录
序号 | 目录 |
1 | HTML满屏跳动的爱心(可写字) |
2 | HTML五彩缤纷的爱心 |
3 | HTML满屏漂浮爱心 |
4 | HTML情人节快乐 |
5 | HTML蓝色爱心射线 |
6 | HTML跳动的爱心(简易版) |
7 | HTML粒子爱心 |
8 | HTML蓝色动态爱心 |
9 | HTML跳动的爱心(双心版) |
10 | HTML橙色动态粒子爱心 |
11 | HTML旋转爱心 |
12 | HTML爱情树 |
13 | HTML3D相册 |
14 | HTML旋转相册 |
15 | HTML基础烟花秀 |
16 | HTML炫酷烟花秀 |
17 | HTML粉色烟花秀 |
18 | HTML新春烟花 |
19 | HTML龙年大吉 |
20 | HTML圣诞树 |
21 | HTML大雪纷飞 |
22 | HTML想见你 |
23 | HTML元素周期表 |
24 | HTML飞舞的花瓣 |
25 | HTML星空特效 |
26 | HTML黑客帝国字母雨 |
27 | HTML哆啦A梦 |
28 | HTML流星雨 |
29 | HTML沙漏爱心 |
30 | HTML爱心字母雨 |
31 | HTML爱心流星雨 |
32 | HTML生日蛋糕 |
33 | HTML流光爱心 |
写在前面
本期博主给大家推荐一个由HTML代码实现的、红蓝色线条组成的流光爱心,一起来看看吧。
完整代码
<!DOCTYPE html>
<!--<div class="menu__subheader"><br>微信公众号:雁卿雁卿呀-->
<html lang="en"><head><meta charset="UTF-8" /><title>流光爱心</title><meta name="author" content="Logical Digit"></head><!-- css部分 --><style>body {background-color: #000;margin: 0;overflow: hidden;background-repeat: no-repeat;
}
</style><body><!-- 绘画爱心 --><canvas id="canvas" width="1400" height="600"></canvas><!-- js部分 --></body><script>
var canvas = document.getElementById("canvas");
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
// Initialize the GL context
var gl = canvas.getContext('webgl');
if (!gl) {console.error("Unable to initialize WebGL.");
}
//Time step
var dt = 0.015;
//Time
var time = 0.0;
//************** Shader sources **************
var vertexSource = `
attribute vec2 position;
void main() {gl_Position = vec4(position, 0.0, 1.0);
}
`;var fragmentSource = `
precision highp float;
uniform float width;
uniform float height;
vec2 resolution = vec2(width, height);
uniform float time;
#define POINT_COUNT 8
vec2 points[POINT_COUNT];
const float speed = -0.5;
const float len = 0.25;
float intensity = 0.9;
float radius = 0.015;
//https://www.shadertoy.com/view/MlKcDD
//Signed distance to a quadratic bezier
float sdBezier(vec2 pos, vec2 A, vec2 B, vec2 C){ vec2 a = B - A;vec2 b = A - 2.0*B + C;vec2 c = a * 2.0;vec2 d = A - pos;float kk = 1.0 / dot(b,b);float kx = kk * dot(a,b);float ky = kk * (2.0*dot(a,a)+dot(d,b)) / 3.0;float kz = kk * dot(d,a); float res = 0.0;float p = ky - kx*kx;float p3 = p*p*p;float q = kx*(2.0*kx*kx - 3.0*ky) + kz;float h = q*q + 4.0*p3;if(h >= 0.0){ h = sqrt(h);vec2 x = (vec2(h, -h) - q) / 2.0;vec2 uv = sign(x)*pow(abs(x), vec2(1.0/3.0));float t = uv.x + uv.y - kx;t = clamp( t, 0.0, 1.0 );// 1 rootvec2 qos = d + (c + b*t)*t;res = length(qos);}else{float z = sqrt(-p);float v = acos( q/(p*z*2.0) ) / 3.0;float m = cos(v);float n = sin(v)*1.732050808;vec3 t = vec3(m + m, -n - m, n - m) * z - kx;t = clamp( t, 0.0, 1.0 );// 3 rootsvec2 qos = d + (c + b*t.x)*t.x;float dis = dot(qos,qos);res = dis;qos = d + (c + b*t.y)*t.y;dis = dot(qos,qos);res = min(res,dis);qos = d + (c + b*t.z)*t.z;dis = dot(qos,qos);res = min(res,dis);res = sqrt( res );}return res;
}
//http://mathworld.wolfram.com/HeartCurve.html
vec2 getHeartPosition(float t){return vec2(16.0 * sin(t) * sin(t) * sin(t),-(13.0 * cos(t) - 5.0 * cos(2.0*t)- 2.0 * cos(3.0*t) - cos(4.0*t)));
}
//https://www.shadertoy.com/view/3s3GDn
float getGlow(float dist, float radius, float intensity){return pow(radius/dist, intensity);
}
float getSegment(float t, vec2 pos, float offset, float scale){for(int i = 0; i < POINT_COUNT; i++){points[i] = getHeartPosition(offset + float(i)*len + fract(speed * t) * 6.28);}vec2 c = (points[0] + points[1]) / 2.0;vec2 c_prev;float dist = 10000.0;for(int i = 0; i < POINT_COUNT-1; i++){//https://tinyurl.com/y2htbwkmc_prev = c;c = (points[i] + points[i+1]) / 2.0;dist = min(dist, sdBezier(pos, scale * c_prev, scale * points[i], scale * c));}return max(0.0, dist);
}
void main(){vec2 uv = gl_FragCoord.xy/resolution.xy;float widthHeightRatio = resolution.x/resolution.y;vec2 centre = vec2(0.5, 0.5);vec2 pos = centre - uv;pos.y /= widthHeightRatio;//Shift upwards to centre heartpos.y += 0.02;float scale = 0.000015 * height;float t = time;//Get first segmentfloat dist = getSegment(t, pos, 0.0, scale);float glow = getGlow(dist, radius, intensity);vec3 col = vec3(0.0);//White corecol += 10.0*vec3(smoothstep(0.003, 0.001, dist));//Pink glowcol += glow * vec3(0.94,0.14,0.4);//Get second segmentdist = getSegment(t, pos, 3.4, scale);glow = getGlow(dist, radius, intensity);//White corecol += 10.0*vec3(smoothstep(0.003, 0.001, dist));//Blue glowcol += glow * vec3(0.2,0.6,1.0);//Tone mappingcol = 1.0 - exp(-col);//Output to screengl_FragColor = vec4(col,1.0);
}
`;//************** Utility functions **************window.addEventListener('resize', onWindowResize, false);function onWindowResize() {canvas.width = window.innerWidth;canvas.height = window.innerHeight;gl.viewport(0, 0, canvas.width, canvas.height);gl.uniform1f(widthHandle, window.innerWidth);gl.uniform1f(heightHandle, window.innerHeight);
}//Compile shader and combine with source
function compileShader(shaderSource, shaderType) {var shader = gl.createShader(shaderType);gl.shaderSource(shader, shaderSource);gl.compileShader(shader);if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {throw "Shader compile failed with: " + gl.getShaderInfoLog(shader);}return shader;
}//From https://codepen.io/jlfwong/pen/GqmroZ
//Utility to complain loudly if we fail to find the attribute/uniform
function getAttribLocation(program, name) {var attributeLocation = gl.getAttribLocation(program, name);if (attributeLocation === -1) {throw 'Cannot find attribute ' + name + '.';}return attributeLocation;
}function getUniformLocation(program, name) {var attributeLocation = gl.getUniformLocation(program, name);if (attributeLocation === -1) {throw 'Cannot find uniform ' + name + '.';}return attributeLocation;
}//************** Create shaders **************//Create vertex and fragment shaders
var vertexShader = compileShader(vertexSource, gl.VERTEX_SHADER);
var fragmentShader = compileShader(fragmentSource, gl.FRAGMENT_SHADER);//Create shader programs
var program = gl.createProgram();
gl.attachShader(program, vertexShader);
gl.attachShader(program, fragmentShader);
gl.linkProgram(program);gl.useProgram(program);//Set up rectangle covering entire canvas
var vertexData = new Float32Array([-1.0, 1.0, // top left-1.0, -1.0, // bottom left1.0, 1.0, // top right1.0, -1.0, // bottom right
]);//Create vertex buffer
var vertexDataBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, vertexDataBuffer);
gl.bufferData(gl.ARRAY_BUFFER, vertexData, gl.STATIC_DRAW);// Layout of our data in the vertex buffer
var positionHandle = getAttribLocation(program, 'position');gl.enableVertexAttribArray(positionHandle);
gl.vertexAttribPointer(positionHandle,2, // position is a vec2 (2 values per component)gl.FLOAT, // each component is a floatfalse, // don't normalize values2 * 4, // two 4 byte float components per vertex (32 bit float is 4 bytes)0 // how many bytes inside the buffer to start from
);//Set uniform handle
var timeHandle = getUniformLocation(program, 'time');
var widthHandle = getUniformLocation(program, 'width');
var heightHandle = getUniformLocation(program, 'height');gl.uniform1f(widthHandle, window.innerWidth);
gl.uniform1f(heightHandle, window.innerHeight);function draw() {//Update timetime += dt;//Send uniforms to programgl.uniform1f(timeHandle, time);//Draw a triangle strip connecting vertices 0-4gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);requestAnimationFrame(draw);
}draw();
</script>
</html>
代码分析
这段代码通过HTML、CSS和WebGL结合实现了一个“流光爱心”效果,以下是对其的详细分析。
1. HTML结构
在HTML部分,主要是一个canvas
元素,它是用于绘制心形动画的区域。canvas
元素通过其ID属性canvas
在JavaScript中被引用,用于初始化WebGL上下文。
<canvas id="canvas" width="1400" height="600"></canvas>
在这里,宽度和高度只是初始设置,代码通过JavaScript调整canvas
的大小以适应浏览器窗口。
2. CSS部分
CSS的作用是设置整个网页的背景颜色为黑色,并使画布占据整个窗口,同时禁用滚动条以确保效果全屏展示。
body {background-color: #000;margin: 0;overflow: hidden;background-repeat: no-repeat;
}
3. WebGL上下文初始化
JavaScript部分通过getContext('webgl')
获取WebGL绘图上下文,这是一种用于在网页中绘制2D和3D图形的API。
var canvas = document.getElementById("canvas");
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
var gl = canvas.getContext('webgl');
if (!gl) {console.error("Unable to initialize WebGL.");
}
这段代码确保WebGL能够正常运行,如果无法初始化WebGL,会在控制台输出错误信息。
4. 着色器程序
代码中定义了顶点着色器和片段着色器,用于处理图形的顶点和颜色计算。顶点着色器vertexSource
负责定义绘制区域,而片段着色器fragmentSource
则负责生成心形动画的光效。
-
顶点着色器:这个简单的顶点着色器只定义了矩形区域,覆盖整个
canvas
。
attribute vec2 position;
void main() {gl_Position = vec4(position, 0.0, 1.0);
}
-
片段着色器:这是核心部分,计算并绘制了心形的流光效果。着色器使用了多种图形技术,如二次贝塞尔曲线距离函数来生成心形轮廓,
getGlow
函数实现光晕效果,getHeartPosition
函数计算心形轨迹。
vec2 getHeartPosition(float t){return vec2(16.0 * sin(t) * sin(t) * sin(t),-(13.0 * cos(t) - 5.0 * cos(2.0*t)- 2.0 * cos(3.0*t) - cos(4.0*t)));
}
这个公式是数学中的经典“心形曲线公式”,通过调整时间参数t
,可以得到心形轨迹上的点。
5. 动态渲染
在draw
函数中,程序使用requestAnimationFrame(draw)
不断调用自己来实现帧动画,逐帧更新time
变量,使得心形的流光效果随着时间变化而持续运行。
function draw() {time += dt;gl.uniform1f(timeHandle, time);gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);requestAnimationFrame(draw);
}
每一帧,WebGL都会根据当前的时间time
重新计算心形上每个点的位置,进而生成流光效果。
6. 响应窗口变化
代码监听了窗口大小的变化,使用onWindowResize
函数动态调整画布的大小,确保动画始终适应窗口尺寸,并且心形保持居中显示。
window.addEventListener('resize', onWindowResize, false);
function onWindowResize() {canvas.width = window.innerWidth;canvas.height = window.innerHeight;gl.viewport(0, 0, canvas.width, canvas.height);gl.uniform1f(widthHandle, window.innerWidth);gl.uniform1f(heightHandle, window.innerHeight);
}
总结
这段代码通过WebGL技术生成了一个心形流光效果。核心部分在于数学公式计算出的心形轨迹和光晕效果,通过着色器来实现。WebGL的强大之处在于它能直接操控GPU,生成高效的动画效果。
写在后面
我是一只有趣的兔子,感谢你的喜欢!