不使用外部库的Webgl循环
我是webgl新手,现在我能够创建三角形和正方形 我发现很难理解如何在没有任何外部脚本或库的情况下创建圆。不使用外部库的Webgl循环,webgl,Webgl,我是webgl新手,现在我能够创建三角形和正方形 我发现很难理解如何在没有任何外部脚本或库的情况下创建圆。var vertexShaderText= var vertexShaderText = [ 'uniform vec2 u_resolution;', '', 'attribute vec2 a_position;', '', 'void main()', '{', '', 'vec2 clipspace =
var vertexShaderText=
var vertexShaderText =
[
'uniform vec2 u_resolution;',
'',
'attribute vec2 a_position;',
'',
'void main()',
'{',
'',
'vec2 clipspace = a_position / u_resolution * 1.0 ;',
'',
'gl_Position = vec4(clipspace * vec2(2.5, 2.0), 0, 1);',
'}'
].join("\n");
var fragmentShaderText =
[
'precision mediump float;',
'',
'void main(void)',
'{',
'',
'gl_FragColor = vec4(0, 0, 0, 1.0);',
'',
'}'
].join("\n");
var uni = function(){
var canvas = document.getElementById("game-surface");
var gl = canvas.getContext("webgl");
console.log("This is working");
gl.clearColor(0.412,0.412,0.412,1);
gl.clear(gl.COLOR_BUFFER_BIT);
var vertextShader = gl.createShader(gl.VERTEX_SHADER);
var fragmentShader = gl.createShader(gl.FRAGMENT_SHADER);
gl.shaderSource(vertextShader,vertexShaderText);
gl.shaderSource(fragmentShader,fragmentShaderText);
gl.compileShader(vertextShader);
gl.compileShader(fragmentShader);
if(!gl.getShaderParameter(vertextShader,gl.COMPILE_STATUS)){
console.error("Error with vertexshader",gl.getShaderInfoLog(vertextShader));
return;
}
if(!gl.getShaderParameter(fragmentShader,gl.COMPILE_STATUS)){
console.error("Error with fragmentShader",gl.getShaderInfoLog(fragmentShader));
return;
}
var program =gl.createProgram();
gl.attachShader(program,vertextShader);
gl.attachShader(program,fragmentShader);
gl.linkProgram(program);
gl.useProgram(program);
if(!gl.getProgramParameter(program,gl.LINK_STATUS)){
console.error("Error linking program",gl.getProgramInfoLog(program));
return;
}
gl.validateProgram(program);
if(!gl.getProgramParameter(program,gl.VALIDATE_STATUS)){
console.error("Error validating",gl.getProgramInfoLog(program));
}
var circle = {x: 0, y:0, r: 75};
var ATTRIBUTES = 2;
var numFans = 64;
var degreePerFan = (2* Math.PI) / numFans;
var vertexData = [circle.x, circle.y];
for(var i = 0; i <= numFans; i++) {
var index = ATTRIBUTES * i + 2; // there is already 2 items in array
var angle = degreePerFan * (i+0.1);
vertexData[index] = circle.x + Math.cos(angle) * circle.r;
vertexData[index + 1] = circle.y + Math.sin(angle) * circle.r;
}
var vertexDataTyped = new Float32Array(vertexData);
var buffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
gl.bufferData(gl.ARRAY_BUFFER, vertexDataTyped, gl.STATIC_DRAW);
var resolutionLocation = gl.getUniformLocation(program, "u_resolution");
gl.uniform2f(resolutionLocation, canvas.width, canvas.height);
gl.enableVertexAttribArray(positionLocation);
var positionLocation = gl.getAttribLocation(program, "a_position");
gl.vertexAttribPointer(positionLocation, 2, gl.FLOAT, false, ATTRIBUTES * Float32Array.BYTES_PER_ELEMENT, 0);
gl.drawArrays(gl.TRIANGLE_FAN, 0, vertexData.length/ATTRIBUTES);
};
[
“统一vec2 u_分辨率;”,
'',
'属性向量2 a_位置;',
'',
“void main()”,
'{',
'',
'vec2 clipspace=a_位置/u_分辨率*1.0;',
'',
‘gl_Position=vec4(clipspace*vec2(2.5,2.0,0,1);’,
'}'
].加入(“\n”);
var fragmentShaderText=
[
“精密中泵浮动;”,
'',
“无效主管道(无效)”,
'{',
'',
“gl_FragColor=vec4(0,0,0,1.0);”,
'',
'}'
].加入(“\n”);
var uni=函数(){
var canvas=document.getElementById(“游戏界面”);
var gl=canvas.getContext(“webgl”);
console.log(“这正在工作”);
gl.clearColor(0.412,0.412,0.412,1);
总账清除(总账颜色缓冲位);
var vertextShader=gl.createShader(gl.vertext\u着色器);
var fragmentShader=gl.createShader(gl.FRAGMENT\u着色器);
gl.shaderSource(vertextShader,vertexShaderText);
gl.shaderSource(fragmentShader,fragmentShaderText);
gl.compileShader(vertextShader);
gl.compileShader(碎片着色器);
if(!gl.getShaderParameter(vertextShader,gl.COMPILE_状态)){
console.error(“vertexshader错误”,gl.getShaderInfoLog(vertexshader));
回来
}
if(!gl.getShaderParameter(fragmentShader,gl.COMPILE_状态)){
console.error(“fragmentShader错误”,gl.getShaderInfoLog(fragmentShader));
回来
}
var program=gl.createProgram();
gl.attachShader(程序,vertextShader);
gl.attachShader(程序、碎片着色器);
总账链接程序(程序);
gl.useProgram(程序);
if(!gl.getProgramParameter(程序、总账链接状态)){
console.error(“错误链接程序”,gl.getProgramInfoLog(程序));
回来
}
总账验证程序(程序);
if(!gl.getProgramParameter(程序,gl.VALIDATE_状态)){
console.error(“错误验证”,gl.getProgramInfoLog(程序));
}
变量圆={x:0,y:0,r:75};
var属性=2;
var numFans=64;
变量degreePerFan=(2*Math.PI)/numFans;
var vertexData=[circle.x,circle.y];
对于(var i=0;很抱歉,但您需要给我们更多信息。您能否编辑您的问题以包含您尝试过的内容(代码片段、错误等)我实际上创建了这个圆,你能帮我吗,我想沿着大圆的圆周生成多达10个随机圆。我有一个想法,可以使用生成的顶点,但不知道如何访问它。你可以看看我在下面发布的答案。不要用答案向我们展示你的尝试。答案是解决方案,而不是q的更多部分uestion。使用“编辑”修改问题文本以显示您的代码。我实际上无法帮助您解决问题,我只是主持人之一。请编辑您的问题并将此代码添加到其中,然后删除此“答案”,因为它不是您问题的解决方案。