如何在以下内容中添加路线高亮属性(给路线增加背景色)
`
uniform sampler2D image;
uniform float speed;
uniform vec4 color;
uniform vec2 repeat;
czm_material czm_getMaterial(czm_materialInput materialInput){
czm_material material=czm_getDefaultMaterial(materialInput);
vec2 st=repeat * materialInput.st;
float time=fract(czm_frameNumber*speed/1000.);
// st.s是横轴方向运动,st.t是纵轴,
// vec2(fract(st.s-time),st.t)是横轴按照时间变化而变化,纵轴保持正常不变化
vec4 colorImage=texture2D(image,vec2(fract(st.s-time),st.t));
vec4 fragColor;
fragColor.rgb=color.rgb / 1.0;
if(color.a==0.){
material.alpha=colorImage.a;
material.diffuse=colorImage.rgb;
}else{
material.alpha=colorImage.a*color.a;
material.diffuse=max(color.rgb*material.alpha*3.,color.rgb);
}
return material;
}
`