Updating width and height of render target on the fly - webgl

Question

I've created a texture and a renderbuffer to render an existing 3d scene to a texture, and using that texture as an input for another webgl program.
Below is pseudo code of the class that handles rendering the scene to a texture.
What's the best way to update the texture width and height as needed (if a browser resize happens for example)? Do I need to create a new texture / render buffer every time ?
I'm wondering if I can do this with less code than I'm currently doing?
class Renderer {
constructor() {
// creates the texture and framebuffer for the first time
this.updateRTT(128, 128);
}
updateRTT(width, height) {
const gl = getContext();
this.rttwidth = width;
this.rttheight = height;
console.log('update RTT', this.rttwidth, this.rttheight);
this.frameBuffer = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, this.frameBuffer);
this.texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, this.texture);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
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.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, this.rttwidth, this.rttheight, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
this.renderBuffer = gl.createRenderbuffer();
gl.bindRenderbuffer(gl.RENDERBUFFER, this.renderBuffer);
gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, this.rttwidth, this.rttheight);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, this.texture, 0);
gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, this.renderBuffer);
gl.bindTexture(gl.TEXTURE_2D, null);
gl.bindRenderbuffer(gl.RENDERBUFFER, null);
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
}
render_to_target(width, height) {
// is there a better way to just update the texture/framebuffer?
if (this.rttwidth !== width || this.rttheight !== height) {
// if the width or height is different from the previous one, update the texture and framebuffer
this.updateRTT(width, height);
}
gl.bindFramebuffer(gl.FRAMEBUFFER, this.frameBuffer);
// draw my scene here
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, this.texture);
gl.generateMipmap(gl.TEXTURE_2D);
// clear
gl.bindTexture(gl.TEXTURE_2D, null);
gl.bindRenderbuffer(gl.RENDERBUFFER, null);
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
}
}

Answer 1

Its enough to reset the texture/renderbuffer attributes like so:
resize(width, height) {
// resize color attachment
gl.bindTexture(gl.TEXTURE_2D, this.texture);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
gl.bindTexture(gl.TEXTURE_2D, null);
// resize depth attachment
gl.bindRenderbuffer(gl.RENDERBUFFER, this.renderBuffer);
gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, width, height);
gl.bindRenderbuffer(gl.RENDERBUFFER, null);
// update internal dimensions
this.rttwidth=width;
this.rttheight=height;
}