Function createFBO

packages/gl-react/src/Node.tsx:172–234

(
  gl: WebGLRenderingContext,
  width: number,
  height: number
)

// minimal version of gl-fbo
const createFBO = (
  gl: WebGLRenderingContext,
  width: number,
  height: number
): Framebuffer => {
  var handle = gl.createFramebuffer()!;
  gl.bindFramebuffer(gl.FRAMEBUFFER, handle);
  var color = gl.createTexture();
  if (!color) throw new Error("createTexture returned null");
  gl.bindTexture(gl.TEXTURE_2D, color);
  gl.texImage2D(
    gl.TEXTURE_2D,
    0,
    gl.RGBA,
    width,
    height,
    0,
    gl.RGBA,
    gl.UNSIGNED_BYTE,
    null
  );
  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.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
  gl.framebufferTexture2D(
    gl.FRAMEBUFFER,
    gl.COLOR_ATTACHMENT0,
    gl.TEXTURE_2D,
    color,
    0
  );
  return {
    handle,
    color,
    bind: () => {
      gl.bindFramebuffer(gl.FRAMEBUFFER, handle);
      gl.viewport(0, 0, width, height);
    },
    syncSize: (w: number, h: number) => {
      if (w !== width || h !== height) {
        width = w;
        height = h;
        gl.bindTexture(gl.TEXTURE_2D, color);
        gl.texImage2D(
          gl.TEXTURE_2D,
          0,
          gl.RGBA,
          w,
          h,
          0,
          gl.RGBA,
          gl.UNSIGNED_BYTE,
          null
        );
      }
    },
    dispose: () => {