message: Fix for WhiteOnWhiteReversal
diff: @@ -25,7 +25,7 @@ export function addWhiteOnWhiteReversal(frag: FragmentShaderBuilder) {
  frag.addUniform("u_reverseWhiteOnWhite", VariableType.Float, (prog) => {
  prog.addGraphicUniform("u_reverseWhiteOnWhite", (uniform, params) => {
  const bgColor: ColorDef = params.target.bgColor.clone();
  - bgColor.setAlpha(0);
  + bgColor.setAlpha(255);
  const doReversal = (bgColor.equals(ColorDef.white) && params.geometry.wantWoWReversal(params)) ? 1.0 : 0.0;
  uniform.setUniform1f(doReversal);
  });
  @@ -62,6 +62,8 @@ const reverseWhiteOnWhite = `
  export namespace GLSLFragment {
  export const assignFragColor = `FragColor = baseColor;`;
  + export const assignFragColorNoAlpha = `FragColor = vec4(baseColor.rgb, 1.0);`;
  +
  export const assignFragData = `
  FragColor0 = baseColor;
  FragColor1 = v_element_id0;
  