diff --git a/examples/mapswipe-ref.png b/examples/mapswipe-ref.png index 121b8e7de45d..dd6520ec175e 100644 Binary files a/examples/mapswipe-ref.png and b/examples/mapswipe-ref.png differ diff --git a/src/map/swipe.js b/src/map/swipe.js index 3f98e648e089..f733264a6d36 100644 --- a/src/map/swipe.js +++ b/src/map/swipe.js @@ -193,12 +193,32 @@ export class SwipeController { ctx.clip(); } else { // ctx instanceof WebGLRenderingContext - ctx.clear(ctx.COLOR_BUFFER_BIT); + this.fixWebGLContextScissorClear(ctx); ctx.enable(ctx.SCISSOR_TEST); ctx.scissor(0, 0, width, height); } } + /** + * Will monkey-patch the context to make sure that clear() calls will not + * take into account any scissor test previously set. + * @param {WebGLRenderingContext} gl WebGL Context + * @private + */ + fixWebGLContextScissorClear(gl) { + if (gl._scissorClearFixed) { + return; + } + const clearFn = gl.clear; + gl.clear = function (...args) { + const scissorEnabled = gl.getParameter(gl.SCISSOR_TEST); + scissorEnabled && gl.disable(gl.SCISSOR_TEST); + clearFn.apply(gl, args); + scissorEnabled && gl.enable(gl.SCISSOR_TEST); + }; + gl._scissorClearFixed = true; + } + /** * @param {?Event|import('ol/events/Event').default} evt OpenLayers object event. * @private