Allow different source and view projection in image layer renderers

To enable image layer reprojection.

src/ol/renderer/canvas/canvasimagelayerrenderer.js

@@ -170,12 +170,14 @@ ol.renderer.canvas.ImageLayer.prototype.prepareFrame =
   if (!hints[ol.ViewHint.ANIMATING] && !hints[ol.ViewHint.INTERACTING] &&
       !ol.extent.isEmpty(renderedExtent)) {
     var projection = viewState.projection;
+    if (!ol.ENABLE_RASTER_REPROJECTION) {
       var sourceProjection = imageSource.getProjection();
       if (sourceProjection) {
         goog.asserts.assert(ol.proj.equivalent(projection, sourceProjection),
             'projection and sourceProjection are equivalent');
         projection = sourceProjection;
       }
+    }
     image = imageSource.getImage(
         renderedExtent, viewResolution, pixelRatio, projection);
     if (image) {

src/ol/renderer/dom/domimagelayerrenderer.js

@@ -101,12 +101,14 @@ ol.renderer.dom.ImageLayer.prototype.prepareFrame =
   if (!hints[ol.ViewHint.ANIMATING] && !hints[ol.ViewHint.INTERACTING] &&
       !ol.extent.isEmpty(renderedExtent)) {
     var projection = viewState.projection;
+    if (!ol.ENABLE_RASTER_REPROJECTION) {
       var sourceProjection = imageSource.getProjection();
       if (sourceProjection) {
         goog.asserts.assert(ol.proj.equivalent(projection, sourceProjection),
             'projection and sourceProjection are equivalent');
         projection = sourceProjection;
       }
+    }
     var image_ = imageSource.getImage(renderedExtent, viewResolution,
         frameState.pixelRatio, projection);
     if (image_) {

src/ol/renderer/layerrenderer.js

@@ -159,8 +159,9 @@ ol.renderer.Layer.prototype.loadImage = function(image) {
   if (imageState == ol.ImageState.IDLE) {
     image.load();
     imageState = image.getState();
-    goog.asserts.assert(imageState == ol.ImageState.LOADING,
+    goog.asserts.assert(imageState == ol.ImageState.LOADING ||
-        'imageState is "loading"');
+        imageState == ol.ImageState.LOADED,
+        'imageState is "loading" or "loaded"');
   }
   return imageState == ol.ImageState.LOADED;
 };

src/ol/renderer/webgl/webglimagelayerrenderer.js

@@ -125,12 +125,14 @@ ol.renderer.webgl.ImageLayer.prototype.prepareFrame =
   if (!hints[ol.ViewHint.ANIMATING] && !hints[ol.ViewHint.INTERACTING] &&
       !ol.extent.isEmpty(renderedExtent)) {
     var projection = viewState.projection;
+    if (!ol.ENABLE_RASTER_REPROJECTION) {
       var sourceProjection = imageSource.getProjection();
       if (sourceProjection) {
         goog.asserts.assert(ol.proj.equivalent(projection, sourceProjection),
             'projection and sourceProjection are equivalent');
         projection = sourceProjection;
       }
+    }
     var image_ = imageSource.getImage(renderedExtent, viewResolution,
         pixelRatio, projection);
     if (image_) {