Refine finalscale for dt_dev_image()

For performance reasons we might not want to do late scaling via finalscale while processing
the pixelpipe via dt_dev_image() but rely on demosaicer downscaling.

This adds another parameter 'gboolean finalscale' to dt_dev_image() using the also introduced
'DT_DEV_PIXELPIPE_IMAGE_FINAL' allowing
a) overlay module use finalscale for quality and performance
b) duplicate, slideshow and snapshot to do it the old way without finalscale for performance.
   Please note that these can still be enforced to use finalscale via the 'Toggle high quality processing' button.

src/develop/develop.c

@@ -3464,14 +3464,15 @@ void dt_dev_image(const dt_imgid_t imgid,
                   float *zoom_y,
                   const int snapshot_id,
                   GList *module_filter_out,
-                  const int devid)
+                  const int devid,
+                  const gboolean finalscale)
 {
   dt_develop_t dev;
   dt_dev_init(&dev, TRUE);
   dev.gui_attached = FALSE;
   dt_dev_pixelpipe_t *pipe = dev.full.pipe;
 
-  pipe->type |= DT_DEV_PIXELPIPE_IMAGE;
+  pipe->type |= DT_DEV_PIXELPIPE_IMAGE | (finalscale ? DT_DEV_PIXELPIPE_IMAGE_FINAL : 0);
   // load image and set history_end
 
   dev.snapshot_id = snapshot_id;

src/develop/develop.h

@@ -646,7 +646,8 @@ void dt_dev_image(const dt_imgid_t imgid,
                   float *zoom_y,
                   const int32_t snapshot_id,
                   GList *module_filter_out,
-                  const int devid);
+                  const int devid,
+                  const gboolean finalscale);
 
 
 gboolean dt_dev_equal_chroma(const float *f, const double *d);

src/develop/pixelpipe.h

@@ -41,7 +41,8 @@ typedef enum dt_dev_pixelpipe_type_t
   DT_DEV_PIXELPIPE_ANY       = DT_DEV_PIXELPIPE_EXPORT | DT_DEV_PIXELPIPE_FULL | DT_DEV_PIXELPIPE_PREVIEW
                                | DT_DEV_PIXELPIPE_THUMBNAIL | DT_DEV_PIXELPIPE_PREVIEW2,
   DT_DEV_PIXELPIPE_FAST      = 1 << 8,
-  DT_DEV_PIXELPIPE_IMAGE     = 1 << 9,  // special additional flag used by dt_dev_image()
+  DT_DEV_PIXELPIPE_IMAGE     = 1 << 9,    // special additional flag used by dt_dev_image()
+  DT_DEV_PIXELPIPE_IMAGE_FINAL = 1 << 10, // special additional flag used by dt_dev_image(), mark to use finalscale
   DT_DEV_PIXELPIPE_BASIC     = DT_DEV_PIXELPIPE_FULL | DT_DEV_PIXELPIPE_PREVIEW
 } dt_dev_pixelpipe_type_t;
 

src/iop/finalscale.c

@@ -162,8 +162,9 @@ void commit_params(dt_iop_module_t *self,
                    dt_dev_pixelpipe_t *pipe,
                    dt_dev_pixelpipe_iop_t *piece)
 {
+  const int use_finalscale = DT_DEV_PIXELPIPE_IMAGE | DT_DEV_PIXELPIPE_IMAGE_FINAL;
   piece->enabled = piece->pipe->type == DT_DEV_PIXELPIPE_EXPORT
-                  || pipe->type & DT_DEV_PIXELPIPE_IMAGE
+                  || (pipe->type & use_finalscale) == use_finalscale
                   || _gui_fullpipe(piece);
 }
 

src/iop/overlay.c

@@ -308,7 +308,7 @@ static void _setup_overlay(dt_iop_module_t *self,
                  -1,
                  &buf, NULL, &bw, &bh,
                  NULL, NULL,
-                 -1, disabled_modules, piece->pipe->devid);
+                 -1, disabled_modules, piece->pipe->devid, TRUE);
 
     uint8_t *old_buf = *pbuf;
 

src/libs/duplicate.c

@@ -223,7 +223,7 @@ void gui_post_expose(dt_lib_module_t *self,
     dt_dev_image(d->imgid, width, height, -1,
                  &d->buf, &d->scale,
                  &d->buf_width, &d->buf_height,
-                 &d->zoom_x, &d->zoom_y, -1, NULL, DT_DEVICE_NONE);
+                 &d->zoom_x, &d->zoom_y, -1, NULL, DT_DEVICE_NONE, FALSE);
 
     d->preview_id = d->imgid;
   }

src/libs/snapshots.c

@@ -199,7 +199,7 @@ void gui_post_expose(dt_lib_module_t *self,
                    &snap->buf, &snap->scale,
                    &snap->width, &snap->height,
                    &snap->zoom_x, &snap->zoom_y,
-                   snap->id, NULL, DT_DEVICE_NONE);
+                   snap->id, NULL, DT_DEVICE_NONE, FALSE);
       d->snap_requested = FALSE;
       d->expose_again_timeout_id = 0;
     }

src/views/slideshow.c

@@ -216,7 +216,8 @@ static int _process_image(dt_slideshow_t *d,
      NULL,
      -1,
      NULL,
-     DT_DEVICE_NONE);
+     DT_DEVICE_NONE,
+     FALSE);
 
   dt_pthread_mutex_lock(&d->lock);