Reduce boilerplate downscaler params handling.

The same sets of parameters (or subsets thereof) are read/
written in many devices get/put_params routines to control
the downscaler.

Arrange to read/write these all in one place to keep the
code simpler.

1 files changed, 28 insertions, 0 deletions

diff --git a/base/gxdownscale.h b/base/gxdownscale.h
index b1092a537..1ecce325a 100644
--- a/base/gxdownscale.h
+++ b/base/gxdownscale.h
@@ -160,4 +160,32 @@ int gx_downscaler_init_planar_trapped(gx_downscaler_t      *ds,
                                       int                   trap_h,
                                       const int            *comp_order);
 
+/* The following structure is used to hold the configuration
+ * parameters for the downscaler.
+ */
+typedef struct gx_downscaler_params_s
+{
+    long downscale_factor;
+    long min_feature_size;
+    int trap_w;
+    int trap_h;
+    int trap_order[GS_CLIENT_COLOR_MAX_COMPONENTS];
+} gx_downscaler_params;
+
+#define GX_DOWNSCALER_PARAMS_DEFAULTS \
+{ 1, 0, 0, 0, { 3, 1, 0, 2 } }
+
+enum {
+    GX_DOWNSCALER_PARAMS_MFS = 1,
+    GX_DOWNSCALER_PARAMS_TRAP = 2
+};
+
+int gx_downscaler_read_params(gs_param_list        *plist,
+                              gx_downscaler_params *params,
+                              int                   features);
+
+int gx_downscaler_write_params(gs_param_list        *plist,
+                               gx_downscaler_params *params,
+                               int                   features);
+
 #endif