circuitpython-stage: allow choosing background color

frozen/circuitpython-stage

@@ -1 +1 @@
-Subproject commit 8d5cc384058b1cb296aaeab86fb8405042d547ed
+Subproject commit 19a66d79f0650a15e502464b42e16692365eab36

shared-bindings/_stage/__init__.c

@@ -51,7 +51,7 @@
 //|     Layer
 //|     Text
 //|
-//| .. function:: render(x0, y0, x1, y1, layers, buffer, display[, scale])
+//| .. function:: render(x0, y0, x1, y1, layers, buffer, display[, scale[, background]])
 //|
 //|     Render and send to the display a fragment of the screen.
 //|
@@ -63,6 +63,7 @@
 //|     :param bytearray buffer: A buffer to use for rendering.
 //|     :param ~displayio.Display display: The display to use.
 //|     :param int scale: How many times should the image be scaled up.
+//|     :param int background: What color to display when nothing is there.
 //|
 //|     There are also no sanity checks, outside of the basic overflow
 //|     checking. The caller is responsible for making the passed parameters
@@ -92,12 +93,16 @@ STATIC mp_obj_t stage_render(size_t n_args, const mp_obj_t *args) {
     }
     displayio_display_obj_t *display = MP_OBJ_TO_PTR(native_display);
     uint8_t scale = 1;
-    if (n_args >= 8) {
+    if (n_args > 7) {
         scale = mp_obj_get_int(args[7]);
     }
+    uint16_t background = 0;
+    if (n_args > 8) {
+        background = mp_obj_get_int(args[8]);
+    }
 
     render_stage(x0, y0, x1, y1, layers, layers_size, buffer, buffer_size,
-                 display, scale);
+                 display, scale, background);
 
     return mp_const_none;
 }

shared-module/_stage/__init__.c

@@ -34,7 +34,8 @@
 void render_stage(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1,
         mp_obj_t *layers, size_t layers_size,
         uint16_t *buffer, size_t buffer_size,
-        displayio_display_obj_t *display, uint8_t scale) {
+        displayio_display_obj_t *display,
+        uint8_t scale, uint16_t background) {
 
 
     displayio_area_t area;
@@ -68,6 +69,9 @@ void render_stage(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1,
                         break;
                     }
                 }
+                if (c == TRANSPARENT) {
+                    c = background;
+                }
                 for (uint8_t xscale = 0; xscale < scale; ++xscale) {
                     buffer[index] = c;
                     index += 1;

shared-module/_stage/__init__.h

@@ -37,6 +37,7 @@
 void render_stage(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1,
         mp_obj_t *layers, size_t layers_size,
         uint16_t *buffer, size_t buffer_size,
-        displayio_display_obj_t *display, uint8_t scale);
+        displayio_display_obj_t *display,
+        uint8_t scale, uint16_t background);
 
 #endif  // MICROPY_INCLUDED_SHARED_MODULE__STAGE