_stage: Fix handling of scaled display in the stage library

The "scale" parameter wasn't exposed in the library, and there
were some problems in how it was handled.

This also fixes some types in the pixel-drawing functions.

Author: deshipu

frozen/circuitpython-stage

@@ -29,7 +29,7 @@
 
 
 // Get the color of the pixel on the layer.
-uint16_t get_layer_pixel(layer_obj_t *layer, uint16_t x, uint16_t y) {
+uint16_t get_layer_pixel(layer_obj_t *layer, int16_t x, int16_t y) {
 
     // Shift by the layer's position offset.
     x -= layer->x;

shared-module/_stage/Layer.c

@@ -43,6 +43,6 @@ typedef struct {
     uint8_t rotation;
 } layer_obj_t;
 
-uint16_t get_layer_pixel(layer_obj_t *layer, uint16_t x, uint16_t y);
+uint16_t get_layer_pixel(layer_obj_t *layer, int16_t x, int16_t y);
 
 #endif  // MICROPY_INCLUDED_SHARED_MODULE__STAGE_LAYER

shared-module/_stage/Layer.h

@@ -29,7 +29,7 @@
 
 
 // Get the color of the pixel on the text.
-uint16_t get_text_pixel(text_obj_t *text, uint16_t x, uint16_t y) {
+uint16_t get_text_pixel(text_obj_t *text, int16_t x, int16_t y) {
 
     // Shift by the text's position offset.
     x -= text->x;

shared-module/_stage/Text.c

@@ -41,6 +41,6 @@ typedef struct {
     uint8_t width, height;
 } text_obj_t;
 
-uint16_t get_text_pixel(text_obj_t *text, uint16_t x, uint16_t y);
+uint16_t get_text_pixel(text_obj_t *text, int16_t x, int16_t y);
 
 #endif  // MICROPY_INCLUDED_SHARED_MODULE__STAGE_TEXT

shared-module/_stage/Text.h

@@ -39,13 +39,14 @@ void render_stage(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1,
 
 
     displayio_area_t area;
-    area.x1 = x0;
-    area.y1 = y0;
-    area.x2 = x1;
-    area.y2 = y1;
+    area.x1 = x0 * scale;
+    area.y1 = y0 * scale;
+    area.x2 = x1 * scale;
+    area.y2 = y1 * scale;
     displayio_display_core_set_region_to_update(
         &display->core, display->set_column_command, display->set_row_command,
-        NO_COMMAND, NO_COMMAND, display->data_as_commands, false, &area, display->SH1107_addressing);
+        NO_COMMAND, NO_COMMAND, display->data_as_commands, false, &area,
+        display->SH1107_addressing);
 
     while (!displayio_display_core_begin_transaction(&display->core)) {
         RUN_BACKGROUND_TASKS;