codal_app/microbithal: Make display.get_pixel return a value in 0-9.

dpgeorge · dpgeorge · commit 8a1dbe4fbc31 · 2021-04-30T20:57:43.000+10:00
Fixes #75. Signed-off-by: Damien George <damien@micropython.org>
diff --git a/src/codal_app/microbithal.cpp b/src/codal_app/microbithal.cpp
@@ -284,7 +284,12 @@ void microbit_hal_display_clear(void) {
 }
 
 int microbit_hal_display_get_pixel(int x, int y) {
-    return uBit.display.image.getPixelValue(x, y);
+    uint32_t pixel = uBit.display.image.getPixelValue(x, y);
+    if (pixel == 255) {
+        return 9;
+    } else {
+        return 32 - __builtin_clz(pixel);
+    }
 }
 
 void microbit_hal_display_set_pixel(int x, int y, int bright) {

Original file line number	Diff line number	Diff line change
`@@ -284,7 +284,12 @@ void microbit_hal_display_clear(void) {`
`284`	`284`	`}`
`285`	`285`
`286`	`286`	`int microbit_hal_display_get_pixel(int x, int y) {`
`287`		`- return uBit.display.image.getPixelValue(x, y);`
	`287`	`+ uint32_t pixel = uBit.display.image.getPixelValue(x, y);`
	`288`	`+ if (pixel == 255) {`
	`289`	`+ return 9;`
	`290`	`+ } else {`
	`291`	`+ return 32 - __builtin_clz(pixel);`
	`292`	`+ }`
`288`	`293`	`}`
`289`	`294`
`290`	`295`	`void microbit_hal_display_set_pixel(int x, int y, int bright) {`