picogame: two RGB444 fixes

main.c

@@ -80,6 +80,10 @@
 #include "shared-bindings/epaperdisplay/EPaperDisplay.h"
 #endif
 
+#if CIRCUITPY_PICOGAME_RGB444
+#include "shared-module/picogame/__init__.h"
+#endif
+
 #if CIRCUITPY_KEYPAD
 #include "shared-module/keypad/__init__.h"
 #endif
@@ -374,6 +378,11 @@ static void cleanup_after_vm(mp_obj_t exception) {
     atexit_reset();
     #endif
 
+    // Restore the panel's pixel format while the display bus is still alive.
+    #if CIRCUITPY_PICOGAME_RGB444
+    picogame_reset();
+    #endif
+
     // Turn off the display and flush the filesystem before the heap disappears.
     #if CIRCUITPY_DISPLAYIO
     reset_displays();

shared-module/picogame/__init__.c

@@ -976,6 +976,12 @@ bool picogame_strip_begin(
     return true;
 }
 
+#if CIRCUITPY_PICOGAME_RGB444
+// The display currently switched to RGB444, or NULL. The strip path packs for it and
+// picogame_reset() restores it to RGB565 at the end of the program.
+static picogame_output_t *rgb444_display = NULL;
+#endif
+
 // --- output transport seam (busdisplay backend): the ONLY per-strip display ops the generic
 // picogame_render_region orchestrator below touches, so a non-CircuitPython port (MicroPython
 // framebuf/SPI) swaps just strip_begin + these two + set_invert/set_pixel_format. See __init__.h.
@@ -993,6 +999,14 @@ void picogame_render_region(
     int16_t x0, int16_t y0, int16_t x1, int16_t y1,
     uint16_t background, int ox, int oy) {
 
+    #if CIRCUITPY_PICOGAME_RGB444
+    // RGB444 packs 2 px into 3 bytes, so widen the region to even x bounds.
+    bool rgb444 = (display == rgb444_display);
+    if (rgb444) {
+        x0 &= ~1;
+        x1 = (x1 + 1) & ~1;
+    }
+    #endif
     int region_w, strip_h;
     int cx0 = x0, cy0 = y0, cx1 = x1, cy1 = y1;   // strip_begin clamps these to the panel in place
     if (!picogame_strip_begin(display, &cx0, &cy0, &cx1, &cy1, buffer_pixels, &region_w, &strip_h)) {
@@ -1001,7 +1015,13 @@ void picogame_render_region(
     for (int sy = cy0; sy < cy1; sy += strip_h) {
         int sh = picogame_imin(strip_h, cy1 - sy);
         mp_obj_t exc = picogame_blit_strip_layers(buffer, region_w, sy, sh, cx0, items, kinds, n, background, ox, oy);
-        picogame_out_strip_send(display, (uint8_t *)buffer, region_w * sh * 2);
+        size_t nbytes = (size_t)region_w * sh * 2;
+        #if CIRCUITPY_PICOGAME_RGB444
+        if (rgb444) {
+            nbytes = picogame_pack_rgb444(buffer, (size_t)region_w * sh);   // in place, 3/4 the bytes
+        }
+        #endif
+        picogame_out_strip_send(display, (uint8_t *)buffer, nbytes);
         if (exc != MP_OBJ_NULL) {                 // a StripDraw callback raised a BaseException: close the
             picogame_out_strip_end(display);      // bus, then re-raise (Ctrl-C / reload)
             nlr_raise(MP_OBJ_TO_PTR(exc));
@@ -1029,6 +1049,7 @@ void picogame_set_invert(picogame_output_t *display, bool on) {
 // Set the panel pixel format (COLMOD 0x3A): rgb444 -> 12-bit RGB444 (0x53), else 16-bit RGB565
 // (0x55). Asserting it on every Display construct also recovers from a previous program that left
 // the panel in the other format (survives soft reset).
+
 void picogame_set_pixel_format(picogame_output_t *display, bool rgb444) {
     uint8_t cmd = 0x3A;
     uint8_t param = rgb444 ? 0x53 : 0x55;
@@ -1038,6 +1059,20 @@ void picogame_set_pixel_format(picogame_output_t *display, bool rgb444) {
     display->bus.send(display->bus.bus, DISPLAY_COMMAND, CHIP_SELECT_TOGGLE_EVERY_BYTE, &cmd, 1);
     display->bus.send(display->bus.bus, DISPLAY_DATA, CHIP_SELECT_UNTOUCHED, &param, 1);
     displayio_display_bus_end_transaction(&display->bus);
+    rgb444_display = rgb444 ? display : NULL;
+}
+
+// Called at the end of a program, before reset_displays() takes the bus away.
+void picogame_reset(void) {
+    if (rgb444_display == NULL) {
+        return;
+    }
+    // A released display has a None bus.
+    if (mp_obj_get_type(rgb444_display->bus.bus) == &mp_type_NoneType) {
+        rgb444_display = NULL;
+        return;
+    }
+    picogame_set_pixel_format(rgb444_display, false);   // clears rgb444_display
 }
 
 // Pack a strip of `npix` (must be even) WIRE-order RGB565 pixels IN-PLACE to ST7789 12-bit RGB444

shared-module/picogame/__init__.h

@@ -184,7 +184,8 @@ void picogame_blit_bitmap_affine(
 //
 // Strip-path contract a backend provides:
 //   picogame_strip_begin      - open a window for [x0,y0,x1,y1); return strip geometry
-//   picogame_out_strip_send   - push one composited strip (region_w*sh px, wire RGB565)
+//   picogame_out_strip_send   - push one composited strip (region_w*sh px, wire RGB565; packed to
+//                               RGB444 first when that panel is in 12-bit mode)
 //   picogame_out_strip_end    - close the transaction
 //   picogame_set_invert       - panel hardware colour inversion (a free full-screen flash)
 //   picogame_set_pixel_format - panel COLMOD (RGB565/RGB444), when CIRCUITPY_PICOGAME_RGB444
@@ -248,6 +249,10 @@ bool picogame_fb_take_invert_dirty(void);
 // Set panel pixel format (COLMOD): rgb444 -> 12-bit RGB444, else 16-bit RGB565.
 void picogame_set_pixel_format(picogame_output_t *display, bool rgb444);
 
+// Put a panel left in RGB444 back to RGB565 at the end of a program, so the console stays
+// readable. Call before reset_displays().
+void picogame_reset(void);
+
 // Pack `npix` (even) wire-order RGB565 pixels in `buf` IN-PLACE to 12-bit RGB444; returns bytes.
 size_t picogame_pack_rgb444(uint16_t *buf, size_t npix);
 #endif