Add support for grayscale displays that are < 8 bit depth.

This also improves Palette so it stores the original RGB888 colors.

Lastly, it adds I2CDisplay as a display bus to talk over I2C. Particularly
useful for the SSD1306.

Fixes #1828. Fixes #1956

1 files changed, 40 insertions, 9 deletions

diff --git a/supervisor/shared/display.c b/supervisor/shared/display.c
index 414f85034..6a39cbe8e 100644
--- a/supervisor/shared/display.c
+++ b/supervisor/shared/display.c
@@ -82,8 +82,7 @@ void supervisor_start_terminal(uint16_t width_px, uint16_t height_px) {
     grid->pixel_height = height_in_tiles * grid->tile_height;
     grid->tiles = tiles;
 
-    supervisor_terminal.cursor_x = 0;
-    supervisor_terminal.cursor_y = 0;
+    common_hal_terminalio_terminal_construct(&supervisor_terminal, grid, &supervisor_terminal_font);
 }
 
 void supervisor_stop_terminal(void) {
@@ -147,17 +146,49 @@ displayio_bitmap_t blinka_bitmap = {
     .read_only = true
 };
 
-uint32_t blinka_transparency[1] = {0x80000000};
-
-// These colors are RGB 565 with the bytes swapped.
-uint32_t blinka_colors[8] = {0x78890000, 0x9F86B8FC, 0xffff0D5A, 0x0000f501,
-                             0x00000000, 0x00000000, 0x00000000, 0x00000000};
+_displayio_color_t blinka_colors[7] = {
+    {
+        .rgb888 = 0x000000,
+        .rgb565 = 0x0000,
+        .luma = 0x00,
+        .transparent = true
+    },
+    {
+        .rgb888 = 0x8428bc,
+        .rgb565 = 0x7889,
+        .luma = 0xff // We cheat the luma here. It is actually 0x60
+    },
+    {
+        .rgb888 = 0xff89bc,
+        .rgb565 = 0xB8FC,
+        .luma = 0xb5
+    },
+    {
+        .rgb888 = 0x7beffe,
+        .rgb565 = 0x9F86,
+        .luma = 0xe0
+    },
+    {
+        .rgb888 = 0x51395f,
+        .rgb565 = 0x0D5A,
+        .luma = 0x47
+    },
+    {
+        .rgb888 = 0xffffff,
+        .rgb565 = 0xffff,
+        .luma = 0xff
+    },
+    {
+        .rgb888 = 0x0736a0,
+        .rgb565 = 0xf501,
+        .luma = 0x44
+    },
+};
 
 displayio_palette_t blinka_palette = {
     .base = {.type = &displayio_palette_type },
-    .opaque = blinka_transparency,
     .colors = blinka_colors,
-    .color_count = 16,
+    .color_count = 7,
     .needs_refresh = false
 };